Merge remote-tracking branch 'origin/master' into unlock-minitest

author: Rafael Mendonça França <rafaelmfranca@gmail.com> 2017-08-01 17:34:14 -0400
committer: Rafael Mendonça França <rafaelmfranca@gmail.com> 2017-08-01 17:34:14 -0400
commit: feb1ddae021c38174f9c22bbd1298c8b73431b45 (patch)
tree: 09a38695596cf80dc362dd4d93cf94d6f7415e7b /activerecord
parent: 3540e60c385286f3517ff56270b31a91ed3024a3 (diff)
parent: f9a43f28c087f8ffd35ff7c33a60c938b60f2be2 (diff)
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684 files changed, 2560 insertions, 1127 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 786bef7359..8181d67816 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,67 @@
+*   When using `Relation#or`, extract the common conditions and put them before the OR condition.
+
+    *Maxime Handfield Lapointe*
+
+*   `Relation#or` now accepts two relations who have different values for
+    `references` only, as `references` can be implicitly called by `where`.
+
+    Fixes #29411.
+
+    *Sean Griffin*
+
+*   ApplicationRecord is no longer generated when generating models.  If you
+    need to generate it, it can be created with `rails g application_record`.
+
+    *Lisa Ugray*
+
+*   Fix `COUNT(DISTINCT ...)` with `ORDER BY` and `LIMIT` to keep the existing select list.
+
+    *Ryuta Kamizono*
+
+*   When a `has_one` association is destroyed by `dependent: destroy`,
+    `destroyed_by_association` will now be set to the reflection, matching the
+    behaviour of `has_many` associations.
+
+    *Lisa Ugray*
+
+*   Fix `unscoped(where: [columns])` removing the wrong bind values
+
+    When the `where` is called on a relation after a `or`, unscoping the column of that later `where` removed
+    bind values used by the `or` instead. (possibly other cases too)
+
+    ```
+    Post.where(id: 1).or(Post.where(id: 2)).where(foo: 3).unscope(where: :foo).to_sql
+    # Currently:
+    #     SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 2 OR "posts"."id" = 3)
+    # With fix:
+    #     SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 1 OR "posts"."id" = 2)
+    ```
+
+    *Maxime Handfield Lapointe*
+
+*   Values constructed using multi-parameter assignment will now use the
+    post-type-cast value for rendering in single-field form inputs.
+
+    *Sean Griffin*
+
+*   `Relation#joins` is no longer affected by the target model's
+    `current_scope`, with the exception of `unscoped`.
+
+    Fixes #29338.
+
+    *Sean Griffin*
+
+*   Change sqlite3 boolean serialization to use 1 and 0
+
+    SQLite natively recognizes 1 and 0 as true and false, but does not natively
+    recognize 't' and 'f' as was previously serialized.
+
+    This change in serialization requires a migration of stored boolean data
+    for SQLite databases, so it's implemented behind a configuration flag
+    whose default false value is deprecated.
+
+    *Lisa Ugray*
+
 *   Skip query caching when working with batches of records (`find_each`, `find_in_batches`,
     `in_batches`).
 
diff --git a/activerecord/Rakefile b/activerecord/Rakefile
index fe5f9d1071..57c82bf469 100644
--- a/activerecord/Rakefile
+++ b/activerecord/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rake/testtask"
 
 require_relative "test/config"
diff --git a/activerecord/activerecord.gemspec b/activerecord/activerecord.gemspec
index a626a1f21b..7ad06fe840 100644
--- a/activerecord/activerecord.gemspec
+++ b/activerecord/activerecord.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 version = File.read(File.expand_path("../RAILS_VERSION", __dir__)).strip
 
 Gem::Specification.new do |s|
@@ -29,5 +31,5 @@ Gem::Specification.new do |s|
   s.add_dependency "activesupport", version
   s.add_dependency "activemodel",   version
 
-  s.add_dependency "arel", "~> 8.0"
+  s.add_dependency "arel", "9.0.0.alpha"
 end
diff --git a/activerecord/bin/test b/activerecord/bin/test
index ab69f4f603..83c192531e 100755
--- a/activerecord/bin/test
+++ b/activerecord/bin/test
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 COMPONENT_ROOT = File.expand_path("..", __dir__)
 require_relative "../../tools/test"
diff --git a/activerecord/examples/performance.rb b/activerecord/examples/performance.rb
index 3257dd4ad7..1a2c78f39b 100644
--- a/activerecord/examples/performance.rb
+++ b/activerecord/examples/performance.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_record"
 require "benchmark/ips"
 
diff --git a/activerecord/examples/simple.rb b/activerecord/examples/simple.rb
index c3648fee48..280b786d73 100644
--- a/activerecord/examples/simple.rb
+++ b/activerecord/examples/simple.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_record"
 
 class Person < ActiveRecord::Base
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 25d5e87317..0c19fed9e1 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #--
 # Copyright (c) 2004-2017 David Heinemeier Hansson
 #
diff --git a/activerecord/lib/active_record/aggregations.rb b/activerecord/lib/active_record/aggregations.rb
index 10cbd5429c..e5e89734d2 100644
--- a/activerecord/lib/active_record/aggregations.rb
+++ b/activerecord/lib/active_record/aggregations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # See ActiveRecord::Aggregations::ClassMethods for documentation
   module Aggregations
diff --git a/activerecord/lib/active_record/association_relation.rb b/activerecord/lib/active_record/association_relation.rb
index de2d03cd0b..2b0b2864bc 100644
--- a/activerecord/lib/active_record/association_relation.rb
+++ b/activerecord/lib/active_record/association_relation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class AssociationRelation < Relation
     def initialize(klass, table, predicate_builder, association)
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index e782196ce6..840f71bef2 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/enumerable"
 require "active_support/core_ext/string/conversions"
 require "active_support/core_ext/module/remove_method"
@@ -222,13 +224,6 @@ module ActiveRecord
     autoload :CollectionAssociation
     autoload :ForeignAssociation
     autoload :CollectionProxy
-
-    autoload :BelongsToAssociation
-    autoload :BelongsToPolymorphicAssociation
-    autoload :HasManyAssociation
-    autoload :HasManyThroughAssociation
-    autoload :HasOneAssociation
-    autoload :HasOneThroughAssociation
     autoload :ThroughAssociation
 
     module Builder #:nodoc:
@@ -243,6 +238,13 @@ module ActiveRecord
     end
 
     eager_autoload do
+      autoload :BelongsToAssociation
+      autoload :BelongsToPolymorphicAssociation
+      autoload :HasManyAssociation
+      autoload :HasManyThroughAssociation
+      autoload :HasOneAssociation
+      autoload :HasOneThroughAssociation
+
       autoload :Preloader
       autoload :JoinDependency
       autoload :AssociationScope
diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb
index 104de4f69d..096f016976 100644
--- a/activerecord/lib/active_record/associations/alias_tracker.rb
+++ b/activerecord/lib/active_record/associations/alias_tracker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/string/conversions"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 1138ae3462..268b022ab8 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/array/wrap"
 
 module ActiveRecord
@@ -171,8 +173,8 @@ module ActiveRecord
         skip_assign = [reflection.foreign_key, reflection.type].compact
         assigned_keys = record.changed_attribute_names_to_save
         assigned_keys += except_from_scope_attributes.keys.map(&:to_s)
-        attributes = create_scope.except(*(assigned_keys - skip_assign))
-        record.assign_attributes(attributes)
+        attributes = scope_for_create.except!(*(assigned_keys - skip_assign))
+        record.send(:_assign_attributes, attributes) if attributes.any?
         set_inverse_instance(record)
       end
 
@@ -185,6 +187,9 @@ module ActiveRecord
       end
 
       private
+        def scope_for_create
+          scope.scope_for_create
+        end
 
         def find_target?
           !loaded? && (!owner.new_record? || foreign_key_present?) && klass
diff --git a/activerecord/lib/active_record/associations/association_scope.rb b/activerecord/lib/active_record/associations/association_scope.rb
index 6ef225b725..9b0b50977d 100644
--- a/activerecord/lib/active_record/associations/association_scope.rb
+++ b/activerecord/lib/active_record/associations/association_scope.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class AssociationScope #:nodoc:
diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb
index 0e61dbfb00..7a9f5f7937 100644
--- a/activerecord/lib/active_record/associations/belongs_to_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Belongs To Association
   module Associations
diff --git a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
index b710cf6bdb..13b4a084ea 100644
--- a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Belongs To Polymorphic Association
   module Associations
diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
index d0534056d9..496b16b58f 100644
--- a/activerecord/lib/active_record/associations/builder/association.rb
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This is the parent Association class which defines the variables
 # used by all associations.
 #
diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb
index 2b9dd8aae8..9904ee4bed 100644
--- a/activerecord/lib/active_record/associations/builder/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Associations::Builder # :nodoc:
   class BelongsTo < SingularAssociation #:nodoc:
     def self.macro
@@ -32,9 +34,7 @@ module ActiveRecord::Associations::Builder # :nodoc:
           foreign_key  = reflection.foreign_key
           cache_column = reflection.counter_cache_column
 
-          if (@_after_create_counter_called ||= false)
-            @_after_create_counter_called = false
-          elsif (@_after_replace_counter_called ||= false)
+          if (@_after_replace_counter_called ||= false)
             @_after_replace_counter_called = false
           elsif saved_change_to_attribute?(foreign_key) && !new_record?
             if reflection.polymorphic?
diff --git a/activerecord/lib/active_record/associations/builder/collection_association.rb b/activerecord/lib/active_record/associations/builder/collection_association.rb
index c58b7d8160..753fde5146 100644
--- a/activerecord/lib/active_record/associations/builder/collection_association.rb
+++ b/activerecord/lib/active_record/associations/builder/collection_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../../associations"
 
 module ActiveRecord::Associations::Builder # :nodoc:
diff --git a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
index 6b71826431..12fcfbcd45 100644
--- a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Associations::Builder # :nodoc:
   class HasAndBelongsToMany # :nodoc:
     class JoinTableResolver # :nodoc:
diff --git a/activerecord/lib/active_record/associations/builder/has_many.rb b/activerecord/lib/active_record/associations/builder/has_many.rb
index 7864d4c536..5b9617bc6d 100644
--- a/activerecord/lib/active_record/associations/builder/has_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_many.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Associations::Builder # :nodoc:
   class HasMany < CollectionAssociation #:nodoc:
     def self.macro
diff --git a/activerecord/lib/active_record/associations/builder/has_one.rb b/activerecord/lib/active_record/associations/builder/has_one.rb
index 4de846d12b..bfb37d6eee 100644
--- a/activerecord/lib/active_record/associations/builder/has_one.rb
+++ b/activerecord/lib/active_record/associations/builder/has_one.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Associations::Builder # :nodoc:
   class HasOne < SingularAssociation #:nodoc:
     def self.macro
diff --git a/activerecord/lib/active_record/associations/builder/singular_association.rb b/activerecord/lib/active_record/associations/builder/singular_association.rb
index 7732b63af6..0a02ef4cc1 100644
--- a/activerecord/lib/active_record/associations/builder/singular_association.rb
+++ b/activerecord/lib/active_record/associations/builder/singular_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This class is inherited by the has_one and belongs_to association classes
 
 module ActiveRecord::Associations::Builder # :nodoc:
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index a49fb155ee..ed2e6d1ae4 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     # = Active Record Association Collection
@@ -374,10 +376,6 @@ module ActiveRecord
           end
         end
 
-        def create_scope
-          scope.scope_for_create.stringify_keys
-        end
-
         def delete_or_destroy(records, method)
           records = records.flatten
           records.each { |record| raise_on_type_mismatch!(record) }
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index d77fcaf668..0678b07699 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     # Association proxies in Active Record are middlemen between the object that
diff --git a/activerecord/lib/active_record/associations/foreign_association.rb b/activerecord/lib/active_record/associations/foreign_association.rb
index 3ceec0ee46..40010cde03 100644
--- a/activerecord/lib/active_record/associations/foreign_association.rb
+++ b/activerecord/lib/active_record/associations/foreign_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Associations
   module ForeignAssociation # :nodoc:
     def foreign_key_present?
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index 10ca0e47ff..88fe33eef2 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Has Many Association
   module Associations
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 2fd20b4368..89ce00f98e 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Has Many Through Association
   module Associations
@@ -152,7 +154,7 @@ module ActiveRecord
               stmt.from scope.klass.arel_table
               stmt.wheres = arel.constraints
 
-              count = scope.klass.connection.delete(stmt, "SQL", scope.bound_attributes)
+              count = scope.klass.connection.delete(stmt, "SQL")
             end
           when :nullify
             count = scope.update_all(source_reflection.foreign_key => nil)
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 8458253ff8..9a88c1af70 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Has One Association
   module Associations
@@ -56,6 +58,7 @@ module ActiveRecord
           when :delete
             target.delete
           when :destroy
+            target.destroyed_by_association = reflection
             target.destroy
           when :nullify
             target.update_columns(reflection.foreign_key => nil) if target.persisted?
@@ -78,6 +81,7 @@ module ActiveRecord
           when :delete
             target.delete
           when :destroy
+            target.destroyed_by_association = reflection
             target.destroy
           else
             nullify_owner_attributes(target)
diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb
index 1183bdf6f4..eb54977aa0 100644
--- a/activerecord/lib/active_record/associations/has_one_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_through_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Has One Through Association
   module Associations
diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
index 04cdcb6a7f..dc029c08bd 100644
--- a/activerecord/lib/active_record/associations/join_dependency.rb
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class JoinDependency # :nodoc:
@@ -33,12 +35,8 @@ module ActiveRecord
         end
 
         Table = Struct.new(:node, :columns) do # :nodoc:
-          def table
-            Arel::Nodes::TableAlias.new node.table, node.aliased_table_name
-          end
-
           def column_aliases
-            t = table
+            t = node.table
             columns.map { |column| t[column.name].as Arel.sql column.alias }
           end
         end
@@ -92,11 +90,11 @@ module ActiveRecord
       #    associations # => [:appointments]
       #    joins # =>  []
       #
-      def initialize(base, associations, joins, eager_loading: true)
+      def initialize(base, table, associations, joins, eager_loading: true)
         @alias_tracker = AliasTracker.create_with_joins(base.connection, base.table_name, joins)
         @eager_loading = eager_loading
         tree = self.class.make_tree associations
-        @join_root = JoinBase.new base, build(tree, base)
+        @join_root = JoinBase.new(base, table, build(tree, base))
         @join_root.children.each { |child| construct_tables! @join_root, child }
       end
 
@@ -176,9 +174,9 @@ module ActiveRecord
 
         def make_join_constraints(parent, child, join_type, aliasing = false)
           tables = aliasing ? table_aliases_for(parent, child) : child.tables
-          info   = make_constraints(parent, child, tables, join_type)
+          joins  = make_constraints(parent, child, tables, join_type)
 
-          [info] + child.children.flat_map { |c| make_join_constraints(child, c, join_type, aliasing) }
+          joins.concat child.children.flat_map { |c| make_join_constraints(child, c, join_type, aliasing) }
         end
 
         def table_aliases_for(parent, node)
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
index b14ddfeeeb..a526468bf6 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "join_part"
 
 module ActiveRecord
@@ -21,11 +23,8 @@ module ActiveRecord
           super && reflection == other.reflection
         end
 
-        JoinInformation = Struct.new :joins, :binds
-
         def join_constraints(foreign_table, foreign_klass, join_type, tables, chain)
           joins         = []
-          binds         = []
           tables        = tables.reverse
 
           # The chain starts with the target table, but we want to end with it here (makes
@@ -41,7 +40,6 @@ module ActiveRecord
             join_scope = reflection.join_scope(table, foreign_klass)
 
             if join_scope.arel.constraints.any?
-              binds.concat join_scope.bound_attributes
               joins.concat join_scope.arel.join_sources
               right = joins.last.right
               right.expr = right.expr.and(join_scope.arel.constraints)
@@ -51,16 +49,12 @@ module ActiveRecord
             foreign_table, foreign_klass = table, klass
           end
 
-          JoinInformation.new joins, binds
+          joins
         end
 
         def table
           tables.first
         end
-
-        def aliased_table_name
-          table.table_alias || table.name
-        end
       end
     end
   end
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_base.rb b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
index 6e0963425d..8a8fa8993b 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_base.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
@@ -1,20 +1,21 @@
+# frozen_string_literal: true
+
 require_relative "join_part"
 
 module ActiveRecord
   module Associations
     class JoinDependency # :nodoc:
       class JoinBase < JoinPart # :nodoc:
-        def match?(other)
-          return true if self == other
-          super && base_klass == other.base_klass
-        end
+        attr_reader :table
 
-        def table
-          base_klass.arel_table
+        def initialize(base_klass, table, children)
+          super(base_klass, children)
+          @table = table
         end
 
-        def aliased_table_name
-          base_klass.table_name
+        def match?(other)
+          return true if self == other
+          super && base_klass == other.base_klass
         end
       end
     end
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
index 80c9fde5d1..2181f308bf 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_part.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class JoinDependency # :nodoc:
@@ -36,11 +38,6 @@ module ActiveRecord
           raise NotImplementedError
         end
 
-        # The alias for the active_record's table
-        def aliased_table_name
-          raise NotImplementedError
-        end
-
         def extract_record(row, column_names_with_alias)
           # This code is performance critical as it is called per row.
           # see: https://github.com/rails/rails/pull/12185
diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb
index a18994cec4..62caf02a2c 100644
--- a/activerecord/lib/active_record/associations/preloader.rb
+++ b/activerecord/lib/active_record/associations/preloader.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     # Implements the details of eager loading of Active Record associations.
diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb
index 85343040db..5ba03c555a 100644
--- a/activerecord/lib/active_record/associations/preloader/association.rb
+++ b/activerecord/lib/active_record/associations/preloader/association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
@@ -114,8 +116,18 @@ module ActiveRecord
             @reflection_scope ||= reflection.scope_for(klass)
           end
 
+          def klass_scope
+            current_scope = klass.current_scope
+
+            if current_scope && current_scope.empty_scope?
+              klass.unscoped
+            else
+              klass.default_scoped
+            end
+          end
+
           def build_scope
-            scope = klass.default_scoped
+            scope = klass_scope
 
             if reflection.type
               scope.where!(reflection.type => model.base_class.sti_name)
diff --git a/activerecord/lib/active_record/associations/preloader/belongs_to.rb b/activerecord/lib/active_record/associations/preloader/belongs_to.rb
index c20145770f..ae9695f26a 100644
--- a/activerecord/lib/active_record/associations/preloader/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/preloader/belongs_to.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/collection_association.rb b/activerecord/lib/active_record/associations/preloader/collection_association.rb
index 26690bf16d..fb920a642c 100644
--- a/activerecord/lib/active_record/associations/preloader/collection_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/collection_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/has_many.rb b/activerecord/lib/active_record/associations/preloader/has_many.rb
index 20df1cc19a..29a1ce099d 100644
--- a/activerecord/lib/active_record/associations/preloader/has_many.rb
+++ b/activerecord/lib/active_record/associations/preloader/has_many.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/has_many_through.rb b/activerecord/lib/active_record/associations/preloader/has_many_through.rb
index 2029871f39..0639fdca44 100644
--- a/activerecord/lib/active_record/associations/preloader/has_many_through.rb
+++ b/activerecord/lib/active_record/associations/preloader/has_many_through.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/has_one.rb b/activerecord/lib/active_record/associations/preloader/has_one.rb
index c4add621ca..d87abf630f 100644
--- a/activerecord/lib/active_record/associations/preloader/has_one.rb
+++ b/activerecord/lib/active_record/associations/preloader/has_one.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/has_one_through.rb b/activerecord/lib/active_record/associations/preloader/has_one_through.rb
index f063f85574..17734d0257 100644
--- a/activerecord/lib/active_record/associations/preloader/has_one_through.rb
+++ b/activerecord/lib/active_record/associations/preloader/has_one_through.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/singular_association.rb b/activerecord/lib/active_record/associations/preloader/singular_association.rb
index 5c5828262e..266b5f6b1c 100644
--- a/activerecord/lib/active_record/associations/preloader/singular_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/singular_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb
index 0999746cd5..de4b847a41 100644
--- a/activerecord/lib/active_record/associations/preloader/through_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/through_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class Preloader
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
index f8bbe4c2ed..c1eee3c630 100644
--- a/activerecord/lib/active_record/associations/singular_association.rb
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Associations
     class SingularAssociation < Association #:nodoc:
@@ -30,9 +32,8 @@ module ActiveRecord
       end
 
       private
-
-        def create_scope
-          scope.scope_for_create.stringify_keys.except(klass.primary_key)
+        def scope_for_create
+          super.except!(klass.primary_key)
         end
 
         def find_target
diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
index 6b87993ba3..76237c4a0c 100644
--- a/activerecord/lib/active_record/associations/through_association.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Through Association
   module Associations
diff --git a/activerecord/lib/active_record/attribute.rb b/activerecord/lib/active_record/attribute.rb
index 78662433eb..fc474edc15 100644
--- a/activerecord/lib/active_record/attribute.rb
+++ b/activerecord/lib/active_record/attribute.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Attribute # :nodoc:
     class << self
@@ -174,7 +176,7 @@ module ActiveRecord
         end
 
         def came_from_user?
-          true
+          !type.value_constructed_by_mass_assignment?(value_before_type_cast)
         end
       end
 
diff --git a/activerecord/lib/active_record/attribute/user_provided_default.rb b/activerecord/lib/active_record/attribute/user_provided_default.rb
index c4e731fb28..690a931615 100644
--- a/activerecord/lib/active_record/attribute/user_provided_default.rb
+++ b/activerecord/lib/active_record/attribute/user_provided_default.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../attribute"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/attribute_assignment.rb b/activerecord/lib/active_record/attribute_assignment.rb
index d0dfca0cac..8b0d9aab01 100644
--- a/activerecord/lib/active_record/attribute_assignment.rb
+++ b/activerecord/lib/active_record/attribute_assignment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_model/forbidden_attributes_protection"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/attribute_decorators.rb b/activerecord/lib/active_record/attribute_decorators.rb
index 5bc8527745..98b7805c0a 100644
--- a/activerecord/lib/active_record/attribute_decorators.rb
+++ b/activerecord/lib/active_record/attribute_decorators.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeDecorators # :nodoc:
     extend ActiveSupport::Concern
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 83c61fad19..e4ca6c8408 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -1,7 +1,6 @@
-require "active_support/core_ext/enumerable"
-require "active_support/core_ext/string/filters"
+# frozen_string_literal: true
+
 require "mutex_m"
-require "concurrent/map"
 
 module ActiveRecord
   # = Active Record Attribute Methods
diff --git a/activerecord/lib/active_record/attribute_methods/before_type_cast.rb b/activerecord/lib/active_record/attribute_methods/before_type_cast.rb
index 115eb1ef3f..5941f51a1a 100644
--- a/activerecord/lib/active_record/attribute_methods/before_type_cast.rb
+++ b/activerecord/lib/active_record/attribute_methods/before_type_cast.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     # = Active Record Attribute Methods Before Type Cast
diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index 8c58e63931..5efe051125 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require "active_support/core_ext/module/attribute_accessors"
 require_relative "../attribute_mutation_tracker"
 
@@ -16,8 +17,8 @@ module ActiveRecord
 
         class_attribute :partial_writes, instance_writer: false, default: true
 
-        after_create { changes_internally_applied }
-        after_update { changes_internally_applied }
+        after_create { changes_applied }
+        after_update { changes_applied }
 
         # Attribute methods for "changed in last call to save?"
         attribute_method_affix(prefix: "saved_change_to_", suffix: "?")
@@ -29,25 +30,10 @@ module ActiveRecord
         attribute_method_suffix("_change_to_be_saved", "_in_database")
       end
 
-      # Attempts to +save+ the record and clears changed attributes if successful.
-      def save(*)
-        if status = super
-          changes_applied
-        end
-        status
-      end
-
-      # Attempts to <tt>save!</tt> the record and clears changed attributes if successful.
-      def save!(*)
-        super.tap do
-          changes_applied
-        end
-      end
-
       # <tt>reload</tt> the record and clears changed attributes.
       def reload(*)
         super.tap do
-          @previous_mutation_tracker = nil
+          @mutations_before_last_save = nil
           clear_mutation_trackers
           @changed_attributes = ActiveSupport::HashWithIndifferentAccess.new
         end
@@ -61,20 +47,16 @@ module ActiveRecord
         clear_mutation_trackers
       end
 
-      def changes_internally_applied # :nodoc:
+      def changes_applied
         @mutations_before_last_save = mutation_tracker
-        forget_attribute_assignments
         @mutations_from_database = AttributeMutationTracker.new(@attributes)
-      end
-
-      def changes_applied
-        @previous_mutation_tracker = mutation_tracker
         @changed_attributes = ActiveSupport::HashWithIndifferentAccess.new
+        forget_attribute_assignments
         clear_mutation_trackers
       end
 
       def clear_changes_information
-        @previous_mutation_tracker = nil
+        @mutations_before_last_save = nil
         @changed_attributes = ActiveSupport::HashWithIndifferentAccess.new
         forget_attribute_assignments
         clear_mutation_trackers
@@ -99,28 +81,18 @@ module ActiveRecord
         if defined?(@cached_changed_attributes)
           @cached_changed_attributes
         else
-          emit_warning_if_needed("changed_attributes", "saved_changes.transform_values(&:first)")
           super.reverse_merge(mutation_tracker.changed_values).freeze
         end
       end
 
       def changes
         cache_changed_attributes do
-          emit_warning_if_needed("changes", "saved_changes")
           super
         end
       end
 
       def previous_changes
-        unless previous_mutation_tracker.equal?(mutations_before_last_save)
-          ActiveSupport::Deprecation.warn(<<-EOW.strip_heredoc)
-            The behavior of `previous_changes` inside of after callbacks is
-            deprecated without replacement. In the next release of Rails,
-            this method inside of `after_save` will return the changes that
-            were just saved.
-          EOW
-        end
-        previous_mutation_tracker.changes
+        mutations_before_last_save.changes
       end
 
       def attribute_changed_in_place?(attr_name)
@@ -210,31 +182,6 @@ module ActiveRecord
         changes_to_save.transform_values(&:first)
       end
 
-      def attribute_was(*)
-        emit_warning_if_needed("attribute_was", "attribute_before_last_save")
-        super
-      end
-
-      def attribute_change(*)
-        emit_warning_if_needed("attribute_change", "saved_change_to_attribute")
-        super
-      end
-
-      def attribute_changed?(*)
-        emit_warning_if_needed("attribute_changed?", "saved_change_to_attribute?")
-        super
-      end
-
-      def changed?(*)
-        emit_warning_if_needed("changed?", "saved_changes?")
-        super
-      end
-
-      def changed(*)
-        emit_warning_if_needed("changed", "saved_changes.keys")
-        super
-      end
-
       private
 
         def mutation_tracker
@@ -244,18 +191,6 @@ module ActiveRecord
           @mutation_tracker ||= AttributeMutationTracker.new(@attributes)
         end
 
-        def emit_warning_if_needed(method_name, new_method_name)
-          unless mutation_tracker.equal?(mutations_from_database)
-            ActiveSupport::Deprecation.warn(<<-EOW.squish)
-              The behavior of `#{method_name}` inside of after callbacks will
-              be changing in the next version of Rails. The new return value will reflect the
-              behavior of calling the method after `save` returned (e.g. the opposite of what
-              it returns now). To maintain the current behavior, use `#{new_method_name}`
-              instead.
-            EOW
-          end
-        end
-
         def mutations_from_database
           unless defined?(@mutations_from_database)
             @mutations_from_database = nil
@@ -274,17 +209,7 @@ module ActiveRecord
 
         def attribute_will_change!(attr_name)
           super
-          if self.class.has_attribute?(attr_name)
-            mutations_from_database.force_change(attr_name)
-          else
-            ActiveSupport::Deprecation.warn(<<-EOW.squish)
-              #{attr_name} is not an attribute known to Active Record.
-              This behavior is deprecated and will be removed in the next
-              version of Rails. If you'd like #{attr_name} to be managed
-              by Active Record, add `attribute :#{attr_name}` to your class.
-            EOW
-            mutations_from_database.deprecated_force_change(attr_name)
-          end
+          mutations_from_database.force_change(attr_name)
         end
 
         def _update_record(*)
@@ -306,15 +231,10 @@ module ActiveRecord
         def clear_mutation_trackers
           @mutation_tracker = nil
           @mutations_from_database = nil
-          @mutations_before_last_save = nil
-        end
-
-        def previous_mutation_tracker
-          @previous_mutation_tracker ||= NullMutationTracker.instance
         end
 
         def mutations_before_last_save
-          @mutations_before_last_save ||= previous_mutation_tracker
+          @mutations_before_last_save ||= NullMutationTracker.instance
         end
 
         def cache_changed_attributes
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index 081aad434d..63c059e291 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "set"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/attribute_methods/query.rb b/activerecord/lib/active_record/attribute_methods/query.rb
index 10498f4322..6757e9b66a 100644
--- a/activerecord/lib/active_record/attribute_methods/query.rb
+++ b/activerecord/lib/active_record/attribute_methods/query.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module Query
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index fdc4bf6621..6adaeb0121 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module Read
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 4d9aff76cc..6ed45d8737 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module Serialization
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index 1f1efe8812..f12a9f915c 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module TimeZoneConversion
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index 54b673c72e..fa01f832ac 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module Write
diff --git a/activerecord/lib/active_record/attribute_mutation_tracker.rb b/activerecord/lib/active_record/attribute_mutation_tracker.rb
index a01a58f8a5..94bf641a5d 100644
--- a/activerecord/lib/active_record/attribute_mutation_tracker.rb
+++ b/activerecord/lib/active_record/attribute_mutation_tracker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class AttributeMutationTracker # :nodoc:
     OPTION_NOT_GIVEN = Object.new
@@ -5,7 +7,6 @@ module ActiveRecord
     def initialize(attributes)
       @attributes = attributes
       @forced_changes = Set.new
-      @deprecated_forced_changes = Set.new
     end
 
     def changed_values
@@ -33,7 +34,7 @@ module ActiveRecord
     end
 
     def any_changes?
-      attr_names.any? { |attr| changed?(attr) } || deprecated_forced_changes.any?
+      attr_names.any? { |attr| changed?(attr) }
     end
 
     def changed?(attr_name, from: OPTION_NOT_GIVEN, to: OPTION_NOT_GIVEN)
@@ -62,15 +63,11 @@ module ActiveRecord
       forced_changes << attr_name.to_s
     end
 
-    def deprecated_force_change(attr_name)
-      deprecated_forced_changes << attr_name.to_s
-    end
-
     # TODO Change this to private once we've dropped Ruby 2.2 support.
     # Workaround for Ruby 2.2 "private attribute?" warning.
     protected
 
-      attr_reader :attributes, :forced_changes, :deprecated_forced_changes
+      attr_reader :attributes, :forced_changes
 
     private
 
diff --git a/activerecord/lib/active_record/attribute_set.rb b/activerecord/lib/active_record/attribute_set.rb
index 6399e3de70..492067e2b3 100644
--- a/activerecord/lib/active_record/attribute_set.rb
+++ b/activerecord/lib/active_record/attribute_set.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "attribute_set/builder"
 require_relative "attribute_set/yaml_encoder"
 
@@ -98,8 +100,6 @@ module ActiveRecord
       attributes == other.attributes
     end
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
     protected
 
       attr_reader :attributes
diff --git a/activerecord/lib/active_record/attribute_set/builder.rb b/activerecord/lib/active_record/attribute_set/builder.rb
index abe22b9ae4..e3a9c7fdb3 100644
--- a/activerecord/lib/active_record/attribute_set/builder.rb
+++ b/activerecord/lib/active_record/attribute_set/builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../attribute"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/attribute_set/yaml_encoder.rb b/activerecord/lib/active_record/attribute_set/yaml_encoder.rb
index 899de14792..9254ce16ab 100644
--- a/activerecord/lib/active_record/attribute_set/yaml_encoder.rb
+++ b/activerecord/lib/active_record/attribute_set/yaml_encoder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class AttributeSet
     # Attempts to do more intelligent YAML dumping of an
diff --git a/activerecord/lib/active_record/attributes.rb b/activerecord/lib/active_record/attributes.rb
index dde22bcdaa..afb559db71 100644
--- a/activerecord/lib/active_record/attributes.rb
+++ b/activerecord/lib/active_record/attributes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "attribute/user_provided_default"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/autosave_association.rb b/activerecord/lib/active_record/autosave_association.rb
index 70f0e2af8e..6974cf74f6 100644
--- a/activerecord/lib/active_record/autosave_association.rb
+++ b/activerecord/lib/active_record/autosave_association.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Autosave Association
   #
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index f0e455478a..541ff51fbe 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "yaml"
 require "active_support/benchmarkable"
 require "active_support/dependencies"
diff --git a/activerecord/lib/active_record/callbacks.rb b/activerecord/lib/active_record/callbacks.rb
index eb44887e18..a2439e6ec7 100644
--- a/activerecord/lib/active_record/callbacks.rb
+++ b/activerecord/lib/active_record/callbacks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \Callbacks
   #
diff --git a/activerecord/lib/active_record/coders/json.rb b/activerecord/lib/active_record/coders/json.rb
index cb185a881e..a69b38487e 100644
--- a/activerecord/lib/active_record/coders/json.rb
+++ b/activerecord/lib/active_record/coders/json.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Coders # :nodoc:
     class JSON # :nodoc:
diff --git a/activerecord/lib/active_record/coders/yaml_column.rb b/activerecord/lib/active_record/coders/yaml_column.rb
index 9c52a31b95..11559141c7 100644
--- a/activerecord/lib/active_record/coders/yaml_column.rb
+++ b/activerecord/lib/active_record/coders/yaml_column.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "yaml"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/collection_cache_key.rb b/activerecord/lib/active_record/collection_cache_key.rb
index 8b937b6703..b1937a3c68 100644
--- a/activerecord/lib/active_record/collection_cache_key.rb
+++ b/activerecord/lib/active_record/collection_cache_key.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module CollectionCacheKey
     def collection_cache_key(collection = all, timestamp_column = :updated_at) # :nodoc:
@@ -14,7 +16,7 @@ module ActiveRecord
         column = "#{connection.quote_table_name(collection.table_name)}.#{connection.quote_column_name(timestamp_column)}"
         select_values = "COUNT(*) AS #{connection.quote_column_name("size")}, MAX(%s) AS timestamp"
 
-        if collection.limit_value || collection.offset_value
+        if collection.has_limit_or_offset?
           query = collection.spawn
           query.select_values = [column]
           subquery_alias = "subquery_for_cache_key"
@@ -27,7 +29,7 @@ module ActiveRecord
           arel = query.arel
         end
 
-        result = connection.select_one(arel, nil, query.bound_attributes)
+        result = connection.select_one(arel, nil)
 
         if result.blank?
           size = 0
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 627b753f01..c11b7b012f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "thread"
 require "concurrent/map"
 require "monitor"
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
index 407e019326..7a9e7add24 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     module DatabaseLimits
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index 879626b72a..314a35207b 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     module DatabaseStatements
@@ -7,30 +9,37 @@ module ActiveRecord
       end
 
       # Converts an arel AST to SQL
-      def to_sql(arel, binds = [])
-        if arel.respond_to?(:ast)
-          collected = visitor.accept(arel.ast, collector)
-          collected.compile(binds, self).freeze
+      def to_sql(arel_or_sql_string, binds = [])
+        if arel_or_sql_string.respond_to?(:ast)
+          unless binds.empty?
+            raise "Passing bind parameters with an arel AST is forbidden. " \
+              "The values must be stored on the AST directly"
+          end
+          sql, binds = visitor.accept(arel_or_sql_string.ast, collector).value
+          [sql.freeze, binds || []]
         else
-          arel.dup.freeze
+          [arel_or_sql_string.dup.freeze, binds]
         end
       end
 
       # This is used in the StatementCache object. It returns an object that
       # can be used to query the database repeatedly.
       def cacheable_query(klass, arel) # :nodoc:
-        collected = visitor.accept(arel.ast, collector)
         if prepared_statements
-          klass.query(collected.value)
+          sql, binds = visitor.accept(arel.ast, collector).value
+          query = klass.query(sql)
         else
-          klass.partial_query(collected.value)
+          collector = PartialQueryCollector.new
+          parts, binds = visitor.accept(arel.ast, collector).value
+          query = klass.partial_query(parts)
         end
+        [query, binds]
       end
 
       # Returns an ActiveRecord::Result instance.
       def select_all(arel, name = nil, binds = [], preparable: nil)
-        arel, binds = binds_from_relation arel, binds
-        sql = to_sql(arel, binds)
+        arel = arel_from_relation(arel)
+        sql, binds = to_sql(arel, binds)
         if !prepared_statements || (arel.is_a?(String) && preparable.nil?)
           preparable = false
         else
@@ -129,20 +138,23 @@ module ActiveRecord
       #
       # If the next id was calculated in advance (as in Oracle), it should be
       # passed in as +id_value+.
-      def insert(arel, name = nil, pk = nil, id_value = nil, sequence_name = nil, binds = [])
-        value = exec_insert(to_sql(arel, binds), name, binds, pk, sequence_name)
+      def insert(arel, name = nil, pk = nil, id_value = nil, sequence_name = nil)
+        sql, binds = to_sql(arel)
+        value = exec_insert(sql, name, binds, pk, sequence_name)
         id_value || last_inserted_id(value)
       end
       alias create insert
 
       # Executes the update statement and returns the number of rows affected.
-      def update(arel, name = nil, binds = [])
-        exec_update(to_sql(arel, binds), name, binds)
+      def update(arel, name = nil)
+        sql, binds = to_sql(arel)
+        exec_update(sql, name, binds)
       end
 
       # Executes the delete statement and returns the number of rows affected.
-      def delete(arel, name = nil, binds = [])
-        exec_delete(to_sql(arel, binds), name, binds)
+      def delete(arel, name = nil)
+        sql, binds = to_sql(arel)
+        exec_delete(sql, name, binds)
       end
 
       # Returns +true+ when the connection adapter supports prepared statement
@@ -215,7 +227,7 @@ module ActiveRecord
       # You should consult the documentation for your database to understand the
       # semantics of these different levels:
       #
-      # * http://www.postgresql.org/docs/current/static/transaction-iso.html
+      # * https://www.postgresql.org/docs/current/static/transaction-iso.html
       # * https://dev.mysql.com/doc/refman/5.7/en/set-transaction.html
       #
       # An ActiveRecord::TransactionIsolationError will be raised if:
@@ -428,11 +440,12 @@ module ActiveRecord
           row && row.first
         end
 
-        def binds_from_relation(relation, binds)
-          if relation.is_a?(Relation) && binds.empty?
-            relation, binds = relation.arel, relation.bound_attributes
+        def arel_from_relation(relation)
+          if relation.is_a?(Relation)
+            relation.arel
+          else
+            relation
           end
-          [relation, binds]
         end
 
         # Fixture value is quoted by Arel, however scalar values
@@ -445,6 +458,28 @@ module ActiveRecord
             value
           end
         end
+
+        class PartialQueryCollector
+          def initialize
+            @parts = []
+            @binds = []
+          end
+
+          def << str
+            @parts << str
+            self
+          end
+
+          def add_bind obj
+            @binds << obj
+            @parts << Arel::Nodes::BindParam.new(1)
+            self
+          end
+
+          def value
+            [@parts, @binds]
+          end
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index c352ddfc11..ecf5201d12 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     module QueryCache
@@ -90,8 +92,8 @@ module ActiveRecord
 
       def select_all(arel, name = nil, binds = [], preparable: nil)
         if @query_cache_enabled && !locked?(arel)
-          arel, binds = binds_from_relation arel, binds
-          sql = to_sql(arel, binds)
+          arel = arel_from_relation(arel)
+          sql, binds = to_sql(arel, binds)
           cache_sql(sql, name, binds) { super(sql, name, binds, preparable: preparable) }
         else
           super
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index 61233dcc51..7b83bc319c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/big_decimal/conversions"
 require "active_support/multibyte/chars"
 
@@ -22,6 +24,10 @@ module ActiveRecord
           return value.quoted_id
         end
 
+        if value.respond_to?(:value_for_database)
+          value = value.value_for_database
+        end
+
         _quote(value)
       end
 
@@ -106,19 +112,19 @@ module ActiveRecord
       end
 
       def quoted_true
-        "'t'".freeze
+        "TRUE".freeze
       end
 
       def unquoted_true
-        "t".freeze
+        true
       end
 
       def quoted_false
-        "'f'".freeze
+        "FALSE".freeze
       end
 
       def unquoted_false
-        "f".freeze
+        false
       end
 
       # Quote date/time values for use in SQL input. Includes microseconds
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/savepoints.rb b/activerecord/lib/active_record/connection_adapters/abstract/savepoints.rb
index 3a06f75292..52a796b926 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/savepoints.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/savepoints.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module Savepoints
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
index 8865e7c703..8bf3879a4c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/string/strip"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index a30fbe0e05..3b2c51ef94 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters #:nodoc:
     # Abstract representation of an index definition on a table. Instances of
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
index 34036d8a1d..9be26254b2 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     # The goal of this module is to move Adapter specific column
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 475463c4fd..e21f93856e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../../migration/join_table"
 require "active_support/core_ext/string/access"
 require "digest"
@@ -509,6 +511,7 @@ module ActiveRecord
       # * <tt>:limit</tt> -
       #   Requests a maximum column length. This is the number of characters for a <tt>:string</tt> column
       #   and number of bytes for <tt>:text</tt>, <tt>:binary</tt> and <tt>:integer</tt> columns.
+      #   This option is ignored by some backends.
       # * <tt>:default</tt> -
       #   The column's default value. Use +nil+ for +NULL+.
       # * <tt>:null</tt> -
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
index f63d09039f..147e16e9fa 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     class TransactionState
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 30b29e7007..7645cf7825 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../type"
 require_relative "determine_if_preparable_visitor"
 require_relative "schema_cache"
@@ -5,7 +7,9 @@ require_relative "sql_type_metadata"
 require_relative "abstract/schema_dumper"
 require_relative "abstract/schema_creation"
 require "arel/collectors/bind"
+require "arel/collectors/composite"
 require "arel/collectors/sql_string"
+require "arel/collectors/substitute_binds"
 
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
@@ -127,19 +131,6 @@ module ActiveRecord
         end
       end
 
-      class BindCollector < Arel::Collectors::Bind
-        def compile(bvs, conn)
-          casted_binds = bvs.map(&:value_for_database)
-          super(casted_binds.map { |value| conn.quote(value) })
-        end
-      end
-
-      class SQLString < Arel::Collectors::SQLString
-        def compile(bvs, conn)
-          super(bvs)
-        end
-      end
-
       def valid_type?(type) # :nodoc:
         !native_database_types[type].nil?
       end
@@ -451,41 +442,22 @@ module ActiveRecord
         pool.checkin self
       end
 
-      def type_map # :nodoc:
-        @type_map ||= Type::TypeMap.new.tap do |mapping|
-          initialize_type_map(mapping)
-        end
-      end
-
       def column_name_for_operation(operation, node) # :nodoc:
         visitor.accept(node, collector).value
       end
 
-      def combine_bind_parameters(
-        from_clause: [],
-        join_clause: [],
-        where_clause: [],
-        having_clause: [],
-        limit: nil,
-        offset: nil
-      ) # :nodoc:
-        result = from_clause + join_clause + where_clause + having_clause
-        if limit
-          result << limit
-        end
-        if offset
-          result << offset
-        end
-        result
-      end
-
       def default_index_type?(index) # :nodoc:
         index.using.nil?
       end
 
       private
+        def type_map
+          @type_map ||= Type::TypeMap.new.tap do |mapping|
+            initialize_type_map(mapping)
+          end
+        end
 
-        def initialize_type_map(m)
+        def initialize_type_map(m = type_map)
           register_class_with_limit m, %r(boolean)i,       Type::Boolean
           register_class_with_limit m, %r(char)i,          Type::String
           register_class_with_limit m, %r(binary)i,        Type::Binary
@@ -518,7 +490,7 @@ module ActiveRecord
 
         def reload_type_map
           type_map.clear
-          initialize_type_map(type_map)
+          initialize_type_map
         end
 
         def register_class_with_limit(mapping, key, klass)
@@ -608,9 +580,15 @@ module ActiveRecord
 
         def collector
           if prepared_statements
-            SQLString.new
+            Arel::Collectors::Composite.new(
+              Arel::Collectors::SQLString.new,
+              Arel::Collectors::Bind.new,
+            )
           else
-            BindCollector.new
+            Arel::Collectors::SubstituteBinds.new(
+              self,
+              Arel::Collectors::SQLString.new,
+            )
           end
         end
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 06976aa769..8a9c497918 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "abstract_adapter"
 require_relative "statement_pool"
 require_relative "mysql/column"
@@ -175,7 +177,8 @@ module ActiveRecord
       #++
 
       def explain(arel, binds = [])
-        sql     = "EXPLAIN #{to_sql(arel, binds)}"
+        sql, binds = to_sql(arel, binds)
+        sql     = "EXPLAIN #{sql}"
         start   = Time.now
         result  = exec_query(sql, "EXPLAIN", binds)
         elapsed = Time.now - start
@@ -545,7 +548,7 @@ module ActiveRecord
           execute("SET @@SESSION.sql_mode = #{sql_mode}")
         end
 
-        def initialize_type_map(m)
+        def initialize_type_map(m = type_map)
           super
 
           register_class_with_limit m, %r(char)i, MysqlString
@@ -861,8 +864,8 @@ module ActiveRecord
         class MysqlString < Type::String # :nodoc:
           def serialize(value)
             case value
-            when true then MySQL::Quoting::QUOTED_TRUE
-            when false then MySQL::Quoting::QUOTED_FALSE
+            when true then "1"
+            when false then "0"
             else super
             end
           end
@@ -871,8 +874,8 @@ module ActiveRecord
 
             def cast_value(value)
               case value
-              when true then MySQL::Quoting::QUOTED_TRUE
-              when false then MySQL::Quoting::QUOTED_FALSE
+              when true then "1"
+              when false then "0"
               else super
               end
             end
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 61cd7ae4cc..16273fb5f1 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # :stopdoc:
   module ConnectionAdapters
diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index 3e4ea28f63..29542f917e 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "uri"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/connection_adapters/determine_if_preparable_visitor.rb b/activerecord/lib/active_record/connection_adapters/determine_if_preparable_visitor.rb
index 0fdc185c45..3dcb916d99 100644
--- a/activerecord/lib/active_record/connection_adapters/determine_if_preparable_visitor.rb
+++ b/activerecord/lib/active_record/connection_adapters/determine_if_preparable_visitor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module DetermineIfPreparableVisitor
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/column.rb b/activerecord/lib/active_record/connection_adapters/mysql/column.rb
index c9ad47c035..fa1541019d 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/column.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
index bda482a00f..a058a72872 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
       module DatabaseStatements
         # Returns an ActiveRecord::Result instance.
-        def select_all(arel, name = nil, binds = [], preparable: nil) # :nodoc:
+        def select_all(*) # :nodoc:
           result = if ExplainRegistry.collect? && prepared_statements
             unprepared_statement { super }
           else
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/explain_pretty_printer.rb b/activerecord/lib/active_record/connection_adapters/mysql/explain_pretty_printer.rb
index 9691060cd3..20c3c83664 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/explain_pretty_printer.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/explain_pretty_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
index d4f5906b33..be038403b8 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
@@ -1,9 +1,9 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
       module Quoting # :nodoc:
-        QUOTED_TRUE, QUOTED_FALSE = "1".freeze, "0".freeze
-
         def quote_column_name(name)
           @quoted_column_names[name] ||= "`#{super.gsub('`', '``')}`".freeze
         end
@@ -12,18 +12,10 @@ module ActiveRecord
           @quoted_table_names[name] ||= super.gsub(".", "`.`").freeze
         end
 
-        def quoted_true
-          QUOTED_TRUE
-        end
-
         def unquoted_true
           1
         end
 
-        def quoted_false
-          QUOTED_FALSE
-        end
-
         def unquoted_false
           0
         end
@@ -39,6 +31,13 @@ module ActiveRecord
         def quoted_binary(value)
           "x'#{value.hex}'"
         end
+
+        def _type_cast(value)
+          case value
+          when Date, Time then value
+          else super
+          end
+        end
       end
     end
   end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb
index eea4984680..5a35823c72 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
index 6d88c14d50..b22a2e4da7 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
index a46d9f8cbb..fbe3596dda 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
index 24f8ff6367..1d87d60ba9 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
index 9ad6a6c0d0..7ad0944d51 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index c5c0a071e7..2c2321872d 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "abstract_mysql_adapter"
 require_relative "mysql/database_statements"
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
index 3ad1911a28..1b67cee24b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     # PostgreSQL-specific extensions to column definitions in a table.
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
index ebf1715ed0..0dd4aac463 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
@@ -1,9 +1,12 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
       module DatabaseStatements
         def explain(arel, binds = [])
-          sql = "EXPLAIN #{to_sql(arel, binds)}"
+          sql, binds = to_sql(arel, binds)
+          sql = "EXPLAIN #{sql}"
           PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query(sql, "EXPLAIN", binds))
         end
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/explain_pretty_printer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/explain_pretty_printer.rb
index 99f3a5bbdf..086a5dcc15 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/explain_pretty_printer.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/explain_pretty_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 6666622c08..b28418d74f 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "oid/array"
 require_relative "oid/bit"
 require_relative "oid/bit_varying"
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
index a73a8c1726..d6852082ac 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
index 0a505f46a7..587e95d192 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit_varying.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit_varying.rb
index 4c21097d48..dc7079dda2 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit_varying.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit_varying.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
index 702fa8175c..a3c60ecef6 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
index 5225609e37..66e99d9404 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "ipaddr"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
index b7acbf7178..cd667422f5 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
index 43d22c8daf..879dba7afd 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
index 950d23d516..f70f09ad95 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
index 49dd4fc73f..aabe83b85d 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
index 96486fa65b..55be71fd26 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/jsonb.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/jsonb.rb
index a1fec289d4..e0216f1089 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/jsonb.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/jsonb.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/legacy_point.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/legacy_point.rb
index 775eecaf85..7b057a8452 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/legacy_point.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/legacy_point.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
index cd7442e751..6434377b57 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/oid.rb
index 9c2ac08b30..d8c044320d 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/oid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
index 7c764e7287..02a9c506f6 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   Point = Struct.new(:x, :y)
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
index 54d5d0902e..7d5d7d91e6 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
index 564e82a4ac..4ad1344f05 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
index d9ae1aa7a2..231278c184 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
@@ -29,8 +31,8 @@ module ActiveRecord
             composites.each { |row| register_composite_type(row) }
           end
 
-          def query_conditions_for_initial_load(type_map)
-            known_type_names = type_map.keys.map { |n| "'#{n}'" }
+          def query_conditions_for_initial_load
+            known_type_names = @store.keys.map { |n| "'#{n}'" }
             known_type_types = %w('r' 'e' 'd')
             <<-SQL % [known_type_names.join(", "), known_type_types.join(", ")]
               WHERE
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
index db92333ef7..bc9b8dbfcf 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
index b26e876b54..88ef626a16 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/xml.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/xml.rb
index d40d837cee..042f32fdc3 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/xml.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/xml.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
index ee4230c6f2..fc458d0c73 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb b/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb
index 44a7338bf5..386d22a9bd 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
index e1d5089115..59f661da25 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_definitions.rb
index 11ea1e5144..f1489e4d69 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_definitions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
index 5555a46b6b..12c6603081 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index a710ea6cc9..780e642f21 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/string/strip"
 
 module ActiveRecord
@@ -222,7 +224,7 @@ module ActiveRecord
 
         # Sets the schema search path to a string of comma-separated schema names.
         # Names beginning with $ have to be quoted (e.g. $user => '$user').
-        # See: http://www.postgresql.org/docs/current/static/ddl-schemas.html
+        # See: https://www.postgresql.org/docs/current/static/ddl-schemas.html
         #
         # This should be not be called manually but set in database.yml.
         def schema_search_path=(schema_csv)
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
index f57179ae59..b252a76caa 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     class PostgreSQLTypeMetadata < DelegateClass(SqlTypeMetadata)
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/utils.rb b/activerecord/lib/active_record/connection_adapters/postgresql/utils.rb
index aa7940188a..bfd300723d 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/utils.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/utils.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 8baef19030..3b4439fc46 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Make sure we're using pg high enough for type casts and Ruby 2.2+ compatibility
 gem "pg", "~> 0.18"
 require "pg"
@@ -62,11 +64,11 @@ module ActiveRecord
     #   defaults to true.
     #
     # Any further options are used as connection parameters to libpq. See
-    # http://www.postgresql.org/docs/current/static/libpq-connect.html for the
+    # https://www.postgresql.org/docs/current/static/libpq-connect.html for the
     # list of parameters.
     #
     # In addition, default connection parameters of libpq can be set per environment variables.
-    # See http://www.postgresql.org/docs/current/static/libpq-envars.html .
+    # See https://www.postgresql.org/docs/current/static/libpq-envars.html .
     class PostgreSQLAdapter < AbstractAdapter
       ADAPTER_NAME = "PostgreSQL".freeze
 
@@ -184,6 +186,7 @@ module ActiveRecord
 
           def dealloc(key)
             @connection.query "DEALLOCATE #{key}" if connection_active?
+          rescue PG::Error
           end
 
           def connection_active?
@@ -215,7 +218,7 @@ module ActiveRecord
         add_pg_decoders
 
         @type_map = Type::HashLookupTypeMap.new
-        initialize_type_map(type_map)
+        initialize_type_map
         @local_tz = execute("SHOW TIME ZONE", "SCHEMA").first["TimeZone"]
         @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
       end
@@ -390,7 +393,7 @@ module ActiveRecord
 
       private
 
-        # See http://www.postgresql.org/docs/current/static/errcodes-appendix.html
+        # See https://www.postgresql.org/docs/current/static/errcodes-appendix.html
         VALUE_LIMIT_VIOLATION = "22001"
         NUMERIC_VALUE_OUT_OF_RANGE = "22003"
         NOT_NULL_VIOLATION    = "23502"
@@ -424,7 +427,7 @@ module ActiveRecord
 
         def get_oid_type(oid, fmod, column_name, sql_type = "".freeze)
           if !type_map.key?(oid)
-            load_additional_types(type_map, [oid])
+            load_additional_types([oid])
           end
 
           type_map.fetch(oid, fmod, sql_type) {
@@ -435,7 +438,7 @@ module ActiveRecord
           }
         end
 
-        def initialize_type_map(m)
+        def initialize_type_map(m = type_map)
           register_class_with_limit m, "int2", Type::Integer
           register_class_with_limit m, "int4", Type::Integer
           register_class_with_limit m, "int8", Type::Integer
@@ -502,7 +505,7 @@ module ActiveRecord
             end
           end
 
-          load_additional_types(m)
+          load_additional_types
         end
 
         def extract_limit(sql_type)
@@ -551,7 +554,7 @@ module ActiveRecord
           !default_value && %r{\w+\(.*\)|\(.*\)::\w+|CURRENT_DATE|CURRENT_TIMESTAMP}.match?(default)
         end
 
-        def load_additional_types(type_map, oids = nil)
+        def load_additional_types(oids = nil)
           initializer = OID::TypeMapInitializer.new(type_map)
 
           if supports_ranges?
@@ -570,7 +573,7 @@ module ActiveRecord
           if oids
             query += "WHERE t.oid::integer IN (%s)" % oids.join(", ")
           else
-            query += initializer.query_conditions_for_initial_load(type_map)
+            query += initializer.query_conditions_for_initial_load
           end
 
           execute_and_clear(query, "SCHEMA", []) do |records|
@@ -710,7 +713,7 @@ module ActiveRecord
           end
 
           # SET statements from :variables config hash
-          # http://www.postgresql.org/docs/current/static/sql-set.html
+          # https://www.postgresql.org/docs/current/static/sql-set.html
           variables = @config[:variables] || {}
           variables.map do |k, v|
             if v == ":default" || v == :default
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index 4d339b0a8c..f34b6733da 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     class SchemaCache
diff --git a/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb b/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
index 9e12ae0de8..8489bcbf1d 100644
--- a/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # :stopdoc:
   module ConnectionAdapters
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/explain_pretty_printer.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/explain_pretty_printer.rb
index 6fe3e1211e..832fdfe5c4 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/explain_pretty_printer.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/explain_pretty_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
index 7276a65098..8042dbfea2 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
@@ -22,6 +24,22 @@ module ActiveRecord
           "x'#{value.hex}'"
         end
 
+        def quoted_true
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "1".freeze : "'t'".freeze
+        end
+
+        def unquoted_true
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 1 : "t".freeze
+        end
+
+        def quoted_false
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "0".freeze : "'f'".freeze
+        end
+
+        def unquoted_false
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 0 : "f".freeze
+        end
+
         private
 
           def _type_cast(value)
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_creation.rb
index bc798d1dbb..b842561317 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_creation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_definitions.rb
index e157e4b218..501f17dbad 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_definitions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_dumper.rb
index eec018eda3..ab057c73f1 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_dumper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
index 31e83f9260..c155e7f1ac 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module SQLite3
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 04129841e4..8c12cb09bd 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "abstract_adapter"
 require_relative "statement_pool"
 require_relative "sqlite3/explain_pretty_printer"
@@ -72,6 +74,23 @@ module ActiveRecord
         boolean:      { name: "boolean" }
       }
 
+      ##
+      # :singleton-method:
+      # Indicates whether boolean values are stored in sqlite3 databases as 1
+      # and 0 or 't' and 'f'. Leaving `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer`
+      # set to false is deprecated. SQLite databases have used 't' and 'f' to
+      # serialize boolean values and must have old data converted to 1 and 0
+      # (its native boolean serialization) before setting this flag to true.
+      # Conversion can be accomplished by setting up a rake task which runs
+      #
+      #   ExampleModel.where("boolean_column = 't'").update_all(boolean_column: 1)
+      #   ExampleModel.where("boolean_column = 'f'").update_all(boolean_column: 0)
+      # for all models and all boolean columns, after which the flag must be set
+      # to true by adding the following to your application.rb file:
+      #
+      #   Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true
+      class_attribute :represent_boolean_as_integer, default: false
+
       class StatementPool < ConnectionAdapters::StatementPool
         private
 
@@ -184,7 +203,8 @@ module ActiveRecord
       #++
 
       def explain(arel, binds = [])
-        sql = "EXPLAIN QUERY PLAN #{to_sql(arel, binds)}"
+        sql, binds = to_sql(arel, binds)
+        sql = "EXPLAIN QUERY PLAN #{sql}"
         SQLite3::ExplainPrettyPrinter.new.pp(exec_query(sql, "EXPLAIN", []))
       end
 
@@ -512,5 +532,6 @@ module ActiveRecord
           execute("PRAGMA foreign_keys = ON", "SCHEMA")
         end
     end
+    ActiveSupport.run_load_hooks(:active_record_sqlite3adapter, SQLite3Adapter)
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/statement_pool.rb b/activerecord/lib/active_record/connection_adapters/statement_pool.rb
index 790db56185..46bd831da7 100644
--- a/activerecord/lib/active_record/connection_adapters/statement_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/statement_pool.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     class StatementPool # :nodoc:
diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb
index b8fbb489b6..9a47edfba4 100644
--- a/activerecord/lib/active_record/connection_handling.rb
+++ b/activerecord/lib/active_record/connection_handling.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionHandling
     RAILS_ENV   = -> { (Rails.env if defined?(Rails.env)) || ENV["RAILS_ENV"].presence || ENV["RACK_ENV"].presence }
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 198c712abc..8b97dbe5bf 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -1,6 +1,6 @@
-require "thread"
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/indifferent_access"
-require "active_support/core_ext/object/duplicable"
 require "active_support/core_ext/string/filters"
 
 module ActiveRecord
@@ -265,16 +265,6 @@ module ActiveRecord
         @arel_table ||= Arel::Table.new(table_name, type_caster: type_caster)
       end
 
-      # Returns the Arel engine.
-      def arel_engine # :nodoc:
-        @arel_engine ||=
-          if Base == self || connection_handler.retrieve_connection_pool(connection_specification_name)
-            self
-          else
-            superclass.arel_engine
-          end
-      end
-
       def arel_attribute(name, table = arel_table) # :nodoc:
         name = attribute_alias(name) if attribute_alias?(name)
         table[name]
diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb
index cbd71a3779..5005d58f1c 100644
--- a/activerecord/lib/active_record/counter_cache.rb
+++ b/activerecord/lib/active_record/counter_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Counter Cache
   module CounterCache
@@ -180,7 +182,6 @@ module ActiveRecord
         each_counter_cached_associations do |association|
           if send(association.reflection.name)
             association.increment_counters
-            @_after_create_counter_called = true
           end
         end
 
diff --git a/activerecord/lib/active_record/define_callbacks.rb b/activerecord/lib/active_record/define_callbacks.rb
index 7d955a24be..2c8783dcc9 100644
--- a/activerecord/lib/active_record/define_callbacks.rb
+++ b/activerecord/lib/active_record/define_callbacks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # This module exists because `ActiveRecord::AttributeMethods::Dirty` needs to
   # define callbacks, but continue to have its version of `save` be the super
diff --git a/activerecord/lib/active_record/dynamic_matchers.rb b/activerecord/lib/active_record/dynamic_matchers.rb
index 3a9625092e..3bb8c6f4e3 100644
--- a/activerecord/lib/active_record/dynamic_matchers.rb
+++ b/activerecord/lib/active_record/dynamic_matchers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module DynamicMatchers #:nodoc:
     private
diff --git a/activerecord/lib/active_record/enum.rb b/activerecord/lib/active_record/enum.rb
index 12ef58a941..f373b98035 100644
--- a/activerecord/lib/active_record/enum.rb
+++ b/activerecord/lib/active_record/enum.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/object/deep_dup"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 60d4fb70e0..933589d4b1 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Errors
   #
@@ -313,7 +315,7 @@ module ActiveRecord
   #
   # See the following:
   #
-  # * http://www.postgresql.org/docs/current/static/transaction-iso.html
+  # * https://www.postgresql.org/docs/current/static/transaction-iso.html
   # * https://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html#error_er_lock_deadlock
   class TransactionRollbackError < StatementInvalid
   end
diff --git a/activerecord/lib/active_record/explain.rb b/activerecord/lib/active_record/explain.rb
index eff5990f3a..8bb54a24b7 100644
--- a/activerecord/lib/active_record/explain.rb
+++ b/activerecord/lib/active_record/explain.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "explain_registry"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/explain_registry.rb b/activerecord/lib/active_record/explain_registry.rb
index ef1ce3dc85..7fd078941a 100644
--- a/activerecord/lib/active_record/explain_registry.rb
+++ b/activerecord/lib/active_record/explain_registry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/per_thread_registry"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/explain_subscriber.rb b/activerecord/lib/active_record/explain_subscriber.rb
index 928720d011..9252fa3fed 100644
--- a/activerecord/lib/active_record/explain_subscriber.rb
+++ b/activerecord/lib/active_record/explain_subscriber.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/notifications"
 require_relative "explain_registry"
 
diff --git a/activerecord/lib/active_record/fixture_set/file.rb b/activerecord/lib/active_record/fixture_set/file.rb
index 6cf2e01179..f1ea0e022f 100644
--- a/activerecord/lib/active_record/fixture_set/file.rb
+++ b/activerecord/lib/active_record/fixture_set/file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "erb"
 require "yaml"
 
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index c9e97d9d2b..ef302fc0a0 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "erb"
 require "yaml"
 require "zlib"
diff --git a/activerecord/lib/active_record/gem_version.rb b/activerecord/lib/active_record/gem_version.rb
index 1a937dbcf7..7ccb57b305 100644
--- a/activerecord/lib/active_record/gem_version.rb
+++ b/activerecord/lib/active_record/gem_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # Returns the version of the currently loaded Active Record as a <tt>Gem::Version</tt>
   def self.gem_version
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index 1753322274..e3deaafeec 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/indifferent_access"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/integration.rb b/activerecord/lib/active_record/integration.rb
index cf954852bc..6cf26a9792 100644
--- a/activerecord/lib/active_record/integration.rb
+++ b/activerecord/lib/active_record/integration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/string/filters"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/internal_metadata.rb b/activerecord/lib/active_record/internal_metadata.rb
index 89e5d153b8..14795cc815 100644
--- a/activerecord/lib/active_record/internal_metadata.rb
+++ b/activerecord/lib/active_record/internal_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "scoping/default"
 require_relative "scoping/named"
 
diff --git a/activerecord/lib/active_record/legacy_yaml_adapter.rb b/activerecord/lib/active_record/legacy_yaml_adapter.rb
index c7683f68c7..23644aab8f 100644
--- a/activerecord/lib/active_record/legacy_yaml_adapter.rb
+++ b/activerecord/lib/active_record/legacy_yaml_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module LegacyYamlAdapter
     def self.convert(klass, coder)
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index 522da6a571..e1e24e2814 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Locking
     # == What is Optimistic Locking
diff --git a/activerecord/lib/active_record/locking/pessimistic.rb b/activerecord/lib/active_record/locking/pessimistic.rb
index 263e2a5f7f..e939a24ad5 100644
--- a/activerecord/lib/active_record/locking/pessimistic.rb
+++ b/activerecord/lib/active_record/locking/pessimistic.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Locking
     # Locking::Pessimistic provides support for row-level locking using
@@ -52,7 +54,7 @@ module ActiveRecord
     #
     # Database-specific information on row locking:
     #   MySQL: http://dev.mysql.com/doc/refman/5.7/en/innodb-locking-reads.html
-    #   PostgreSQL: http://www.postgresql.org/docs/current/interactive/sql-select.html#SQL-FOR-UPDATE-SHARE
+    #   PostgreSQL: https://www.postgresql.org/docs/current/interactive/sql-select.html#SQL-FOR-UPDATE-SHARE
     module Pessimistic
       # Obtain a row lock on this record. Reloads the record to obtain the requested
       # lock. Pass an SQL locking clause to append the end of the SELECT statement
diff --git a/activerecord/lib/active_record/log_subscriber.rb b/activerecord/lib/active_record/log_subscriber.rb
index e39ca5f6dc..405f3a30c6 100644
--- a/activerecord/lib/active_record/log_subscriber.rb
+++ b/activerecord/lib/active_record/log_subscriber.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class LogSubscriber < ActiveSupport::LogSubscriber
     IGNORE_PAYLOAD_NAMES = ["SCHEMA", "EXPLAIN"]
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index 42220b9a5e..52ca4671c2 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "set"
 require "zlib"
 require "active_support/core_ext/module/attribute_accessors"
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb
index f9cf59b283..a3a5e0fa16 100644
--- a/activerecord/lib/active_record/migration/command_recorder.rb
+++ b/activerecord/lib/active_record/migration/command_recorder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Migration
     # <tt>ActiveRecord::Migration::CommandRecorder</tt> records commands done during
diff --git a/activerecord/lib/active_record/migration/compatibility.rb b/activerecord/lib/active_record/migration/compatibility.rb
index 188dd0acef..d6595c9355 100644
--- a/activerecord/lib/active_record/migration/compatibility.rb
+++ b/activerecord/lib/active_record/migration/compatibility.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Migration
     module Compatibility # :nodoc: all
diff --git a/activerecord/lib/active_record/migration/join_table.rb b/activerecord/lib/active_record/migration/join_table.rb
index 89789f00ea..9abb289bb0 100644
--- a/activerecord/lib/active_record/migration/join_table.rb
+++ b/activerecord/lib/active_record/migration/join_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Migration
     module JoinTable #:nodoc:
diff --git a/activerecord/lib/active_record/model_schema.rb b/activerecord/lib/active_record/model_schema.rb
index 14e0f5bff7..34c0ef4e75 100644
--- a/activerecord/lib/active_record/model_schema.rb
+++ b/activerecord/lib/active_record/model_schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "monitor"
 
 module ActiveRecord
@@ -467,7 +469,6 @@ module ActiveRecord
         end
 
         def reload_schema_from_cache
-          @arel_engine = nil
           @arel_table = nil
           @column_names = nil
           @attribute_types = nil
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 917bc76993..1864ca5ad2 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/except"
 require "active_support/core_ext/object/try"
 require "active_support/core_ext/hash/indifferent_access"
diff --git a/activerecord/lib/active_record/no_touching.rb b/activerecord/lib/active_record/no_touching.rb
index 4059020e25..c573deb63a 100644
--- a/activerecord/lib/active_record/no_touching.rb
+++ b/activerecord/lib/active_record/no_touching.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record No Touching
   module NoTouching
diff --git a/activerecord/lib/active_record/null_relation.rb b/activerecord/lib/active_record/null_relation.rb
index 26966f9433..cf0de0fdeb 100644
--- a/activerecord/lib/active_record/null_relation.rb
+++ b/activerecord/lib/active_record/null_relation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module NullRelation # :nodoc:
     def pluck(*column_names)
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index a9509e562a..1297e0cde7 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \Persistence
   module Persistence
@@ -175,7 +177,7 @@ module ActiveRecord
     # callbacks or any <tt>:dependent</tt> association
     # options, use <tt>#destroy</tt>.
     def delete
-      self.class.delete(id) if persisted?
+      _relation_for_itself.delete_all if persisted?
       @destroyed = true
       freeze
     end
@@ -330,7 +332,7 @@ module ActiveRecord
         verify_readonly_attribute(key.to_s)
       end
 
-      updated_count = self.class.unscoped.where(self.class.primary_key => id).update_all(attributes)
+      updated_count = _relation_for_itself.update_all(attributes)
 
       attributes.each do |k, v|
         write_attribute_without_type_cast(k, v)
@@ -521,8 +523,7 @@ module ActiveRecord
           changes[column] = write_attribute(column, time)
         end
 
-        primary_key = self.class.primary_key
-        scope = self.class.unscoped.where(primary_key => _read_attribute(primary_key))
+        scope = _relation_for_itself
 
         if locking_enabled?
           locking_column = self.class.locking_column
@@ -555,6 +556,10 @@ module ActiveRecord
     end
 
     def relation_for_destroy
+      _relation_for_itself
+    end
+
+    def _relation_for_itself
       self.class.unscoped.where(self.class.primary_key => id)
     end
 
diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index e4c2e1f86f..3d5babb8b7 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Query Cache
   class QueryCache
diff --git a/activerecord/lib/active_record/querying.rb b/activerecord/lib/active_record/querying.rb
index b16e178358..f780538319 100644
--- a/activerecord/lib/active_record/querying.rb
+++ b/activerecord/lib/active_record/querying.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Querying
     delegate :find, :take, :take!, :first, :first!, :last, :last!, :exists?, :any?, :many?, :none?, :one?, to: :all
diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index 9cca103a18..ead42d64ec 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_record"
 require "rails"
 require "active_model/railtie"
@@ -26,6 +28,9 @@ module ActiveRecord
     config.active_record.use_schema_cache_dump = true
     config.active_record.maintain_test_schema = true
 
+    config.active_record.sqlite3 = ActiveSupport::OrderedOptions.new
+    config.active_record.sqlite3.represent_boolean_as_integer = nil
+
     config.eager_load_namespaces << ActiveRecord
 
     rake_tasks do
@@ -108,7 +113,9 @@ module ActiveRecord
 
     initializer "active_record.set_configs" do |app|
       ActiveSupport.on_load(:active_record) do
-        app.config.active_record.each do |k, v|
+        configs = app.config.active_record.dup
+        configs.delete(:sqlite3)
+        configs.each do |k, v|
           send "#{k}=", v
         end
       end
@@ -174,5 +181,34 @@ end_warning
         end
       end
     end
+
+    initializer "active_record.check_represent_sqlite3_boolean_as_integer" do
+      config.after_initialize do
+        ActiveSupport.on_load(:active_record_sqlite3adapter) do
+          represent_boolean_as_integer = Rails.application.config.active_record.sqlite3.delete(:represent_boolean_as_integer)
+          unless represent_boolean_as_integer.nil?
+            ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = represent_boolean_as_integer
+          end
+
+          unless ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer
+            ActiveSupport::Deprecation.warn <<-MSG
+Leaving `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer`
+set to false is deprecated. SQLite databases have used 't' and 'f' to serialize
+boolean values and must have old data converted to 1 and 0 (its native boolean
+serialization) before setting this flag to true. Conversion can be accomplished
+by setting up a rake task which runs
+
+  ExampleModel.where("boolean_column = 't'").update_all(boolean_column: 1)
+  ExampleModel.where("boolean_column = 'f'").update_all(boolean_column: 0)
+
+for all models and all boolean columns, after which the flag must be set to
+true by adding the following to your application.rb file:
+
+  Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true
+MSG
+          end
+        end
+      end
+    end
   end
 end
diff --git a/activerecord/lib/active_record/railties/console_sandbox.rb b/activerecord/lib/active_record/railties/console_sandbox.rb
index 604a220303..8917638a5d 100644
--- a/activerecord/lib/active_record/railties/console_sandbox.rb
+++ b/activerecord/lib/active_record/railties/console_sandbox.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveRecord::Base.connection.begin_transaction(joinable: false)
 
 at_exit do
diff --git a/activerecord/lib/active_record/railties/controller_runtime.rb b/activerecord/lib/active_record/railties/controller_runtime.rb
index 4030cdc158..3cf66980a5 100644
--- a/activerecord/lib/active_record/railties/controller_runtime.rb
+++ b/activerecord/lib/active_record/railties/controller_runtime.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/module/attr_internal"
 require_relative "../log_subscriber"
 
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index abc7323341..691b3612d8 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_record"
 
 db_namespace = namespace :db do
diff --git a/activerecord/lib/active_record/railties/jdbcmysql_error.rb b/activerecord/lib/active_record/railties/jdbcmysql_error.rb
index d7cf4df339..72c75ddd52 100644
--- a/activerecord/lib/active_record/railties/jdbcmysql_error.rb
+++ b/activerecord/lib/active_record/railties/jdbcmysql_error.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #FIXME Remove if ArJdbcMysql will give.
 module ArJdbcMySQL #:nodoc:
   class Error < StandardError #:nodoc:
diff --git a/activerecord/lib/active_record/readonly_attributes.rb b/activerecord/lib/active_record/readonly_attributes.rb
index af6473d250..7bc26993d5 100644
--- a/activerecord/lib/active_record/readonly_attributes.rb
+++ b/activerecord/lib/active_record/readonly_attributes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ReadonlyAttributes
     extend ActiveSupport::Concern
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index a453ca55c7..efe56454d0 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "thread"
 require "active_support/core_ext/string/filters"
 require "active_support/deprecation"
@@ -219,10 +221,10 @@ module ActiveRecord
       end
 
       def klass_join_scope(table, predicate_builder) # :nodoc:
-        if klass.current_scope
-          klass.current_scope.clone.tap { |scope|
-            scope.joins_values = scope.left_outer_joins_values = [].freeze
-          }
+        current_scope = klass.current_scope
+
+        if current_scope && current_scope.empty_scope?
+          build_scope(table, predicate_builder)
         else
           klass.default_scoped(build_scope(table, predicate_builder))
         end
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 76cf47a3ed..caabad6055 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \Relation
   class Relation
@@ -51,7 +53,7 @@ module ActiveRecord
       im = arel.create_insert
       im.into @table
 
-      substitutes, binds = substitute_values values
+      substitutes = substitute_values values
 
       if values.empty? # empty insert
         im.values = Arel.sql(connection.empty_insert_statement_value)
@@ -65,11 +67,11 @@ module ActiveRecord
         primary_key || false,
         primary_key_value,
         nil,
-        binds)
+      )
     end
 
     def _update_record(values, id, id_was) # :nodoc:
-      substitutes, binds = substitute_values values
+      substitutes = substitute_values values
 
       scope = @klass.unscoped
 
@@ -78,7 +80,6 @@ module ActiveRecord
       end
 
       relation = scope.where(@klass.primary_key => (id_was || id))
-      bvs = binds + relation.bound_attributes
       um = relation
         .arel
         .compile_update(substitutes, @klass.primary_key)
@@ -86,20 +87,14 @@ module ActiveRecord
       @klass.connection.update(
         um,
         "SQL",
-        bvs,
       )
     end
 
     def substitute_values(values) # :nodoc:
-      binds = []
-      substitutes = []
-
-      values.each do |arel_attr, value|
-        binds.push QueryAttribute.new(arel_attr.name, value, klass.type_for_attribute(arel_attr.name))
-        substitutes.push [arel_attr, Arel::Nodes::BindParam.new]
+      values.map do |arel_attr, value|
+        bind = predicate_builder.build_bind_attribute(arel_attr.name, value)
+        [arel_attr, bind]
       end
-
-      [substitutes, binds]
     end
 
     def arel_attribute(name) # :nodoc:
@@ -378,7 +373,7 @@ module ActiveRecord
         stmt.wheres = arel.constraints
       end
 
-      @klass.connection.update stmt, "SQL", bound_attributes
+      @klass.connection.update stmt, "SQL"
     end
 
     # Updates an object (or multiple objects) and saves it to the database, if validations pass.
@@ -508,7 +503,7 @@ module ActiveRecord
         stmt.wheres = arel.constraints
       end
 
-      affected = @klass.connection.delete(stmt, "SQL", bound_attributes)
+      affected = @klass.connection.delete(stmt, "SQL")
 
       reset
       affected
@@ -556,8 +551,7 @@ module ActiveRecord
     end
 
     def reset
-      @last = @to_sql = @order_clause = @scope_for_create = @arel = @loaded = nil
-      @should_eager_load = @join_dependency = nil
+      @to_sql = @arel = @loaded = @should_eager_load = nil
       @records = [].freeze
       @offsets = {}
       self
@@ -577,7 +571,8 @@ module ActiveRecord
 
                     conn = klass.connection
                     conn.unprepared_statement {
-                      conn.to_sql(relation.arel, relation.bound_attributes)
+                      sql, _ = conn.to_sql(relation.arel)
+                      sql
                     }
                   end
     end
@@ -591,7 +586,7 @@ module ActiveRecord
     end
 
     def scope_for_create
-      @scope_for_create ||= where_values_hash.merge(create_with_value)
+      where_values_hash.merge!(create_with_value.stringify_keys)
     end
 
     # Returns true if relation needs eager loading.
@@ -643,6 +638,14 @@ module ActiveRecord
       "#<#{self.class.name} [#{entries.join(', ')}]>"
     end
 
+    def empty_scope? # :nodoc:
+      @values == klass.unscoped.values
+    end
+
+    def has_limit_or_offset? # :nodoc:
+      limit_value || offset_value
+    end
+
     protected
 
       def load_records(records)
@@ -658,7 +661,7 @@ module ActiveRecord
 
       def exec_queries(&block)
         skip_query_cache_if_necessary do
-          @records = eager_loading? ? find_with_associations.freeze : @klass.find_by_sql(arel, bound_attributes, &block).freeze
+          @records = eager_loading? ? find_with_associations.freeze : @klass.find_by_sql(arel, &block).freeze
 
           preload = preload_values
           preload += includes_values unless eager_loading?
diff --git a/activerecord/lib/active_record/relation/batches.rb b/activerecord/lib/active_record/relation/batches.rb
index c7e4f8a88a..141ad176ea 100644
--- a/activerecord/lib/active_record/relation/batches.rb
+++ b/activerecord/lib/active_record/relation/batches.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "batches/batch_enumerator"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/relation/batches/batch_enumerator.rb b/activerecord/lib/active_record/relation/batches/batch_enumerator.rb
index 3555779ec2..49697da3bf 100644
--- a/activerecord/lib/active_record/relation/batches/batch_enumerator.rb
+++ b/activerecord/lib/active_record/relation/batches/batch_enumerator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Batches
     class BatchEnumerator
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index aaba6c71f2..d3b5be6bce 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Calculations
     # Count the records.
@@ -129,7 +131,7 @@ module ActiveRecord
     def calculate(operation, column_name)
       if has_include?(column_name)
         relation = construct_relation_for_association_calculations
-        relation = relation.distinct if operation.to_s.downcase == "count"
+        relation.distinct! if operation.to_s.downcase == "count"
 
         relation.calculate(operation, column_name)
       else
@@ -184,7 +186,7 @@ module ActiveRecord
         relation.select_values = column_names.map { |cn|
           @klass.has_attribute?(cn) || @klass.attribute_alias?(cn) ? arel_attribute(cn) : cn
         }
-        result = skip_query_cache_if_necessary { klass.connection.select_all(relation.arel, nil, bound_attributes) }
+        result = skip_query_cache_if_necessary { klass.connection.select_all(relation.arel, nil) }
         result.cast_values(klass.attribute_types)
       end
     end
@@ -212,8 +214,13 @@ module ActiveRecord
 
         if operation == "count"
           column_name ||= select_for_count
-          column_name = primary_key if column_name == :all && distinct
-          distinct = nil if column_name =~ /\s*DISTINCT[\s(]+/i
+          if column_name == :all
+            if distinct && !(has_limit_or_offset? && order_values.any?)
+              column_name = primary_key
+            end
+          elsif column_name =~ /\s*DISTINCT[\s(]+/i
+            distinct = nil
+          end
         end
 
         if group_values.any?
@@ -240,7 +247,7 @@ module ActiveRecord
       def execute_simple_calculation(operation, column_name, distinct) #:nodoc:
         column_alias = column_name
 
-        if operation == "count" && (limit_value || offset_value)
+        if operation == "count" && has_limit_or_offset?
           # Shortcut when limit is zero.
           return 0 if limit_value == 0
 
@@ -260,7 +267,7 @@ module ActiveRecord
           query_builder = relation.arel
         end
 
-        result = skip_query_cache_if_necessary { @klass.connection.select_all(query_builder, nil, bound_attributes) }
+        result = skip_query_cache_if_necessary { @klass.connection.select_all(query_builder, nil) }
         row    = result.first
         value  = row && row.values.first
         type   = result.column_types.fetch(column_alias) do
@@ -311,7 +318,7 @@ module ActiveRecord
         relation.group_values  = group_fields
         relation.select_values = select_values
 
-        calculated_data = skip_query_cache_if_necessary { @klass.connection.select_all(relation.arel, nil, relation.bound_attributes) }
+        calculated_data = skip_query_cache_if_necessary { @klass.connection.select_all(relation.arel, nil) }
 
         if association
           key_ids     = calculated_data.collect { |row| row[group_aliases.first] }
@@ -379,14 +386,18 @@ module ActiveRecord
       end
 
       def build_count_subquery(relation, column_name, distinct)
-        column_alias = Arel.sql("count_column")
-        subquery_alias = Arel.sql("subquery_for_count")
+        relation.select_values = [
+          if column_name == :all
+            distinct ? table[Arel.star] : Arel.sql("1")
+          else
+            column_alias = Arel.sql("count_column")
+            aggregate_column(column_name).as(column_alias)
+          end
+        ]
 
-        aliased_column = aggregate_column(column_name == :all ? 1 : column_name).as(column_alias)
-        relation.select_values = [aliased_column]
-        subquery = relation.arel.as(subquery_alias)
+        subquery = relation.arel.as(Arel.sql("subquery_for_count"))
+        select_value = operation_over_aggregate_column(column_alias || Arel.star, "count", false)
 
-        select_value = operation_over_aggregate_column(column_alias, "count", distinct)
         Arel::SelectManager.new(subquery).project(select_value)
       end
   end
diff --git a/activerecord/lib/active_record/relation/delegation.rb b/activerecord/lib/active_record/relation/delegation.rb
index 48c4dcdef4..4793f2a49b 100644
--- a/activerecord/lib/active_record/relation/delegation.rb
+++ b/activerecord/lib/active_record/relation/delegation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Delegation # :nodoc:
     module DelegateCache # :nodoc:
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index ac0b4f597e..626c50470e 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/string/filters"
 
 module ActiveRecord
@@ -315,7 +317,7 @@ module ActiveRecord
 
       relation = construct_relation_for_exists(relation, conditions)
 
-      skip_query_cache_if_necessary { connection.select_value(relation.arel, "#{name} Exists", relation.bound_attributes) } ? true : false
+      skip_query_cache_if_necessary { connection.select_value(relation.arel, "#{name} Exists") } ? true : false
     rescue ::RangeError
       false
     end
@@ -329,7 +331,7 @@ module ActiveRecord
     # the expected number of results should be provided in the +expected_size+
     # argument.
     def raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil, key = primary_key) # :nodoc:
-      conditions = arel.where_sql(@klass.arel_engine)
+      conditions = arel.where_sql(@klass)
       conditions = " [#{conditions}]" if conditions
       name = @klass.name
 
@@ -376,7 +378,7 @@ module ActiveRecord
           if ActiveRecord::NullRelation === relation
             []
           else
-            rows = skip_query_cache_if_necessary { connection.select_all(relation.arel, "SQL", relation.bound_attributes) }
+            rows = skip_query_cache_if_necessary { connection.select_all(relation.arel, "SQL") }
             join_dependency.instantiate(rows, aliases)
           end
         end
@@ -397,7 +399,7 @@ module ActiveRecord
 
       def construct_join_dependency(joins = [], eager_loading: true)
         including = eager_load_values + includes_values
-        ActiveRecord::Associations::JoinDependency.new(@klass, including, joins, eager_loading: eager_loading)
+        ActiveRecord::Associations::JoinDependency.new(klass, table, including, joins, eager_loading: eager_loading)
       end
 
       def construct_relation_for_association_calculations
@@ -424,7 +426,7 @@ module ActiveRecord
 
         relation = relation.except(:select).select(values).distinct!
 
-        id_rows = skip_query_cache_if_necessary { @klass.connection.select_all(relation.arel, "SQL", relation.bound_attributes) }
+        id_rows = skip_query_cache_if_necessary { @klass.connection.select_all(relation.arel, "SQL") }
         id_rows.map { |row| row[primary_key] }
       end
 
diff --git a/activerecord/lib/active_record/relation/from_clause.rb b/activerecord/lib/active_record/relation/from_clause.rb
index 8945cb0cc5..c53a682aee 100644
--- a/activerecord/lib/active_record/relation/from_clause.rb
+++ b/activerecord/lib/active_record/relation/from_clause.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Relation
     class FromClause # :nodoc:
@@ -8,14 +10,6 @@ module ActiveRecord
         @name = name
       end
 
-      def binds
-        if value.is_a?(Relation)
-          value.bound_attributes
-        else
-          []
-        end
-      end
-
       def merge(other)
         self
       end
diff --git a/activerecord/lib/active_record/relation/merger.rb b/activerecord/lib/active_record/relation/merger.rb
index 5dac00724a..182f654897 100644
--- a/activerecord/lib/active_record/relation/merger.rb
+++ b/activerecord/lib/active_record/relation/merger.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/keys"
 
 module ActiveRecord
@@ -119,9 +121,10 @@ module ActiveRecord
               end
             end
 
-            join_dependency = ActiveRecord::Associations::JoinDependency.new(other.klass,
-                                                                             joins_dependency,
-                                                                             [])
+            join_dependency = ActiveRecord::Associations::JoinDependency.new(
+              other.klass, other.table, joins_dependency, []
+            )
+
             relation.joins! rest
 
             @relation = relation.joins join_dependency
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index eb80c9a00d..5c42414072 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder # :nodoc:
     delegate :resolve_column_aliases, to: :table
@@ -6,10 +8,9 @@ module ActiveRecord
       @table = table
       @handlers = []
 
-      register_handler(BasicObject, BasicObjectHandler.new)
+      register_handler(BasicObject, BasicObjectHandler.new(self))
       register_handler(Base, BaseHandler.new(self))
-      register_handler(Range, RangeHandler.new)
-      register_handler(RangeHandler::RangeWithBinds, RangeHandler.new)
+      register_handler(Range, RangeHandler.new(self))
       register_handler(Relation, RelationHandler.new)
       register_handler(Array, ArrayHandler.new(self))
     end
@@ -19,11 +20,6 @@ module ActiveRecord
       expand_from_hash(attributes)
     end
 
-    def create_binds(attributes)
-      attributes = convert_dot_notation_to_hash(attributes)
-      create_binds_for_hash(attributes)
-    end
-
     def self.references(attributes)
       attributes.map do |key, value|
         if value.is_a?(Hash)
@@ -54,8 +50,11 @@ module ActiveRecord
       handler_for(value).call(attribute, value)
     end
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
+    def build_bind_attribute(column_name, value)
+      attr = Relation::QueryAttribute.new(column_name.to_s, value, table.type(column_name))
+      Arel::Nodes::BindParam.new(attr)
+    end
+
     protected
 
       attr_reader :table
@@ -66,29 +65,13 @@ module ActiveRecord
         attributes.flat_map do |key, value|
           if value.is_a?(Hash) && !table.has_column?(key)
             associated_predicate_builder(key).expand_from_hash(value)
-          else
-            build(table.arel_attribute(key), value)
-          end
-        end
-      end
-
-      def create_binds_for_hash(attributes)
-        result = attributes.dup
-        binds = []
-
-        attributes.each do |column_name, value|
-          case
-          when value.is_a?(Hash) && !table.has_column?(column_name)
-            attrs, bvs = associated_predicate_builder(column_name).create_binds_for_hash(value)
-            result[column_name] = attrs
-            binds += bvs
-          when table.associated_with?(column_name)
+          elsif table.associated_with?(key)
             # Find the foreign key when using queries such as:
             # Post.where(author: author)
             #
             # For polymorphic relationships, find the foreign key and type:
             # PriceEstimate.where(estimate_of: treasure)
-            associated_table = table.associated_table(column_name)
+            associated_table = table.associated_table(key)
             if associated_table.polymorphic_association?
               case value.is_a?(Array) ? value.first : value
               when Base, Relation
@@ -98,40 +81,18 @@ module ActiveRecord
             end
 
             klass ||= AssociationQueryValue
-            result[column_name] = klass.new(associated_table, value).queries.map do |query|
-              attrs, bvs = create_binds_for_hash(query)
-              binds.concat(bvs)
-              attrs
-            end
-          when value.is_a?(Range) && !table.type(column_name).respond_to?(:subtype)
-            first = value.begin
-            last = value.end
-            unless first.respond_to?(:infinite?) && first.infinite?
-              binds << build_bind_attribute(column_name, first)
-              first = Arel::Nodes::BindParam.new
+            queries = klass.new(associated_table, value).queries.map do |query|
+              expand_from_hash(query).reduce(&:and)
             end
-            unless last.respond_to?(:infinite?) && last.infinite?
-              binds << build_bind_attribute(column_name, last)
-              last = Arel::Nodes::BindParam.new
-            end
-
-            result[column_name] = RangeHandler::RangeWithBinds.new(first, last, value.exclude_end?)
-          when value.is_a?(Relation)
-            binds.concat(value.bound_attributes)
+            queries.reduce(&:or)
+          # FIXME: Deprecate this and provide a public API to force equality
+          elsif (value.is_a?(Range) || value.is_a?(Array)) &&
+            table.type(key.to_s).respond_to?(:subtype)
+            BasicObjectHandler.new(self).call(table.arel_attribute(key), value)
           else
-            if can_be_bound?(column_name, value)
-              bind_attribute = build_bind_attribute(column_name, value)
-              if value.is_a?(StatementCache::Substitute) || !bind_attribute.value_for_database.nil?
-                result[column_name] = Arel::Nodes::BindParam.new
-                binds << bind_attribute
-              else
-                result[column_name] = nil
-              end
-            end
+            build(table.arel_attribute(key), value)
           end
         end
-
-        [result, binds]
       end
 
     private
@@ -159,19 +120,6 @@ module ActiveRecord
       def handler_for(object)
         @handlers.detect { |klass, _| klass === object }.last
       end
-
-      def can_be_bound?(column_name, value)
-        case value
-        when Array, Range
-          table.type(column_name).respond_to?(:subtype)
-        else
-          !value.nil? && handler_for(value).is_a?(BasicObjectHandler)
-        end
-      end
-
-      def build_bind_attribute(column_name, value)
-        Relation::QueryAttribute.new(column_name.to_s, value, table.type(column_name))
-      end
   end
 end
 
diff --git a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
index 1068e700e2..2fd75c8958 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class ArrayHandler # :nodoc:
@@ -7,7 +9,6 @@ module ActiveRecord
 
       def call(attribute, value)
         return attribute.in([]) if value.empty?
-        return queries_predicates(value) if value.all? { |v| v.is_a?(Hash) }
 
         values = value.map { |x| x.is_a?(Base) ? x.id : x }
         nils, values = values.partition(&:nil?)
@@ -17,7 +18,11 @@ module ActiveRecord
           case values.length
           when 0 then NullPredicate
           when 1 then predicate_builder.build(attribute, values.first)
-          else attribute.in(values)
+          else
+            bind_values = values.map do |v|
+              predicate_builder.build_bind_attribute(attribute.name, v)
+            end
+            attribute.in(bind_values)
           end
 
         unless nils.empty?
@@ -29,8 +34,6 @@ module ActiveRecord
         array_predicates.inject(&:or)
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :predicate_builder
@@ -40,17 +43,6 @@ module ActiveRecord
             other
           end
         end
-
-      private
-        def queries_predicates(queries)
-          if queries.size > 1
-            queries.map do |query|
-              Arel::Nodes::And.new(predicate_builder.build_from_hash(query))
-            end.inject(&:or)
-          else
-            predicate_builder.build_from_hash(queries.first)
-          end
-        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb b/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb
index 3e19646ae5..e64d9fdf2a 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class AssociationQueryValue # :nodoc:
diff --git a/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
index 3bb1037885..112821135f 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class BaseHandler # :nodoc:
@@ -9,8 +11,6 @@ module ActiveRecord
         predicate_builder.build(attribute, value.id)
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :predicate_builder
diff --git a/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
index 79cde00303..34db266f05 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
@@ -1,9 +1,20 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class BasicObjectHandler # :nodoc:
+      def initialize(predicate_builder)
+        @predicate_builder = predicate_builder
+      end
+
       def call(attribute, value)
-        attribute.eq(value)
+        bind = predicate_builder.build_bind_attribute(attribute.name, value)
+        attribute.eq(bind)
       end
+
+      protected
+
+        attr_reader :predicate_builder
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/predicate_builder/polymorphic_array_value.rb b/activerecord/lib/active_record/relation/predicate_builder/polymorphic_array_value.rb
index 7029ae5f47..b87b5c36dd 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/polymorphic_array_value.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/polymorphic_array_value.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class PolymorphicArrayValue # :nodoc:
@@ -10,7 +12,7 @@ module ActiveRecord
         type_to_ids_mapping.map do |type, ids|
           {
             associated_table.association_foreign_type.to_s => type,
-            associated_table.association_foreign_key.to_s => ids.size > 1 ? ids : ids.first
+            associated_table.association_foreign_key.to_s => ids
           }
         end
       end
diff --git a/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
index 5db778e19c..6d16579708 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
@@ -1,25 +1,41 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class RangeHandler # :nodoc:
-      RangeWithBinds = Struct.new(:begin, :end, :exclude_end?)
+      class RangeWithBinds < Struct.new(:begin, :end)
+        def exclude_end?
+          false
+        end
+      end
+
+      def initialize(predicate_builder)
+        @predicate_builder = predicate_builder
+      end
 
       def call(attribute, value)
+        begin_bind = predicate_builder.build_bind_attribute(attribute.name, value.begin)
+        end_bind = predicate_builder.build_bind_attribute(attribute.name, value.end)
         if value.begin.respond_to?(:infinite?) && value.begin.infinite?
           if value.end.respond_to?(:infinite?) && value.end.infinite?
             attribute.not_in([])
           elsif value.exclude_end?
-            attribute.lt(value.end)
+            attribute.lt(end_bind)
           else
-            attribute.lteq(value.end)
+            attribute.lteq(end_bind)
           end
         elsif value.end.respond_to?(:infinite?) && value.end.infinite?
-          attribute.gteq(value.begin)
+          attribute.gteq(begin_bind)
         elsif value.exclude_end?
-          attribute.gteq(value.begin).and(attribute.lt(value.end))
+          attribute.gteq(begin_bind).and(attribute.lt(end_bind))
         else
-          attribute.between(value)
+          attribute.between(RangeWithBinds.new(begin_bind, end_bind))
         end
       end
+
+      protected
+
+        attr_reader :predicate_builder
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/predicate_builder/relation_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/relation_handler.rb
index 8a910a82fe..f51ea4fde0 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/relation_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/relation_handler.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class PredicateBuilder
     class RelationHandler # :nodoc:
diff --git a/activerecord/lib/active_record/relation/query_attribute.rb b/activerecord/lib/active_record/relation/query_attribute.rb
index 0e1f64775d..5a9a7fd432 100644
--- a/activerecord/lib/active_record/relation/query_attribute.rb
+++ b/activerecord/lib/active_record/relation/query_attribute.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../attribute"
 
 module ActiveRecord
@@ -14,6 +16,11 @@ module ActiveRecord
       def with_cast_value(value)
         QueryAttribute.new(name, value, type)
       end
+
+      def nil?
+        !value_before_type_cast.is_a?(StatementCache::Substitute) &&
+          (value_before_type_cast.nil? || value_for_database.nil?)
+      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 79495ead91..f7fe968b55 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "from_clause"
 require_relative "query_attribute"
 require_relative "where_clause"
@@ -74,31 +76,6 @@ module ActiveRecord
       CODE
     end
 
-    def bound_attributes
-      if limit_value
-        limit_bind = Attribute.with_cast_value(
-          "LIMIT".freeze,
-          connection.sanitize_limit(limit_value),
-          Type.default_value,
-        )
-      end
-      if offset_value
-        offset_bind = Attribute.with_cast_value(
-          "OFFSET".freeze,
-          offset_value.to_i,
-          Type.default_value,
-        )
-      end
-      connection.combine_bind_parameters(
-        from_clause: from_clause.binds,
-        join_clause: arel.bind_values,
-        where_clause: where_clause.binds,
-        having_clause: having_clause.binds,
-        limit: limit_bind,
-        offset: offset_bind,
-      )
-    end
-
     alias extensions extending_values
 
     # Specify relationships to be included in the result set. For
@@ -202,12 +179,13 @@ module ActiveRecord
 
     # Works in two unique ways.
     #
-    # First: takes a block so it can be used just like +Array#select+.
+    # First: takes a block so it can be used just like <tt>Array#select</tt>.
     #
     #   Model.all.select { |m| m.field == value }
     #
     # This will build an array of objects from the database for the scope,
-    # converting them into an array and iterating through them using +Array#select+.
+    # converting them into an array and iterating through them using
+    # <tt>Array#select</tt>.
     #
     # Second: Modifies the SELECT statement for the query so that only certain
     # fields are retrieved:
@@ -657,6 +635,7 @@ module ActiveRecord
 
       self.where_clause = self.where_clause.or(other.where_clause)
       self.having_clause = having_clause.or(other.having_clause)
+      self.references_values += other.references_values
 
       self
     end
@@ -797,7 +776,7 @@ module ActiveRecord
         value = sanitize_forbidden_attributes(value)
         self.create_with_value = create_with_value.merge(value)
       else
-        self.create_with_value = {}
+        self.create_with_value = FROZEN_EMPTY_HASH
       end
 
       self
@@ -949,8 +928,22 @@ module ActiveRecord
 
         arel.where(where_clause.ast) unless where_clause.empty?
         arel.having(having_clause.ast) unless having_clause.empty?
-        arel.take(Arel::Nodes::BindParam.new) if limit_value
-        arel.skip(Arel::Nodes::BindParam.new) if offset_value
+        if limit_value
+          limit_attribute = Attribute.with_cast_value(
+            "LIMIT".freeze,
+            connection.sanitize_limit(limit_value),
+            Type.default_value,
+          )
+          arel.take(Arel::Nodes::BindParam.new(limit_attribute))
+        end
+        if offset_value
+          offset_attribute = Attribute.with_cast_value(
+            "OFFSET".freeze,
+            offset_value.to_i,
+            Type.default_value,
+          )
+          arel.skip(Arel::Nodes::BindParam.new(offset_attribute))
+        end
         arel.group(*arel_columns(group_values.uniq.reject(&:blank?))) unless group_values.empty?
 
         build_order(arel)
@@ -1019,17 +1012,11 @@ module ActiveRecord
         join_list = join_nodes + convert_join_strings_to_ast(manager, string_joins)
 
         join_dependency = ActiveRecord::Associations::JoinDependency.new(
-          @klass,
-          association_joins,
-          join_list
+          klass, table, association_joins, join_list
         )
 
-        join_infos = join_dependency.join_constraints stashed_association_joins, join_type
-
-        join_infos.each do |info|
-          info.joins.each { |join| manager.from(join) }
-          manager.bind_values.concat info.binds
-        end
+        joins = join_dependency.join_constraints(stashed_association_joins, join_type)
+        joins.each { |join| manager.from(join) }
 
         manager.join_sources.concat(join_list)
 
@@ -1047,7 +1034,7 @@ module ActiveRecord
         if select_values.any?
           arel.project(*arel_columns(select_values.uniq))
         else
-          arel.project(@klass.arel_table[Arel.star])
+          arel.project(table[Arel.star])
         end
       end
 
@@ -1172,7 +1159,7 @@ module ActiveRecord
         end
       end
 
-      STRUCTURAL_OR_METHODS = Relation::VALUE_METHODS - [:extending, :where, :having, :unscope]
+      STRUCTURAL_OR_METHODS = Relation::VALUE_METHODS - [:extending, :where, :having, :unscope, :references]
       def structurally_incompatible_values_for_or(other)
         STRUCTURAL_OR_METHODS.reject do |method|
           get_value(method) == other.get_value(method)
diff --git a/activerecord/lib/active_record/relation/record_fetch_warning.rb b/activerecord/lib/active_record/relation/record_fetch_warning.rb
index 31544c730e..a7d07d23e1 100644
--- a/activerecord/lib/active_record/relation/record_fetch_warning.rb
+++ b/activerecord/lib/active_record/relation/record_fetch_warning.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Relation
     module RecordFetchWarning
diff --git a/activerecord/lib/active_record/relation/spawn_methods.rb b/activerecord/lib/active_record/relation/spawn_methods.rb
index ddf7f825c1..424894f835 100644
--- a/activerecord/lib/active_record/relation/spawn_methods.rb
+++ b/activerecord/lib/active_record/relation/spawn_methods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/except"
 require "active_support/core_ext/hash/slice"
 require_relative "merger"
diff --git a/activerecord/lib/active_record/relation/where_clause.rb b/activerecord/lib/active_record/relation/where_clause.rb
index 119910ee79..752bb38481 100644
--- a/activerecord/lib/active_record/relation/where_clause.rb
+++ b/activerecord/lib/active_record/relation/where_clause.rb
@@ -1,43 +1,48 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Relation
     class WhereClause # :nodoc:
-      attr_reader :binds
-
       delegate :any?, :empty?, to: :predicates
 
-      def initialize(predicates, binds)
+      def initialize(predicates)
         @predicates = predicates
-        @binds = binds
       end
 
       def +(other)
         WhereClause.new(
           predicates + other.predicates,
-          binds + other.binds,
+        )
+      end
+
+      def -(other)
+        WhereClause.new(
+          predicates - other.predicates,
         )
       end
 
       def merge(other)
         WhereClause.new(
           predicates_unreferenced_by(other) + other.predicates,
-          non_conflicting_binds(other) + other.binds,
         )
       end
 
       def except(*columns)
-        WhereClause.new(*except_predicates_and_binds(columns))
+        WhereClause.new(except_predicates(columns))
       end
 
       def or(other)
-        if empty?
-          self
-        elsif other.empty?
-          other
+        left = self - other
+        common = self - left
+        right = other - common
+
+        if left.empty? || right.empty?
+          common
         else
-          WhereClause.new(
-            [ast.or(other.ast)],
-            binds + other.binds
+          or_clause = WhereClause.new(
+            [left.ast.or(right.ast)],
           )
+          common + or_clause
         end
       end
 
@@ -49,17 +54,10 @@ module ActiveRecord
           end
         end
 
-        binds = self.binds.map { |attr| [attr.name, attr.value] }.to_h
-
         equalities.map { |node|
-          name = node.left.name
-          [name, binds.fetch(name.to_s) {
-            case node.right
-            when Array then node.right.map(&:val)
-            when Arel::Nodes::Casted, Arel::Nodes::Quoted
-              node.right.val
-            end
-          }]
+          name = node.left.name.to_s
+          value = extract_node_value(node.right)
+          [name, value]
         }.to_h
       end
 
@@ -69,20 +67,17 @@ module ActiveRecord
 
       def ==(other)
         other.is_a?(WhereClause) &&
-          predicates == other.predicates &&
-          binds == other.binds
+          predicates == other.predicates
       end
 
       def invert
-        WhereClause.new(inverted_predicates, binds)
+        WhereClause.new(inverted_predicates)
       end
 
       def self.empty
-        @empty ||= new([], [])
+        @empty ||= new([])
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :predicates
@@ -106,12 +101,6 @@ module ActiveRecord
           node.respond_to?(:operator) && node.operator == :==
         end
 
-        def non_conflicting_binds(other)
-          conflicts = referenced_columns & other.referenced_columns
-          conflicts.map! { |node| node.name.to_s }
-          binds.reject { |attr| conflicts.include?(attr.name) }
-        end
-
         def inverted_predicates
           predicates.map { |node| invert_predicate(node) }
         end
@@ -131,43 +120,22 @@ module ActiveRecord
           end
         end
 
-        def except_predicates_and_binds(columns)
-          except_binds = []
-          binds_index = 0
-
-          predicates = self.predicates.reject do |node|
-            except = \
-              case node
-              when Arel::Nodes::Between, Arel::Nodes::In, Arel::Nodes::NotIn, Arel::Nodes::Equality, Arel::Nodes::NotEqual, Arel::Nodes::LessThan, Arel::Nodes::LessThanOrEqual, Arel::Nodes::GreaterThan, Arel::Nodes::GreaterThanOrEqual
-                binds_contains = node.grep(Arel::Nodes::BindParam).size
-                subrelation = (node.left.kind_of?(Arel::Attributes::Attribute) ? node.left : node.right)
-                columns.include?(subrelation.name.to_s)
-              end
-
-            if except && binds_contains > 0
-              (binds_index...(binds_index + binds_contains)).each do |i|
-                except_binds[i] = true
-              end
+        def except_predicates(columns)
+          self.predicates.reject do |node|
+            case node
+            when Arel::Nodes::Between, Arel::Nodes::In, Arel::Nodes::NotIn, Arel::Nodes::Equality, Arel::Nodes::NotEqual, Arel::Nodes::LessThan, Arel::Nodes::LessThanOrEqual, Arel::Nodes::GreaterThan, Arel::Nodes::GreaterThanOrEqual
+              subrelation = (node.left.kind_of?(Arel::Attributes::Attribute) ? node.left : node.right)
+              columns.include?(subrelation.name.to_s)
             end
-
-            binds_index += binds_contains if binds_contains
-
-            except
-          end
-
-          binds = self.binds.reject.with_index do |_, i|
-            except_binds[i]
           end
-
-          [predicates, binds]
         end
 
         def predicates_with_wrapped_sql_literals
           non_empty_predicates.map do |node|
-            if Arel::Nodes::Equality === node
-              node
-            else
+            case node
+            when Arel::Nodes::SqlLiteral, ::String
               wrap_sql_literal(node)
+            else node
             end
           end
         end
@@ -183,6 +151,22 @@ module ActiveRecord
           end
           Arel::Nodes::Grouping.new(node)
         end
+
+        def extract_node_value(node)
+          case node
+          when Array
+            node.map { |v| extract_node_value(v) }
+          when Arel::Nodes::Casted, Arel::Nodes::Quoted
+            node.val
+          when Arel::Nodes::BindParam
+            value = node.value
+            if value.respond_to?(:value_before_type_cast)
+              value.value_before_type_cast
+            else
+              value
+            end
+          end
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/where_clause_factory.rb b/activerecord/lib/active_record/relation/where_clause_factory.rb
index b862dd56a5..1374785354 100644
--- a/activerecord/lib/active_record/relation/where_clause_factory.rb
+++ b/activerecord/lib/active_record/relation/where_clause_factory.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Relation
     class WhereClauseFactory # :nodoc:
@@ -15,63 +17,19 @@ module ActiveRecord
           attributes = klass.send(:expand_hash_conditions_for_aggregates, attributes)
           attributes.stringify_keys!
 
-          if perform_case_sensitive?(options = other.last)
-            parts, binds = build_for_case_sensitive(attributes, options)
-          else
-            attributes, binds = predicate_builder.create_binds(attributes)
-            parts = predicate_builder.build_from_hash(attributes)
-          end
+          parts = predicate_builder.build_from_hash(attributes)
         when Arel::Nodes::Node
           parts = [opts]
         else
           raise ArgumentError, "Unsupported argument type: #{opts} (#{opts.class})"
         end
 
-        WhereClause.new(parts, binds || [])
+        WhereClause.new(parts)
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :klass, :predicate_builder
-
-      private
-
-        def perform_case_sensitive?(options)
-          options && options.key?(:case_sensitive)
-        end
-
-        def build_for_case_sensitive(attributes, options)
-          parts, binds = [], []
-          table = klass.arel_table
-
-          attributes.each do |attribute, value|
-            if reflection = klass._reflect_on_association(attribute)
-              attribute = reflection.foreign_key.to_s
-              value = value[reflection.klass.primary_key] unless value.nil?
-            end
-
-            if value.nil?
-              parts << table[attribute].eq(value)
-            else
-              column = klass.column_for_attribute(attribute)
-
-              binds << predicate_builder.send(:build_bind_attribute, attribute, value)
-              value = Arel::Nodes::BindParam.new
-
-              predicate = if options[:case_sensitive]
-                klass.connection.case_sensitive_comparison(table, attribute, column, value)
-              else
-                klass.connection.case_insensitive_comparison(table, attribute, column, value)
-              end
-
-              parts << predicate
-            end
-          end
-
-          [parts, binds]
-        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/result.rb b/activerecord/lib/active_record/result.rb
index 26b1d48e9e..e54e8086dd 100644
--- a/activerecord/lib/active_record/result.rb
+++ b/activerecord/lib/active_record/result.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   ###
   # This class encapsulates a result returned from calling
diff --git a/activerecord/lib/active_record/runtime_registry.rb b/activerecord/lib/active_record/runtime_registry.rb
index b79eb2263f..4975cb8967 100644
--- a/activerecord/lib/active_record/runtime_registry.rb
+++ b/activerecord/lib/active_record/runtime_registry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/per_thread_registry"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index 64bda1539c..91a4f1fad6 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Sanitization
     extend ActiveSupport::Concern
diff --git a/activerecord/lib/active_record/schema.rb b/activerecord/lib/active_record/schema.rb
index 5104427339..f166c27fd9 100644
--- a/activerecord/lib/active_record/schema.rb
+++ b/activerecord/lib/active_record/schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \Schema
   #
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 66a2846f3a..27a1c89bd1 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "stringio"
 
 module ActiveRecord
@@ -85,7 +87,7 @@ HEADER
         extensions = @connection.extensions
         if extensions.any?
           stream.puts "  # These are extensions that must be enabled in order to support this database"
-          extensions.each do |extension|
+          extensions.sort.each do |extension|
             stream.puts "  enable_extension #{extension.inspect}"
           end
           stream.puts
diff --git a/activerecord/lib/active_record/schema_migration.rb b/activerecord/lib/active_record/schema_migration.rb
index 6dbabd69a1..339a5334a8 100644
--- a/activerecord/lib/active_record/schema_migration.rb
+++ b/activerecord/lib/active_record/schema_migration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "scoping/default"
 require_relative "scoping/named"
 
diff --git a/activerecord/lib/active_record/scoping.rb b/activerecord/lib/active_record/scoping.rb
index 94e0ef6724..da585a9562 100644
--- a/activerecord/lib/active_record/scoping.rb
+++ b/activerecord/lib/active_record/scoping.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/per_thread_registry"
 
 module ActiveRecord
@@ -33,9 +35,8 @@ module ActiveRecord
     def populate_with_current_scope_attributes # :nodoc:
       return unless self.class.scope_attributes?
 
-      self.class.scope_attributes.each do |att, value|
-        send("#{att}=", value) if respond_to?("#{att}=")
-      end
+      attributes = self.class.scope_attributes
+      _assign_attributes(attributes) if attributes.any?
     end
 
     def initialize_internals_callback # :nodoc:
diff --git a/activerecord/lib/active_record/scoping/default.rb b/activerecord/lib/active_record/scoping/default.rb
index 70b2693b28..86ae374318 100644
--- a/activerecord/lib/active_record/scoping/default.rb
+++ b/activerecord/lib/active_record/scoping/default.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Scoping
     module Default
diff --git a/activerecord/lib/active_record/scoping/named.rb b/activerecord/lib/active_record/scoping/named.rb
index b4026fabb2..43cce19c1f 100644
--- a/activerecord/lib/active_record/scoping/named.rb
+++ b/activerecord/lib/active_record/scoping/named.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/array"
 require "active_support/core_ext/hash/except"
 require "active_support/core_ext/kernel/singleton_class"
diff --git a/activerecord/lib/active_record/secure_token.rb b/activerecord/lib/active_record/secure_token.rb
index 115799cc20..bcdb33901b 100644
--- a/activerecord/lib/active_record/secure_token.rb
+++ b/activerecord/lib/active_record/secure_token.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module SecureToken
     extend ActiveSupport::Concern
diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index db2bd0b55e..741fea43ce 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord #:nodoc:
   # = Active Record \Serialization
   module Serialization
diff --git a/activerecord/lib/active_record/statement_cache.rb b/activerecord/lib/active_record/statement_cache.rb
index 1877489e55..64657089b5 100644
--- a/activerecord/lib/active_record/statement_cache.rb
+++ b/activerecord/lib/active_record/statement_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # Statement cache is used to cache a single statement in order to avoid creating the AST again.
   # Initializing the cache is done by passing the statement in the create block:
@@ -88,9 +90,9 @@ module ActiveRecord
     attr_reader :bind_map, :query_builder
 
     def self.create(connection, block = Proc.new)
-      relation      = block.call Params.new
-      bind_map      = BindMap.new relation.bound_attributes
-      query_builder = connection.cacheable_query(self, relation.arel)
+      relation = block.call Params.new
+      query_builder, binds = connection.cacheable_query(self, relation.arel)
+      bind_map = BindMap.new(binds)
       new query_builder, bind_map
     end
 
diff --git a/activerecord/lib/active_record/store.rb b/activerecord/lib/active_record/store.rb
index 006afe7495..202b82fa61 100644
--- a/activerecord/lib/active_record/store.rb
+++ b/activerecord/lib/active_record/store.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/hash/indifferent_access"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/suppressor.rb b/activerecord/lib/active_record/suppressor.rb
index d9acb1a1dc..8cdb8e0765 100644
--- a/activerecord/lib/active_record/suppressor.rb
+++ b/activerecord/lib/active_record/suppressor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # ActiveRecord::Suppressor prevents the receiver from being saved during
   # a given block.
diff --git a/activerecord/lib/active_record/table_metadata.rb b/activerecord/lib/active_record/table_metadata.rb
index 71efc1829a..71351449e1 100644
--- a/activerecord/lib/active_record/table_metadata.rb
+++ b/activerecord/lib/active_record/table_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class TableMetadata # :nodoc:
     delegate :foreign_type, :foreign_key, to: :association, prefix: true
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index ba686fc562..0f3f84ca08 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Tasks # :nodoc:
     class DatabaseAlreadyExists < StandardError; end # :nodoc:
@@ -259,8 +261,8 @@ module ActiveRecord
 
       def check_schema_file(filename)
         unless File.exist?(filename)
-          message = %{#{filename} doesn't exist yet. Run `rails db:migrate` to create it, then try again.}
-          message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails)
+          message = %{#{filename} doesn't exist yet. Run `rails db:migrate` to create it, then try again.}.dup
+          message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails.root)
           Kernel.abort message
         end
       end
diff --git a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
index ff6745f7b5..84265aa9e3 100644
--- a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Tasks # :nodoc:
     class MySQLDatabaseTasks # :nodoc:
diff --git a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
index 7f1a768d8b..a2e74efc2b 100644
--- a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "tempfile"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
index 01562b21e9..abdd6db64a 100644
--- a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Tasks # :nodoc:
     class SQLiteDatabaseTasks # :nodoc:
diff --git a/activerecord/lib/active_record/timestamp.rb b/activerecord/lib/active_record/timestamp.rb
index 26eea0bc24..5da3759e5a 100644
--- a/activerecord/lib/active_record/timestamp.rb
+++ b/activerecord/lib/active_record/timestamp.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \Timestamp
   #
diff --git a/activerecord/lib/active_record/touch_later.rb b/activerecord/lib/active_record/touch_later.rb
index cacde9c881..f70b7c50a2 100644
--- a/activerecord/lib/active_record/touch_later.rb
+++ b/activerecord/lib/active_record/touch_later.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record Touch Later
   module TouchLater
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index 463bb1f314..3e8a0789df 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # See ActiveRecord::Transactions::ClassMethods for documentation.
   module Transactions
diff --git a/activerecord/lib/active_record/translation.rb b/activerecord/lib/active_record/translation.rb
index ddcb5f2a7a..3cf70eafb8 100644
--- a/activerecord/lib/active_record/translation.rb
+++ b/activerecord/lib/active_record/translation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Translation
     include ActiveModel::Translation
diff --git a/activerecord/lib/active_record/type.rb b/activerecord/lib/active_record/type.rb
index 6f4e35b159..fa22df92b8 100644
--- a/activerecord/lib/active_record/type.rb
+++ b/activerecord/lib/active_record/type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_model/type"
 
 require_relative "type/internal/timezone"
diff --git a/activerecord/lib/active_record/type/adapter_specific_registry.rb b/activerecord/lib/active_record/type/adapter_specific_registry.rb
index 7cc866f7a7..e7468aa542 100644
--- a/activerecord/lib/active_record/type/adapter_specific_registry.rb
+++ b/activerecord/lib/active_record/type/adapter_specific_registry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_model/type/registry"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/type/date.rb b/activerecord/lib/active_record/type/date.rb
index ccafed054e..8177074a20 100644
--- a/activerecord/lib/active_record/type/date.rb
+++ b/activerecord/lib/active_record/type/date.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class Date < ActiveModel::Type::Date
diff --git a/activerecord/lib/active_record/type/date_time.rb b/activerecord/lib/active_record/type/date_time.rb
index 1fb9380ecd..4acde6b9f8 100644
--- a/activerecord/lib/active_record/type/date_time.rb
+++ b/activerecord/lib/active_record/type/date_time.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class DateTime < ActiveModel::Type::DateTime
diff --git a/activerecord/lib/active_record/type/decimal_without_scale.rb b/activerecord/lib/active_record/type/decimal_without_scale.rb
index 53a5e205da..a207940dc7 100644
--- a/activerecord/lib/active_record/type/decimal_without_scale.rb
+++ b/activerecord/lib/active_record/type/decimal_without_scale.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class DecimalWithoutScale < ActiveModel::Type::BigInteger # :nodoc:
diff --git a/activerecord/lib/active_record/type/hash_lookup_type_map.rb b/activerecord/lib/active_record/type/hash_lookup_type_map.rb
index 0145d5d6c1..db9853fbcc 100644
--- a/activerecord/lib/active_record/type/hash_lookup_type_map.rb
+++ b/activerecord/lib/active_record/type/hash_lookup_type_map.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class HashLookupTypeMap < TypeMap # :nodoc:
diff --git a/activerecord/lib/active_record/type/internal/timezone.rb b/activerecord/lib/active_record/type/internal/timezone.rb
index 947e06158a..3059755752 100644
--- a/activerecord/lib/active_record/type/internal/timezone.rb
+++ b/activerecord/lib/active_record/type/internal/timezone.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     module Internal
diff --git a/activerecord/lib/active_record/type/json.rb b/activerecord/lib/active_record/type/json.rb
index c4732fe388..3f9ff22796 100644
--- a/activerecord/lib/active_record/type/json.rb
+++ b/activerecord/lib/active_record/type/json.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class Json < ActiveModel::Type::Value
diff --git a/activerecord/lib/active_record/type/serialized.rb b/activerecord/lib/active_record/type/serialized.rb
index edbd20a6c1..e882784691 100644
--- a/activerecord/lib/active_record/type/serialized.rb
+++ b/activerecord/lib/active_record/type/serialized.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class Serialized < DelegateClass(ActiveModel::Type::Value) # :nodoc:
diff --git a/activerecord/lib/active_record/type/text.rb b/activerecord/lib/active_record/type/text.rb
index cb1949700a..6d19696671 100644
--- a/activerecord/lib/active_record/type/text.rb
+++ b/activerecord/lib/active_record/type/text.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class Text < ActiveModel::Type::String # :nodoc:
diff --git a/activerecord/lib/active_record/type/time.rb b/activerecord/lib/active_record/type/time.rb
index b9bac87c67..f4da1ecf2c 100644
--- a/activerecord/lib/active_record/type/time.rb
+++ b/activerecord/lib/active_record/type/time.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class Time < ActiveModel::Type::Time
diff --git a/activerecord/lib/active_record/type/type_map.rb b/activerecord/lib/active_record/type/type_map.rb
index 7bce82a1ff..fc40b460f0 100644
--- a/activerecord/lib/active_record/type/type_map.rb
+++ b/activerecord/lib/active_record/type/type_map.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "concurrent/map"
 
 module ActiveRecord
diff --git a/activerecord/lib/active_record/type/unsigned_integer.rb b/activerecord/lib/active_record/type/unsigned_integer.rb
index 9ae0109f9f..4619528f81 100644
--- a/activerecord/lib/active_record/type/unsigned_integer.rb
+++ b/activerecord/lib/active_record/type/unsigned_integer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Type
     class UnsignedInteger < ActiveModel::Type::Integer # :nodoc:
diff --git a/activerecord/lib/active_record/type_caster.rb b/activerecord/lib/active_record/type_caster.rb
index 8b12a30c6a..ed2e4fb79c 100644
--- a/activerecord/lib/active_record/type_caster.rb
+++ b/activerecord/lib/active_record/type_caster.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "type_caster/map"
 require_relative "type_caster/connection"
 
diff --git a/activerecord/lib/active_record/type_caster/connection.rb b/activerecord/lib/active_record/type_caster/connection.rb
index 9f7bbe8843..af4e4e37e2 100644
--- a/activerecord/lib/active_record/type_caster/connection.rb
+++ b/activerecord/lib/active_record/type_caster/connection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module TypeCaster
     class Connection # :nodoc:
diff --git a/activerecord/lib/active_record/type_caster/map.rb b/activerecord/lib/active_record/type_caster/map.rb
index 9f79723125..d51350ba83 100644
--- a/activerecord/lib/active_record/type_caster/map.rb
+++ b/activerecord/lib/active_record/type_caster/map.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module TypeCaster
     class Map # :nodoc:
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 046b69bee2..3f5c879f2f 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   # = Active Record \RecordInvalid
   #
diff --git a/activerecord/lib/active_record/validations/absence.rb b/activerecord/lib/active_record/validations/absence.rb
index 641d041f3d..6afb9eabd2 100644
--- a/activerecord/lib/active_record/validations/absence.rb
+++ b/activerecord/lib/active_record/validations/absence.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Validations
     class AbsenceValidator < ActiveModel::Validations::AbsenceValidator # :nodoc:
diff --git a/activerecord/lib/active_record/validations/associated.rb b/activerecord/lib/active_record/validations/associated.rb
index c695965d7b..3538aeec22 100644
--- a/activerecord/lib/active_record/validations/associated.rb
+++ b/activerecord/lib/active_record/validations/associated.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Validations
     class AssociatedValidator < ActiveModel::EachValidator #:nodoc:
diff --git a/activerecord/lib/active_record/validations/length.rb b/activerecord/lib/active_record/validations/length.rb
index 0e0cebce4a..f47b14ae3a 100644
--- a/activerecord/lib/active_record/validations/length.rb
+++ b/activerecord/lib/active_record/validations/length.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Validations
     class LengthValidator < ActiveModel::Validations::LengthValidator # :nodoc:
diff --git a/activerecord/lib/active_record/validations/presence.rb b/activerecord/lib/active_record/validations/presence.rb
index 7cfd55f516..75e97e1997 100644
--- a/activerecord/lib/active_record/validations/presence.rb
+++ b/activerecord/lib/active_record/validations/presence.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Validations
     class PresenceValidator < ActiveModel::Validations::PresenceValidator # :nodoc:
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 154cf5f1a4..2677fade18 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Validations
     class UniquenessValidator < ActiveModel::EachValidator # :nodoc:
@@ -50,7 +52,33 @@ module ActiveRecord
       end
 
       def build_relation(klass, attribute, value)
-        klass.unscoped.where!({ attribute => value }, options)
+        if reflection = klass._reflect_on_association(attribute)
+          attribute = reflection.foreign_key
+          value = value.attributes[reflection.klass.primary_key] unless value.nil?
+        end
+
+        if value.nil?
+          return klass.unscoped.where!(attribute => value)
+        end
+
+        # the attribute may be an aliased attribute
+        if klass.attribute_alias?(attribute)
+          attribute = klass.attribute_alias(attribute)
+        end
+
+        attribute_name = attribute.to_s
+        value = klass.predicate_builder.build_bind_attribute(attribute_name, value)
+
+        table = klass.arel_table
+        column = klass.columns_hash[attribute_name]
+
+        comparison = if !options[:case_sensitive]
+          # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
+          klass.connection.case_insensitive_comparison(table, attribute, column, value)
+        else
+          klass.connection.case_sensitive_comparison(table, attribute, column, value)
+        end
+        klass.unscoped.where!(comparison)
       end
 
       def scope_relation(record, relation)
diff --git a/activerecord/lib/active_record/version.rb b/activerecord/lib/active_record/version.rb
index 146cfacc18..6b0d82d8fc 100644
--- a/activerecord/lib/active_record/version.rb
+++ b/activerecord/lib/active_record/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "gem_version"
 
 module ActiveRecord
diff --git a/activerecord/lib/rails/generators/active_record.rb b/activerecord/lib/rails/generators/active_record.rb
index a79b8eafea..a7e5e373a7 100644
--- a/activerecord/lib/rails/generators/active_record.rb
+++ b/activerecord/lib/rails/generators/active_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails/generators/named_base"
 require "rails/generators/active_model"
 require "rails/generators/active_record/migration"
diff --git a/activerecord/lib/rails/generators/active_record/application_record/application_record_generator.rb b/activerecord/lib/rails/generators/active_record/application_record/application_record_generator.rb
new file mode 100644
index 0000000000..d18330f5b2
--- /dev/null
+++ b/activerecord/lib/rails/generators/active_record/application_record/application_record_generator.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require "rails/generators/active_record"
+
+module ActiveRecord
+  module Generators # :nodoc:
+    class ApplicationRecordGenerator < ::Rails::Generators::Base # :nodoc:
+      source_root File.expand_path("templates", __dir__)
+
+      # FIXME: Change this file to a symlink once RubyGems 2.5.0 is required.
+      def create_application_record
+        template "application_record.rb", application_record_file_name
+      end
+
+      private
+
+        def application_record_file_name
+          @application_record_file_name ||= if namespaced?
+                                              "app/models/#{namespaced_path}/application_record.rb"
+                                            else
+                                              "app/models/application_record.rb"
+                                            end
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/rails/generators/active_record/model/templates/application_record.rb b/activerecord/lib/rails/generators/active_record/application_record/templates/application_record.rb
index 60050e0bf8..60050e0bf8 100644
--- a/activerecord/lib/rails/generators/active_record/model/templates/application_record.rb
+++ b/activerecord/lib/rails/generators/active_record/application_record/templates/application_record.rb
diff --git a/activerecord/lib/rails/generators/active_record/migration.rb b/activerecord/lib/rails/generators/active_record/migration.rb
index 47c0981a49..4ceb502c5d 100644
--- a/activerecord/lib/rails/generators/active_record/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/migration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails/generators/migration"
 
 module ActiveRecord
diff --git a/activerecord/lib/rails/generators/active_record/migration/migration_generator.rb b/activerecord/lib/rails/generators/active_record/migration/migration_generator.rb
index 1f1c47499b..0174c7ea31 100644
--- a/activerecord/lib/rails/generators/active_record/migration/migration_generator.rb
+++ b/activerecord/lib/rails/generators/active_record/migration/migration_generator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails/generators/active_record"
 
 module ActiveRecord
diff --git a/activerecord/lib/rails/generators/active_record/model/model_generator.rb b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
index 5cec07d2e3..25e54f3ac8 100644
--- a/activerecord/lib/rails/generators/active_record/model/model_generator.rb
+++ b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails/generators/active_record"
 
 module ActiveRecord
@@ -21,13 +23,11 @@ module ActiveRecord
       end
 
       def create_model_file
-        generate_application_record
         template "model.rb", File.join("app/models", class_path, "#{file_name}.rb")
       end
 
       def create_module_file
         return if regular_class_path.empty?
-        generate_application_record
         template "module.rb", File.join("app/models", "#{class_path.join('/')}.rb") if behavior == :invoke
       end
 
@@ -39,31 +39,10 @@ module ActiveRecord
           attributes.select { |a| !a.reference? && a.has_index? }
         end
 
-        # FIXME: Change this file to a symlink once RubyGems 2.5.0 is required.
-        def generate_application_record
-          if behavior == :invoke && !application_record_exist?
-            template "application_record.rb", application_record_file_name
-          end
-        end
-
         # Used by the migration template to determine the parent name of the model
         def parent_class_name
           options[:parent] || "ApplicationRecord"
         end
-
-        def application_record_exist?
-          file_exist = nil
-          in_root { file_exist = File.exist?(application_record_file_name) }
-          file_exist
-        end
-
-        def application_record_file_name
-          @application_record_file_name ||= if mountable_engine?
-            "app/models/#{namespaced_path}/application_record.rb"
-          else
-            "app/models/application_record.rb"
-          end
-        end
     end
   end
 end
diff --git a/activerecord/test/active_record/connection_adapters/fake_adapter.rb b/activerecord/test/active_record/connection_adapters/fake_adapter.rb
index b0d8050721..f977b2997b 100644
--- a/activerecord/test/active_record/connection_adapters/fake_adapter.rb
+++ b/activerecord/test/active_record/connection_adapters/fake_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionHandling
     def fake_connection(config)
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index eccd250d19..6e04578576 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/book"
 require "models/post"
@@ -222,7 +224,7 @@ module ActiveRecord
       def test_select_all_with_legacy_binds
         post = Post.create!(title: "foo", body: "bar")
         expected = @connection.select_all("SELECT * FROM posts WHERE id = #{post.id}")
-        result = @connection.select_all("SELECT * FROM posts WHERE id = #{bind_param.to_sql}", nil, [[nil, post.id]])
+        result = @connection.select_all("SELECT * FROM posts WHERE id = #{Arel::Nodes::BindParam.new(nil).to_sql}", nil, [[nil, post.id]])
         assert_equal expected.to_hash, result.to_hash
       end
     end
@@ -231,7 +233,6 @@ module ActiveRecord
       author = Author.create!(name: "john")
       Post.create!(author: author, title: "foo", body: "bar")
       query = author.posts.where(title: "foo").select(:title)
-      assert_equal({ "title" => "foo" }, @connection.select_one(query.arel, nil, query.bound_attributes))
       assert_equal({ "title" => "foo" }, @connection.select_one(query))
       assert @connection.select_all(query).is_a?(ActiveRecord::Result)
       assert_equal "foo", @connection.select_value(query)
@@ -241,7 +242,6 @@ module ActiveRecord
     def test_select_methods_passing_a_relation
       Post.create!(title: "foo", body: "bar")
       query = Post.where(title: "foo").select(:title)
-      assert_equal({ "title" => "foo" }, @connection.select_one(query.arel, nil, query.bound_attributes))
       assert_equal({ "title" => "foo" }, @connection.select_one(query))
       assert @connection.select_all(query).is_a?(ActiveRecord::Result)
       assert_equal "foo", @connection.select_value(query)
diff --git a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
index 67e1efde27..a6b83ec377 100644
--- a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/bind_parameter_test.rb b/activerecord/test/cases/adapters/mysql2/bind_parameter_test.rb
index 8f7c803a21..825bddfb73 100644
--- a/activerecord/test/cases/adapters/mysql2/bind_parameter_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/bind_parameter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/adapters/mysql2/boolean_test.rb b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
index 58698d59db..db09b30361 100644
--- a/activerecord/test/cases/adapters/mysql2/boolean_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mysql2BooleanTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/case_sensitivity_test.rb b/activerecord/test/cases/adapters/mysql2/case_sensitivity_test.rb
index 50ba9ab831..fd5f712f1a 100644
--- a/activerecord/test/cases/adapters/mysql2/case_sensitivity_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/case_sensitivity_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mysql2CaseSensitivityTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/charset_collation_test.rb b/activerecord/test/cases/adapters/mysql2/charset_collation_test.rb
index e4a6ed5482..d0c57de65d 100644
--- a/activerecord/test/cases/adapters/mysql2/charset_collation_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/charset_collation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/connection_test.rb b/activerecord/test/cases/adapters/mysql2/connection_test.rb
index a2faf43b0d..9d81d506a0 100644
--- a/activerecord/test/cases/adapters/mysql2/connection_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/connection_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/datetime_precision_quoting_test.rb b/activerecord/test/cases/adapters/mysql2/datetime_precision_quoting_test.rb
index c131a5169c..fa54f39992 100644
--- a/activerecord/test/cases/adapters/mysql2/datetime_precision_quoting_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/datetime_precision_quoting_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mysql2DatetimePrecisionQuotingTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/enum_test.rb b/activerecord/test/cases/adapters/mysql2/enum_test.rb
index 7ad3e3ca2d..108bec832c 100644
--- a/activerecord/test/cases/adapters/mysql2/enum_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/enum_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mysql2EnumTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/explain_test.rb b/activerecord/test/cases/adapters/mysql2/explain_test.rb
index 7916921e5a..2736f7cf0e 100644
--- a/activerecord/test/cases/adapters/mysql2/explain_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/explain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
diff --git a/activerecord/test/cases/adapters/mysql2/json_test.rb b/activerecord/test/cases/adapters/mysql2/json_test.rb
index 26c69edc7b..de78ba91f5 100644
--- a/activerecord/test/cases/adapters/mysql2/json_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/json_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "cases/json_shared_test_cases"
 
diff --git a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
index 565130c38f..d18fb97e05 100644
--- a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/ddl_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
index e7459546e4..62abd694bb 100644
--- a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class SchemaMigrationsTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/schema_test.rb b/activerecord/test/cases/adapters/mysql2/schema_test.rb
index 1fad5585de..b587e756cf 100644
--- a/activerecord/test/cases/adapters/mysql2/schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
diff --git a/activerecord/test/cases/adapters/mysql2/sp_test.rb b/activerecord/test/cases/adapters/mysql2/sp_test.rb
index 4182532535..47cedc5edf 100644
--- a/activerecord/test/cases/adapters/mysql2/sp_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/sp_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/adapters/mysql2/sql_types_test.rb b/activerecord/test/cases/adapters/mysql2/sql_types_test.rb
index d6e7f29a5c..e10642cbb4 100644
--- a/activerecord/test/cases/adapters/mysql2/sql_types_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/sql_types_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mysql2SqlTypesTest < ActiveRecord::Mysql2TestCase
diff --git a/activerecord/test/cases/adapters/mysql2/table_options_test.rb b/activerecord/test/cases/adapters/mysql2/table_options_test.rb
index 61a8ce9bc0..6183d66b63 100644
--- a/activerecord/test/cases/adapters/mysql2/table_options_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/table_options_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/transaction_test.rb b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
index 16101e38cb..e603baab69 100644
--- a/activerecord/test/cases/adapters/mysql2/transaction_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/unsigned_type_test.rb b/activerecord/test/cases/adapters/mysql2/unsigned_type_test.rb
index 71dcfaa241..d0a09f6481 100644
--- a/activerecord/test/cases/adapters/mysql2/unsigned_type_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/unsigned_type_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/mysql2/virtual_column_test.rb b/activerecord/test/cases/adapters/mysql2/virtual_column_test.rb
index 1c5ef2aa41..ffde8ed4d8 100644
--- a/activerecord/test/cases/adapters/mysql2/virtual_column_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/virtual_column_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
index b787de8453..9929237546 100644
--- a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlActiveSchemaTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/array_test.rb b/activerecord/test/cases/adapters/postgresql/array_test.rb
index 121c62dadf..8507dbb463 100644
--- a/activerecord/test/cases/adapters/postgresql/array_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/array_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/bit_string_test.rb b/activerecord/test/cases/adapters/postgresql/bit_string_test.rb
index 7712e809a2..df04299569 100644
--- a/activerecord/test/cases/adapters/postgresql/bit_string_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/bit_string_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 require "support/schema_dumping_helper"
diff --git a/activerecord/test/cases/adapters/postgresql/bytea_test.rb b/activerecord/test/cases/adapters/postgresql/bytea_test.rb
index 65baed34e9..a6bee113ff 100644
--- a/activerecord/test/cases/adapters/postgresql/bytea_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/bytea_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/case_insensitive_test.rb b/activerecord/test/cases/adapters/postgresql/case_insensitive_test.rb
index 03b44feab6..305e033642 100644
--- a/activerecord/test/cases/adapters/postgresql/case_insensitive_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/case_insensitive_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlCaseInsensitiveTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/change_schema_test.rb b/activerecord/test/cases/adapters/postgresql/change_schema_test.rb
index ea642069d2..adf461a9cc 100644
--- a/activerecord/test/cases/adapters/postgresql/change_schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/change_schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/adapters/postgresql/cidr_test.rb b/activerecord/test/cases/adapters/postgresql/cidr_test.rb
index 52f2a0096c..f20958fbd2 100644
--- a/activerecord/test/cases/adapters/postgresql/cidr_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/cidr_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "ipaddr"
 
diff --git a/activerecord/test/cases/adapters/postgresql/citext_test.rb b/activerecord/test/cases/adapters/postgresql/citext_test.rb
index ca95e4b626..050614cade 100644
--- a/activerecord/test/cases/adapters/postgresql/citext_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/citext_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/collation_test.rb b/activerecord/test/cases/adapters/postgresql/collation_test.rb
index a603221d8f..7468f4c4f8 100644
--- a/activerecord/test/cases/adapters/postgresql/collation_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/collation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/composite_test.rb b/activerecord/test/cases/adapters/postgresql/composite_test.rb
index 1da2a9e2ac..5da95f7e2c 100644
--- a/activerecord/test/cases/adapters/postgresql/composite_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/composite_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
@@ -104,7 +106,7 @@ class PostgresqlCompositeWithCustomOIDTest < ActiveRecord::PostgreSQLTestCase
   def setup
     super
 
-    @connection.type_map.register_type "full_address", FullAddressType.new
+    @connection.send(:type_map).register_type "full_address", FullAddressType.new
   end
 
   def test_column
diff --git a/activerecord/test/cases/adapters/postgresql/connection_test.rb b/activerecord/test/cases/adapters/postgresql/connection_test.rb
index 32afe331fa..24875c6678 100644
--- a/activerecord/test/cases/adapters/postgresql/connection_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/connection_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
@@ -133,8 +135,8 @@ module ActiveRecord
 
     if ActiveRecord::Base.connection.prepared_statements
       def test_statement_key_is_logged
-        binds = [bind_attribute(nil, 1)]
-        @connection.exec_query("SELECT $1::integer", "SQL", binds, prepare: true)
+        bind = Relation::QueryAttribute.new(nil, 1, Type::Value.new)
+        @connection.exec_query("SELECT $1::integer", "SQL", [bind], prepare: true)
         name = @subscriber.payloads.last[:statement_name]
         assert name
         res = @connection.exec_query("EXPLAIN (FORMAT JSON) EXECUTE #{name}(1)")
diff --git a/activerecord/test/cases/adapters/postgresql/datatype_test.rb b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
index 0725fde5ae..b7535d5c9a 100644
--- a/activerecord/test/cases/adapters/postgresql/datatype_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/ddl_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/domain_test.rb b/activerecord/test/cases/adapters/postgresql/domain_test.rb
index f1eb8adb15..9c3817e2ad 100644
--- a/activerecord/test/cases/adapters/postgresql/domain_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/domain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/enum_test.rb b/activerecord/test/cases/adapters/postgresql/enum_test.rb
index 5e5a3158ba..3d3cbe11a3 100644
--- a/activerecord/test/cases/adapters/postgresql/enum_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/enum_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/explain_test.rb b/activerecord/test/cases/adapters/postgresql/explain_test.rb
index d79fbccf47..16fec94ede 100644
--- a/activerecord/test/cases/adapters/postgresql/explain_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/explain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
@@ -15,6 +17,6 @@ class PostgreSQLExplainTest < ActiveRecord::PostgreSQLTestCase
     explain = Developer.where(id: 1).includes(:audit_logs).explain
     assert_match %(QUERY PLAN), explain
     assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\$1 \[\["id", 1\]\]|1)), explain
-    assert_match %(EXPLAIN for: SELECT "audit_logs".* FROM "audit_logs" WHERE "audit_logs"."developer_id" = 1), explain
+    assert_match %r(EXPLAIN for: SELECT "audit_logs"\.\* FROM "audit_logs" WHERE "audit_logs"\."developer_id" = (?:\$1 \[\["developer_id", 1\]\]|1)), explain
   end
 end
diff --git a/activerecord/test/cases/adapters/postgresql/extension_migration_test.rb b/activerecord/test/cases/adapters/postgresql/extension_migration_test.rb
index b56c226763..e589e3ab1b 100644
--- a/activerecord/test/cases/adapters/postgresql/extension_migration_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/extension_migration_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlExtensionMigrationTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/full_text_test.rb b/activerecord/test/cases/adapters/postgresql/full_text_test.rb
index 5ddfe32007..c6f1e1727f 100644
--- a/activerecord/test/cases/adapters/postgresql/full_text_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/full_text_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/geometric_test.rb b/activerecord/test/cases/adapters/postgresql/geometric_test.rb
index 3b6840a1c9..e1ba00e07b 100644
--- a/activerecord/test/cases/adapters/postgresql/geometric_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/geometric_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 require "support/schema_dumping_helper"
diff --git a/activerecord/test/cases/adapters/postgresql/hstore_test.rb b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
index 4d650bd431..97a8a257c5 100644
--- a/activerecord/test/cases/adapters/postgresql/hstore_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/infinity_test.rb b/activerecord/test/cases/adapters/postgresql/infinity_test.rb
index b9e177e6ec..0b18c0c9d7 100644
--- a/activerecord/test/cases/adapters/postgresql/infinity_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/infinity_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlInfinityTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/integer_test.rb b/activerecord/test/cases/adapters/postgresql/integer_test.rb
index b4e55964b9..3e45b057ff 100644
--- a/activerecord/test/cases/adapters/postgresql/integer_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/integer_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_support/core_ext/numeric/bytes"
 
diff --git a/activerecord/test/cases/adapters/postgresql/json_test.rb b/activerecord/test/cases/adapters/postgresql/json_test.rb
index 6aa60630c2..aa5e03df41 100644
--- a/activerecord/test/cases/adapters/postgresql/json_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/json_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "cases/json_shared_test_cases"
 
diff --git a/activerecord/test/cases/adapters/postgresql/ltree_test.rb b/activerecord/test/cases/adapters/postgresql/ltree_test.rb
index 2b5ac1cac6..eca29f2892 100644
--- a/activerecord/test/cases/adapters/postgresql/ltree_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/ltree_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/money_test.rb b/activerecord/test/cases/adapters/postgresql/money_test.rb
index ea060345a7..563f0bbfae 100644
--- a/activerecord/test/cases/adapters/postgresql/money_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/money_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/network_test.rb b/activerecord/test/cases/adapters/postgresql/network_test.rb
index a33b0ef8a7..f461544a85 100644
--- a/activerecord/test/cases/adapters/postgresql/network_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/network_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/numbers_test.rb b/activerecord/test/cases/adapters/postgresql/numbers_test.rb
index bfb2b7c27a..b53a12254d 100644
--- a/activerecord/test/cases/adapters/postgresql/numbers_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/numbers_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlNumberTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
index 26bf4d2090..f199519d86 100644
--- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/ddl_helper"
 require "support/connection_helper"
@@ -202,8 +204,8 @@ module ActiveRecord
             string = @connection.quote("foo")
             @connection.exec_query("INSERT INTO ex (id, data) VALUES (1, #{string})")
 
-            binds = [bind_attribute("id", 1)]
-            result = @connection.exec_query("SELECT id, data FROM ex WHERE id = $1", nil, binds)
+            bind = Relation::QueryAttribute.new("id", 1, Type::Value.new)
+            result = @connection.exec_query("SELECT id, data FROM ex WHERE id = $1", nil, [bind])
 
             assert_equal 1, result.rows.length
             assert_equal 2, result.columns.length
@@ -217,8 +219,8 @@ module ActiveRecord
             string = @connection.quote("foo")
             @connection.exec_query("INSERT INTO ex (id, data) VALUES (1, #{string})")
 
-            binds = [bind_attribute("id", "1-fuu", Type::Integer.new)]
-            result = @connection.exec_query("SELECT id, data FROM ex WHERE id = $1", nil, binds)
+            bind = Relation::QueryAttribute.new("id", "1-fuu", Type::Integer.new)
+            result = @connection.exec_query("SELECT id, data FROM ex WHERE id = $1", nil, [bind])
 
             assert_equal 1, result.rows.length
             assert_equal 2, result.columns.length
diff --git a/activerecord/test/cases/adapters/postgresql/prepared_statements_disabled_test.rb b/activerecord/test/cases/adapters/postgresql/prepared_statements_disabled_test.rb
index 8c62690866..f7478b50c3 100644
--- a/activerecord/test/cases/adapters/postgresql/prepared_statements_disabled_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/prepared_statements_disabled_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/computer"
 require "models/developer"
diff --git a/activerecord/test/cases/adapters/postgresql/quoting_test.rb b/activerecord/test/cases/adapters/postgresql/quoting_test.rb
index a1e966b915..d50dc49276 100644
--- a/activerecord/test/cases/adapters/postgresql/quoting_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/quoting_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
@@ -9,11 +11,11 @@ module ActiveRecord
         end
 
         def test_type_cast_true
-          assert_equal "t", @conn.type_cast(true)
+          assert_equal true, @conn.type_cast(true)
         end
 
         def test_type_cast_false
-          assert_equal "f", @conn.type_cast(false)
+          assert_equal false, @conn.type_cast(false)
         end
 
         def test_quote_float_nan
diff --git a/activerecord/test/cases/adapters/postgresql/range_test.rb b/activerecord/test/cases/adapters/postgresql/range_test.rb
index f411884dfd..b4a776d04d 100644
--- a/activerecord/test/cases/adapters/postgresql/range_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/range_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb b/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
index 0ff04bfa27..0bcc214c24 100644
--- a/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/rename_table_test.rb b/activerecord/test/cases/adapters/postgresql/rename_table_test.rb
index e9e7f717ac..100d247113 100644
--- a/activerecord/test/cases/adapters/postgresql/rename_table_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/rename_table_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlRenameTableTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/schema_authorization_test.rb b/activerecord/test/cases/adapters/postgresql/schema_authorization_test.rb
index f86a76e08a..fcb0aec81b 100644
--- a/activerecord/test/cases/adapters/postgresql/schema_authorization_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/schema_authorization_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class SchemaThing < ActiveRecord::Base
@@ -68,7 +70,7 @@ class SchemaAuthorizationTest < ActiveRecord::PostgreSQLTestCase
         USERS.each do |u|
           @connection.clear_cache!
           set_session_auth u
-          assert_equal u, @connection.select_value("SELECT name FROM #{TABLE_NAME} WHERE id = $1", "SQL", [bind_attribute("id", 1)])
+          assert_equal u, @connection.select_value("SELECT name FROM #{TABLE_NAME} WHERE id = $1", "SQL", [bind_param(1)])
           set_session_auth
         end
       end
@@ -101,4 +103,8 @@ class SchemaAuthorizationTest < ActiveRecord::PostgreSQLTestCase
     def set_session_auth(auth = nil)
       @connection.session_auth = auth || "default"
     end
+
+    def bind_param(value)
+      ActiveRecord::Relation::QueryAttribute.new(nil, value, ActiveRecord::Type::Value.new)
+    end
 end
diff --git a/activerecord/test/cases/adapters/postgresql/schema_test.rb b/activerecord/test/cases/adapters/postgresql/schema_test.rb
index f6b957476b..5a64da028b 100644
--- a/activerecord/test/cases/adapters/postgresql/schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/default"
 require "support/schema_dumping_helper"
@@ -169,17 +171,17 @@ class SchemaTest < ActiveRecord::PostgreSQLTestCase
 
   def test_raise_wrapped_exception_on_bad_prepare
     assert_raises(ActiveRecord::StatementInvalid) do
-      @connection.exec_query "select * from developers where id = ?", "sql", [bind_attribute("id", 1)]
+      @connection.exec_query "select * from developers where id = ?", "sql", [bind_param(1)]
     end
   end
 
   if ActiveRecord::Base.connection.prepared_statements
     def test_schema_change_with_prepared_stmt
       altered = false
-      @connection.exec_query "select * from developers where id = $1", "sql", [bind_attribute("id", 1)]
+      @connection.exec_query "select * from developers where id = $1", "sql", [bind_param(1)]
       @connection.exec_query "alter table developers add column zomg int", "sql", []
       altered = true
-      @connection.exec_query "select * from developers where id = $1", "sql", [bind_attribute("id", 1)]
+      @connection.exec_query "select * from developers where id = $1", "sql", [bind_param(1)]
     ensure
       # We are not using DROP COLUMN IF EXISTS because that syntax is only
       # supported by pg 9.X
@@ -467,6 +469,10 @@ class SchemaTest < ActiveRecord::PostgreSQLTestCase
       assert_equal this_index_column, this_index.columns[0]
       assert_equal this_index_name, this_index.name
     end
+
+    def bind_param(value)
+      ActiveRecord::Relation::QueryAttribute.new(nil, value, ActiveRecord::Type::Value.new)
+    end
 end
 
 class SchemaForeignKeyTest < ActiveRecord::PostgreSQLTestCase
diff --git a/activerecord/test/cases/adapters/postgresql/serial_test.rb b/activerecord/test/cases/adapters/postgresql/serial_test.rb
index d711b3b729..3c020a88d0 100644
--- a/activerecord/test/cases/adapters/postgresql/serial_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/serial_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/statement_pool_test.rb b/activerecord/test/cases/adapters/postgresql/statement_pool_test.rb
index 146b619a4b..a3eb4f9e67 100644
--- a/activerecord/test/cases/adapters/postgresql/statement_pool_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/statement_pool_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/adapters/postgresql/timestamp_test.rb b/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
index 962450aada..b7f213efc8 100644
--- a/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/topic"
diff --git a/activerecord/test/cases/adapters/postgresql/transaction_test.rb b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
index 9b42d0383d..f56adf4a5e 100644
--- a/activerecord/test/cases/adapters/postgresql/transaction_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 require "concurrent/atomic/cyclic_barrier"
diff --git a/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb b/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb
index 784d77a8d1..449023b6eb 100644
--- a/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class PostgresqlTypeLookupTest < ActiveRecord::PostgreSQLTestCase
@@ -6,16 +8,16 @@ class PostgresqlTypeLookupTest < ActiveRecord::PostgreSQLTestCase
   end
 
   test "array delimiters are looked up correctly" do
-    box_array = @connection.type_map.lookup(1020)
-    int_array = @connection.type_map.lookup(1007)
+    box_array = @connection.send(:type_map).lookup(1020)
+    int_array = @connection.send(:type_map).lookup(1007)
 
     assert_equal ";", box_array.delimiter
     assert_equal ",", int_array.delimiter
   end
 
   test "array types correctly respect registration of subtypes" do
-    int_array = @connection.type_map.lookup(1007, -1, "integer[]")
-    bigint_array = @connection.type_map.lookup(1016, -1, "bigint[]")
+    int_array = @connection.send(:type_map).lookup(1007, -1, "integer[]")
+    bigint_array = @connection.send(:type_map).lookup(1016, -1, "bigint[]")
     big_array = [123456789123456789]
 
     assert_raises(ActiveModel::RangeError) { int_array.serialize(big_array) }
@@ -23,8 +25,8 @@ class PostgresqlTypeLookupTest < ActiveRecord::PostgreSQLTestCase
   end
 
   test "range types correctly respect registration of subtypes" do
-    int_range = @connection.type_map.lookup(3904, -1, "int4range")
-    bigint_range = @connection.type_map.lookup(3926, -1, "int8range")
+    int_range = @connection.send(:type_map).lookup(3904, -1, "int4range")
+    bigint_range = @connection.send(:type_map).lookup(3926, -1, "int8range")
     big_range = 0..123456789123456789
 
     assert_raises(ActiveModel::RangeError) { int_range.serialize(big_range) }
diff --git a/activerecord/test/cases/adapters/postgresql/utils_test.rb b/activerecord/test/cases/adapters/postgresql/utils_test.rb
index 9f9e3bda2f..c91884f384 100644
--- a/activerecord/test/cases/adapters/postgresql/utils_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/utils_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/connection_adapters/postgresql/utils"
 
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 00de92cdfd..76cb1bc354 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/postgresql/xml_test.rb b/activerecord/test/cases/adapters/postgresql/xml_test.rb
index 826b384fb3..71ead6f7f3 100644
--- a/activerecord/test/cases/adapters/postgresql/xml_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/xml_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/sqlite3/collation_test.rb b/activerecord/test/cases/adapters/sqlite3/collation_test.rb
index dd88ed3656..76c8f7d8dd 100644
--- a/activerecord/test/cases/adapters/sqlite3/collation_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/collation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb b/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
index e1cfd703e8..ffb1d6afce 100644
--- a/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class CopyTableTest < ActiveRecord::SQLite3TestCase
diff --git a/activerecord/test/cases/adapters/sqlite3/explain_test.rb b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
index 29d97ae78c..3b081d34e1 100644
--- a/activerecord/test/cases/adapters/sqlite3/explain_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
@@ -15,7 +17,7 @@ class SQLite3ExplainTest < ActiveRecord::SQLite3TestCase
     explain = Developer.where(id: 1).includes(:audit_logs).explain
     assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\? \[\["id", 1\]\]|1)), explain
     assert_match(/(SEARCH )?TABLE developers USING (INTEGER )?PRIMARY KEY/, explain)
-    assert_match %(EXPLAIN for: SELECT "audit_logs".* FROM "audit_logs" WHERE "audit_logs"."developer_id" = 1), explain
+    assert_match %r(EXPLAIN for: SELECT "audit_logs"\.\* FROM "audit_logs" WHERE "audit_logs"\."developer_id" = (?:\? \[\["developer_id", 1\]\]|1)), explain
     assert_match(/(SCAN )?TABLE audit_logs/, explain)
   end
 end
diff --git a/activerecord/test/cases/adapters/sqlite3/quoting_test.rb b/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
index aefbb309e6..de422fad23 100644
--- a/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "bigdecimal"
 require "securerandom"
@@ -5,6 +7,11 @@ require "securerandom"
 class SQLite3QuotingTest < ActiveRecord::SQLite3TestCase
   def setup
     @conn = ActiveRecord::Base.connection
+    @initial_represent_boolean_as_integer = ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer
+  end
+
+  def teardown
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = @initial_represent_boolean_as_integer
   end
 
   def test_type_cast_binary_encoding_without_logger
@@ -15,11 +22,19 @@ class SQLite3QuotingTest < ActiveRecord::SQLite3TestCase
   end
 
   def test_type_cast_true
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = false
     assert_equal "t", @conn.type_cast(true)
+
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = true
+    assert_equal 1, @conn.type_cast(true)
   end
 
   def test_type_cast_false
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = false
     assert_equal "f", @conn.type_cast(false)
+
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = true
+    assert_equal 0, @conn.type_cast(false)
   end
 
   def test_type_cast_bigdecimal
diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
index cf0c37f70c..2b51a32db6 100644
--- a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/owner"
 require "tempfile"
@@ -66,11 +68,11 @@ module ActiveRecord
 
       def test_exec_insert
         with_example_table do
-          binds = [bind_attribute("number", 10)]
-          @conn.exec_insert("insert into ex (number) VALUES (?)", "SQL", binds)
+          vals = [Relation::QueryAttribute.new("number", 10, Type::Value.new)]
+          @conn.exec_insert("insert into ex (number) VALUES (?)", "SQL", vals)
 
           result = @conn.exec_query(
-            "select number from ex where number = ?", "SQL", binds)
+            "select number from ex where number = ?", "SQL", vals)
 
           assert_equal 1, result.rows.length
           assert_equal 10, result.rows.first.first
@@ -134,7 +136,7 @@ module ActiveRecord
         with_example_table "id int, data string" do
           @conn.exec_query('INSERT INTO ex (id, data) VALUES (1, "foo")')
           result = @conn.exec_query(
-            "SELECT id, data FROM ex WHERE id = ?", nil, [bind_attribute("id", 1)])
+            "SELECT id, data FROM ex WHERE id = ?", nil, [Relation::QueryAttribute.new(nil, 1, Type::Value.new)])
 
           assert_equal 1, result.rows.length
           assert_equal 2, result.columns.length
@@ -148,7 +150,7 @@ module ActiveRecord
           @conn.exec_query('INSERT INTO ex (id, data) VALUES (1, "foo")')
 
           result = @conn.exec_query(
-            "SELECT id, data FROM ex WHERE id = ?", nil, [bind_attribute("id", "1-fuu", Type::Integer.new)])
+            "SELECT id, data FROM ex WHERE id = ?", nil, [Relation::QueryAttribute.new("id", "1-fuu", Type::Integer.new)])
 
           assert_equal 1, result.rows.length
           assert_equal 2, result.columns.length
diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
index b1b4463bf1..d70486605f 100644
--- a/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/owner"
 
diff --git a/activerecord/test/cases/adapters/sqlite3/statement_pool_test.rb b/activerecord/test/cases/adapters/sqlite3/statement_pool_test.rb
index 37ff973397..42b3841d41 100644
--- a/activerecord/test/cases/adapters/sqlite3/statement_pool_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/statement_pool_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class SQLite3StatementPoolTest < ActiveRecord::SQLite3TestCase
diff --git a/activerecord/test/cases/aggregations_test.rb b/activerecord/test/cases/aggregations_test.rb
index f8136fde72..7f654ec6f6 100644
--- a/activerecord/test/cases/aggregations_test.rb
+++ b/activerecord/test/cases/aggregations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/customer"
 
diff --git a/activerecord/test/cases/ar_schema_test.rb b/activerecord/test/cases/ar_schema_test.rb
index 5b608d8e83..83974f327e 100644
--- a/activerecord/test/cases/ar_schema_test.rb
+++ b/activerecord/test/cases/ar_schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class ActiveRecordSchemaTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/associations/association_scope_test.rb b/activerecord/test/cases/associations/association_scope_test.rb
deleted file mode 100644
index c54542ff7b..0000000000
--- a/activerecord/test/cases/associations/association_scope_test.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-require "cases/helper"
-require "models/post"
-require "models/author"
-
-module ActiveRecord
-  module Associations
-    class AssociationScopeTest < ActiveRecord::TestCase
-      test "does not duplicate conditions" do
-        scope = AssociationScope.scope(Author.new.association(:welcome_posts))
-        binds = scope.where_clause.binds.map(&:value)
-        assert_equal binds.uniq, binds
-      end
-    end
-  end
-end
diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 61389e29cf..0f7a249bf3 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/project"
@@ -649,8 +651,7 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
 
   def test_new_record_with_foreign_key_but_no_object
     client = Client.new("firm_id" => 1)
-    # sometimes tests on Oracle fail if ORDER BY is not provided therefore add always :order with :first
-    assert_equal Firm.all.merge!(order: "id").first, client.firm_with_basic_id
+    assert_equal Firm.first, client.firm_with_basic_id
   end
 
   def test_setting_foreign_key_after_nil_target_loaded
@@ -1170,6 +1171,17 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     Column.create! record: record
     assert_equal 1, Column.count
   end
+
+  def test_multiple_counter_cache_with_after_create_update
+    post = posts(:welcome)
+    parent = comments(:greetings)
+
+    assert_difference "parent.reload.children_count", +1 do
+      assert_difference "post.reload.comments_count", +1 do
+        CommentWithAfterCreateUpdate.create(body: "foo", post: post, parent: parent)
+      end
+    end
+  end
 end
 
 class BelongsToWithForeignKeyTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/associations/bidirectional_destroy_dependencies_test.rb b/activerecord/test/cases/associations/bidirectional_destroy_dependencies_test.rb
index 8a0e041864..88221b012e 100644
--- a/activerecord/test/cases/associations/bidirectional_destroy_dependencies_test.rb
+++ b/activerecord/test/cases/associations/bidirectional_destroy_dependencies_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/content"
 
diff --git a/activerecord/test/cases/associations/callbacks_test.rb b/activerecord/test/cases/associations/callbacks_test.rb
index f9d1e44595..e096cd4a0b 100644
--- a/activerecord/test/cases/associations/callbacks_test.rb
+++ b/activerecord/test/cases/associations/callbacks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/author"
diff --git a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
index 7b0445025c..e69cfe5e52 100644
--- a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
+++ b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
diff --git a/activerecord/test/cases/associations/eager_load_includes_full_sti_class_test.rb b/activerecord/test/cases/associations/eager_load_includes_full_sti_class_test.rb
index 61f39b4136..8754889143 100644
--- a/activerecord/test/cases/associations/eager_load_includes_full_sti_class_test.rb
+++ b/activerecord/test/cases/associations/eager_load_includes_full_sti_class_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/tagging"
diff --git a/activerecord/test/cases/associations/eager_load_nested_include_test.rb b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
index e9f551b6b2..c5b2b77bd4 100644
--- a/activerecord/test/cases/associations/eager_load_nested_include_test.rb
+++ b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/tag"
diff --git a/activerecord/test/cases/associations/eager_singularization_test.rb b/activerecord/test/cases/associations/eager_singularization_test.rb
index 16eff15026..420a5a805b 100644
--- a/activerecord/test/cases/associations/eager_singularization_test.rb
+++ b/activerecord/test/cases/associations/eager_singularization_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class EagerSingularizationTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index c0bab19e82..1f5f9eddb5 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/tagging"
diff --git a/activerecord/test/cases/associations/extension_test.rb b/activerecord/test/cases/associations/extension_test.rb
index f707a170f5..5eacb5a3d8 100644
--- a/activerecord/test/cases/associations/extension_test.rb
+++ b/activerecord/test/cases/associations/extension_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
index f73005b3cb..979dd986de 100644
--- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index eeba8fa74f..cedb621b4f 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
@@ -500,21 +502,20 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_predicate person.references, :exists?
   end
 
-  # sometimes tests on Oracle fail if ORDER BY is not provided therefore add always :order with :first
   def test_counting_with_counter_sql
-    assert_equal 3, Firm.all.merge!(order: "id").first.clients.count
+    assert_equal 3, Firm.first.clients.count
   end
 
   def test_counting
-    assert_equal 3, Firm.all.merge!(order: "id").first.plain_clients.count
+    assert_equal 3, Firm.first.plain_clients.count
   end
 
   def test_counting_with_single_hash
-    assert_equal 1, Firm.all.merge!(order: "id").first.plain_clients.where(name: "Microsoft").count
+    assert_equal 1, Firm.first.plain_clients.where(name: "Microsoft").count
   end
 
   def test_counting_with_column_name_and_hash
-    assert_equal 3, Firm.all.merge!(order: "id").first.plain_clients.count(:name)
+    assert_equal 3, Firm.first.plain_clients.count(:name)
   end
 
   def test_counting_with_association_limit
@@ -524,7 +525,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_finding
-    assert_equal 3, Firm.all.merge!(order: "id").first.clients.length
+    assert_equal 3, Firm.first.clients.length
   end
 
   def test_finding_array_compatibility
@@ -596,27 +597,27 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_finding_default_orders
-    assert_equal "Summit", Firm.all.merge!(order: "id").first.clients.first.name
+    assert_equal "Summit", Firm.first.clients.first.name
   end
 
   def test_finding_with_different_class_name_and_order
-    assert_equal "Apex", Firm.all.merge!(order: "id").first.clients_sorted_desc.first.name
+    assert_equal "Apex", Firm.first.clients_sorted_desc.first.name
   end
 
   def test_finding_with_foreign_key
-    assert_equal "Microsoft", Firm.all.merge!(order: "id").first.clients_of_firm.first.name
+    assert_equal "Microsoft", Firm.first.clients_of_firm.first.name
   end
 
   def test_finding_with_condition
-    assert_equal "Microsoft", Firm.all.merge!(order: "id").first.clients_like_ms.first.name
+    assert_equal "Microsoft", Firm.first.clients_like_ms.first.name
   end
 
   def test_finding_with_condition_hash
-    assert_equal "Microsoft", Firm.all.merge!(order: "id").first.clients_like_ms_with_hash_conditions.first.name
+    assert_equal "Microsoft", Firm.first.clients_like_ms_with_hash_conditions.first.name
   end
 
   def test_finding_using_primary_key
-    assert_equal "Summit", Firm.all.merge!(order: "id").first.clients_using_primary_key.first.name
+    assert_equal "Summit", Firm.first.clients_using_primary_key.first.name
   end
 
   def test_update_all_on_association_accessed_before_save
@@ -639,7 +640,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_ids
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
 
     assert_raise(ActiveRecord::RecordNotFound) { firm.clients.find }
 
@@ -659,7 +660,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_one_message_on_primary_key
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
 
     e = assert_raises(ActiveRecord::RecordNotFound) do
       firm.clients.find(0)
@@ -685,7 +686,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_all
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     assert_equal 3, firm.clients.where("#{QUOTED_TYPE} = 'Client'").to_a.length
     assert_equal 1, firm.clients.where("name = 'Summit'").to_a.length
   end
@@ -730,29 +731,28 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_all_sanitized
-    # sometimes tests on Oracle fail if ORDER BY is not provided therefore add always :order with :first
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     summit = firm.clients.where("name = 'Summit'").to_a
     assert_equal summit, firm.clients.where("name = ?", "Summit").to_a
     assert_equal summit, firm.clients.where("name = :name", name: "Summit").to_a
   end
 
   def test_find_first
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     client2 = Client.find(2)
     assert_equal firm.clients.first, firm.clients.order("id").first
     assert_equal client2, firm.clients.where("#{QUOTED_TYPE} = 'Client'").order("id").first
   end
 
   def test_find_first_sanitized
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     client2 = Client.find(2)
-    assert_equal client2, firm.clients.merge!(where: ["#{QUOTED_TYPE} = ?", "Client"], order: "id").first
-    assert_equal client2, firm.clients.merge!(where: ["#{QUOTED_TYPE} = :type", { type: "Client" }], order: "id").first
+    assert_equal client2, firm.clients.where("#{QUOTED_TYPE} = ?", "Client").first
+    assert_equal client2, firm.clients.where("#{QUOTED_TYPE} = :type", type: "Client").first
   end
 
   def test_find_first_after_reset_scope
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     collection = firm.clients
 
     original_object = collection.first
@@ -763,7 +763,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_first_after_reset
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     collection = firm.clients
 
     original_object = collection.first
@@ -775,7 +775,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_first_after_reload
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     collection = firm.clients
 
     original_object = collection.first
@@ -878,7 +878,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
 
   def test_create_with_bang_on_has_many_raises_when_record_not_saved
     assert_raise(ActiveRecord::RecordInvalid) do
-      firm = Firm.all.merge!(order: "id").first
+      firm = Firm.first
       firm.plain_clients.create!
     end
   end
@@ -1560,8 +1560,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_destroy_dependent_when_deleted_from_association
-    # sometimes tests on Oracle fail if ORDER BY is not provided therefore add always :order with :first
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     assert_equal 3, firm.clients.size
 
     client = firm.clients.first
@@ -1671,7 +1670,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_replace_with_less
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     firm.clients = [companies(:first_client)]
     assert firm.save, "Could not save firm"
     firm.reload
@@ -1685,7 +1684,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_replace_with_new
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     firm.clients = [companies(:second_client), Client.new("name" => "New Client")]
     firm.save
     firm.reload
@@ -2083,7 +2082,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_creating_using_primary_key
-    firm = Firm.all.merge!(order: "id").first
+    firm = Firm.first
     client = firm.clients_using_primary_key.create!(name: "test")
     assert_equal firm.name, client.firm_name
   end
diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index 1c2138a3d0..5797ffef38 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/person"
@@ -946,6 +948,13 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_has_many_through_polymorphic_with_rewhere
+    post = TaggedPost.create!(title: "Tagged", body: "Post")
+    tag = post.tags.create!(name: "Tag")
+    assert_equal [tag], TaggedPost.preload(:tags).last.tags
+    assert_equal [tag], TaggedPost.eager_load(:tags).last.tags
+  end
+
   def test_has_many_through_polymorphic_with_primary_key_option
     assert_equal [categories(:general)], authors(:david).essay_categories
 
diff --git a/activerecord/test/cases/associations/has_one_associations_test.rb b/activerecord/test/cases/associations/has_one_associations_test.rb
index bf3b8dcd63..2eb6cef1d9 100644
--- a/activerecord/test/cases/associations/has_one_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
@@ -688,4 +690,38 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
       SpecialAuthor.joins(book: :subscription).where.not(where_clause)
     end
   end
+
+  class DestroyByParentBook < ActiveRecord::Base
+    self.table_name = "books"
+    belongs_to :author, class_name: "DestroyByParentAuthor"
+    before_destroy :dont, unless: :destroyed_by_association
+
+    def dont
+      throw(:abort)
+    end
+  end
+
+  class DestroyByParentAuthor < ActiveRecord::Base
+    self.table_name = "authors"
+    has_one :book, class_name: "DestroyByParentBook", foreign_key: "author_id", dependent: :destroy
+  end
+
+  test "destroyed_by_association set in child destroy callback on parent destroy" do
+    author = DestroyByParentAuthor.create!(name: "Test")
+    book = DestroyByParentBook.create!(author: author)
+
+    author.destroy
+
+    assert_not DestroyByParentBook.exists?(book.id)
+  end
+
+  test "destroyed_by_association set in child destroy callback on replace" do
+    author = DestroyByParentAuthor.create!(name: "Test")
+    book = DestroyByParentBook.create!(author: author)
+
+    author.book = DestroyByParentBook.create!
+    author.save!
+
+    assert_not DestroyByParentBook.exists?(book.id)
+  end
 end
diff --git a/activerecord/test/cases/associations/has_one_through_associations_test.rb b/activerecord/test/cases/associations/has_one_through_associations_test.rb
index 28b883586d..fe24c465b2 100644
--- a/activerecord/test/cases/associations/has_one_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_through_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/club"
 require "models/member_type"
diff --git a/activerecord/test/cases/associations/inner_join_association_test.rb b/activerecord/test/cases/associations/inner_join_association_test.rb
index ddf5bc6f0b..23be344419 100644
--- a/activerecord/test/cases/associations/inner_join_association_test.rb
+++ b/activerecord/test/cases/associations/inner_join_association_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index 9fbaa43274..536077fb92 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/man"
 require "models/face"
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index c078cef064..2f68bc5141 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/tag"
 require "models/tagging"
diff --git a/activerecord/test/cases/associations/left_outer_join_association_test.rb b/activerecord/test/cases/associations/left_outer_join_association_test.rb
index 6d3757f467..c95d0425cd 100644
--- a/activerecord/test/cases/associations/left_outer_join_association_test.rb
+++ b/activerecord/test/cases/associations/left_outer_join_association_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
diff --git a/activerecord/test/cases/associations/nested_through_associations_test.rb b/activerecord/test/cases/associations/nested_through_associations_test.rb
index 67ff7355b3..3e37e512ca 100644
--- a/activerecord/test/cases/associations/nested_through_associations_test.rb
+++ b/activerecord/test/cases/associations/nested_through_associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/post"
diff --git a/activerecord/test/cases/associations/required_test.rb b/activerecord/test/cases/associations/required_test.rb
index 45e1803858..65a3bb5efe 100644
--- a/activerecord/test/cases/associations/required_test.rb
+++ b/activerecord/test/cases/associations/required_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class RequiredAssociationsTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/associations_test.rb b/activerecord/test/cases/associations_test.rb
index 2eb31326a5..9d1999bcb1 100644
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/computer"
 require "models/developer"
diff --git a/activerecord/test/cases/attribute_decorators_test.rb b/activerecord/test/cases/attribute_decorators_test.rb
index cfa6ed1da6..42eca233ce 100644
--- a/activerecord/test/cases/attribute_decorators_test.rb
+++ b/activerecord/test/cases/attribute_decorators_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/attribute_methods/read_test.rb b/activerecord/test/cases/attribute_methods/read_test.rb
index 1fc63a49d4..0170a6e98d 100644
--- a/activerecord/test/cases/attribute_methods/read_test.rb
+++ b/activerecord/test/cases/attribute_methods/read_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
@@ -8,11 +10,10 @@ module ActiveRecord
       end
 
       def setup
-        @klass = Class.new do
+        @klass = Class.new(Class.new { def self.initialize_generated_modules; end }) do
           def self.superclass; Base; end
           def self.base_class; self; end
           def self.decorate_matching_attribute_types(*); end
-          def self.initialize_generated_modules; end
 
           include ActiveRecord::DefineCallbacks
           include ActiveRecord::AttributeMethods
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index 4d24a980dc..0ea8ef5cea 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/minimalistic"
 require "models/developer"
@@ -1005,7 +1007,7 @@ class AttributeMethodsTest < ActiveRecord::TestCase
         class_eval(&block)
       end
 
-      assert_empty klass.generated_attribute_methods.instance_methods(false)
+      assert_empty klass.send(:generated_attribute_methods).instance_methods(false)
       klass
     end
 
diff --git a/activerecord/test/cases/attribute_set_test.rb b/activerecord/test/cases/attribute_set_test.rb
index bd4b200735..006372a757 100644
--- a/activerecord/test/cases/attribute_set_test.rb
+++ b/activerecord/test/cases/attribute_set_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/attribute_test.rb b/activerecord/test/cases/attribute_test.rb
index e856d551c0..1731e7926e 100644
--- a/activerecord/test/cases/attribute_test.rb
+++ b/activerecord/test/cases/attribute_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/attributes_test.rb b/activerecord/test/cases/attributes_test.rb
index 3705a6be89..29a25b4461 100644
--- a/activerecord/test/cases/attributes_test.rb
+++ b/activerecord/test/cases/attributes_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class OverloadedType < ActiveRecord::Base
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index f72a9520e0..ae492f1c1c 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/bird"
 require "models/post"
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index dc32e995a4..1d33564989 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/author"
@@ -1052,29 +1054,15 @@ class BasicsTest < ActiveRecord::TestCase
 
   def test_count_with_join
     res = Post.count_by_sql "SELECT COUNT(*) FROM posts LEFT JOIN comments ON posts.id=comments.post_id WHERE posts.#{QUOTED_TYPE} = 'Post'"
-
     res2 = Post.where("posts.#{QUOTED_TYPE} = 'Post'").joins("LEFT JOIN comments ON posts.id=comments.post_id").count
     assert_equal res, res2
 
-    res3 = nil
-    assert_nothing_raised do
-      res3 = Post.where("posts.#{QUOTED_TYPE} = 'Post'").joins("LEFT JOIN comments ON posts.id=comments.post_id").count
-    end
-    assert_equal res, res3
-
     res4 = Post.count_by_sql "SELECT COUNT(p.id) FROM posts p, comments co WHERE p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id"
-    res5 = nil
-    assert_nothing_raised do
-      res5 = Post.where("p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id").joins("p, comments co").select("p.id").count
-    end
-
+    res5 = Post.where("p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id").joins("p, comments co").select("p.id").count
     assert_equal res4, res5
 
     res6 = Post.count_by_sql "SELECT COUNT(DISTINCT p.id) FROM posts p, comments co WHERE p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id"
-    res7 = nil
-    assert_nothing_raised do
-      res7 = Post.where("p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id").joins("p, comments co").select("p.id").distinct.count
-    end
+    res7 = Post.where("p.#{QUOTED_TYPE} = 'Post' AND p.id=co.post_id").joins("p, comments co").select("p.id").distinct.count
     assert_equal res6, res7
   end
 
diff --git a/activerecord/test/cases/batches_test.rb b/activerecord/test/cases/batches_test.rb
index dcd3af487b..53c1e61ad1 100644
--- a/activerecord/test/cases/batches_test.rb
+++ b/activerecord/test/cases/batches_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/comment"
 require "models/post"
diff --git a/activerecord/test/cases/binary_test.rb b/activerecord/test/cases/binary_test.rb
index f6ac7990d1..d5376ece69 100644
--- a/activerecord/test/cases/binary_test.rb
+++ b/activerecord/test/cases/binary_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 # Without using prepared statements, it makes no sense to test
diff --git a/activerecord/test/cases/bind_parameter_test.rb b/activerecord/test/cases/bind_parameter_test.rb
index 5af44c27eb..91cc49385c 100644
--- a/activerecord/test/cases/bind_parameter_test.rb
+++ b/activerecord/test/cases/bind_parameter_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/author"
@@ -39,8 +41,9 @@ if ActiveRecord::Base.connection.prepared_statements
       end
 
       def test_binds_are_logged
-        binds = [bind_attribute("id", 1)]
-        sql   = "select * from topics where id = #{bind_param.to_sql}"
+        sub   = Arel::Nodes::BindParam.new(1)
+        binds = [Relation::QueryAttribute.new("id", 1, Type::Value.new)]
+        sql   = "select * from topics where id = #{sub.to_sql}"
 
         @connection.exec_query(sql, "SQL", binds)
 
@@ -55,7 +58,7 @@ if ActiveRecord::Base.connection.prepared_statements
       end
 
       def test_logs_binds_after_type_cast
-        binds = [bind_attribute("id", "10", Type::Integer.new)]
+        binds = [Relation::QueryAttribute.new("id", "10", Type::Integer.new)]
         assert_logs_binds(binds)
       end
 
diff --git a/activerecord/test/cases/cache_key_test.rb b/activerecord/test/cases/cache_key_test.rb
index 7b8264e6e8..8f2f2c6186 100644
--- a/activerecord/test/cases/cache_key_test.rb
+++ b/activerecord/test/cases/cache_key_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 9f44b583f6..39dff19b78 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/book"
 require "models/club"
@@ -234,6 +236,30 @@ class CalculationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_distinct_count_with_order_and_limit
+    assert_equal 4, Account.distinct.order(:firm_id).limit(4).count
+  end
+
+  def test_distinct_count_with_order_and_offset
+    assert_equal 4, Account.distinct.order(:firm_id).offset(2).count
+  end
+
+  def test_distinct_count_with_order_and_limit_and_offset
+    assert_equal 4, Account.distinct.order(:firm_id).limit(4).offset(2).count
+  end
+
+  def test_distinct_joins_count_with_order_and_limit
+    assert_equal 3, Account.joins(:firm).distinct.order(:firm_id).limit(3).count
+  end
+
+  def test_distinct_joins_count_with_order_and_offset
+    assert_equal 3, Account.joins(:firm).distinct.order(:firm_id).offset(2).count
+  end
+
+  def test_distinct_joins_count_with_order_and_limit_and_offset
+    assert_equal 3, Account.joins(:firm).distinct.order(:firm_id).limit(3).offset(2).count
+  end
+
   def test_should_group_by_summed_field_having_condition
     c = Account.group(:firm_id).having("sum(credit_limit) > 50").sum(:credit_limit)
     assert_nil        c[1]
diff --git a/activerecord/test/cases/callbacks_test.rb b/activerecord/test/cases/callbacks_test.rb
index b3c86586d0..55c7475f46 100644
--- a/activerecord/test/cases/callbacks_test.rb
+++ b/activerecord/test/cases/callbacks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/developer"
 require "models/computer"
diff --git a/activerecord/test/cases/clone_test.rb b/activerecord/test/cases/clone_test.rb
index b89294c094..3187e6aed5 100644
--- a/activerecord/test/cases/clone_test.rb
+++ b/activerecord/test/cases/clone_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/coders/json_test.rb b/activerecord/test/cases/coders/json_test.rb
index d22d93d129..e40d576b39 100644
--- a/activerecord/test/cases/coders/json_test.rb
+++ b/activerecord/test/cases/coders/json_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/coders/yaml_column_test.rb b/activerecord/test/cases/coders/yaml_column_test.rb
index a26a72712d..4a5559c62f 100644
--- a/activerecord/test/cases/coders/yaml_column_test.rb
+++ b/activerecord/test/cases/coders/yaml_column_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/collection_cache_key_test.rb b/activerecord/test/cases/collection_cache_key_test.rb
index f344c77691..dbe6857487 100644
--- a/activerecord/test/cases/collection_cache_key_test.rb
+++ b/activerecord/test/cases/collection_cache_key_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/computer"
 require "models/developer"
diff --git a/activerecord/test/cases/column_alias_test.rb b/activerecord/test/cases/column_alias_test.rb
index 9893ba9580..a883d21fb8 100644
--- a/activerecord/test/cases/column_alias_test.rb
+++ b/activerecord/test/cases/column_alias_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/column_definition_test.rb b/activerecord/test/cases/column_definition_test.rb
index 90c8d21c43..cbd2b44589 100644
--- a/activerecord/test/cases/column_definition_test.rb
+++ b/activerecord/test/cases/column_definition_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/comment_test.rb b/activerecord/test/cases/comment_test.rb
index c23be52a6c..f2ec5d6518 100644
--- a/activerecord/test/cases/comment_test.rb
+++ b/activerecord/test/cases/comment_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
@@ -113,8 +115,10 @@ if ActiveRecord::Base.connection.supports_comments?
       assert_match %r[t\.string\s+"name",\s+comment: "Comment should help clarify the column purpose"], output
       assert_match %r[t\.string\s+"obvious"\n], output
       assert_match %r[t\.string\s+"content",\s+comment: "Whoa, content describes itself!"], output
-      assert_match %r[t\.integer\s+"rating",\s+comment: "I am running out of imagination"], output
-      unless current_adapter?(:OracleAdapter)
+      if current_adapter?(:OracleAdapter)
+        assert_match %r[t\.integer\s+"rating",\s+precision: 38,\s+comment: "I am running out of imagination"], output
+      else
+        assert_match %r[t\.integer\s+"rating",\s+comment: "I am running out of imagination"], output
         assert_match %r[t\.index\s+.+\s+comment: "\\\"Very important\\\" index that powers all the performance.\\nAnd it's fun!"], output
         assert_match %r[t\.index\s+.+\s+name: "idx_obvious",\s+comment: "We need to see obvious comments"], output
       end
diff --git a/activerecord/test/cases/connection_adapters/adapter_leasing_test.rb b/activerecord/test/cases/connection_adapters/adapter_leasing_test.rb
index 64189381cb..82c6cf8dea 100644
--- a/activerecord/test/cases/connection_adapters/adapter_leasing_test.rb
+++ b/activerecord/test/cases/connection_adapters/adapter_leasing_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/connection_adapters/connection_handler_test.rb b/activerecord/test/cases/connection_adapters/connection_handler_test.rb
index 2a71f08d90..74d0ed348e 100644
--- a/activerecord/test/cases/connection_adapters/connection_handler_test.rb
+++ b/activerecord/test/cases/connection_adapters/connection_handler_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/connection_adapters/connection_specification_test.rb b/activerecord/test/cases/connection_adapters/connection_specification_test.rb
index 10a3521c79..f81b73c344 100644
--- a/activerecord/test/cases/connection_adapters/connection_specification_test.rb
+++ b/activerecord/test/cases/connection_adapters/connection_specification_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/connection_adapters/merge_and_resolve_default_url_config_test.rb b/activerecord/test/cases/connection_adapters/merge_and_resolve_default_url_config_test.rb
index 8faa67255d..1b64324cc4 100644
--- a/activerecord/test/cases/connection_adapters/merge_and_resolve_default_url_config_test.rb
+++ b/activerecord/test/cases/connection_adapters/merge_and_resolve_default_url_config_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb b/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
index 736eb3e3a0..02e76ce146 100644
--- a/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
+++ b/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
@@ -54,7 +56,7 @@ if current_adapter?(:Mysql2Adapter)
         private
 
           def assert_lookup_type(type, lookup)
-            cast_type = @connection.type_map.lookup(lookup)
+            cast_type = @connection.send(:type_map).lookup(lookup)
             assert_equal type, cast_type.type
           end
 
diff --git a/activerecord/test/cases/connection_adapters/schema_cache_test.rb b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
index 106323ccc9..006be9e65d 100644
--- a/activerecord/test/cases/connection_adapters/schema_cache_test.rb
+++ b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/connection_adapters/type_lookup_test.rb b/activerecord/test/cases/connection_adapters/type_lookup_test.rb
index a348c2d783..917a04ebc3 100644
--- a/activerecord/test/cases/connection_adapters/type_lookup_test.rb
+++ b/activerecord/test/cases/connection_adapters/type_lookup_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 unless current_adapter?(:PostgreSQLAdapter) # PostgreSQL does not use type strings for lookup
@@ -80,7 +82,7 @@ unless current_adapter?(:PostgreSQLAdapter) # PostgreSQL does not use type strin
         end
 
         def test_bigint_limit
-          cast_type = @connection.type_map.lookup("bigint")
+          cast_type = @connection.send(:type_map).lookup("bigint")
           if current_adapter?(:OracleAdapter)
             assert_equal 19, cast_type.limit
           else
@@ -98,7 +100,7 @@ unless current_adapter?(:PostgreSQLAdapter) # PostgreSQL does not use type strin
             { decimal: %w{decimal(2) decimal(2,0) numeric(2) numeric(2,0) number(2) number(2,0)} }
           end.each do |expected_type, types|
             types.each do |type|
-              cast_type = @connection.type_map.lookup(type)
+              cast_type = @connection.send(:type_map).lookup(type)
 
               assert_equal expected_type, cast_type.type
               assert_equal 2, cast_type.cast(2.1)
@@ -109,7 +111,7 @@ unless current_adapter?(:PostgreSQLAdapter) # PostgreSQL does not use type strin
         private
 
           def assert_lookup_type(type, lookup)
-            cast_type = @connection.type_map.lookup(lookup)
+            cast_type = @connection.send(:type_map).lookup(lookup)
             assert_equal type, cast_type.type
           end
       end
diff --git a/activerecord/test/cases/connection_management_test.rb b/activerecord/test/cases/connection_management_test.rb
index d1e946d401..9d6ecbde78 100644
--- a/activerecord/test/cases/connection_management_test.rb
+++ b/activerecord/test/cases/connection_management_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "rack"
 
diff --git a/activerecord/test/cases/connection_pool_test.rb b/activerecord/test/cases/connection_pool_test.rb
index 00a0187b57..2bfe490602 100644
--- a/activerecord/test/cases/connection_pool_test.rb
+++ b/activerecord/test/cases/connection_pool_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "concurrent/atomic/count_down_latch"
 
diff --git a/activerecord/test/cases/connection_specification/resolver_test.rb b/activerecord/test/cases/connection_specification/resolver_test.rb
index 13b5bae13c..3fa0ca8366 100644
--- a/activerecord/test/cases/connection_specification/resolver_test.rb
+++ b/activerecord/test/cases/connection_specification/resolver_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/core_test.rb b/activerecord/test/cases/core_test.rb
index 936f26ce04..356afdbd2b 100644
--- a/activerecord/test/cases/core_test.rb
+++ b/activerecord/test/cases/core_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/person"
 require "models/topic"
diff --git a/activerecord/test/cases/counter_cache_test.rb b/activerecord/test/cases/counter_cache_test.rb
index 46d7526cc0..e0948f90ac 100644
--- a/activerecord/test/cases/counter_cache_test.rb
+++ b/activerecord/test/cases/counter_cache_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/car"
diff --git a/activerecord/test/cases/custom_locking_test.rb b/activerecord/test/cases/custom_locking_test.rb
index 15c8b684e4..f52b26e9ec 100644
--- a/activerecord/test/cases/custom_locking_test.rb
+++ b/activerecord/test/cases/custom_locking_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/person"
 
diff --git a/activerecord/test/cases/database_statements_test.rb b/activerecord/test/cases/database_statements_test.rb
index 66035865be..1c934602ec 100644
--- a/activerecord/test/cases/database_statements_test.rb
+++ b/activerecord/test/cases/database_statements_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class DatabaseStatementsTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/date_test.rb b/activerecord/test/cases/date_test.rb
index 2edc0415cd..9f412cdb63 100644
--- a/activerecord/test/cases/date_test.rb
+++ b/activerecord/test/cases/date_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/date_time_precision_test.rb b/activerecord/test/cases/date_time_precision_test.rb
index e4a2f9ee17..51f6164138 100644
--- a/activerecord/test/cases/date_time_precision_test.rb
+++ b/activerecord/test/cases/date_time_precision_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/date_time_test.rb b/activerecord/test/cases/date_time_test.rb
index 6cd98fe254..b5f35aff0e 100644
--- a/activerecord/test/cases/date_time_test.rb
+++ b/activerecord/test/cases/date_time_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/task"
diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index 996d298689..4690682cd8 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 require "models/default"
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index f72e0d2ead..fb3d691d51 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"    # For booleans
 require "models/pirate"   # For timestamps
@@ -299,11 +301,9 @@ class DirtyTest < ActiveRecord::TestCase
   end
 
   def test_virtual_attribute_will_change
-    assert_deprecated do
-      parrot = Parrot.create!(name: "Ruby")
-      parrot.send(:attribute_will_change!, :cancel_save_from_callback)
-      assert parrot.has_changes_to_save?
-    end
+    parrot = Parrot.create!(name: "Ruby")
+    parrot.send(:attribute_will_change!, :cancel_save_from_callback)
+    assert parrot.has_changes_to_save?
   end
 
   def test_association_assignment_changes_foreign_key
@@ -839,15 +839,14 @@ class DirtyTest < ActiveRecord::TestCase
     assert_equal %w(first_name lock_version updated_at).sort, person.saved_changes.keys.sort
   end
 
-  test "changed? in after callbacks returns true but is deprecated" do
+  test "changed? in after callbacks returns false" do
     klass = Class.new(ActiveRecord::Base) do
       self.table_name = "people"
 
       after_save do
-        ActiveSupport::Deprecation.silence do
-          raise "changed? should be true" unless changed?
-        end
+        raise "changed? should be false" if changed?
         raise "has_changes_to_save? should be false" if has_changes_to_save?
+        raise "saved_changes? should be true" unless saved_changes?
       end
     end
 
diff --git a/activerecord/test/cases/disconnected_test.rb b/activerecord/test/cases/disconnected_test.rb
index c25089a420..533665d0f4 100644
--- a/activerecord/test/cases/disconnected_test.rb
+++ b/activerecord/test/cases/disconnected_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class TestRecord < ActiveRecord::Base
diff --git a/activerecord/test/cases/dup_test.rb b/activerecord/test/cases/dup_test.rb
index 000ed27efb..2fefdbf204 100644
--- a/activerecord/test/cases/dup_test.rb
+++ b/activerecord/test/cases/dup_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/reply"
 require "models/topic"
diff --git a/activerecord/test/cases/enum_test.rb b/activerecord/test/cases/enum_test.rb
index 4ef9a125e6..abbc011b34 100644
--- a/activerecord/test/cases/enum_test.rb
+++ b/activerecord/test/cases/enum_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/book"
diff --git a/activerecord/test/cases/errors_test.rb b/activerecord/test/cases/errors_test.rb
index e90669e0c7..b90e6a66c5 100644
--- a/activerecord/test/cases/errors_test.rb
+++ b/activerecord/test/cases/errors_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class ErrorsTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/explain_subscriber_test.rb b/activerecord/test/cases/explain_subscriber_test.rb
index ca87e04012..fb698c47cd 100644
--- a/activerecord/test/cases/explain_subscriber_test.rb
+++ b/activerecord/test/cases/explain_subscriber_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/explain_subscriber"
 require "active_record/explain_registry"
diff --git a/activerecord/test/cases/explain_test.rb b/activerecord/test/cases/explain_test.rb
index 4f6bd9327c..17654027a9 100644
--- a/activerecord/test/cases/explain_test.rb
+++ b/activerecord/test/cases/explain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/car"
 require "active_support/core_ext/string/strip"
@@ -47,7 +49,7 @@ if ActiveRecord::Base.connection.supports_explain?
 
     def test_exec_explain_with_binds
       sqls    = %w(foo bar)
-      binds   = [[bind_attribute("wadus", 1)], [bind_attribute("chaflan", 2)]]
+      binds   = [[bind_param("wadus", 1)], [bind_param("chaflan", 2)]]
       queries = sqls.zip(binds)
 
       stub_explain_for_query_plans(["query plan foo\n", "query plan bar\n"]) do
@@ -79,5 +81,9 @@ if ActiveRecord::Base.connection.supports_explain?
           yield
         end
       end
+
+      def bind_param(name, value)
+        ActiveRecord::Relation::QueryAttribute.new(name, value, ActiveRecord::Type::Value.new)
+      end
   end
 end
diff --git a/activerecord/test/cases/finder_respond_to_test.rb b/activerecord/test/cases/finder_respond_to_test.rb
index 3eaa993d45..4039af66d0 100644
--- a/activerecord/test/cases/finder_respond_to_test.rb
+++ b/activerecord/test/cases/finder_respond_to_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index af21cd529f..0b4dce37cc 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/author"
diff --git a/activerecord/test/cases/fixture_set/file_test.rb b/activerecord/test/cases/fixture_set/file_test.rb
index 533edcc2e0..ff99988cb5 100644
--- a/activerecord/test/cases/fixture_set/file_test.rb
+++ b/activerecord/test/cases/fixture_set/file_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "tempfile"
 
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index f2fe724095..6b014bcb3d 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/admin"
 require "models/admin/account"
diff --git a/activerecord/test/cases/forbidden_attributes_protection_test.rb b/activerecord/test/cases/forbidden_attributes_protection_test.rb
index ffa3f63e0d..101fa118c8 100644
--- a/activerecord/test/cases/forbidden_attributes_protection_test.rb
+++ b/activerecord/test/cases/forbidden_attributes_protection_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_support/core_ext/hash/indifferent_access"
 
diff --git a/activerecord/test/cases/habtm_destroy_order_test.rb b/activerecord/test/cases/habtm_destroy_order_test.rb
index 365d4576dd..5e503272e1 100644
--- a/activerecord/test/cases/habtm_destroy_order_test.rb
+++ b/activerecord/test/cases/habtm_destroy_order_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/lesson"
 require "models/student"
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 8506a44d6a..6ea02ac191 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "config"
 
 require "stringio"
diff --git a/activerecord/test/cases/hot_compatibility_test.rb b/activerecord/test/cases/hot_compatibility_test.rb
index e107ff2362..e7778af55b 100644
--- a/activerecord/test/cases/hot_compatibility_test.rb
+++ b/activerecord/test/cases/hot_compatibility_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/connection_helper"
 
diff --git a/activerecord/test/cases/i18n_test.rb b/activerecord/test/cases/i18n_test.rb
index 7f03c5b23d..22981c142a 100644
--- a/activerecord/test/cases/i18n_test.rb
+++ b/activerecord/test/cases/i18n_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/inheritance_test.rb b/activerecord/test/cases/inheritance_test.rb
index fb5a7bcc31..a263106f6d 100644
--- a/activerecord/test/cases/inheritance_test.rb
+++ b/activerecord/test/cases/inheritance_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/company"
@@ -418,7 +420,8 @@ class InheritanceTest < ActiveRecord::TestCase
 
   def test_eager_load_belongs_to_primary_key_quoting
     con = Account.connection
-    assert_sql(/#{con.quote_table_name('companies')}\.#{con.quote_column_name('id')} = 1/) do
+    bind_param = Arel::Nodes::BindParam.new(nil)
+    assert_sql(/#{con.quote_table_name('companies')}\.#{con.quote_column_name('id')} = (?:#{Regexp.quote(bind_param.to_sql)}|1)/) do
       Account.all.merge!(includes: :firm).find(1)
     end
   end
diff --git a/activerecord/test/cases/integration_test.rb b/activerecord/test/cases/integration_test.rb
index 9104976126..36cd63c4d4 100644
--- a/activerecord/test/cases/integration_test.rb
+++ b/activerecord/test/cases/integration_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/company"
 require "models/developer"
diff --git a/activerecord/test/cases/invalid_connection_test.rb b/activerecord/test/cases/invalid_connection_test.rb
index 1367af2859..a1be9c2780 100644
--- a/activerecord/test/cases/invalid_connection_test.rb
+++ b/activerecord/test/cases/invalid_connection_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 if current_adapter?(:Mysql2Adapter)
diff --git a/activerecord/test/cases/invertible_migration_test.rb b/activerecord/test/cases/invertible_migration_test.rb
index cc3951e2ba..20e747142b 100644
--- a/activerecord/test/cases/invertible_migration_test.rb
+++ b/activerecord/test/cases/invertible_migration_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Horse < ActiveRecord::Base
diff --git a/activerecord/test/cases/json_attribute_test.rb b/activerecord/test/cases/json_attribute_test.rb
index e5848b45f8..63f3c77fc3 100644
--- a/activerecord/test/cases/json_attribute_test.rb
+++ b/activerecord/test/cases/json_attribute_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "cases/json_shared_test_cases"
 
diff --git a/activerecord/test/cases/json_serialization_test.rb b/activerecord/test/cases/json_serialization_test.rb
index 9b4b61b16e..52fe488cd5 100644
--- a/activerecord/test/cases/json_serialization_test.rb
+++ b/activerecord/test/cases/json_serialization_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/contact"
 require "models/post"
@@ -160,10 +162,8 @@ class JsonSerializationTest < ActiveRecord::TestCase
   end
 
   def test_serializable_hash_should_not_modify_options_in_argument
-    options = { only: :name }
-    @contact.serializable_hash(options)
-
-    assert_nil options[:except]
+    options = { only: :name }.freeze
+    assert_nothing_raised { @contact.serializable_hash(options) }
   end
 end
 
diff --git a/activerecord/test/cases/json_shared_test_cases.rb b/activerecord/test/cases/json_shared_test_cases.rb
index 9a1c1c3f3f..f708acf0aa 100644
--- a/activerecord/test/cases/json_shared_test_cases.rb
+++ b/activerecord/test/cases/json_shared_test_cases.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "support/schema_dumping_helper"
 
 module JSONSharedTestCases
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index 2fc52393f2..743680ba92 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "thread"
 require "cases/helper"
 require "models/person"
diff --git a/activerecord/test/cases/log_subscriber_test.rb b/activerecord/test/cases/log_subscriber_test.rb
index b80257962c..208e54ed0b 100644
--- a/activerecord/test/cases/log_subscriber_test.rb
+++ b/activerecord/test/cases/log_subscriber_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/binary"
 require "models/developer"
diff --git a/activerecord/test/cases/migration/change_schema_test.rb b/activerecord/test/cases/migration/change_schema_test.rb
index 1d305fa11f..7b0644e9c0 100644
--- a/activerecord/test/cases/migration/change_schema_test.rb
+++ b/activerecord/test/cases/migration/change_schema_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
@@ -271,6 +273,8 @@ module ActiveRecord
           assert_equal "timestamp without time zone", klass.columns_hash["foo"].sql_type
         elsif current_adapter?(:Mysql2Adapter)
           assert_equal "timestamp", klass.columns_hash["foo"].sql_type
+        elsif current_adapter?(:OracleAdapter)
+          assert_equal "TIMESTAMP(6)", klass.columns_hash["foo"].sql_type
         else
           assert_equal klass.connection.type_to_sql("datetime"), klass.columns_hash["foo"].sql_type
         end
diff --git a/activerecord/test/cases/migration/change_table_test.rb b/activerecord/test/cases/migration/change_table_test.rb
index ec817a579b..034bf32165 100644
--- a/activerecord/test/cases/migration/change_table_test.rb
+++ b/activerecord/test/cases/migration/change_table_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/migration/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/column_attributes_test.rb b/activerecord/test/cases/migration/column_attributes_test.rb
index 48df931543..9200d32caf 100644
--- a/activerecord/test/cases/migration/column_attributes_test.rb
+++ b/activerecord/test/cases/migration/column_attributes_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/migration/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/column_positioning_test.rb b/activerecord/test/cases/migration/column_positioning_test.rb
index f2162d91b1..23414419dc 100644
--- a/activerecord/test/cases/migration/column_positioning_test.rb
+++ b/activerecord/test/cases/migration/column_positioning_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/columns_test.rb b/activerecord/test/cases/migration/columns_test.rb
index 2329888345..1b1d0af132 100644
--- a/activerecord/test/cases/migration/columns_test.rb
+++ b/activerecord/test/cases/migration/columns_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/migration/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/command_recorder_test.rb b/activerecord/test/cases/migration/command_recorder_test.rb
index 007926f1b9..0b5e983f14 100644
--- a/activerecord/test/cases/migration/command_recorder_test.rb
+++ b/activerecord/test/cases/migration/command_recorder_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/compatibility_test.rb b/activerecord/test/cases/migration/compatibility_test.rb
index 596a21dcbc..cb3b02c02a 100644
--- a/activerecord/test/cases/migration/compatibility_test.rb
+++ b/activerecord/test/cases/migration/compatibility_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/migration/create_join_table_test.rb b/activerecord/test/cases/migration/create_join_table_test.rb
index c4896f3d6e..77d32a24a5 100644
--- a/activerecord/test/cases/migration/create_join_table_test.rb
+++ b/activerecord/test/cases/migration/create_join_table_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/foreign_key_test.rb b/activerecord/test/cases/migration/foreign_key_test.rb
index 7762d37915..499d072de5 100644
--- a/activerecord/test/cases/migration/foreign_key_test.rb
+++ b/activerecord/test/cases/migration/foreign_key_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/migration/helper.rb b/activerecord/test/cases/migration/helper.rb
index 9c0fa7339d..c056199140 100644
--- a/activerecord/test/cases/migration/helper.rb
+++ b/activerecord/test/cases/migration/helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/index_test.rb b/activerecord/test/cases/migration/index_test.rb
index f10fcf1398..bf1ebdb4c5 100644
--- a/activerecord/test/cases/migration/index_test.rb
+++ b/activerecord/test/cases/migration/index_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/logger_test.rb b/activerecord/test/cases/migration/logger_test.rb
index 3d7c7ad469..28f4cc124b 100644
--- a/activerecord/test/cases/migration/logger_test.rb
+++ b/activerecord/test/cases/migration/logger_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/pending_migrations_test.rb b/activerecord/test/cases/migration/pending_migrations_test.rb
index 6970fdcc87..d0066f68be 100644
--- a/activerecord/test/cases/migration/pending_migrations_test.rb
+++ b/activerecord/test/cases/migration/pending_migrations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/references_foreign_key_test.rb b/activerecord/test/cases/migration/references_foreign_key_test.rb
index 718b9a0613..7a092103c7 100644
--- a/activerecord/test/cases/migration/references_foreign_key_test.rb
+++ b/activerecord/test/cases/migration/references_foreign_key_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 if ActiveRecord::Base.connection.supports_foreign_keys_in_create?
diff --git a/activerecord/test/cases/migration/references_index_test.rb b/activerecord/test/cases/migration/references_index_test.rb
index 2866cabab6..e41377d817 100644
--- a/activerecord/test/cases/migration/references_index_test.rb
+++ b/activerecord/test/cases/migration/references_index_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/references_statements_test.rb b/activerecord/test/cases/migration/references_statements_test.rb
index e9eb9968cb..769241ba12 100644
--- a/activerecord/test/cases/migration/references_statements_test.rb
+++ b/activerecord/test/cases/migration/references_statements_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/migration/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration/rename_table_test.rb b/activerecord/test/cases/migration/rename_table_test.rb
index 5da3ad33a3..dfce266253 100644
--- a/activerecord/test/cases/migration/rename_table_test.rb
+++ b/activerecord/test/cases/migration/rename_table_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/migration/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index eff6e09eb7..0fa43583ac 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "cases/migration/helper"
 require "bigdecimal/util"
@@ -912,7 +914,7 @@ class CopyMigrationsTest < ActiveRecord::TestCase
     assert_equal [@migrations_path + "/4_people_have_hobbies.bukkits.rb", @migrations_path + "/5_people_have_descriptions.bukkits.rb"], copied.map(&:filename)
 
     expected = "# This migration comes from bukkits (originally 1)"
-    assert_equal expected, IO.readlines(@migrations_path + "/4_people_have_hobbies.bukkits.rb")[0].chomp
+    assert_equal expected, IO.readlines(@migrations_path + "/4_people_have_hobbies.bukkits.rb")[1].chomp
 
     files_count = Dir[@migrations_path + "/*.rb"].length
     copied = ActiveRecord::Migration.copy(@migrations_path, bukkits: MIGRATIONS_ROOT + "/to_copy")
diff --git a/activerecord/test/cases/migrator_test.rb b/activerecord/test/cases/migrator_test.rb
index 2e4b454a86..ee10be119c 100644
--- a/activerecord/test/cases/migrator_test.rb
+++ b/activerecord/test/cases/migrator_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "cases/migration/helper"
 
diff --git a/activerecord/test/cases/mixin_test.rb b/activerecord/test/cases/mixin_test.rb
index a8af8e30f7..fdb8ac6ab3 100644
--- a/activerecord/test/cases/mixin_test.rb
+++ b/activerecord/test/cases/mixin_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class Mixin < ActiveRecord::Base
@@ -10,10 +12,6 @@ class TouchTest < ActiveRecord::TestCase
     travel_to Time.now
   end
 
-  teardown do
-    travel_back
-  end
-
   def test_update
     stamped = Mixin.new
 
diff --git a/activerecord/test/cases/modules_test.rb b/activerecord/test/cases/modules_test.rb
index f8a7bab35f..060d555607 100644
--- a/activerecord/test/cases/modules_test.rb
+++ b/activerecord/test/cases/modules_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/company_in_module"
 require "models/shop"
diff --git a/activerecord/test/cases/multiparameter_attributes_test.rb b/activerecord/test/cases/multiparameter_attributes_test.rb
index ceb5724377..59be4dc5a8 100644
--- a/activerecord/test/cases/multiparameter_attributes_test.rb
+++ b/activerecord/test/cases/multiparameter_attributes_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/customer"
@@ -271,6 +273,12 @@ class MultiParameterAttributeTest < ActiveRecord::TestCase
     ensure
       Topic.reset_column_information
     end
+
+    def test_multiparameter_attributes_setting_time_attribute
+      topic = Topic.new("bonus_time(4i)" => "01", "bonus_time(5i)" => "05")
+      assert_equal 1, topic.bonus_time.hour
+      assert_equal 5, topic.bonus_time.min
+    end
   end
 
   def test_multiparameter_attributes_on_time_with_empty_seconds
@@ -285,14 +293,6 @@ class MultiParameterAttributeTest < ActiveRecord::TestCase
     end
   end
 
-  unless current_adapter? :OracleAdapter
-    def test_multiparameter_attributes_setting_time_attribute
-      topic = Topic.new("bonus_time(4i)" => "01", "bonus_time(5i)" => "05")
-      assert_equal 1, topic.bonus_time.hour
-      assert_equal 5, topic.bonus_time.min
-    end
-  end
-
   def test_multiparameter_attributes_setting_date_attribute
     topic = Topic.new("written_on(1i)" => "1952", "written_on(2i)" => "3", "written_on(3i)" => "11")
     assert_equal 1952, topic.written_on.year
@@ -300,13 +300,34 @@ class MultiParameterAttributeTest < ActiveRecord::TestCase
     assert_equal 11, topic.written_on.day
   end
 
+  def test_create_with_multiparameter_attributes_setting_date_attribute
+    topic = Topic.create_with("written_on(1i)" => "1952", "written_on(2i)" => "3", "written_on(3i)" => "11").new
+    assert_equal 1952, topic.written_on.year
+    assert_equal 3, topic.written_on.month
+    assert_equal 11, topic.written_on.day
+  end
+
   def test_multiparameter_attributes_setting_date_and_time_attribute
     topic = Topic.new(
-        "written_on(1i)" => "1952",
-        "written_on(2i)" => "3",
-        "written_on(3i)" => "11",
-        "written_on(4i)" => "13",
-        "written_on(5i)" => "55")
+      "written_on(1i)" => "1952",
+      "written_on(2i)" => "3",
+      "written_on(3i)" => "11",
+      "written_on(4i)" => "13",
+      "written_on(5i)" => "55")
+    assert_equal 1952, topic.written_on.year
+    assert_equal 3, topic.written_on.month
+    assert_equal 11, topic.written_on.day
+    assert_equal 13, topic.written_on.hour
+    assert_equal 55, topic.written_on.min
+  end
+
+  def test_create_with_multiparameter_attributes_setting_date_and_time_attribute
+    topic = Topic.create_with(
+      "written_on(1i)" => "1952",
+      "written_on(2i)" => "3",
+      "written_on(3i)" => "11",
+      "written_on(4i)" => "13",
+      "written_on(5i)" => "55").new
     assert_equal 1952, topic.written_on.year
     assert_equal 3, topic.written_on.month
     assert_equal 11, topic.written_on.day
@@ -364,4 +385,15 @@ class MultiParameterAttributeTest < ActiveRecord::TestCase
 
     assert_equal("address", ex.errors[0].attribute)
   end
+
+  def test_multiparameter_assigned_attributes_did_not_come_from_user
+    topic = Topic.new(
+      "written_on(1i)" => "1952",
+      "written_on(2i)" => "3",
+      "written_on(3i)" => "11",
+      "written_on(4i)" => "13",
+      "written_on(5i)" => "55",
+    )
+    refute_predicate topic, :written_on_came_from_user?
+  end
 end
diff --git a/activerecord/test/cases/multiple_db_test.rb b/activerecord/test/cases/multiple_db_test.rb
index e3bb51bd77..192d2f5251 100644
--- a/activerecord/test/cases/multiple_db_test.rb
+++ b/activerecord/test/cases/multiple_db_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/entrant"
 require "models/bird"
@@ -90,14 +92,9 @@ class MultipleDbTest < ActiveRecord::TestCase
     assert_equal "Ruby Developer", Entrant.find(1).name
   end
 
-  def test_arel_table_engines
-    assert_not_equal Entrant.arel_engine, Bird.arel_engine
-    assert_not_equal Entrant.arel_engine, Course.arel_engine
-  end
-
   def test_connection
-    assert_equal Entrant.arel_engine.connection.object_id, Bird.arel_engine.connection.object_id
-    assert_not_equal Entrant.arel_engine.connection.object_id, Course.arel_engine.connection.object_id
+    assert_same Entrant.connection, Bird.connection
+    assert_not_same Entrant.connection, Course.connection
   end
 
   unless in_memory_db?
diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index 154faa56aa..a2ccb603a9 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/pirate"
 require "models/ship"
diff --git a/activerecord/test/cases/nested_attributes_with_callbacks_test.rb b/activerecord/test/cases/nested_attributes_with_callbacks_test.rb
index b9d2acbed2..f04c68b08f 100644
--- a/activerecord/test/cases/nested_attributes_with_callbacks_test.rb
+++ b/activerecord/test/cases/nested_attributes_with_callbacks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/pirate"
 require "models/bird"
diff --git a/activerecord/test/cases/null_relation_test.rb b/activerecord/test/cases/null_relation_test.rb
new file mode 100644
index 0000000000..17527568f8
--- /dev/null
+++ b/activerecord/test/cases/null_relation_test.rb
@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "models/developer"
+require "models/comment"
+require "models/post"
+require "models/topic"
+
+class NullRelationTest < ActiveRecord::TestCase
+  fixtures :posts, :comments
+
+  def test_none
+    assert_no_queries(ignore_none: false) do
+      assert_equal [], Developer.none
+      assert_equal [], Developer.all.none
+    end
+  end
+
+  def test_none_chainable
+    assert_no_queries(ignore_none: false) do
+      assert_equal [], Developer.none.where(name: "David")
+    end
+  end
+
+  def test_none_chainable_to_existing_scope_extension_method
+    assert_no_queries(ignore_none: false) do
+      assert_equal 1, Topic.anonymous_extension.none.one
+    end
+  end
+
+  def test_none_chained_to_methods_firing_queries_straight_to_db
+    assert_no_queries(ignore_none: false) do
+      assert_equal [],    Developer.none.pluck(:id, :name)
+      assert_equal 0,     Developer.none.delete_all
+      assert_equal 0,     Developer.none.update_all(name: "David")
+      assert_equal 0,     Developer.none.delete(1)
+      assert_equal false, Developer.none.exists?(1)
+    end
+  end
+
+  def test_null_relation_content_size_methods
+    assert_no_queries(ignore_none: false) do
+      assert_equal 0,     Developer.none.size
+      assert_equal 0,     Developer.none.count
+      assert_equal true,  Developer.none.empty?
+      assert_equal true,  Developer.none.none?
+      assert_equal false, Developer.none.any?
+      assert_equal false, Developer.none.one?
+      assert_equal false, Developer.none.many?
+    end
+  end
+
+  def test_null_relation_metadata_methods
+    assert_equal "", Developer.none.to_sql
+    assert_equal({}, Developer.none.where_values_hash)
+  end
+
+  def test_null_relation_where_values_hash
+    assert_equal({ "salary" => 100_000 }, Developer.none.where(salary: 100_000).where_values_hash)
+  end
+
+  [:count, :sum].each do |method|
+    define_method "test_null_relation_#{method}" do
+      assert_no_queries(ignore_none: false) do
+        assert_equal 0, Comment.none.public_send(method, :id)
+        assert_equal Hash.new, Comment.none.group(:post_id).public_send(method, :id)
+      end
+    end
+  end
+
+  [:average, :minimum, :maximum].each do |method|
+    define_method "test_null_relation_#{method}" do
+      assert_no_queries(ignore_none: false) do
+        assert_nil Comment.none.public_send(method, :id)
+        assert_equal Hash.new, Comment.none.group(:post_id).public_send(method, :id)
+      end
+    end
+  end
+
+  def test_null_relation_in_where_condition
+    assert_operator Comment.count, :>, 0 # precondition, make sure there are comments.
+    assert_equal 0, Comment.where(post_id: Post.none).count
+  end
+end
diff --git a/activerecord/test/cases/numeric_data_test.rb b/activerecord/test/cases/numeric_data_test.rb
index 76b97033af..f917c8f727 100644
--- a/activerecord/test/cases/numeric_data_test.rb
+++ b/activerecord/test/cases/numeric_data_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/numeric_data"
 
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index e9df570176..c887f54560 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/aircraft"
 require "models/post"
@@ -437,6 +439,13 @@ class PersistenceTest < ActiveRecord::TestCase
     assert_not_nil Topic.find(2)
   end
 
+  def test_delete_isnt_affected_by_scoping
+    topic = Topic.find(1)
+    assert_difference("Topic.count", -1) do
+      Topic.where("1=0").scoping { topic.delete }
+    end
+  end
+
   def test_destroy
     topic = Topic.find(1)
     assert_equal topic, topic.destroy, "topic.destroy did not return self"
diff --git a/activerecord/test/cases/pooled_connections_test.rb b/activerecord/test/cases/pooled_connections_test.rb
index f1b0d08765..fa7f759e51 100644
--- a/activerecord/test/cases/pooled_connections_test.rb
+++ b/activerecord/test/cases/pooled_connections_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/project"
 require "timeout"
diff --git a/activerecord/test/cases/primary_keys_test.rb b/activerecord/test/cases/primary_keys_test.rb
index 31892cfff0..df83fe0ea1 100644
--- a/activerecord/test/cases/primary_keys_test.rb
+++ b/activerecord/test/cases/primary_keys_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 require "models/topic"
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 54b65d1a86..d3f4b5bf75 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/task"
@@ -400,10 +402,8 @@ class QueryCacheTest < ActiveRecord::TestCase
       # Warm the cache
       Task.find(1)
 
-      Task.connection.type_map.clear
-
       # Preload the type cache again (so we don't have those queries issued during our assertions)
-      Task.connection.send(:initialize_type_map, Task.connection.type_map)
+      Task.connection.send(:reload_type_map)
 
       # Clear places where type information is cached
       Task.reset_column_information
diff --git a/activerecord/test/cases/quoting_test.rb b/activerecord/test/cases/quoting_test.rb
index 0819776fbf..59d3bbb573 100644
--- a/activerecord/test/cases/quoting_test.rb
+++ b/activerecord/test/cases/quoting_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
@@ -8,11 +10,11 @@ module ActiveRecord
       end
 
       def test_quoted_true
-        assert_equal "'t'", @quoter.quoted_true
+        assert_equal "TRUE", @quoter.quoted_true
       end
 
       def test_quoted_false
-        assert_equal "'f'", @quoter.quoted_false
+        assert_equal "FALSE", @quoter.quoted_false
       end
 
       def test_quote_column_name
@@ -174,13 +176,21 @@ module ActiveRecord
 
       def test_type_cast_date
         date = Date.today
-        expected = @conn.quoted_date(date)
+        if current_adapter?(:Mysql2Adapter)
+          expected = date
+        else
+          expected = @conn.quoted_date(date)
+        end
         assert_equal expected, @conn.type_cast(date)
       end
 
       def test_type_cast_time
         time = Time.now
-        expected = @conn.quoted_date(time)
+        if current_adapter?(:Mysql2Adapter)
+          expected = time
+        else
+          expected = @conn.quoted_date(time)
+        end
         assert_equal expected, @conn.type_cast(time)
       end
 
@@ -257,7 +267,7 @@ module ActiveRecord
 
         def test_type_cast_ar_object
           value = DatetimePrimaryKey.new(id: @time)
-          assert_equal "2017-02-14 12:34:56.789000",  @connection.type_cast(value)
+          assert_equal @connection.type_cast(value.id),  @connection.type_cast(value)
         end
       end
     end
diff --git a/activerecord/test/cases/readonly_test.rb b/activerecord/test/cases/readonly_test.rb
index 24b678310d..d1b85cb4ef 100644
--- a/activerecord/test/cases/readonly_test.rb
+++ b/activerecord/test/cases/readonly_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/post"
diff --git a/activerecord/test/cases/reaper_test.rb b/activerecord/test/cases/reaper_test.rb
index 249878b67d..49170abe6f 100644
--- a/activerecord/test/cases/reaper_test.rb
+++ b/activerecord/test/cases/reaper_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index c1c2efb9c8..4cd2d3aedc 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/customer"
diff --git a/activerecord/test/cases/relation/delegation_test.rb b/activerecord/test/cases/relation/delegation_test.rb
index 3b15f051b2..3089aee959 100644
--- a/activerecord/test/cases/relation/delegation_test.rb
+++ b/activerecord/test/cases/relation/delegation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
@@ -24,7 +26,7 @@ module ActiveRecord
   module DeprecatedArelDelegationTests
     AREL_METHODS = [
       :with, :orders, :froms, :project, :projections, :taken, :constraints, :exists, :locked, :where_sql,
-      :ast, :source, :join_sources, :to_dot, :bind_values, :create_insert, :create_true, :create_false
+      :ast, :source, :join_sources, :to_dot, :create_insert, :create_true, :create_false
     ]
 
     def test_deprecate_arel_delegation
diff --git a/activerecord/test/cases/relation/merging_test.rb b/activerecord/test/cases/relation/merging_test.rb
index 3901824aac..b68b3723f6 100644
--- a/activerecord/test/cases/relation/merging_test.rb
+++ b/activerecord/test/cases/relation/merging_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/comment"
@@ -79,13 +81,11 @@ class RelationMergingTest < ActiveRecord::TestCase
   end
 
   test "merge collapses wheres from the LHS only" do
-    left  = Post.where(title: "omg").where(comments_count: 1)
+    left = Post.where(title: "omg").where(comments_count: 1)
     right = Post.where(title: "wtf").where(title: "bbq")
 
-    expected = [left.bound_attributes[1]] + right.bound_attributes
-    merged   = left.merge(right)
+    merged = left.merge(right)
 
-    assert_equal expected, merged.bound_attributes
     assert_not_includes merged.to_sql, "omg"
     assert_includes merged.to_sql, "wtf"
     assert_includes merged.to_sql, "bbq"
diff --git a/activerecord/test/cases/relation/mutation_test.rb b/activerecord/test/cases/relation/mutation_test.rb
index 8e73baa70a..ad3700b73a 100644
--- a/activerecord/test/cases/relation/mutation_test.rb
+++ b/activerecord/test/cases/relation/mutation_test.rb
@@ -1,41 +1,10 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 
 module ActiveRecord
   class RelationMutationTest < ActiveRecord::TestCase
-    FakeKlass = Struct.new(:table_name, :name) do
-      extend ActiveRecord::Delegation::DelegateCache
-      inherited self
-
-      def connection
-        Post.connection
-      end
-
-      def relation_delegate_class(klass)
-        self.class.relation_delegate_class(klass)
-      end
-
-      def attribute_alias?(name)
-        false
-      end
-
-      def sanitize_sql(sql)
-        sql
-      end
-
-      def sanitize_sql_for_order(sql)
-        sql
-      end
-
-      def arel_attribute(name, table)
-        table[name]
-      end
-    end
-
-    def relation
-      @relation ||= Relation.new FakeKlass.new("posts"), Post.arel_table, Post.predicate_builder
-    end
-
     (Relation::MULTI_VALUE_METHODS - [:references, :extending, :order, :unscope, :select]).each do |method|
       test "##{method}!" do
         assert relation.public_send("#{method}!", :foo).equal?(relation)
@@ -167,5 +136,10 @@ module ActiveRecord
       relation.skip_query_cache!
       assert relation.skip_query_cache_value
     end
+
+    private
+      def relation
+        @relation ||= Relation.new(FakeKlass, Post.arel_table, Post.predicate_builder)
+      end
   end
 end
diff --git a/activerecord/test/cases/relation/or_test.rb b/activerecord/test/cases/relation/or_test.rb
index 61b6601580..b01801b41f 100644
--- a/activerecord/test/cases/relation/or_test.rb
+++ b/activerecord/test/cases/relation/or_test.rb
@@ -1,9 +1,14 @@
+# frozen_string_literal: true
+
 require "cases/helper"
+require "models/author"
+require "models/categorization"
 require "models/post"
 
 module ActiveRecord
   class OrTest < ActiveRecord::TestCase
     fixtures :posts
+    fixtures :authors
 
     def test_or_with_relation
       expected = Post.where("id = 1 or id = 2").to_a
@@ -113,5 +118,13 @@ module ActiveRecord
         Post.where(id: [1, 2, 3]).or(title: "Rails")
       end
     end
+
+    def test_or_with_references_inequality
+      joined = Post.includes(:author)
+      actual = joined.where(authors: { id: 1 })
+        .or(joined.where(title: "I don't have any comments"))
+      expected = Author.find(1).posts + Post.where(title: "I don't have any comments")
+      assert_equal expected.sort_by(&:id), actual.sort_by(&:id)
+    end
   end
 end
diff --git a/activerecord/test/cases/relation/predicate_builder_test.rb b/activerecord/test/cases/relation/predicate_builder_test.rb
index 48758dc148..b432330deb 100644
--- a/activerecord/test/cases/relation/predicate_builder_test.rb
+++ b/activerecord/test/cases/relation/predicate_builder_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/relation/record_fetch_warning_test.rb b/activerecord/test/cases/relation/record_fetch_warning_test.rb
index 62ca051431..22d32d75bc 100644
--- a/activerecord/test/cases/relation/record_fetch_warning_test.rb
+++ b/activerecord/test/cases/relation/record_fetch_warning_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "active_record/relation/record_fetch_warning"
diff --git a/activerecord/test/cases/relation/where_chain_test.rb b/activerecord/test/cases/relation/where_chain_test.rb
index 86e150ed79..a68eb2b446 100644
--- a/activerecord/test/cases/relation/where_chain_test.rb
+++ b/activerecord/test/cases/relation/where_chain_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
@@ -25,7 +27,7 @@ module ActiveRecord
     end
 
     def test_association_not_eq
-      expected = Arel::Nodes::Grouping.new(Comment.arel_table[@name].not_eq(bind_param))
+      expected = Comment.arel_table[@name].not_eq(Arel::Nodes::BindParam.new(1))
       relation = Post.joins(:comments).where.not(comments: { title: "hello" })
       assert_equal(expected.to_sql, relation.where_clause.ast.to_sql)
     end
diff --git a/activerecord/test/cases/relation/where_clause_test.rb b/activerecord/test/cases/relation/where_clause_test.rb
index f8eb0dee91..e5eb159d36 100644
--- a/activerecord/test/cases/relation/where_clause_test.rb
+++ b/activerecord/test/cases/relation/where_clause_test.rb
@@ -1,78 +1,86 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class ActiveRecord::Relation
   class WhereClauseTest < ActiveRecord::TestCase
     test "+ combines two where clauses" do
-      first_clause = WhereClause.new([table["id"].eq(bind_param)], [["id", 1]])
-      second_clause = WhereClause.new([table["name"].eq(bind_param)], [["name", "Sean"]])
+      first_clause = WhereClause.new([table["id"].eq(bind_param(1))])
+      second_clause = WhereClause.new([table["name"].eq(bind_param("Sean"))])
       combined = WhereClause.new(
-        [table["id"].eq(bind_param), table["name"].eq(bind_param)],
-        [["id", 1], ["name", "Sean"]],
+        [table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Sean"))],
       )
 
       assert_equal combined, first_clause + second_clause
     end
 
     test "+ is associative, but not commutative" do
-      a = WhereClause.new(["a"], ["bind a"])
-      b = WhereClause.new(["b"], ["bind b"])
-      c = WhereClause.new(["c"], ["bind c"])
+      a = WhereClause.new(["a"])
+      b = WhereClause.new(["b"])
+      c = WhereClause.new(["c"])
 
       assert_equal a + (b + c), (a + b) + c
       assert_not_equal a + b, b + a
     end
 
     test "an empty where clause is the identity value for +" do
-      clause = WhereClause.new([table["id"].eq(bind_param)], [["id", 1]])
+      clause = WhereClause.new([table["id"].eq(bind_param(1))])
 
       assert_equal clause, clause + WhereClause.empty
     end
 
     test "merge combines two where clauses" do
-      a = WhereClause.new([table["id"].eq(1)], [])
-      b = WhereClause.new([table["name"].eq("Sean")], [])
-      expected = WhereClause.new([table["id"].eq(1), table["name"].eq("Sean")], [])
+      a = WhereClause.new([table["id"].eq(1)])
+      b = WhereClause.new([table["name"].eq("Sean")])
+      expected = WhereClause.new([table["id"].eq(1), table["name"].eq("Sean")])
 
       assert_equal expected, a.merge(b)
     end
 
     test "merge keeps the right side, when two equality clauses reference the same column" do
-      a = WhereClause.new([table["id"].eq(1), table["name"].eq("Sean")], [])
-      b = WhereClause.new([table["name"].eq("Jim")], [])
-      expected = WhereClause.new([table["id"].eq(1), table["name"].eq("Jim")], [])
+      a = WhereClause.new([table["id"].eq(1), table["name"].eq("Sean")])
+      b = WhereClause.new([table["name"].eq("Jim")])
+      expected = WhereClause.new([table["id"].eq(1), table["name"].eq("Jim")])
 
       assert_equal expected, a.merge(b)
     end
 
     test "merge removes bind parameters matching overlapping equality clauses" do
       a = WhereClause.new(
-        [table["id"].eq(bind_param), table["name"].eq(bind_param)],
-        [bind_attribute("id", 1), bind_attribute("name", "Sean")],
+        [table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Sean"))],
       )
       b = WhereClause.new(
-        [table["name"].eq(bind_param)],
-        [bind_attribute("name", "Jim")]
+        [table["name"].eq(bind_param("Jim"))],
       )
       expected = WhereClause.new(
-        [table["id"].eq(bind_param), table["name"].eq(bind_param)],
-        [bind_attribute("id", 1), bind_attribute("name", "Jim")],
+        [table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Jim"))],
       )
 
       assert_equal expected, a.merge(b)
     end
 
     test "merge allows for columns with the same name from different tables" do
-      skip "This is not possible as of 4.2, and the binds do not yet contain sufficient information for this to happen"
-      # We might be able to change the implementation to remove conflicts by index, rather than column name
+      table2 = Arel::Table.new("table2")
+      a = WhereClause.new(
+        [table["id"].eq(bind_param(1)), table2["id"].eq(bind_param(2))],
+      )
+      b = WhereClause.new(
+        [table["id"].eq(bind_param(3))],
+      )
+      expected = WhereClause.new(
+        [table2["id"].eq(bind_param(2)), table["id"].eq(bind_param(3))],
+      )
+
+      assert_equal expected, a.merge(b)
     end
 
     test "a clause knows if it is empty" do
       assert WhereClause.empty.empty?
-      assert_not WhereClause.new(["anything"], []).empty?
+      assert_not WhereClause.new(["anything"]).empty?
     end
 
     test "invert cannot handle nil" do
-      where_clause = WhereClause.new([nil], [])
+      where_clause = WhereClause.new([nil])
 
       assert_raises ArgumentError do
         where_clause.invert
@@ -86,37 +94,47 @@ class ActiveRecord::Relation
         table["id"].eq(1),
         "sql literal",
         random_object
-      ], [])
+      ])
       expected = WhereClause.new([
         table["id"].not_in([1, 2, 3]),
         table["id"].not_eq(1),
         Arel::Nodes::Not.new(Arel::Nodes::SqlLiteral.new("sql literal")),
         Arel::Nodes::Not.new(random_object)
-      ], [])
+      ])
 
       assert_equal expected, original.invert
     end
 
-    test "accept removes binary predicates referencing a given column" do
+    test "except removes binary predicates referencing a given column" do
       where_clause = WhereClause.new([
         table["id"].in([1, 2, 3]),
-        table["name"].eq(bind_param),
-        table["age"].gteq(bind_param),
-      ], [
-        bind_attribute("name", "Sean"),
-        bind_attribute("age", 30),
+        table["name"].eq(bind_param("Sean")),
+        table["age"].gteq(bind_param(30)),
       ])
-      expected = WhereClause.new([table["age"].gteq(bind_param)], [bind_attribute("age", 30)])
+      expected = WhereClause.new([table["age"].gteq(bind_param(30))])
 
       assert_equal expected, where_clause.except("id", "name")
     end
 
+    test "except jumps over unhandled binds (like with OR) correctly" do
+      wcs = (0..9).map do |i|
+        WhereClause.new([table["id#{i}"].eq(bind_param(i))])
+      end
+
+      wc = wcs[0] + wcs[1] + wcs[2].or(wcs[3]) + wcs[4] + wcs[5] + wcs[6].or(wcs[7]) + wcs[8] + wcs[9]
+
+      expected = wcs[0] + wcs[2].or(wcs[3]) + wcs[5] + wcs[6].or(wcs[7]) + wcs[9]
+      actual = wc.except("id1", "id2", "id4", "id7", "id8")
+
+      assert_equal expected, actual
+    end
+
     test "ast groups its predicates with AND" do
       predicates = [
         table["id"].in([1, 2, 3]),
-        table["name"].eq(bind_param),
+        table["name"].eq(bind_param(nil)),
       ]
-      where_clause = WhereClause.new(predicates, [])
+      where_clause = WhereClause.new(predicates)
       expected = Arel::Nodes::And.new(predicates)
 
       assert_equal expected, where_clause.ast
@@ -128,47 +146,96 @@ class ActiveRecord::Relation
         table["id"].in([1, 2, 3]),
         "foo = bar",
         random_object,
-      ], [])
+      ])
       expected = Arel::Nodes::And.new([
         table["id"].in([1, 2, 3]),
         Arel::Nodes::Grouping.new(Arel.sql("foo = bar")),
-        Arel::Nodes::Grouping.new(random_object),
+        random_object,
       ])
 
       assert_equal expected, where_clause.ast
     end
 
     test "ast removes any empty strings" do
-      where_clause = WhereClause.new([table["id"].in([1, 2, 3])], [])
-      where_clause_with_empty = WhereClause.new([table["id"].in([1, 2, 3]), ""], [])
+      where_clause = WhereClause.new([table["id"].in([1, 2, 3])])
+      where_clause_with_empty = WhereClause.new([table["id"].in([1, 2, 3]), ""])
 
       assert_equal where_clause.ast, where_clause_with_empty.ast
     end
 
     test "or joins the two clauses using OR" do
-      where_clause = WhereClause.new([table["id"].eq(bind_param)], [bind_attribute("id", 1)])
-      other_clause = WhereClause.new([table["name"].eq(bind_param)], [bind_attribute("name", "Sean")])
+      where_clause = WhereClause.new([table["id"].eq(bind_param(1))])
+      other_clause = WhereClause.new([table["name"].eq(bind_param("Sean"))])
       expected_ast =
         Arel::Nodes::Grouping.new(
-          Arel::Nodes::Or.new(table["id"].eq(bind_param), table["name"].eq(bind_param))
+          Arel::Nodes::Or.new(table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Sean")))
         )
-      expected_binds = where_clause.binds + other_clause.binds
 
       assert_equal expected_ast.to_sql, where_clause.or(other_clause).ast.to_sql
-      assert_equal expected_binds, where_clause.or(other_clause).binds
     end
 
     test "or returns an empty where clause when either side is empty" do
-      where_clause = WhereClause.new([table["id"].eq(bind_param)], [bind_attribute("id", 1)])
+      where_clause = WhereClause.new([table["id"].eq(bind_param(1))])
 
       assert_equal WhereClause.empty, where_clause.or(WhereClause.empty)
       assert_equal WhereClause.empty, WhereClause.empty.or(where_clause)
     end
 
+    test "or places common conditions before the OR" do
+      a = WhereClause.new(
+        [table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Sean"))],
+      )
+      b = WhereClause.new(
+        [table["id"].eq(bind_param(1)), table["hair_color"].eq(bind_param("black"))],
+      )
+
+      common = WhereClause.new(
+        [table["id"].eq(bind_param(1))],
+      )
+
+      or_clause = WhereClause.new([table["name"].eq(bind_param("Sean"))])
+        .or(WhereClause.new([table["hair_color"].eq(bind_param("black"))]))
+
+      assert_equal common + or_clause, a.or(b)
+    end
+
+    test "or can detect identical or as being a common condition" do
+      common_or = WhereClause.new([table["name"].eq(bind_param("Sean"))])
+        .or(WhereClause.new([table["hair_color"].eq(bind_param("black"))]))
+
+      a = common_or + WhereClause.new([table["id"].eq(bind_param(1))])
+      b = common_or + WhereClause.new([table["foo"].eq(bind_param("bar"))])
+
+      new_or = WhereClause.new([table["id"].eq(bind_param(1))])
+        .or(WhereClause.new([table["foo"].eq(bind_param("bar"))]))
+
+      assert_equal common_or + new_or, a.or(b)
+    end
+
+    test "or will use only common conditions if one side only has common conditions" do
+      only_common = WhereClause.new([
+        table["id"].eq(bind_param(1)),
+        "foo = bar",
+      ])
+
+      common_with_extra = WhereClause.new([
+        table["id"].eq(bind_param(1)),
+        "foo = bar",
+        table["extra"].eq(bind_param("pluto")),
+      ])
+
+      assert_equal only_common, only_common.or(common_with_extra)
+      assert_equal only_common, common_with_extra.or(only_common)
+    end
+
     private
 
       def table
         Arel::Table.new("table")
       end
+
+      def bind_param(value)
+        Arel::Nodes::BindParam.new(value)
+      end
   end
 end
diff --git a/activerecord/test/cases/relation/where_test.rb b/activerecord/test/cases/relation/where_test.rb
index 42dae4d569..c45fd38bc9 100644
--- a/activerecord/test/cases/relation/where_test.rb
+++ b/activerecord/test/cases/relation/where_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/author"
 require "models/binary"
@@ -125,7 +127,7 @@ module ActiveRecord
       car = cars(:honda)
 
       expected = [price_estimates(:diamond), price_estimates(:sapphire_1), price_estimates(:sapphire_2), price_estimates(:honda)].sort
-      actual   = PriceEstimate.where(estimate_of: [treasure_1, treasure_2, car]).to_a.sort
+      actual = PriceEstimate.where(estimate_of: [treasure_1, treasure_2, car]).to_a.sort
 
       assert_equal expected, actual
     end
diff --git a/activerecord/test/cases/relation_test.rb b/activerecord/test/cases/relation_test.rb
index a403824f1a..f22fcd7b5a 100644
--- a/activerecord/test/cases/relation_test.rb
+++ b/activerecord/test/cases/relation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
@@ -8,24 +10,6 @@ module ActiveRecord
   class RelationTest < ActiveRecord::TestCase
     fixtures :posts, :comments, :authors, :author_addresses, :ratings
 
-    FakeKlass = Struct.new(:table_name, :name) do
-      extend ActiveRecord::Delegation::DelegateCache
-
-      inherited self
-
-      def self.connection
-        Post.connection
-      end
-
-      def self.table_name
-        "fake_table"
-      end
-
-      def self.sanitize_sql_for_order(sql)
-        sql
-      end
-    end
-
     def test_construction
       relation = Relation.new(FakeKlass, :b, nil)
       assert_equal FakeKlass, relation.klass
@@ -70,8 +54,8 @@ module ActiveRecord
 
     def test_has_values
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      relation.where! relation.table[:id].eq(10)
-      assert_equal({ id: 10 }, relation.where_values_hash)
+      relation.where!(id: 10)
+      assert_equal({ "id" => 10 }, relation.where_values_hash)
     end
 
     def test_values_wrong_table
@@ -90,7 +74,7 @@ module ActiveRecord
     end
 
     def test_table_name_delegates_to_klass
-      relation = Relation.new(FakeKlass.new("posts"), :b, Post.predicate_builder)
+      relation = Relation.new(FakeKlass, :b, Post.predicate_builder)
       assert_equal "posts", relation.table_name
     end
 
@@ -101,28 +85,19 @@ module ActiveRecord
 
     def test_create_with_value
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      hash = { hello: "world" }
-      relation.create_with_value = hash
-      assert_equal hash, relation.scope_for_create
-    end
-
-    def test_create_with_value_with_wheres
-      relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      relation.where! relation.table[:id].eq(10)
       relation.create_with_value = { hello: "world" }
-      assert_equal({ hello: "world", id: 10 }, relation.scope_for_create)
+      assert_equal({ "hello" => "world" }, relation.scope_for_create)
     end
 
-    # FIXME: is this really wanted or expected behavior?
-    def test_scope_for_create_is_cached
+    def test_create_with_value_with_wheres
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
       assert_equal({}, relation.scope_for_create)
 
-      relation.where! relation.table[:id].eq(10)
-      assert_equal({}, relation.scope_for_create)
+      relation.where!(id: 10)
+      assert_equal({ "id" => 10 }, relation.scope_for_create)
 
       relation.create_with_value = { hello: "world" }
-      assert_equal({}, relation.scope_for_create)
+      assert_equal({ "hello" => "world", "id" => 10 }, relation.scope_for_create)
     end
 
     def test_bad_constants_raise_errors
@@ -210,7 +185,7 @@ module ActiveRecord
 
       relation = Relation.new(klass, :b, nil)
       relation.merge!(where: ["foo = ?", "bar"])
-      assert_equal Relation::WhereClause.new(["foo = bar"], []), relation.where_clause
+      assert_equal Relation::WhereClause.new(["foo = bar"]), relation.where_clause
     end
 
     def test_merging_readonly_false
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index eb3449b331..ae1dc35bff 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/tag"
 require "models/tagging"
@@ -15,7 +17,6 @@ require "models/car"
 require "models/engine"
 require "models/tyre"
 require "models/minivan"
-require "models/aircraft"
 require "models/possession"
 require "models/reader"
 require "models/categorization"
@@ -420,123 +421,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal [2, 4, 6, 8, 10], even_ids.sort
   end
 
-  def test_none
-    assert_no_queries(ignore_none: false) do
-      assert_equal [], Developer.none
-      assert_equal [], Developer.all.none
-    end
-  end
-
-  def test_none_chainable
-    assert_no_queries(ignore_none: false) do
-      assert_equal [], Developer.none.where(name: "David")
-    end
-  end
-
-  def test_none_chainable_to_existing_scope_extension_method
-    assert_no_queries(ignore_none: false) do
-      assert_equal 1, Topic.anonymous_extension.none.one
-    end
-  end
-
-  def test_none_chained_to_methods_firing_queries_straight_to_db
-    assert_no_queries(ignore_none: false) do
-      assert_equal [],    Developer.none.pluck(:id, :name)
-      assert_equal 0,     Developer.none.delete_all
-      assert_equal 0,     Developer.none.update_all(name: "David")
-      assert_equal 0,     Developer.none.delete(1)
-      assert_equal false, Developer.none.exists?(1)
-    end
-  end
-
-  def test_null_relation_content_size_methods
-    assert_no_queries(ignore_none: false) do
-      assert_equal 0,     Developer.none.size
-      assert_equal 0,     Developer.none.count
-      assert_equal true,  Developer.none.empty?
-      assert_equal true, Developer.none.none?
-      assert_equal false, Developer.none.any?
-      assert_equal false, Developer.none.one?
-      assert_equal false, Developer.none.many?
-    end
-  end
-
-  def test_null_relation_calculations_methods
-    assert_no_queries(ignore_none: false) do
-      assert_equal 0, Developer.none.count
-      assert_equal 0, Developer.none.calculate(:count, nil)
-      assert_nil Developer.none.calculate(:average, "salary")
-    end
-  end
-
-  def test_null_relation_metadata_methods
-    assert_equal "", Developer.none.to_sql
-    assert_equal({}, Developer.none.where_values_hash)
-  end
-
-  def test_null_relation_where_values_hash
-    assert_equal({ "salary" => 100_000 }, Developer.none.where(salary: 100_000).where_values_hash)
-  end
-
-  def test_null_relation_sum
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:id).sum(:id)
-    assert_equal 0, ac.engines.count
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:id).sum(:id)
-    assert_equal 0, ac.engines.count
-  end
-
-  def test_null_relation_count
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:id).count
-    assert_equal 0, ac.engines.count
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:id).count
-    assert_equal 0, ac.engines.count
-  end
-
-  def test_null_relation_size
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:id).size
-    assert_equal 0, ac.engines.size
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:id).size
-    assert_equal 0, ac.engines.size
-  end
-
-  def test_null_relation_average
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:car_id).average(:id)
-    assert_nil ac.engines.average(:id)
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:car_id).average(:id)
-    assert_nil ac.engines.average(:id)
-  end
-
-  def test_null_relation_minimum
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:car_id).minimum(:id)
-    assert_nil ac.engines.minimum(:id)
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:car_id).minimum(:id)
-    assert_nil ac.engines.minimum(:id)
-  end
-
-  def test_null_relation_maximum
-    ac = Aircraft.new
-    assert_equal Hash.new, ac.engines.group(:car_id).maximum(:id)
-    assert_nil ac.engines.maximum(:id)
-    ac.save
-    assert_equal Hash.new, ac.engines.group(:car_id).maximum(:id)
-    assert_nil ac.engines.maximum(:id)
-  end
-
-  def test_null_relation_in_where_condition
-    assert_operator Comment.count, :>, 0 # precondition, make sure there are comments.
-    assert_equal 0, Comment.where(post_id: Post.none).to_a.size
-  end
-
   def test_joins_with_nil_argument
     assert_nothing_raised { DependentFirm.joins(nil).first }
   end
@@ -586,14 +470,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_nothing_raised { Topic.reorder([]) }
   end
 
-  def test_scoped_responds_to_delegated_methods
-    relation = Topic.all
-
-    ["map", "uniq", "sort", "insert", "delete", "update"].each do |method|
-      assert_respond_to relation, method, "Topic.all should respond to #{method.inspect}"
-    end
-  end
-
   def test_respond_to_delegates_to_arel
     relation = Topic.all
     fake_arel = Struct.new(:responds) {
@@ -1482,7 +1358,7 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal bird, Bird.find_or_initialize_by(name: "bob")
   end
 
-  def test_explicit_create_scope
+  def test_explicit_create_with
     hens = Bird.where(name: "hen")
     assert_equal "hen", hens.new.name
 
@@ -1718,7 +1594,11 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal ["comments"], scope.references_values
 
     scope = Post.order("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}")
-    assert_equal ["comments"], scope.references_values
+    if current_adapter?(:OracleAdapter)
+      assert_equal ["COMMENTS"], scope.references_values
+    else
+      assert_equal ["comments"], scope.references_values
+    end
 
     scope = Post.order("comments.body", "yaks.body")
     assert_equal ["comments", "yaks"], scope.references_values
@@ -1739,7 +1619,11 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal %w(comments), scope.references_values
 
     scope = Post.reorder("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}")
-    assert_equal ["comments"], scope.references_values
+    if current_adapter?(:OracleAdapter)
+      assert_equal ["COMMENTS"], scope.references_values
+    else
+      assert_equal ["comments"], scope.references_values
+    end
 
     scope = Post.reorder("comments.body", "yaks.body")
     assert_equal %w(comments yaks), scope.references_values
@@ -1877,7 +1761,7 @@ class RelationTest < ActiveRecord::TestCase
 
   test "relations with cached arel can't be mutated [internal API]" do
     relation = Post.all
-    relation.count
+    relation.arel
 
     assert_raises(ActiveRecord::ImmutableRelation) { relation.limit!(5) }
     assert_raises(ActiveRecord::ImmutableRelation) { relation.where!("1 = 2") }
@@ -1911,15 +1795,15 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   test "using a custom table affects the wheres" do
-    table_alias = Post.arel_table.alias("omg_posts")
+    post = posts(:welcome)
 
-    table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
-    predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
-    relation = ActiveRecord::Relation.new(Post, table_alias, predicate_builder)
-    relation.where!(foo: "bar")
+    assert_equal post, custom_post_relation.where!(title: post.title).take
+  end
 
-    node = relation.arel.constraints.first.grep(Arel::Attributes::Attribute).first
-    assert_equal table_alias, node.relation
+  test "using a custom table with joins affects the joins" do
+    post = posts(:welcome)
+
+    assert_equal post, custom_post_relation.joins(:author).where!(title: post.title).take
   end
 
   test "#load" do
@@ -1976,37 +1860,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal 1, posts.unscope(where: :body).count
   end
 
-  def test_unscope_removes_binds
-    left = Post.where(id: 20)
-
-    binds = [bind_attribute("id", 20, Post.type_for_attribute("id"))]
-    assert_equal binds, left.bound_attributes
-
-    relation = left.unscope(where: :id)
-    assert_equal [], relation.bound_attributes
-  end
-
-  def test_merging_removes_rhs_binds
-    left = Post.where(id: 20)
-    right = Post.where(id: [1, 2, 3, 4])
-
-    binds = [bind_attribute("id", 20, Post.type_for_attribute("id"))]
-    assert_equal binds, left.bound_attributes
-
-    merged = left.merge(right)
-    assert_equal [], merged.bound_attributes
-  end
-
-  def test_merging_keeps_lhs_binds
-    binds = [bind_attribute("id", 20, Post.type_for_attribute("id"))]
-
-    right  = Post.where(id: 20)
-    left   = Post.where(id: 10)
-
-    merged = left.merge(right)
-    assert_equal binds, merged.bound_attributes
-  end
-
   def test_locked_should_not_build_arel
     posts = Post.locked
     assert posts.locked?
@@ -2017,24 +1870,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal "Thank you for the welcome,Thank you again for the welcome", Post.first.comments.join(",")
   end
 
-  def test_connection_adapters_can_reorder_binds
-    posts = Post.limit(1).offset(2)
-
-    stubbed_connection = Post.connection.dup
-    def stubbed_connection.combine_bind_parameters(**kwargs)
-      offset = kwargs[:offset]
-      kwargs[:offset] = kwargs[:limit]
-      kwargs[:limit] = offset
-      super(**kwargs)
-    end
-
-    posts.define_singleton_method(:connection) do
-      stubbed_connection
-    end
-
-    assert_equal 2, posts.to_a.length
-  end
-
   test "#skip_query_cache!" do
     Post.cache do
       assert_queries(1) do
@@ -2076,4 +1911,13 @@ class RelationTest < ActiveRecord::TestCase
       end
     end
   end
+
+  private
+    def custom_post_relation
+      table_alias = Post.arel_table.alias("omg_posts")
+      table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
+      predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
+
+      ActiveRecord::Relation.create(Post, table_alias, predicate_builder)
+    end
 end
diff --git a/activerecord/test/cases/reload_models_test.rb b/activerecord/test/cases/reload_models_test.rb
index 38a8d84107..72f4bfaf6d 100644
--- a/activerecord/test/cases/reload_models_test.rb
+++ b/activerecord/test/cases/reload_models_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/owner"
 require "models/pet"
diff --git a/activerecord/test/cases/reserved_word_test.rb b/activerecord/test/cases/reserved_word_test.rb
index f3019a5326..0214dbec17 100644
--- a/activerecord/test/cases/reserved_word_test.rb
+++ b/activerecord/test/cases/reserved_word_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class ReservedWordTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/result_test.rb b/activerecord/test/cases/result_test.rb
index 1a0b7c6ca7..db52c108ac 100644
--- a/activerecord/test/cases/result_test.rb
+++ b/activerecord/test/cases/result_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/sanitize_test.rb b/activerecord/test/cases/sanitize_test.rb
index 72f09186e2..082d663675 100644
--- a/activerecord/test/cases/sanitize_test.rb
+++ b/activerecord/test/cases/sanitize_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/binary"
 require "models/author"
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 4c81e825fa..01ec3e06ad 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
@@ -301,6 +303,20 @@ class SchemaDumperTest < ActiveRecord::TestCase
         assert_no_match "# These are extensions that must be enabled", output
         assert_no_match %r{enable_extension}, output
       end
+
+      def test_schema_dump_includes_extensions_in_alphabetic_order
+        connection = ActiveRecord::Base.connection
+
+        connection.stubs(:extensions).returns(["hstore", "uuid-ossp", "xml2"])
+        output = perform_schema_dump
+        enabled_extensions = output.scan(%r{enable_extension "(.+)"}).flatten
+        assert_equal ["hstore", "uuid-ossp", "xml2"], enabled_extensions
+
+        connection.stubs(:extensions).returns(["uuid-ossp", "xml2", "hstore"])
+        output = perform_schema_dump
+        enabled_extensions = output.scan(%r{enable_extension "(.+)"}).flatten
+        assert_equal ["hstore", "uuid-ossp", "xml2"], enabled_extensions
+      end
     end
   end
 
diff --git a/activerecord/test/cases/schema_loading_test.rb b/activerecord/test/cases/schema_loading_test.rb
index 362370ac61..f539156466 100644
--- a/activerecord/test/cases/schema_loading_test.rb
+++ b/activerecord/test/cases/schema_loading_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module SchemaLoadCounter
diff --git a/activerecord/test/cases/scoping/default_scoping_test.rb b/activerecord/test/cases/scoping/default_scoping_test.rb
index 6f1010d701..716ca29eda 100644
--- a/activerecord/test/cases/scoping/default_scoping_test.rb
+++ b/activerecord/test/cases/scoping/default_scoping_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/comment"
@@ -332,7 +334,7 @@ class DefaultScopingTest < ActiveRecord::TestCase
 
   def test_create_with_merge
     aaron = PoorDeveloperCalledJamis.create_with(name: "foo", salary: 20).merge(
-              PoorDeveloperCalledJamis.create_with(name: "Aaron")).new
+      PoorDeveloperCalledJamis.create_with(name: "Aaron")).new
     assert_equal 20, aaron.salary
     assert_equal "Aaron", aaron.name
 
@@ -342,6 +344,11 @@ class DefaultScopingTest < ActiveRecord::TestCase
     assert_equal "Aaron", aaron.name
   end
 
+  def test_create_with_using_both_string_and_symbol
+    jamis = PoorDeveloperCalledJamis.create_with(name: "foo").create_with("name" => "Aaron").new
+    assert_equal "Aaron", jamis.name
+  end
+
   def test_create_with_reset
     jamis = PoorDeveloperCalledJamis.create_with(name: "Aaron").create_with(nil).new
     assert_equal "Jamis", jamis.name
@@ -372,11 +379,39 @@ class DefaultScopingTest < ActiveRecord::TestCase
                  Comment.joins(:post).count
   end
 
+  def test_joins_not_affected_by_scope_other_than_default_or_unscoped
+    without_scope_on_post = Comment.joins(:post).to_a
+    with_scope_on_post = nil
+    Post.where(id: [1, 5, 6]).scoping do
+      with_scope_on_post = Comment.joins(:post).to_a
+    end
+
+    assert_equal with_scope_on_post, without_scope_on_post
+  end
+
   def test_unscoped_with_joins_should_not_have_default_scope
     assert_equal SpecialPostWithDefaultScope.unscoped { Comment.joins(:special_post_with_default_scope).to_a },
                  Comment.joins(:post).to_a
   end
 
+  def test_sti_association_with_unscoped_not_affected_by_default_scope
+    post = posts(:thinking)
+    comments = [comments(:does_it_hurt)]
+
+    post.special_comments.update_all(deleted_at: Time.now)
+
+    assert_raises(ActiveRecord::RecordNotFound) { Post.joins(:special_comments).find(post.id) }
+    assert_equal [], post.special_comments
+
+    SpecialComment.unscoped do
+      assert_equal post, Post.joins(:special_comments).find(post.id)
+      assert_equal comments, Post.joins(:special_comments).find(post.id).special_comments
+      assert_equal comments, Post.eager_load(:special_comments).find(post.id).special_comments
+      assert_equal comments, Post.includes(:special_comments).find(post.id).special_comments
+      assert_equal comments, Post.preload(:special_comments).find(post.id).special_comments
+    end
+  end
+
   def test_default_scope_select_ignored_by_aggregations
     assert_equal DeveloperWithSelect.all.to_a.count, DeveloperWithSelect.count
   end
diff --git a/activerecord/test/cases/scoping/named_scoping_test.rb b/activerecord/test/cases/scoping/named_scoping_test.rb
index 483ea7128d..1db7432e34 100644
--- a/activerecord/test/cases/scoping/named_scoping_test.rb
+++ b/activerecord/test/cases/scoping/named_scoping_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/topic"
diff --git a/activerecord/test/cases/scoping/relation_scoping_test.rb b/activerecord/test/cases/scoping/relation_scoping_test.rb
index 10553bf057..f3b84d88c2 100644
--- a/activerecord/test/cases/scoping/relation_scoping_test.rb
+++ b/activerecord/test/cases/scoping/relation_scoping_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/post"
 require "models/author"
diff --git a/activerecord/test/cases/secure_token_test.rb b/activerecord/test/cases/secure_token_test.rb
index 7b9cbee40a..f5fa6aa302 100644
--- a/activerecord/test/cases/secure_token_test.rb
+++ b/activerecord/test/cases/secure_token_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/user"
 
diff --git a/activerecord/test/cases/serialization_test.rb b/activerecord/test/cases/serialization_test.rb
index ec33ad38f2..2d829ad4ba 100644
--- a/activerecord/test/cases/serialization_test.rb
+++ b/activerecord/test/cases/serialization_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/contact"
 require "models/topic"
diff --git a/activerecord/test/cases/serialized_attribute_test.rb b/activerecord/test/cases/serialized_attribute_test.rb
index e1bdaab5cf..32dafbd458 100644
--- a/activerecord/test/cases/serialized_attribute_test.rb
+++ b/activerecord/test/cases/serialized_attribute_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/statement_cache_test.rb b/activerecord/test/cases/statement_cache_test.rb
index fab3648564..e2142267ea 100644
--- a/activerecord/test/cases/statement_cache_test.rb
+++ b/activerecord/test/cases/statement_cache_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/book"
 require "models/liquid"
diff --git a/activerecord/test/cases/store_test.rb b/activerecord/test/cases/store_test.rb
index 633a8a0ebc..ebf4016960 100644
--- a/activerecord/test/cases/store_test.rb
+++ b/activerecord/test/cases/store_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/admin"
 require "models/admin/user"
diff --git a/activerecord/test/cases/suppressor_test.rb b/activerecord/test/cases/suppressor_test.rb
index a7d16b7cdb..b68f0033d9 100644
--- a/activerecord/test/cases/suppressor_test.rb
+++ b/activerecord/test/cases/suppressor_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/notification"
 require "models/user"
diff --git a/activerecord/test/cases/tasks/database_tasks_test.rb b/activerecord/test/cases/tasks/database_tasks_test.rb
index c47c97e9d9..1495d2ab89 100644
--- a/activerecord/test/cases/tasks/database_tasks_test.rb
+++ b/activerecord/test/cases/tasks/database_tasks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/tasks/database_tasks"
 
diff --git a/activerecord/test/cases/tasks/mysql_rake_test.rb b/activerecord/test/cases/tasks/mysql_rake_test.rb
index 9c6fb14376..98fe24baa0 100644
--- a/activerecord/test/cases/tasks/mysql_rake_test.rb
+++ b/activerecord/test/cases/tasks/mysql_rake_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/tasks/database_tasks"
 
diff --git a/activerecord/test/cases/tasks/postgresql_rake_test.rb b/activerecord/test/cases/tasks/postgresql_rake_test.rb
index a2e968aedf..693503250b 100644
--- a/activerecord/test/cases/tasks/postgresql_rake_test.rb
+++ b/activerecord/test/cases/tasks/postgresql_rake_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/tasks/database_tasks"
 
diff --git a/activerecord/test/cases/tasks/sqlite_rake_test.rb b/activerecord/test/cases/tasks/sqlite_rake_test.rb
index ccb3834fee..8ac4878c37 100644
--- a/activerecord/test/cases/tasks/sqlite_rake_test.rb
+++ b/activerecord/test/cases/tasks/sqlite_rake_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "active_record/tasks/database_tasks"
 require "pathname"
diff --git a/activerecord/test/cases/test_case.rb b/activerecord/test/cases/test_case.rb
index 9f594fef85..e57ebf56c8 100644
--- a/activerecord/test/cases/test_case.rb
+++ b/activerecord/test/cases/test_case.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/test_case"
 require "active_support/testing/autorun"
 require "active_support/testing/method_call_assertions"
@@ -75,14 +77,6 @@ module ActiveRecord
       model.reset_column_information
       model.column_names.include?(column_name.to_s)
     end
-
-    def bind_param
-      Arel::Nodes::BindParam.new
-    end
-
-    def bind_attribute(name, value, type = ActiveRecord::Type.default_value)
-      ActiveRecord::Relation::QueryAttribute.new(name, value, type)
-    end
   end
 
   class PostgreSQLTestCase < TestCase
diff --git a/activerecord/test/cases/test_fixtures_test.rb b/activerecord/test/cases/test_fixtures_test.rb
index 58d3bea3a2..4411410eda 100644
--- a/activerecord/test/cases/test_fixtures_test.rb
+++ b/activerecord/test/cases/test_fixtures_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class TestFixturesTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/time_precision_test.rb b/activerecord/test/cases/time_precision_test.rb
index 09c585167e..41455637bb 100644
--- a/activerecord/test/cases/time_precision_test.rb
+++ b/activerecord/test/cases/time_precision_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/schema_dumping_helper"
 
diff --git a/activerecord/test/cases/timestamp_test.rb b/activerecord/test/cases/timestamp_test.rb
index 39b40e3411..ba0bc6c45d 100644
--- a/activerecord/test/cases/timestamp_test.rb
+++ b/activerecord/test/cases/timestamp_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "support/ddl_helper"
 require "models/developer"
diff --git a/activerecord/test/cases/touch_later_test.rb b/activerecord/test/cases/touch_later_test.rb
index d1e8c649d9..1757031371 100644
--- a/activerecord/test/cases/touch_later_test.rb
+++ b/activerecord/test/cases/touch_later_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/invoice"
 require "models/line_item"
diff --git a/activerecord/test/cases/transaction_callbacks_test.rb b/activerecord/test/cases/transaction_callbacks_test.rb
index eaa4dd09a9..1f370a80ee 100644
--- a/activerecord/test/cases/transaction_callbacks_test.rb
+++ b/activerecord/test/cases/transaction_callbacks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/owner"
 require "models/pet"
diff --git a/activerecord/test/cases/transaction_isolation_test.rb b/activerecord/test/cases/transaction_isolation_test.rb
index 58abfadaf4..b1ebccdcc3 100644
--- a/activerecord/test/cases/transaction_isolation_test.rb
+++ b/activerecord/test/cases/transaction_isolation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 unless ActiveRecord::Base.connection.supports_transaction_isolation?
diff --git a/activerecord/test/cases/transactions_test.rb b/activerecord/test/cases/transactions_test.rb
index 76a997ba8b..b771a1d12c 100644
--- a/activerecord/test/cases/transactions_test.rb
+++ b/activerecord/test/cases/transactions_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/type/adapter_specific_registry_test.rb b/activerecord/test/cases/type/adapter_specific_registry_test.rb
index 8b836b4793..b58bdd5549 100644
--- a/activerecord/test/cases/type/adapter_specific_registry_test.rb
+++ b/activerecord/test/cases/type/adapter_specific_registry_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/type/date_time_test.rb b/activerecord/test/cases/type/date_time_test.rb
index 6848619ece..c9558e25b5 100644
--- a/activerecord/test/cases/type/date_time_test.rb
+++ b/activerecord/test/cases/type/date_time_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/task"
 
diff --git a/activerecord/test/cases/type/integer_test.rb b/activerecord/test/cases/type/integer_test.rb
index 368b6d7199..15d1a675a1 100644
--- a/activerecord/test/cases/type/integer_test.rb
+++ b/activerecord/test/cases/type/integer_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/company"
 
diff --git a/activerecord/test/cases/type/string_test.rb b/activerecord/test/cases/type/string_test.rb
index a95da864fa..8c51b30fdd 100644
--- a/activerecord/test/cases/type/string_test.rb
+++ b/activerecord/test/cases/type/string_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/type/type_map_test.rb b/activerecord/test/cases/type/type_map_test.rb
index 2959d36466..f3699c11a2 100644
--- a/activerecord/test/cases/type/type_map_test.rb
+++ b/activerecord/test/cases/type/type_map_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/type/unsigned_integer_test.rb b/activerecord/test/cases/type/unsigned_integer_test.rb
index 1cd4dbc2c5..dd05cf3fff 100644
--- a/activerecord/test/cases/type/unsigned_integer_test.rb
+++ b/activerecord/test/cases/type/unsigned_integer_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/type_test.rb b/activerecord/test/cases/type_test.rb
index d45a9b3141..93ae563c8b 100644
--- a/activerecord/test/cases/type_test.rb
+++ b/activerecord/test/cases/type_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class TypeTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/types_test.rb b/activerecord/test/cases/types_test.rb
index 11476ea0ef..3f7fb0a604 100644
--- a/activerecord/test/cases/types_test.rb
+++ b/activerecord/test/cases/types_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 module ActiveRecord
diff --git a/activerecord/test/cases/unconnected_test.rb b/activerecord/test/cases/unconnected_test.rb
index b210584644..f4d8be5897 100644
--- a/activerecord/test/cases/unconnected_test.rb
+++ b/activerecord/test/cases/unconnected_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 
 class TestRecord < ActiveRecord::Base
diff --git a/activerecord/test/cases/validations/absence_validation_test.rb b/activerecord/test/cases/validations/absence_validation_test.rb
index 870619e4e7..a997f8be9c 100644
--- a/activerecord/test/cases/validations/absence_validation_test.rb
+++ b/activerecord/test/cases/validations/absence_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/face"
 require "models/interest"
diff --git a/activerecord/test/cases/validations/association_validation_test.rb b/activerecord/test/cases/validations/association_validation_test.rb
index f5ceb27d97..80fe375ae5 100644
--- a/activerecord/test/cases/validations/association_validation_test.rb
+++ b/activerecord/test/cases/validations/association_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb b/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
index a57065ba75..703c24b340 100644
--- a/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
+++ b/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 
diff --git a/activerecord/test/cases/validations/i18n_validation_test.rb b/activerecord/test/cases/validations/i18n_validation_test.rb
index fd88a3ea67..b7c52ea18c 100644
--- a/activerecord/test/cases/validations/i18n_validation_test.rb
+++ b/activerecord/test/cases/validations/i18n_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/validations/length_validation_test.rb b/activerecord/test/cases/validations/length_validation_test.rb
index ba45c6dcc1..87ce4c6f37 100644
--- a/activerecord/test/cases/validations/length_validation_test.rb
+++ b/activerecord/test/cases/validations/length_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/owner"
 require "models/pet"
diff --git a/activerecord/test/cases/validations/presence_validation_test.rb b/activerecord/test/cases/validations/presence_validation_test.rb
index 13956e26ec..3ab1567b51 100644
--- a/activerecord/test/cases/validations/presence_validation_test.rb
+++ b/activerecord/test/cases/validations/presence_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/man"
 require "models/face"
diff --git a/activerecord/test/cases/validations/uniqueness_validation_test.rb b/activerecord/test/cases/validations/uniqueness_validation_test.rb
index 28605d2f8e..fad55916c7 100644
--- a/activerecord/test/cases/validations/uniqueness_validation_test.rb
+++ b/activerecord/test/cases/validations/uniqueness_validation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/validations_repair_helper.rb b/activerecord/test/cases/validations_repair_helper.rb
index b30666d876..6dc3b64b2b 100644
--- a/activerecord/test/cases/validations_repair_helper.rb
+++ b/activerecord/test/cases/validations_repair_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ValidationsRepairHelper
     extend ActiveSupport::Concern
diff --git a/activerecord/test/cases/validations_test.rb b/activerecord/test/cases/validations_test.rb
index a305aa295a..7f84939027 100644
--- a/activerecord/test/cases/validations_test.rb
+++ b/activerecord/test/cases/validations_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/cases/view_test.rb b/activerecord/test/cases/view_test.rb
index 1d21a2454f..7e2d66c62a 100644
--- a/activerecord/test/cases/view_test.rb
+++ b/activerecord/test/cases/view_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/book"
 require "support/schema_dumping_helper"
diff --git a/activerecord/test/cases/yaml_serialization_test.rb b/activerecord/test/cases/yaml_serialization_test.rb
index dd8d2c1178..578881f754 100644
--- a/activerecord/test/cases/yaml_serialization_test.rb
+++ b/activerecord/test/cases/yaml_serialization_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cases/helper"
 require "models/topic"
 require "models/reply"
diff --git a/activerecord/test/config.rb b/activerecord/test/config.rb
index a65e6ff776..72cdfb16ef 100644
--- a/activerecord/test/config.rb
+++ b/activerecord/test/config.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 TEST_ROOT       = __dir__
 ASSETS_ROOT     = TEST_ROOT + "/assets"
 FIXTURES_ROOT   = TEST_ROOT + "/fixtures"
diff --git a/activerecord/test/migrations/10_urban/9_add_expressions.rb b/activerecord/test/migrations/10_urban/9_add_expressions.rb
index e908c9eabc..4b0d5fb6fa 100644
--- a/activerecord/test/migrations/10_urban/9_add_expressions.rb
+++ b/activerecord/test/migrations/10_urban/9_add_expressions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddExpressions < ActiveRecord::Migration::Current
   def self.up
     create_table("expressions") do |t|
diff --git a/activerecord/test/migrations/decimal/1_give_me_big_numbers.rb b/activerecord/test/migrations/decimal/1_give_me_big_numbers.rb
index 43c79bc20b..b892f50e41 100644
--- a/activerecord/test/migrations/decimal/1_give_me_big_numbers.rb
+++ b/activerecord/test/migrations/decimal/1_give_me_big_numbers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GiveMeBigNumbers < ActiveRecord::Migration::Current
   def self.up
     create_table :big_numbers do |table|
diff --git a/activerecord/test/migrations/missing/1000_people_have_middle_names.rb b/activerecord/test/migrations/missing/1000_people_have_middle_names.rb
index e046944e31..d3c9b127fb 100644
--- a/activerecord/test/migrations/missing/1000_people_have_middle_names.rb
+++ b/activerecord/test/migrations/missing/1000_people_have_middle_names.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveMiddleNames < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "middle_name", :string
diff --git a/activerecord/test/migrations/missing/1_people_have_last_names.rb b/activerecord/test/migrations/missing/1_people_have_last_names.rb
index 50fe2a9c8e..bd5f5ea11e 100644
--- a/activerecord/test/migrations/missing/1_people_have_last_names.rb
+++ b/activerecord/test/migrations/missing/1_people_have_last_names.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveLastNames < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "last_name", :string
diff --git a/activerecord/test/migrations/missing/3_we_need_reminders.rb b/activerecord/test/migrations/missing/3_we_need_reminders.rb
index d7c63ac892..4647268c6e 100644
--- a/activerecord/test/migrations/missing/3_we_need_reminders.rb
+++ b/activerecord/test/migrations/missing/3_we_need_reminders.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WeNeedReminders < ActiveRecord::Migration::Current
   def self.up
     create_table("reminders") do |t|
diff --git a/activerecord/test/migrations/missing/4_innocent_jointable.rb b/activerecord/test/migrations/missing/4_innocent_jointable.rb
index bd3bf21576..8063bc0558 100644
--- a/activerecord/test/migrations/missing/4_innocent_jointable.rb
+++ b/activerecord/test/migrations/missing/4_innocent_jointable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class InnocentJointable < ActiveRecord::Migration::Current
   def self.up
     create_table("people_reminders", id: false) do |t|
diff --git a/activerecord/test/migrations/rename/1_we_need_things.rb b/activerecord/test/migrations/rename/1_we_need_things.rb
index 9dce01acfd..8e71a1d996 100644
--- a/activerecord/test/migrations/rename/1_we_need_things.rb
+++ b/activerecord/test/migrations/rename/1_we_need_things.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WeNeedThings < ActiveRecord::Migration::Current
   def self.up
     create_table("things") do |t|
diff --git a/activerecord/test/migrations/rename/2_rename_things.rb b/activerecord/test/migrations/rename/2_rename_things.rb
index cb8484e7dc..110fe3f0fa 100644
--- a/activerecord/test/migrations/rename/2_rename_things.rb
+++ b/activerecord/test/migrations/rename/2_rename_things.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameThings < ActiveRecord::Migration::Current
   def self.up
     rename_table "things", "awesome_things"
diff --git a/activerecord/test/migrations/to_copy/1_people_have_hobbies.rb b/activerecord/test/migrations/to_copy/1_people_have_hobbies.rb
index 76734bcd7d..badccf65cc 100644
--- a/activerecord/test/migrations/to_copy/1_people_have_hobbies.rb
+++ b/activerecord/test/migrations/to_copy/1_people_have_hobbies.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveHobbies < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "hobbies", :text
diff --git a/activerecord/test/migrations/to_copy/2_people_have_descriptions.rb b/activerecord/test/migrations/to_copy/2_people_have_descriptions.rb
index 7f883dbb45..1d19d5d6f4 100644
--- a/activerecord/test/migrations/to_copy/2_people_have_descriptions.rb
+++ b/activerecord/test/migrations/to_copy/2_people_have_descriptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveDescriptions < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "description", :text
diff --git a/activerecord/test/migrations/to_copy2/1_create_articles.rb b/activerecord/test/migrations/to_copy2/1_create_articles.rb
index 2e9f5ec6bc..85c166b319 100644
--- a/activerecord/test/migrations/to_copy2/1_create_articles.rb
+++ b/activerecord/test/migrations/to_copy2/1_create_articles.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateArticles < ActiveRecord::Migration::Current
   def self.up
   end
diff --git a/activerecord/test/migrations/to_copy2/2_create_comments.rb b/activerecord/test/migrations/to_copy2/2_create_comments.rb
index d361847d4b..1d213a1705 100644
--- a/activerecord/test/migrations/to_copy2/2_create_comments.rb
+++ b/activerecord/test/migrations/to_copy2/2_create_comments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateComments < ActiveRecord::Migration::Current
   def self.up
   end
diff --git a/activerecord/test/migrations/to_copy_with_name_collision/1_people_have_hobbies.rb b/activerecord/test/migrations/to_copy_with_name_collision/1_people_have_hobbies.rb
index 1a863367dd..d9fef596f5 100644
--- a/activerecord/test/migrations/to_copy_with_name_collision/1_people_have_hobbies.rb
+++ b/activerecord/test/migrations/to_copy_with_name_collision/1_people_have_hobbies.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveHobbies < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "hobbies", :string
diff --git a/activerecord/test/migrations/to_copy_with_timestamps/20090101010101_people_have_hobbies.rb b/activerecord/test/migrations/to_copy_with_timestamps/20090101010101_people_have_hobbies.rb
index 76734bcd7d..badccf65cc 100644
--- a/activerecord/test/migrations/to_copy_with_timestamps/20090101010101_people_have_hobbies.rb
+++ b/activerecord/test/migrations/to_copy_with_timestamps/20090101010101_people_have_hobbies.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveHobbies < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "hobbies", :text
diff --git a/activerecord/test/migrations/to_copy_with_timestamps/20090101010202_people_have_descriptions.rb b/activerecord/test/migrations/to_copy_with_timestamps/20090101010202_people_have_descriptions.rb
index 7f883dbb45..1d19d5d6f4 100644
--- a/activerecord/test/migrations/to_copy_with_timestamps/20090101010202_people_have_descriptions.rb
+++ b/activerecord/test/migrations/to_copy_with_timestamps/20090101010202_people_have_descriptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PeopleHaveDescriptions < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "description", :text
diff --git a/activerecord/test/migrations/to_copy_with_timestamps2/20090101010101_create_articles.rb b/activerecord/test/migrations/to_copy_with_timestamps2/20090101010101_create_articles.rb
index 2e9f5ec6bc..85c166b319 100644
--- a/activerecord/test/migrations/to_copy_with_timestamps2/20090101010101_create_articles.rb
+++ b/activerecord/test/migrations/to_copy_with_timestamps2/20090101010101_create_articles.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateArticles < ActiveRecord::Migration::Current
   def self.up
   end
diff --git a/activerecord/test/migrations/to_copy_with_timestamps2/20090101010202_create_comments.rb b/activerecord/test/migrations/to_copy_with_timestamps2/20090101010202_create_comments.rb
index d361847d4b..1d213a1705 100644
--- a/activerecord/test/migrations/to_copy_with_timestamps2/20090101010202_create_comments.rb
+++ b/activerecord/test/migrations/to_copy_with_timestamps2/20090101010202_create_comments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateComments < ActiveRecord::Migration::Current
   def self.up
   end
diff --git a/activerecord/test/migrations/valid/1_valid_people_have_last_names.rb b/activerecord/test/migrations/valid/1_valid_people_have_last_names.rb
index c450211d8c..3bedcdcdf0 100644
--- a/activerecord/test/migrations/valid/1_valid_people_have_last_names.rb
+++ b/activerecord/test/migrations/valid/1_valid_people_have_last_names.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ValidPeopleHaveLastNames < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "last_name", :string
diff --git a/activerecord/test/migrations/valid/2_we_need_reminders.rb b/activerecord/test/migrations/valid/2_we_need_reminders.rb
index d7c63ac892..4647268c6e 100644
--- a/activerecord/test/migrations/valid/2_we_need_reminders.rb
+++ b/activerecord/test/migrations/valid/2_we_need_reminders.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WeNeedReminders < ActiveRecord::Migration::Current
   def self.up
     create_table("reminders") do |t|
diff --git a/activerecord/test/migrations/valid/3_innocent_jointable.rb b/activerecord/test/migrations/valid/3_innocent_jointable.rb
index bd3bf21576..8063bc0558 100644
--- a/activerecord/test/migrations/valid/3_innocent_jointable.rb
+++ b/activerecord/test/migrations/valid/3_innocent_jointable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class InnocentJointable < ActiveRecord::Migration::Current
   def self.up
     create_table("people_reminders", id: false) do |t|
diff --git a/activerecord/test/migrations/valid_with_subdirectories/1_valid_people_have_last_names.rb b/activerecord/test/migrations/valid_with_subdirectories/1_valid_people_have_last_names.rb
index c450211d8c..3bedcdcdf0 100644
--- a/activerecord/test/migrations/valid_with_subdirectories/1_valid_people_have_last_names.rb
+++ b/activerecord/test/migrations/valid_with_subdirectories/1_valid_people_have_last_names.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ValidPeopleHaveLastNames < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "last_name", :string
diff --git a/activerecord/test/migrations/valid_with_subdirectories/sub/2_we_need_reminders.rb b/activerecord/test/migrations/valid_with_subdirectories/sub/2_we_need_reminders.rb
index d7c63ac892..4647268c6e 100644
--- a/activerecord/test/migrations/valid_with_subdirectories/sub/2_we_need_reminders.rb
+++ b/activerecord/test/migrations/valid_with_subdirectories/sub/2_we_need_reminders.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WeNeedReminders < ActiveRecord::Migration::Current
   def self.up
     create_table("reminders") do |t|
diff --git a/activerecord/test/migrations/valid_with_subdirectories/sub1/3_innocent_jointable.rb b/activerecord/test/migrations/valid_with_subdirectories/sub1/3_innocent_jointable.rb
index bd3bf21576..8063bc0558 100644
--- a/activerecord/test/migrations/valid_with_subdirectories/sub1/3_innocent_jointable.rb
+++ b/activerecord/test/migrations/valid_with_subdirectories/sub1/3_innocent_jointable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class InnocentJointable < ActiveRecord::Migration::Current
   def self.up
     create_table("people_reminders", id: false) do |t|
diff --git a/activerecord/test/migrations/valid_with_timestamps/20100101010101_valid_with_timestamps_people_have_last_names.rb b/activerecord/test/migrations/valid_with_timestamps/20100101010101_valid_with_timestamps_people_have_last_names.rb
index 9fd27593f0..b938847170 100644
--- a/activerecord/test/migrations/valid_with_timestamps/20100101010101_valid_with_timestamps_people_have_last_names.rb
+++ b/activerecord/test/migrations/valid_with_timestamps/20100101010101_valid_with_timestamps_people_have_last_names.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ValidWithTimestampsPeopleHaveLastNames < ActiveRecord::Migration::Current
   def self.up
     add_column "people", "last_name", :string
diff --git a/activerecord/test/migrations/valid_with_timestamps/20100201010101_valid_with_timestamps_we_need_reminders.rb b/activerecord/test/migrations/valid_with_timestamps/20100201010101_valid_with_timestamps_we_need_reminders.rb
index 4a59921136..94551e8208 100644
--- a/activerecord/test/migrations/valid_with_timestamps/20100201010101_valid_with_timestamps_we_need_reminders.rb
+++ b/activerecord/test/migrations/valid_with_timestamps/20100201010101_valid_with_timestamps_we_need_reminders.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ValidWithTimestampsWeNeedReminders < ActiveRecord::Migration::Current
   def self.up
     create_table("reminders") do |t|
diff --git a/activerecord/test/migrations/valid_with_timestamps/20100301010101_valid_with_timestamps_innocent_jointable.rb b/activerecord/test/migrations/valid_with_timestamps/20100301010101_valid_with_timestamps_innocent_jointable.rb
index be24de6d70..672edc5253 100644
--- a/activerecord/test/migrations/valid_with_timestamps/20100301010101_valid_with_timestamps_innocent_jointable.rb
+++ b/activerecord/test/migrations/valid_with_timestamps/20100301010101_valid_with_timestamps_innocent_jointable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ValidWithTimestampsInnocentJointable < ActiveRecord::Migration::Current
   def self.up
     create_table("people_reminders", id: false) do |t|
diff --git a/activerecord/test/migrations/version_check/20131219224947_migration_version_check.rb b/activerecord/test/migrations/version_check/20131219224947_migration_version_check.rb
index 6f314c881c..91bfbbdfd1 100644
--- a/activerecord/test/migrations/version_check/20131219224947_migration_version_check.rb
+++ b/activerecord/test/migrations/version_check/20131219224947_migration_version_check.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MigrationVersionCheck < ActiveRecord::Migration::Current
   def self.up
     raise "incorrect migration version" unless version == 20131219224947
diff --git a/activerecord/test/models/account.rb b/activerecord/test/models/account.rb
new file mode 100644
index 0000000000..0c3cd45a81
--- /dev/null
+++ b/activerecord/test/models/account.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class Account < ActiveRecord::Base
+  belongs_to :firm, class_name: "Company"
+  belongs_to :unautosaved_firm, foreign_key: "firm_id", class_name: "Firm", autosave: false
+
+  alias_attribute :available_credit, :credit_limit
+
+  def self.destroyed_account_ids
+    @destroyed_account_ids ||= Hash.new { |h, k| h[k] = [] }
+  end
+
+  # Test private kernel method through collection proxy using has_many.
+  def self.open
+    where("firm_name = ?", "37signals")
+  end
+
+  before_destroy do |account|
+    if account.firm
+      Account.destroyed_account_ids[account.firm.id] << account.id
+    end
+  end
+
+  validate :check_empty_credit_limit
+
+  private
+    def check_empty_credit_limit
+      errors.add("credit_limit", :blank) if credit_limit.blank?
+    end
+
+    def private_method
+      "Sir, yes sir!"
+    end
+end
diff --git a/activerecord/test/models/admin.rb b/activerecord/test/models/admin.rb
index bc3ce23447..a40b5a33b2 100644
--- a/activerecord/test/models/admin.rb
+++ b/activerecord/test/models/admin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   def self.table_name_prefix
     "admin_"
diff --git a/activerecord/test/models/admin/account.rb b/activerecord/test/models/admin/account.rb
index bd23192d20..41fe2d782b 100644
--- a/activerecord/test/models/admin/account.rb
+++ b/activerecord/test/models/admin/account.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Admin::Account < ActiveRecord::Base
   has_many :users
 end
diff --git a/activerecord/test/models/admin/randomly_named_c1.rb b/activerecord/test/models/admin/randomly_named_c1.rb
index b64ae7fc41..d89b8dd293 100644
--- a/activerecord/test/models/admin/randomly_named_c1.rb
+++ b/activerecord/test/models/admin/randomly_named_c1.rb
@@ -1,7 +1,9 @@
-class Admin::ClassNameThatDoesNotFollowCONVENTIONS1 < ActiveRecord::Base
-  self.table_name = :randomly_named_table2
-end
-
-class Admin::ClassNameThatDoesNotFollowCONVENTIONS2 < ActiveRecord::Base
-  self.table_name = :randomly_named_table3
-end
+# frozen_string_literal: true
+
+class Admin::ClassNameThatDoesNotFollowCONVENTIONS1 < ActiveRecord::Base
+  self.table_name = :randomly_named_table2
+end
+
+class Admin::ClassNameThatDoesNotFollowCONVENTIONS2 < ActiveRecord::Base
+  self.table_name = :randomly_named_table3
+end
diff --git a/activerecord/test/models/admin/user.rb b/activerecord/test/models/admin/user.rb
index a76e4b6795..abb5cb28e7 100644
--- a/activerecord/test/models/admin/user.rb
+++ b/activerecord/test/models/admin/user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Admin::User < ActiveRecord::Base
   class Coder
     def initialize(default = {})
diff --git a/activerecord/test/models/aircraft.rb b/activerecord/test/models/aircraft.rb
index ebd42ff824..4fdea46cf7 100644
--- a/activerecord/test/models/aircraft.rb
+++ b/activerecord/test/models/aircraft.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Aircraft < ActiveRecord::Base
   self.pluralize_table_names = false
   has_many :engines, foreign_key: "car_id"
diff --git a/activerecord/test/models/arunit2_model.rb b/activerecord/test/models/arunit2_model.rb
index 04b8b15d3d..5b0da8a249 100644
--- a/activerecord/test/models/arunit2_model.rb
+++ b/activerecord/test/models/arunit2_model.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ARUnit2Model < ActiveRecord::Base
   self.abstract_class = true
 end
diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index 2d9cba77e0..09958ca257 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Author < ActiveRecord::Base
   has_many :posts
   has_many :serialized_posts
diff --git a/activerecord/test/models/auto_id.rb b/activerecord/test/models/auto_id.rb
index 82c6544bd5..fd672603bb 100644
--- a/activerecord/test/models/auto_id.rb
+++ b/activerecord/test/models/auto_id.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AutoId < ActiveRecord::Base
   self.table_name = "auto_id_tests"
   self.primary_key = "auto_id"
diff --git a/activerecord/test/models/autoloadable/extra_firm.rb b/activerecord/test/models/autoloadable/extra_firm.rb
index 5578ba0d9b..c46e34c101 100644
--- a/activerecord/test/models/autoloadable/extra_firm.rb
+++ b/activerecord/test/models/autoloadable/extra_firm.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ExtraFirm < Company
 end
diff --git a/activerecord/test/models/binary.rb b/activerecord/test/models/binary.rb
index 39b2f5090a..b93f87519f 100644
--- a/activerecord/test/models/binary.rb
+++ b/activerecord/test/models/binary.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Binary < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/bird.rb b/activerecord/test/models/bird.rb
index 24b839135d..be08636ac6 100644
--- a/activerecord/test/models/bird.rb
+++ b/activerecord/test/models/bird.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Bird < ActiveRecord::Base
   belongs_to :pirate
   validates_presence_of :name
diff --git a/activerecord/test/models/book.rb b/activerecord/test/models/book.rb
index 6466e1b341..afdda1a81e 100644
--- a/activerecord/test/models/book.rb
+++ b/activerecord/test/models/book.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Book < ActiveRecord::Base
   belongs_to :author
 
diff --git a/activerecord/test/models/boolean.rb b/activerecord/test/models/boolean.rb
index 0da228aac2..bee757fb9c 100644
--- a/activerecord/test/models/boolean.rb
+++ b/activerecord/test/models/boolean.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Boolean < ActiveRecord::Base
   def has_fun
     super
diff --git a/activerecord/test/models/bulb.rb b/activerecord/test/models/bulb.rb
index 113d21cb84..ab92f7025d 100644
--- a/activerecord/test/models/bulb.rb
+++ b/activerecord/test/models/bulb.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Bulb < ActiveRecord::Base
   default_scope { where(name: "defaulty") }
   belongs_to :car, touch: true
diff --git a/activerecord/test/models/cake_designer.rb b/activerecord/test/models/cake_designer.rb
index 9c57ef573a..0b2a00edfd 100644
--- a/activerecord/test/models/cake_designer.rb
+++ b/activerecord/test/models/cake_designer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CakeDesigner < ActiveRecord::Base
   has_one :chef, as: :employable
 end
diff --git a/activerecord/test/models/car.rb b/activerecord/test/models/car.rb
index 92bff7ff96..3d6a7a96c2 100644
--- a/activerecord/test/models/car.rb
+++ b/activerecord/test/models/car.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Car < ActiveRecord::Base
   has_many :bulbs
   has_many :all_bulbs, -> { unscope where: :name }, class_name: "Bulb"
diff --git a/activerecord/test/models/carrier.rb b/activerecord/test/models/carrier.rb
index 230be118c3..995a9d3bef 100644
--- a/activerecord/test/models/carrier.rb
+++ b/activerecord/test/models/carrier.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Carrier < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/cat.rb b/activerecord/test/models/cat.rb
index dfdde18641..43013964b6 100644
--- a/activerecord/test/models/cat.rb
+++ b/activerecord/test/models/cat.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Cat < ActiveRecord::Base
   self.abstract_class = true
 
diff --git a/activerecord/test/models/categorization.rb b/activerecord/test/models/categorization.rb
index b99383d0b1..68b0ea90d3 100644
--- a/activerecord/test/models/categorization.rb
+++ b/activerecord/test/models/categorization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Categorization < ActiveRecord::Base
   belongs_to :post
   belongs_to :category, counter_cache: true
diff --git a/activerecord/test/models/category.rb b/activerecord/test/models/category.rb
index 4b2840c653..2ccc00bed9 100644
--- a/activerecord/test/models/category.rb
+++ b/activerecord/test/models/category.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Category < ActiveRecord::Base
   has_and_belongs_to_many :posts
   has_and_belongs_to_many :special_posts, class_name: "Post"
diff --git a/activerecord/test/models/chef.rb b/activerecord/test/models/chef.rb
index 9d3dd01016..ff528644bc 100644
--- a/activerecord/test/models/chef.rb
+++ b/activerecord/test/models/chef.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Chef < ActiveRecord::Base
   belongs_to :employable, polymorphic: true
   has_many :recipes
diff --git a/activerecord/test/models/citation.rb b/activerecord/test/models/citation.rb
index 7d06387f56..3d786f27eb 100644
--- a/activerecord/test/models/citation.rb
+++ b/activerecord/test/models/citation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Citation < ActiveRecord::Base
   belongs_to :reference_of, class_name: "Book", foreign_key: :book2_id
 end
diff --git a/activerecord/test/models/club.rb b/activerecord/test/models/club.rb
index 3d441b1d48..2006e05fcf 100644
--- a/activerecord/test/models/club.rb
+++ b/activerecord/test/models/club.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Club < ActiveRecord::Base
   has_one :membership
   has_many :memberships, inverse_of: false
diff --git a/activerecord/test/models/college.rb b/activerecord/test/models/college.rb
index c9dbe1ecc2..52017dda42 100644
--- a/activerecord/test/models/college.rb
+++ b/activerecord/test/models/college.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "models/arunit2_model"
 require "active_support/core_ext/object/with_options"
 
diff --git a/activerecord/test/models/column.rb b/activerecord/test/models/column.rb
index 499358b4cf..d3cd419a00 100644
--- a/activerecord/test/models/column.rb
+++ b/activerecord/test/models/column.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Column < ActiveRecord::Base
   belongs_to :record
 end
diff --git a/activerecord/test/models/column_name.rb b/activerecord/test/models/column_name.rb
index 460eb4fe20..c6047c507b 100644
--- a/activerecord/test/models/column_name.rb
+++ b/activerecord/test/models/column_name.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ColumnName < ActiveRecord::Base
   self.table_name = "colnametests"
 end
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index eecf923046..61c54a77a7 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Comment < ActiveRecord::Base
   scope :limit_by, lambda { |l| limit(l) }
   scope :containing_the_letter_e, -> { where("comments.body LIKE '%e%'") }
@@ -54,6 +56,7 @@ class Comment < ActiveRecord::Base
 end
 
 class SpecialComment < Comment
+  default_scope { where(deleted_at: nil) }
 end
 
 class SubSpecialComment < SpecialComment
@@ -74,3 +77,9 @@ class CommentWithDefaultScopeReferencesAssociation < Comment
   default_scope -> { includes(:developer).order("developers.name").references(:developer) }
   belongs_to :developer
 end
+
+class CommentWithAfterCreateUpdate < Comment
+  after_create do
+    update_attributes(body: "bar")
+  end
+end
diff --git a/activerecord/test/models/company.rb b/activerecord/test/models/company.rb
index c6a5bf1c92..bbc5fc2b2d 100644
--- a/activerecord/test/models/company.rb
+++ b/activerecord/test/models/company.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AbstractCompany < ActiveRecord::Base
   self.abstract_class = true
 end
@@ -185,37 +187,4 @@ end
 class VerySpecialClient < SpecialClient
 end
 
-class Account < ActiveRecord::Base
-  belongs_to :firm, class_name: "Company"
-  belongs_to :unautosaved_firm, foreign_key: "firm_id", class_name: "Firm", autosave: false
-
-  alias_attribute :available_credit, :credit_limit
-
-  def self.destroyed_account_ids
-    @destroyed_account_ids ||= Hash.new { |h, k| h[k] = [] }
-  end
-
-  # Test private kernel method through collection proxy using has_many.
-  def self.open
-    where("firm_name = ?", "37signals")
-  end
-
-  before_destroy do |account|
-    if account.firm
-      Account.destroyed_account_ids[account.firm.id] << account.id
-    end
-    true
-  end
-
-  validate :check_empty_credit_limit
-
-  private
-
-    def check_empty_credit_limit
-      errors.add("credit_limit", :blank) if credit_limit.blank?
-    end
-
-    def private_method
-      "Sir, yes sir!"
-    end
-end
+require "models/account"
diff --git a/activerecord/test/models/company_in_module.rb b/activerecord/test/models/company_in_module.rb
index 0782c1eff4..52b7e06a63 100644
--- a/activerecord/test/models/company_in_module.rb
+++ b/activerecord/test/models/company_in_module.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/core_ext/object/with_options"
 
 module MyApplication
diff --git a/activerecord/test/models/computer.rb b/activerecord/test/models/computer.rb
index 1c9856e1af..582b4a38b5 100644
--- a/activerecord/test/models/computer.rb
+++ b/activerecord/test/models/computer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Computer < ActiveRecord::Base
   belongs_to :developer, foreign_key: "developer"
 end
diff --git a/activerecord/test/models/contact.rb b/activerecord/test/models/contact.rb
index 47bbbbfd8b..6e02ff199b 100644
--- a/activerecord/test/models/contact.rb
+++ b/activerecord/test/models/contact.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContactFakeColumns
   def self.extended(base)
     base.class_eval do
diff --git a/activerecord/test/models/content.rb b/activerecord/test/models/content.rb
index 68db2127d8..14bbee53d8 100644
--- a/activerecord/test/models/content.rb
+++ b/activerecord/test/models/content.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Content < ActiveRecord::Base
   self.table_name = "content"
   has_one :content_position, dependent: :destroy
diff --git a/activerecord/test/models/contract.rb b/activerecord/test/models/contract.rb
index 32bd581377..9454217e8d 100644
--- a/activerecord/test/models/contract.rb
+++ b/activerecord/test/models/contract.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Contract < ActiveRecord::Base
   belongs_to :company
   belongs_to :developer
diff --git a/activerecord/test/models/country.rb b/activerecord/test/models/country.rb
index 7912719ddd..0c84a40de2 100644
--- a/activerecord/test/models/country.rb
+++ b/activerecord/test/models/country.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Country < ActiveRecord::Base
   self.primary_key = :country_id
 
diff --git a/activerecord/test/models/course.rb b/activerecord/test/models/course.rb
index 348f2bf1e0..4f346124ea 100644
--- a/activerecord/test/models/course.rb
+++ b/activerecord/test/models/course.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "models/arunit2_model"
 
 class Course < ARUnit2Model
diff --git a/activerecord/test/models/customer.rb b/activerecord/test/models/customer.rb
index 3d40cb1ace..524a9d7bd9 100644
--- a/activerecord/test/models/customer.rb
+++ b/activerecord/test/models/customer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Customer < ActiveRecord::Base
   cattr_accessor :gps_conversion_was_run
 
diff --git a/activerecord/test/models/customer_carrier.rb b/activerecord/test/models/customer_carrier.rb
index 37186903ff..6cb9d5239d 100644
--- a/activerecord/test/models/customer_carrier.rb
+++ b/activerecord/test/models/customer_carrier.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CustomerCarrier < ActiveRecord::Base
   cattr_accessor :current_customer
 
diff --git a/activerecord/test/models/dashboard.rb b/activerecord/test/models/dashboard.rb
index 1b3b54545f..d25ceeafb1 100644
--- a/activerecord/test/models/dashboard.rb
+++ b/activerecord/test/models/dashboard.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Dashboard < ActiveRecord::Base
   self.primary_key = :dashboard_id
 end
diff --git a/activerecord/test/models/default.rb b/activerecord/test/models/default.rb
index 887e9cc999..90f1046d87 100644
--- a/activerecord/test/models/default.rb
+++ b/activerecord/test/models/default.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Default < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/department.rb b/activerecord/test/models/department.rb
index 08004a0ed3..868b9bf4bf 100644
--- a/activerecord/test/models/department.rb
+++ b/activerecord/test/models/department.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Department < ActiveRecord::Base
   has_many :chefs
   belongs_to :hotel
diff --git a/activerecord/test/models/developer.rb b/activerecord/test/models/developer.rb
index 654830ba11..56aafca60b 100644
--- a/activerecord/test/models/developer.rb
+++ b/activerecord/test/models/developer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "ostruct"
 
 module DeveloperProjectsAssociationExtension2
diff --git a/activerecord/test/models/dog.rb b/activerecord/test/models/dog.rb
index b02b8447b8..75d284ac25 100644
--- a/activerecord/test/models/dog.rb
+++ b/activerecord/test/models/dog.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Dog < ActiveRecord::Base
   belongs_to :breeder, class_name: "DogLover", counter_cache: :bred_dogs_count
   belongs_to :trainer, class_name: "DogLover", counter_cache: :trained_dogs_count
diff --git a/activerecord/test/models/dog_lover.rb b/activerecord/test/models/dog_lover.rb
index 2c5be94aea..aabe914f77 100644
--- a/activerecord/test/models/dog_lover.rb
+++ b/activerecord/test/models/dog_lover.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DogLover < ActiveRecord::Base
   has_many :trained_dogs, class_name: "Dog", foreign_key: :trainer_id, dependent: :destroy
   has_many :bred_dogs, class_name: "Dog", foreign_key: :breeder_id
diff --git a/activerecord/test/models/doubloon.rb b/activerecord/test/models/doubloon.rb
index 7272504666..febadc3a5a 100644
--- a/activerecord/test/models/doubloon.rb
+++ b/activerecord/test/models/doubloon.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AbstractDoubloon < ActiveRecord::Base
   # This has functionality that might be shared by multiple classes.
 
diff --git a/activerecord/test/models/drink_designer.rb b/activerecord/test/models/drink_designer.rb
index 2db968ef11..1c407844c5 100644
--- a/activerecord/test/models/drink_designer.rb
+++ b/activerecord/test/models/drink_designer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DrinkDesigner < ActiveRecord::Base
   has_one :chef, as: :employable
 end
diff --git a/activerecord/test/models/edge.rb b/activerecord/test/models/edge.rb
index e61d25c9bc..a04ab103de 100644
--- a/activerecord/test/models/edge.rb
+++ b/activerecord/test/models/edge.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This class models an edge in a directed graph.
 class Edge < ActiveRecord::Base
   belongs_to :source, class_name: "Vertex", foreign_key: "source_id"
diff --git a/activerecord/test/models/electron.rb b/activerecord/test/models/electron.rb
index 6fc270673f..902006b314 100644
--- a/activerecord/test/models/electron.rb
+++ b/activerecord/test/models/electron.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Electron < ActiveRecord::Base
   belongs_to :molecule
 
diff --git a/activerecord/test/models/engine.rb b/activerecord/test/models/engine.rb
index eada171f6a..396a52b3b9 100644
--- a/activerecord/test/models/engine.rb
+++ b/activerecord/test/models/engine.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Engine < ActiveRecord::Base
   belongs_to :my_car, class_name: "Car", foreign_key: "car_id",  counter_cache: :engines_count
 end
diff --git a/activerecord/test/models/entrant.rb b/activerecord/test/models/entrant.rb
index 4682ce48c8..2c086e451f 100644
--- a/activerecord/test/models/entrant.rb
+++ b/activerecord/test/models/entrant.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Entrant < ActiveRecord::Base
   belongs_to :course
 end
diff --git a/activerecord/test/models/essay.rb b/activerecord/test/models/essay.rb
index 1f9772870e..e59db4d877 100644
--- a/activerecord/test/models/essay.rb
+++ b/activerecord/test/models/essay.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Essay < ActiveRecord::Base
   belongs_to :author
   belongs_to :writer, primary_key: :name, polymorphic: true
diff --git a/activerecord/test/models/event.rb b/activerecord/test/models/event.rb
index 365ab32b0b..a7cdc39e5c 100644
--- a/activerecord/test/models/event.rb
+++ b/activerecord/test/models/event.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Event < ActiveRecord::Base
   validates_uniqueness_of :title
 end
diff --git a/activerecord/test/models/eye.rb b/activerecord/test/models/eye.rb
index f53c34e4b1..f3608b62ef 100644
--- a/activerecord/test/models/eye.rb
+++ b/activerecord/test/models/eye.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Eye < ActiveRecord::Base
   attr_reader :after_create_callbacks_stack
   attr_reader :after_update_callbacks_stack
diff --git a/activerecord/test/models/face.rb b/activerecord/test/models/face.rb
index 5913bfa969..796aaa4dc9 100644
--- a/activerecord/test/models/face.rb
+++ b/activerecord/test/models/face.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Face < ActiveRecord::Base
   belongs_to :man, inverse_of: :face
   belongs_to :polymorphic_man, polymorphic: true, inverse_of: :polymorphic_face
diff --git a/activerecord/test/models/family.rb b/activerecord/test/models/family.rb
index 5ae5a78c95..0713dba1a6 100644
--- a/activerecord/test/models/family.rb
+++ b/activerecord/test/models/family.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Family < ActiveRecord::Base
   has_many :family_trees, -> { where(token: nil) }
   has_many :members, through: :family_trees
diff --git a/activerecord/test/models/family_tree.rb b/activerecord/test/models/family_tree.rb
index cd9829fedd..a8ea907c05 100644
--- a/activerecord/test/models/family_tree.rb
+++ b/activerecord/test/models/family_tree.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FamilyTree < ActiveRecord::Base
   belongs_to :member, class_name: "User", foreign_key: "member_id"
   belongs_to :family
diff --git a/activerecord/test/models/friendship.rb b/activerecord/test/models/friendship.rb
index 578382b494..9f1712a8ec 100644
--- a/activerecord/test/models/friendship.rb
+++ b/activerecord/test/models/friendship.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Friendship < ActiveRecord::Base
   belongs_to :friend, class_name: "Person"
   # friend_too exists to test a bug, and probably shouldn't be used elsewhere
diff --git a/activerecord/test/models/guid.rb b/activerecord/test/models/guid.rb
index 05653ba498..ec71c37690 100644
--- a/activerecord/test/models/guid.rb
+++ b/activerecord/test/models/guid.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Guid < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/guitar.rb b/activerecord/test/models/guitar.rb
index cd068ff53d..649b998665 100644
--- a/activerecord/test/models/guitar.rb
+++ b/activerecord/test/models/guitar.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Guitar < ActiveRecord::Base
   has_many :tuning_pegs, index_errors: true
   accepts_nested_attributes_for :tuning_pegs
diff --git a/activerecord/test/models/hotel.rb b/activerecord/test/models/hotel.rb
index 7bc717c891..1a433c3cab 100644
--- a/activerecord/test/models/hotel.rb
+++ b/activerecord/test/models/hotel.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Hotel < ActiveRecord::Base
   has_many :departments
   has_many :chefs, through: :departments
diff --git a/activerecord/test/models/image.rb b/activerecord/test/models/image.rb
index 7ae8e4a7f6..b4808293cc 100644
--- a/activerecord/test/models/image.rb
+++ b/activerecord/test/models/image.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Image < ActiveRecord::Base
   belongs_to :imageable, foreign_key: :imageable_identifier, foreign_type: :imageable_class
 end
diff --git a/activerecord/test/models/interest.rb b/activerecord/test/models/interest.rb
index ec79416ee7..899b8f9b9d 100644
--- a/activerecord/test/models/interest.rb
+++ b/activerecord/test/models/interest.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Interest < ActiveRecord::Base
   belongs_to :man, inverse_of: :interests
   belongs_to :polymorphic_man, polymorphic: true, inverse_of: :polymorphic_interests
diff --git a/activerecord/test/models/invoice.rb b/activerecord/test/models/invoice.rb
index 4be5a00193..1851792ed5 100644
--- a/activerecord/test/models/invoice.rb
+++ b/activerecord/test/models/invoice.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Invoice < ActiveRecord::Base
   has_many :line_items, autosave: true
   before_save { |record| record.balance = record.line_items.map(&:amount).sum }
diff --git a/activerecord/test/models/item.rb b/activerecord/test/models/item.rb
index 336fb1769a..8d079d56e6 100644
--- a/activerecord/test/models/item.rb
+++ b/activerecord/test/models/item.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AbstractItem < ActiveRecord::Base
   self.abstract_class = true
   has_one :tagging, as: :taggable
diff --git a/activerecord/test/models/job.rb b/activerecord/test/models/job.rb
index bbaef2792c..52817a8435 100644
--- a/activerecord/test/models/job.rb
+++ b/activerecord/test/models/job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Job < ActiveRecord::Base
   has_many :references
   has_many :people, through: :references
diff --git a/activerecord/test/models/joke.rb b/activerecord/test/models/joke.rb
index eeb5818a1f..436ffb6471 100644
--- a/activerecord/test/models/joke.rb
+++ b/activerecord/test/models/joke.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Joke < ActiveRecord::Base
   self.table_name = "funny_jokes"
 end
diff --git a/activerecord/test/models/keyboard.rb b/activerecord/test/models/keyboard.rb
index bcede53ec9..d200e0fb56 100644
--- a/activerecord/test/models/keyboard.rb
+++ b/activerecord/test/models/keyboard.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Keyboard < ActiveRecord::Base
   self.primary_key = "key_number"
 end
diff --git a/activerecord/test/models/legacy_thing.rb b/activerecord/test/models/legacy_thing.rb
index eead181a0e..e0210c8922 100644
--- a/activerecord/test/models/legacy_thing.rb
+++ b/activerecord/test/models/legacy_thing.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class LegacyThing < ActiveRecord::Base
   self.locking_column = :version
 end
diff --git a/activerecord/test/models/lesson.rb b/activerecord/test/models/lesson.rb
index 4c88153068..e546339689 100644
--- a/activerecord/test/models/lesson.rb
+++ b/activerecord/test/models/lesson.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class LessonError < Exception
 end
 
diff --git a/activerecord/test/models/line_item.rb b/activerecord/test/models/line_item.rb
index 93f7cceb13..3a51cf03b2 100644
--- a/activerecord/test/models/line_item.rb
+++ b/activerecord/test/models/line_item.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class LineItem < ActiveRecord::Base
   belongs_to :invoice, touch: true
 end
diff --git a/activerecord/test/models/liquid.rb b/activerecord/test/models/liquid.rb
index 69d4d7df1a..b2fd305d66 100644
--- a/activerecord/test/models/liquid.rb
+++ b/activerecord/test/models/liquid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Liquid < ActiveRecord::Base
   self.table_name = :liquid
   has_many :molecules, -> { distinct }
diff --git a/activerecord/test/models/man.rb b/activerecord/test/models/man.rb
index d2436a735c..3acd89a48e 100644
--- a/activerecord/test/models/man.rb
+++ b/activerecord/test/models/man.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Man < ActiveRecord::Base
   has_one :face, inverse_of: :man
   has_one :polymorphic_face, class_name: "Face", as: :polymorphic_man, inverse_of: :polymorphic_man
diff --git a/activerecord/test/models/matey.rb b/activerecord/test/models/matey.rb
index 80ee5f47c5..a77ac21e96 100644
--- a/activerecord/test/models/matey.rb
+++ b/activerecord/test/models/matey.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Matey < ActiveRecord::Base
   belongs_to :pirate
   belongs_to :target, class_name: "Pirate"
diff --git a/activerecord/test/models/member.rb b/activerecord/test/models/member.rb
index b9597c6b9a..4315ba1941 100644
--- a/activerecord/test/models/member.rb
+++ b/activerecord/test/models/member.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Member < ActiveRecord::Base
   has_one :current_membership
   has_one :selected_membership
diff --git a/activerecord/test/models/member_detail.rb b/activerecord/test/models/member_detail.rb
index 157130986c..87f7aab9a2 100644
--- a/activerecord/test/models/member_detail.rb
+++ b/activerecord/test/models/member_detail.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MemberDetail < ActiveRecord::Base
   belongs_to :member, inverse_of: false
   belongs_to :organization
diff --git a/activerecord/test/models/member_type.rb b/activerecord/test/models/member_type.rb
index a13561c72a..b49b168d03 100644
--- a/activerecord/test/models/member_type.rb
+++ b/activerecord/test/models/member_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MemberType < ActiveRecord::Base
   has_many :members
 end
diff --git a/activerecord/test/models/membership.rb b/activerecord/test/models/membership.rb
index 0f8be0ad85..09ee7544b3 100644
--- a/activerecord/test/models/membership.rb
+++ b/activerecord/test/models/membership.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Membership < ActiveRecord::Base
   enum type: %i(Membership CurrentMembership SuperMembership SelectedMembership TenantMembership)
   belongs_to :member
diff --git a/activerecord/test/models/mentor.rb b/activerecord/test/models/mentor.rb
index 66504b4e91..2fbb62c435 100644
--- a/activerecord/test/models/mentor.rb
+++ b/activerecord/test/models/mentor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Mentor < ActiveRecord::Base
   has_many :developers
 end
diff --git a/activerecord/test/models/minimalistic.rb b/activerecord/test/models/minimalistic.rb
index 2e3f8e081a..c67b086853 100644
--- a/activerecord/test/models/minimalistic.rb
+++ b/activerecord/test/models/minimalistic.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Minimalistic < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/minivan.rb b/activerecord/test/models/minivan.rb
index e9b05dadf2..d9d331798a 100644
--- a/activerecord/test/models/minivan.rb
+++ b/activerecord/test/models/minivan.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Minivan < ActiveRecord::Base
   self.primary_key = :minivan_id
 
diff --git a/activerecord/test/models/mixed_case_monkey.rb b/activerecord/test/models/mixed_case_monkey.rb
index 1c35006665..8e92f68817 100644
--- a/activerecord/test/models/mixed_case_monkey.rb
+++ b/activerecord/test/models/mixed_case_monkey.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MixedCaseMonkey < ActiveRecord::Base
   belongs_to :man
 end
diff --git a/activerecord/test/models/mocktail_designer.rb b/activerecord/test/models/mocktail_designer.rb
index 77b44651a3..123ff4fb3d 100644
--- a/activerecord/test/models/mocktail_designer.rb
+++ b/activerecord/test/models/mocktail_designer.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class MocktailDesigner < DrinkDesigner
 end
diff --git a/activerecord/test/models/molecule.rb b/activerecord/test/models/molecule.rb
index 26870c8f88..7da08a85c4 100644
--- a/activerecord/test/models/molecule.rb
+++ b/activerecord/test/models/molecule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Molecule < ActiveRecord::Base
   belongs_to :liquid
   has_many :electrons
diff --git a/activerecord/test/models/movie.rb b/activerecord/test/models/movie.rb
index 0302abad1e..fa2ea900c7 100644
--- a/activerecord/test/models/movie.rb
+++ b/activerecord/test/models/movie.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Movie < ActiveRecord::Base
   self.primary_key = "movieid"
 
diff --git a/activerecord/test/models/node.rb b/activerecord/test/models/node.rb
index 459ea8cf95..ae46c76b46 100644
--- a/activerecord/test/models/node.rb
+++ b/activerecord/test/models/node.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Node < ActiveRecord::Base
   belongs_to :tree, touch: true
   belongs_to :parent,   class_name: "Node", touch: true, optional: true
diff --git a/activerecord/test/models/non_primary_key.rb b/activerecord/test/models/non_primary_key.rb
index 1cafb09608..e954375989 100644
--- a/activerecord/test/models/non_primary_key.rb
+++ b/activerecord/test/models/non_primary_key.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class NonPrimaryKey < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/notification.rb b/activerecord/test/models/notification.rb
index 82edc64b68..3f8728af5e 100644
--- a/activerecord/test/models/notification.rb
+++ b/activerecord/test/models/notification.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Notification < ActiveRecord::Base
   validates_presence_of :message
 end
diff --git a/activerecord/test/models/numeric_data.rb b/activerecord/test/models/numeric_data.rb
index c6e025a9ce..666e1a5778 100644
--- a/activerecord/test/models/numeric_data.rb
+++ b/activerecord/test/models/numeric_data.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NumericData < ActiveRecord::Base
   self.table_name = "numeric_data"
   # Decimal columns with 0 scale being automatically treated as integers
diff --git a/activerecord/test/models/order.rb b/activerecord/test/models/order.rb
index 699be53959..36866b398f 100644
--- a/activerecord/test/models/order.rb
+++ b/activerecord/test/models/order.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Order < ActiveRecord::Base
   belongs_to :billing, class_name: "Customer", foreign_key: "billing_customer_id"
   belongs_to :shipping, class_name: "Customer", foreign_key: "shipping_customer_id"
diff --git a/activerecord/test/models/organization.rb b/activerecord/test/models/organization.rb
index 462830dadc..099e7e38e0 100644
--- a/activerecord/test/models/organization.rb
+++ b/activerecord/test/models/organization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Organization < ActiveRecord::Base
   has_many :member_details
   has_many :members, through: :member_details
diff --git a/activerecord/test/models/other_dog.rb b/activerecord/test/models/other_dog.rb
index 418caf34be..a0fda5ae1b 100644
--- a/activerecord/test/models/other_dog.rb
+++ b/activerecord/test/models/other_dog.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "models/arunit2_model"
 
 class OtherDog < ARUnit2Model
diff --git a/activerecord/test/models/owner.rb b/activerecord/test/models/owner.rb
index 21fc9b6eb8..5fa50d9918 100644
--- a/activerecord/test/models/owner.rb
+++ b/activerecord/test/models/owner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Owner < ActiveRecord::Base
   self.primary_key = :owner_id
   has_many :pets, -> { order "pets.name desc" }
diff --git a/activerecord/test/models/parrot.rb b/activerecord/test/models/parrot.rb
index 1e5f9285a8..ba9ddb8c6a 100644
--- a/activerecord/test/models/parrot.rb
+++ b/activerecord/test/models/parrot.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Parrot < ActiveRecord::Base
   self.inheritance_column = :parrot_sti_class
 
@@ -8,7 +10,7 @@ class Parrot < ActiveRecord::Base
 
   validates_presence_of :name
 
-  attr_accessor :cancel_save_from_callback
+  attribute :cancel_save_from_callback
   before_save :cancel_save_callback_method, if: :cancel_save_from_callback
   def cancel_save_callback_method
     throw(:abort)
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index 18994d6f18..5cba1e440e 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Person < ActiveRecord::Base
   has_many :readers
   has_many :secure_readers
diff --git a/activerecord/test/models/personal_legacy_thing.rb b/activerecord/test/models/personal_legacy_thing.rb
index adde7a504a..ed8b70cfcc 100644
--- a/activerecord/test/models/personal_legacy_thing.rb
+++ b/activerecord/test/models/personal_legacy_thing.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PersonalLegacyThing < ActiveRecord::Base
   self.locking_column = :version
   belongs_to :person, counter_cache: true
diff --git a/activerecord/test/models/pet.rb b/activerecord/test/models/pet.rb
index 51a3e42815..9bda2109e6 100644
--- a/activerecord/test/models/pet.rb
+++ b/activerecord/test/models/pet.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Pet < ActiveRecord::Base
   attr_accessor :current_user
 
diff --git a/activerecord/test/models/pet_treasure.rb b/activerecord/test/models/pet_treasure.rb
index 1fe7807ffe..47b9f57fad 100644
--- a/activerecord/test/models/pet_treasure.rb
+++ b/activerecord/test/models/pet_treasure.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PetTreasure < ActiveRecord::Base
   self.table_name = "pets_treasures"
 
diff --git a/activerecord/test/models/pirate.rb b/activerecord/test/models/pirate.rb
index c532ab426e..c8617d1cfe 100644
--- a/activerecord/test/models/pirate.rb
+++ b/activerecord/test/models/pirate.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Pirate < ActiveRecord::Base
   belongs_to :parrot, validate: true
   belongs_to :non_validated_parrot, class_name: "Parrot"
diff --git a/activerecord/test/models/possession.rb b/activerecord/test/models/possession.rb
index 0226336c16..9b843e1525 100644
--- a/activerecord/test/models/possession.rb
+++ b/activerecord/test/models/possession.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Possession < ActiveRecord::Base
   self.table_name = "having"
 end
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index ed64e0ee52..4b3576fce8 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Post < ActiveRecord::Base
   class CategoryPost < ActiveRecord::Base
     self.table_name = "categories_posts"
@@ -199,6 +201,11 @@ class FirstPost < ActiveRecord::Base
   has_one  :comment,  foreign_key: :post_id
 end
 
+class TaggedPost < Post
+  has_many :taggings, -> { rewhere(taggable_type: "TaggedPost") }, as: :taggable
+  has_many :tags, through: :taggings
+end
+
 class PostWithDefaultInclude < ActiveRecord::Base
   self.inheritance_column = :disabled
   self.table_name = "posts"
@@ -276,3 +283,35 @@ end
 
 class SubConditionalStiPost < ConditionalStiPost
 end
+
+class FakeKlass
+  extend ActiveRecord::Delegation::DelegateCache
+
+  inherited self
+
+  class << self
+    def connection
+      Post.connection
+    end
+
+    def table_name
+      "posts"
+    end
+
+    def attribute_alias?(name)
+      false
+    end
+
+    def sanitize_sql(sql)
+      sql
+    end
+
+    def sanitize_sql_for_order(sql)
+      sql
+    end
+
+    def arel_attribute(name, table)
+      table[name]
+    end
+  end
+end
diff --git a/activerecord/test/models/price_estimate.rb b/activerecord/test/models/price_estimate.rb
index ce086e40a3..f1f88d8d8d 100644
--- a/activerecord/test/models/price_estimate.rb
+++ b/activerecord/test/models/price_estimate.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PriceEstimate < ActiveRecord::Base
   belongs_to :estimate_of, polymorphic: true
   belongs_to :thing, polymorphic: true
diff --git a/activerecord/test/models/professor.rb b/activerecord/test/models/professor.rb
index 4dfb1a9602..abc23f40ff 100644
--- a/activerecord/test/models/professor.rb
+++ b/activerecord/test/models/professor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "models/arunit2_model"
 
 class Professor < ARUnit2Model
diff --git a/activerecord/test/models/project.rb b/activerecord/test/models/project.rb
index 4fbd986e40..846cef625b 100644
--- a/activerecord/test/models/project.rb
+++ b/activerecord/test/models/project.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Project < ActiveRecord::Base
   belongs_to :mentor
   has_and_belongs_to_many :developers, -> { distinct.order "developers.name desc, developers.id desc" }
diff --git a/activerecord/test/models/publisher.rb b/activerecord/test/models/publisher.rb
index 0d4a7f9235..53677197c4 100644
--- a/activerecord/test/models/publisher.rb
+++ b/activerecord/test/models/publisher.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 module Publisher
 end
diff --git a/activerecord/test/models/publisher/article.rb b/activerecord/test/models/publisher/article.rb
index d73a8eb936..355c22dcc5 100644
--- a/activerecord/test/models/publisher/article.rb
+++ b/activerecord/test/models/publisher/article.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Publisher::Article < ActiveRecord::Base
   has_and_belongs_to_many :magazines
   has_and_belongs_to_many :tags
diff --git a/activerecord/test/models/publisher/magazine.rb b/activerecord/test/models/publisher/magazine.rb
index 82e1a14008..425ede8df2 100644
--- a/activerecord/test/models/publisher/magazine.rb
+++ b/activerecord/test/models/publisher/magazine.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Publisher::Magazine < ActiveRecord::Base
   has_and_belongs_to_many :articles
 end
diff --git a/activerecord/test/models/randomly_named_c1.rb b/activerecord/test/models/randomly_named_c1.rb
index d4be1e13b4..f90a7b9336 100644
--- a/activerecord/test/models/randomly_named_c1.rb
+++ b/activerecord/test/models/randomly_named_c1.rb
@@ -1,3 +1,5 @@
-class ClassNameThatDoesNotFollowCONVENTIONS < ActiveRecord::Base
-  self.table_name = :randomly_named_table1
-end
+# frozen_string_literal: true
+
+class ClassNameThatDoesNotFollowCONVENTIONS < ActiveRecord::Base
+  self.table_name = :randomly_named_table1
+end
diff --git a/activerecord/test/models/rating.rb b/activerecord/test/models/rating.rb
index 7420821db0..cf06bc6931 100644
--- a/activerecord/test/models/rating.rb
+++ b/activerecord/test/models/rating.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Rating < ActiveRecord::Base
   belongs_to :comment
   has_many :taggings, as: :taggable
diff --git a/activerecord/test/models/reader.rb b/activerecord/test/models/reader.rb
index 7c5a159fe0..d25627e430 100644
--- a/activerecord/test/models/reader.rb
+++ b/activerecord/test/models/reader.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Reader < ActiveRecord::Base
   belongs_to :post
   belongs_to :person, inverse_of: :readers
diff --git a/activerecord/test/models/recipe.rb b/activerecord/test/models/recipe.rb
index c387230603..e53f5c8fb1 100644
--- a/activerecord/test/models/recipe.rb
+++ b/activerecord/test/models/recipe.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Recipe < ActiveRecord::Base
   belongs_to :chef
 end
diff --git a/activerecord/test/models/record.rb b/activerecord/test/models/record.rb
index f77ac9fc03..63143e296a 100644
--- a/activerecord/test/models/record.rb
+++ b/activerecord/test/models/record.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Record < ActiveRecord::Base
 end
diff --git a/activerecord/test/models/reference.rb b/activerecord/test/models/reference.rb
index e2bb980fed..2a7a1e3b77 100644
--- a/activerecord/test/models/reference.rb
+++ b/activerecord/test/models/reference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Reference < ActiveRecord::Base
   belongs_to :person
   belongs_to :job
diff --git a/activerecord/test/models/reply.rb b/activerecord/test/models/reply.rb
index a2d169292a..bc829ec67f 100644
--- a/activerecord/test/models/reply.rb
+++ b/activerecord/test/models/reply.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "models/topic"
 
 class Reply < Topic
diff --git a/activerecord/test/models/ship.rb b/activerecord/test/models/ship.rb
index 77a7b22315..7973219a79 100644
--- a/activerecord/test/models/ship.rb
+++ b/activerecord/test/models/ship.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Ship < ActiveRecord::Base
   self.record_timestamps = false
 
diff --git a/activerecord/test/models/ship_part.rb b/activerecord/test/models/ship_part.rb
index 1a633b8d77..f6d7a8ae5e 100644
--- a/activerecord/test/models/ship_part.rb
+++ b/activerecord/test/models/ship_part.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ShipPart < ActiveRecord::Base
   belongs_to :ship
   has_many :trinkets, class_name: "Treasure", as: :looter
diff --git a/activerecord/test/models/shop.rb b/activerecord/test/models/shop.rb
index f9d23d13b0..92afe70b92 100644
--- a/activerecord/test/models/shop.rb
+++ b/activerecord/test/models/shop.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shop
   class Collection < ActiveRecord::Base
     has_many :products, dependent: :nullify
diff --git a/activerecord/test/models/shop_account.rb b/activerecord/test/models/shop_account.rb
index 1580e8b20c..97fb058331 100644
--- a/activerecord/test/models/shop_account.rb
+++ b/activerecord/test/models/shop_account.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ShopAccount < ActiveRecord::Base
   belongs_to :customer
   belongs_to :customer_carrier
diff --git a/activerecord/test/models/speedometer.rb b/activerecord/test/models/speedometer.rb
index 497c3aba9a..e456907a22 100644
--- a/activerecord/test/models/speedometer.rb
+++ b/activerecord/test/models/speedometer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Speedometer < ActiveRecord::Base
   self.primary_key = :speedometer_id
   belongs_to :dashboard
diff --git a/activerecord/test/models/sponsor.rb b/activerecord/test/models/sponsor.rb
index 3f142b25fe..f190860fd1 100644
--- a/activerecord/test/models/sponsor.rb
+++ b/activerecord/test/models/sponsor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Sponsor < ActiveRecord::Base
   belongs_to :sponsor_club, class_name: "Club", foreign_key: "club_id"
   belongs_to :sponsorable, polymorphic: true
diff --git a/activerecord/test/models/string_key_object.rb b/activerecord/test/models/string_key_object.rb
index f084ec1bdc..473c145f4c 100644
--- a/activerecord/test/models/string_key_object.rb
+++ b/activerecord/test/models/string_key_object.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StringKeyObject < ActiveRecord::Base
   self.primary_key = :id
 end
diff --git a/activerecord/test/models/student.rb b/activerecord/test/models/student.rb
index 28a0b6c99b..e750798f74 100644
--- a/activerecord/test/models/student.rb
+++ b/activerecord/test/models/student.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Student < ActiveRecord::Base
   has_and_belongs_to_many :lessons
   belongs_to :college
diff --git a/activerecord/test/models/subscriber.rb b/activerecord/test/models/subscriber.rb
index a820329003..b21969ca2d 100644
--- a/activerecord/test/models/subscriber.rb
+++ b/activerecord/test/models/subscriber.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Subscriber < ActiveRecord::Base
   self.primary_key = "nick"
   has_many :subscriptions
diff --git a/activerecord/test/models/subscription.rb b/activerecord/test/models/subscription.rb
index 1cedf6deae..d1d5d21621 100644
--- a/activerecord/test/models/subscription.rb
+++ b/activerecord/test/models/subscription.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Subscription < ActiveRecord::Base
   belongs_to :subscriber, counter_cache: :books_count
   belongs_to :book
diff --git a/activerecord/test/models/tag.rb b/activerecord/test/models/tag.rb
index c907aea10f..4495ac4a09 100644
--- a/activerecord/test/models/tag.rb
+++ b/activerecord/test/models/tag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tag < ActiveRecord::Base
   has_many :taggings
   has_many :taggables, through: :taggings
diff --git a/activerecord/test/models/tagging.rb b/activerecord/test/models/tagging.rb
index f739b4a197..fc0af026c5 100644
--- a/activerecord/test/models/tagging.rb
+++ b/activerecord/test/models/tagging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # test that attr_readonly isn't called on the :taggable polymorphic association
 module Taggable
 end
diff --git a/activerecord/test/models/task.rb b/activerecord/test/models/task.rb
index e36989dd56..dabe3ce06b 100644
--- a/activerecord/test/models/task.rb
+++ b/activerecord/test/models/task.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Task < ActiveRecord::Base
   def updated_at
     ending
diff --git a/activerecord/test/models/topic.rb b/activerecord/test/models/topic.rb
index d9381ac9cf..2154b50ef7 100644
--- a/activerecord/test/models/topic.rb
+++ b/activerecord/test/models/topic.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Topic < ActiveRecord::Base
   scope :base, -> { all }
   scope :written_before, lambda { |time|
diff --git a/activerecord/test/models/toy.rb b/activerecord/test/models/toy.rb
index ddc7048a56..4a5697eeb1 100644
--- a/activerecord/test/models/toy.rb
+++ b/activerecord/test/models/toy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Toy < ActiveRecord::Base
   self.primary_key = :toy_id
   belongs_to :pet
diff --git a/activerecord/test/models/traffic_light.rb b/activerecord/test/models/traffic_light.rb
index a6b7edb882..0b88815cbd 100644
--- a/activerecord/test/models/traffic_light.rb
+++ b/activerecord/test/models/traffic_light.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TrafficLight < ActiveRecord::Base
   serialize :state, Array
   serialize :long_state, Array
diff --git a/activerecord/test/models/treasure.rb b/activerecord/test/models/treasure.rb
index fb2a5d44e2..b51db56c37 100644
--- a/activerecord/test/models/treasure.rb
+++ b/activerecord/test/models/treasure.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Treasure < ActiveRecord::Base
   has_and_belongs_to_many :parrots
   belongs_to :looter, polymorphic: true
diff --git a/activerecord/test/models/treaty.rb b/activerecord/test/models/treaty.rb
index 373cd48f71..5c1d75aa09 100644
--- a/activerecord/test/models/treaty.rb
+++ b/activerecord/test/models/treaty.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Treaty < ActiveRecord::Base
   self.primary_key = :treaty_id
 
diff --git a/activerecord/test/models/tree.rb b/activerecord/test/models/tree.rb
index dc29cccc9c..77050c5fff 100644
--- a/activerecord/test/models/tree.rb
+++ b/activerecord/test/models/tree.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tree < ActiveRecord::Base
   has_many :nodes, dependent: :destroy
 end
diff --git a/activerecord/test/models/tuning_peg.rb b/activerecord/test/models/tuning_peg.rb
index 1252d6dc1d..6e052e1d0f 100644
--- a/activerecord/test/models/tuning_peg.rb
+++ b/activerecord/test/models/tuning_peg.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TuningPeg < ActiveRecord::Base
   belongs_to :guitar
   validates_numericality_of :pitch
diff --git a/activerecord/test/models/tyre.rb b/activerecord/test/models/tyre.rb
index e50a21ca68..d627026585 100644
--- a/activerecord/test/models/tyre.rb
+++ b/activerecord/test/models/tyre.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tyre < ActiveRecord::Base
   belongs_to :car
 
diff --git a/activerecord/test/models/user.rb b/activerecord/test/models/user.rb
index 5089a795f4..3efbc45d2a 100644
--- a/activerecord/test/models/user.rb
+++ b/activerecord/test/models/user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "models/job"
 
 class User < ActiveRecord::Base
diff --git a/activerecord/test/models/uuid_child.rb b/activerecord/test/models/uuid_child.rb
index a3d0962ad6..9fce361cc8 100644
--- a/activerecord/test/models/uuid_child.rb
+++ b/activerecord/test/models/uuid_child.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UuidChild < ActiveRecord::Base
   belongs_to :uuid_parent
 end
diff --git a/activerecord/test/models/uuid_item.rb b/activerecord/test/models/uuid_item.rb
index 2353e40213..41f68c4c18 100644
--- a/activerecord/test/models/uuid_item.rb
+++ b/activerecord/test/models/uuid_item.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UuidItem < ActiveRecord::Base
 end
 
diff --git a/activerecord/test/models/uuid_parent.rb b/activerecord/test/models/uuid_parent.rb
index 5634f22d0c..05db61855e 100644
--- a/activerecord/test/models/uuid_parent.rb
+++ b/activerecord/test/models/uuid_parent.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UuidParent < ActiveRecord::Base
   has_many :uuid_children
 end
diff --git a/activerecord/test/models/vegetables.rb b/activerecord/test/models/vegetables.rb
index a4590d06e0..cfaab08ed1 100644
--- a/activerecord/test/models/vegetables.rb
+++ b/activerecord/test/models/vegetables.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vegetable < ActiveRecord::Base
   validates_presence_of :name
 
diff --git a/activerecord/test/models/vehicle.rb b/activerecord/test/models/vehicle.rb
index 855bc4e325..c9b3338522 100644
--- a/activerecord/test/models/vehicle.rb
+++ b/activerecord/test/models/vehicle.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vehicle < ActiveRecord::Base
   self.abstract_class = true
   default_scope -> { where("tires_count IS NOT NULL") }
diff --git a/activerecord/test/models/vertex.rb b/activerecord/test/models/vertex.rb
index 3d19433b6f..0ad8114898 100644
--- a/activerecord/test/models/vertex.rb
+++ b/activerecord/test/models/vertex.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This class models a vertex in a directed graph.
 class Vertex < ActiveRecord::Base
   has_many :sink_edges, class_name: "Edge", foreign_key: "source_id"
diff --git a/activerecord/test/models/warehouse_thing.rb b/activerecord/test/models/warehouse_thing.rb
index f20bd1a245..099633af55 100644
--- a/activerecord/test/models/warehouse_thing.rb
+++ b/activerecord/test/models/warehouse_thing.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WarehouseThing < ActiveRecord::Base
   self.table_name = "warehouse-things"
 
diff --git a/activerecord/test/models/wheel.rb b/activerecord/test/models/wheel.rb
index cba2b3e518..e05fb64477 100644
--- a/activerecord/test/models/wheel.rb
+++ b/activerecord/test/models/wheel.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Wheel < ActiveRecord::Base
   belongs_to :wheelable, polymorphic: true, counter_cache: true
 end
diff --git a/activerecord/test/models/without_table.rb b/activerecord/test/models/without_table.rb
index 7c0fc286e1..fc0a52d6ad 100644
--- a/activerecord/test/models/without_table.rb
+++ b/activerecord/test/models/without_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WithoutTable < ActiveRecord::Base
   default_scope -> { where(published: true) }
 end
diff --git a/activerecord/test/models/zine.rb b/activerecord/test/models/zine.rb
index 3f2b348b46..6f361665ef 100644
--- a/activerecord/test/models/zine.rb
+++ b/activerecord/test/models/zine.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Zine < ActiveRecord::Base
   has_many :interests, inverse_of: :zine
 end
diff --git a/activerecord/test/schema/mysql2_specific_schema.rb b/activerecord/test/schema/mysql2_specific_schema.rb
index 90a314c83c..e634e9e6b1 100644
--- a/activerecord/test/schema/mysql2_specific_schema.rb
+++ b/activerecord/test/schema/mysql2_specific_schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveRecord::Schema.define do
 
   if ActiveRecord::Base.connection.version >= "5.6.0"
diff --git a/activerecord/test/schema/oracle_specific_schema.rb b/activerecord/test/schema/oracle_specific_schema.rb
index 264d9b8910..e236571caa 100644
--- a/activerecord/test/schema/oracle_specific_schema.rb
+++ b/activerecord/test/schema/oracle_specific_schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveRecord::Schema.define do
 
   execute "drop table test_oracle_defaults" rescue nil
diff --git a/activerecord/test/schema/postgresql_specific_schema.rb b/activerecord/test/schema/postgresql_specific_schema.rb
index e56e8fa36a..f15178d695 100644
--- a/activerecord/test/schema/postgresql_specific_schema.rb
+++ b/activerecord/test/schema/postgresql_specific_schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveRecord::Schema.define do
 
   enable_extension!("uuid-ossp", ActiveRecord::Base.connection)
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index f534e9c00e..05420a4240 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveRecord::Schema.define do
   # ------------------------------------------------------------------- #
   #                                                                     #
@@ -189,6 +191,7 @@ ActiveRecord::Schema.define do
     t.string :resource_id
     t.string :resource_type
     t.integer :developer_id
+    t.datetime :deleted_at
   end
 
   create_table :companies, force: true do |t|
diff --git a/activerecord/test/support/config.rb b/activerecord/test/support/config.rb
index aaff408b41..bd6d5c339b 100644
--- a/activerecord/test/support/config.rb
+++ b/activerecord/test/support/config.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "yaml"
 require "erb"
 require "fileutils"
diff --git a/activerecord/test/support/connection.rb b/activerecord/test/support/connection.rb
index 1a609e13c3..2a4fa53460 100644
--- a/activerecord/test/support/connection.rb
+++ b/activerecord/test/support/connection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_support/logger"
 require "models/college"
 require "models/course"
diff --git a/activerecord/test/support/connection_helper.rb b/activerecord/test/support/connection_helper.rb
index 4a19e5df44..3bb1b370c1 100644
--- a/activerecord/test/support/connection_helper.rb
+++ b/activerecord/test/support/connection_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ConnectionHelper
   def run_without_connection
     original_connection = ActiveRecord::Base.remove_connection
diff --git a/activerecord/test/support/ddl_helper.rb b/activerecord/test/support/ddl_helper.rb
index 43cb235e01..a18bf5ea0a 100644
--- a/activerecord/test/support/ddl_helper.rb
+++ b/activerecord/test/support/ddl_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DdlHelper
   def with_example_table(connection, table_name, definition = nil)
     connection.execute("CREATE TABLE #{table_name}(#{definition})")
diff --git a/activerecord/test/support/schema_dumping_helper.rb b/activerecord/test/support/schema_dumping_helper.rb
index 666c1b6a14..777e6a7c1b 100644
--- a/activerecord/test/support/schema_dumping_helper.rb
+++ b/activerecord/test/support/schema_dumping_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SchemaDumpingHelper
   def dump_table_schema(table, connection = ActiveRecord::Base.connection)
     old_ignore_tables = ActiveRecord::SchemaDumper.ignore_tables
author	Rafael Mendonça França <rafaelmfranca@gmail.com>	2017-08-01 17:34:14 -0400
committer	Rafael Mendonça França <rafaelmfranca@gmail.com>	2017-08-01 17:34:14 -0400
commit	feb1ddae021c38174f9c22bbd1298c8b73431b45 (patch)
tree	09a38695596cf80dc362dd4d93cf94d6f7415e7b /activerecord
parent	3540e60c385286f3517ff56270b31a91ed3024a3 (diff)
parent	f9a43f28c087f8ffd35ff7c33a60c938b60f2be2 (diff)
download	rails-feb1ddae021c38174f9c22bbd1298c8b73431b45.tar.gz rails-feb1ddae021c38174f9c22bbd1298c8b73431b45.tar.bz2 rails-feb1ddae021c38174f9c22bbd1298c8b73431b45.zip