Merge pull request #27503 from rails/activerecord-deprecation

Remove all ActiveRecord deprecations

28 files changed, 140 insertions, 358 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 7eb008fc27..d97d4c7ed0 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -107,6 +107,21 @@ module ActiveRecord
     end
   end
 
+  class AmbiguousSourceReflectionForThroughAssociation < ActiveRecordError # :nodoc:
+    def initialize(klass, macro, association_name, options, possible_sources)
+      example_options = options.dup
+      example_options[:source] = possible_sources.first
+
+      super("Ambiguous source reflection for through association. Please " \
+            "specify a :source directive on your declaration like:\n" \
+            "\n" \
+            "  class #{klass} < ActiveRecord::Base\n" \
+            "    #{macro} :#{association_name}, #{example_options}\n" \
+            "  end"
+           )
+    end
+  end
+
   class HasManyThroughCantAssociateThroughHasOneOrManyReflection < ThroughCantAssociateThroughHasOneOrManyReflection #:nodoc:
   end
 
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 13f77c7d4d..974405e019 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -25,16 +25,8 @@ module ActiveRecord
     # +load_target+ and the +loaded+ flag are your friends.
     class CollectionAssociation < Association #:nodoc:
       # Implements the reader method, e.g. foo.items for Foo.has_many :items
-      def reader(force_reload = false)
-        if force_reload
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing an argument to force an association to reload is now
-            deprecated and will be removed in Rails 5.1. Please call `reload`
-            on the result collection proxy instead.
-          MSG
-
-          klass.uncached { reload }
-        elsif stale_target?
+      def reader
+        if stale_target?
           reload
         end
 
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index 742cd25509..c5a7d92a2b 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -16,14 +16,7 @@ module ActiveRecord
         when :restrict_with_error
           unless empty?
             record = owner.class.human_attribute_name(reflection.name).downcase
-            message = owner.errors.generate_message(:base, :'restrict_dependent_destroy.many', record: record, raise: true) rescue nil
-            if message
-              ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
-                The error key `:'restrict_dependent_destroy.many'` has been deprecated and will be removed in Rails 5.1.
-                Please use `:'restrict_dependent_destroy.has_many'` instead.
-              MESSAGE
-            end
-            owner.errors.add(:base, message || :'restrict_dependent_destroy.has_many', record: record)
+            owner.errors.add(:base, :'restrict_dependent_destroy.has_many', record: record)
             throw(:abort)
           end
 
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 21bd668dff..b624154def 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -12,14 +12,7 @@ module ActiveRecord
         when :restrict_with_error
           if load_target
             record = owner.class.human_attribute_name(reflection.name).downcase
-            message = owner.errors.generate_message(:base, :'restrict_dependent_destroy.one', record: record, raise: true) rescue nil
-            if message
-              ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
-                The error key `:'restrict_dependent_destroy.one'` has been deprecated and will be removed in Rails 5.1.
-                Please use `:'restrict_dependent_destroy.has_one'` instead.
-              MESSAGE
-            end
-            owner.errors.add(:base, message || :'restrict_dependent_destroy.has_one', record: record)
+            owner.errors.add(:base, :'restrict_dependent_destroy.has_one', record: record)
             throw(:abort)
           end
 
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
index ee7b7c8bea..91580a28d0 100644
--- a/activerecord/lib/active_record/associations/singular_association.rb
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -2,16 +2,8 @@ module ActiveRecord
   module Associations
     class SingularAssociation < Association #:nodoc:
       # Implements the reader method, e.g. foo.bar for Foo.has_one :bar
-      def reader(force_reload = false)
-        if force_reload && klass
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing an argument to force an association to reload is now
-            deprecated and will be removed in Rails 5.1. Please call `reload`
-            on the parent object instead.
-          MSG
-
-          klass.uncached { reload }
-        elsif !loaded? || stale_target?
+      def reader
+        if !loaded? || stale_target?
           reload
         end
 
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 500d903857..df1231ad47 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -63,7 +63,7 @@ module ActiveRecord
         self.skip_time_zone_conversion_for_attributes = []
 
         class_attribute :time_zone_aware_types, instance_writer: false
-        self.time_zone_aware_types = [:datetime, :not_explicitly_configured]
+        self.time_zone_aware_types = [:datetime, :time]
       end
 
       module ClassMethods
@@ -86,29 +86,8 @@ module ActiveRecord
           def create_time_zone_conversion_attribute?(name, cast_type)
             enabled_for_column = time_zone_aware_attributes &&
               !skip_time_zone_conversion_for_attributes.include?(name.to_sym)
-            result = enabled_for_column &&
-              time_zone_aware_types.include?(cast_type.type)
 
-            if enabled_for_column &&
-              !result &&
-              cast_type.type == :time &&
-              time_zone_aware_types.include?(:not_explicitly_configured)
-              ActiveSupport::Deprecation.warn(<<-MESSAGE.strip_heredoc)
-                Time columns will become time zone aware in Rails 5.1. This
-                still causes `String`s to be parsed as if they were in `Time.zone`,
-                and `Time`s to be converted to `Time.zone`.
-
-                To keep the old behavior, you must add the following to your initializer:
-
-                    config.active_record.time_zone_aware_types = [:datetime]
-
-                To silence this deprecation warning, add the following:
-
-                    config.active_record.time_zone_aware_types = [:datetime, :time]
-              MESSAGE
-            end
-
-            result
+            enabled_for_column && time_zone_aware_types.include?(cast_type.type)
           end
       end
     end
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 e444cec72b..7e7a3881f5 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -334,17 +334,12 @@ module ActiveRecord
       # Sanitizes the given LIMIT parameter in order to prevent SQL injection.
       #
       # The +limit+ may be anything that can evaluate to a string via #to_s. It
-      # should look like an integer, or a comma-delimited list of integers, or
-      # an Arel SQL literal.
+      # should look like an integer, or an Arel SQL literal.
       #
       # Returns Integer and Arel::Nodes::SqlLiteral limits as is.
-      # Returns the sanitized limit parameter, either as an integer, or as a
-      # string which contains a comma-delimited list of integers.
       def sanitize_limit(limit)
         if limit.is_a?(Integer) || limit.is_a?(Arel::Nodes::SqlLiteral)
           limit
-        elsif limit.to_s.include?(",")
-          Arel.sql limit.to_s.split(",").map { |i| Integer(i) }.join(",")
         else
           Integer(limit)
         end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index bbd52b8a91..0c6bc16e6f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -5,20 +5,10 @@ module ActiveRecord
     module Quoting
       # Quotes the column value to help prevent
       # {SQL injection attacks}[http://en.wikipedia.org/wiki/SQL_injection].
-      def quote(value, column = nil)
+      def quote(value)
         # records are quoted as their primary key
         return value.quoted_id if value.respond_to?(:quoted_id)
 
-        if column
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing a column to `quote` has been deprecated. It is only used
-            for type casting, which should be handled elsewhere. See
-            https://github.com/rails/arel/commit/6160bfbda1d1781c3b08a33ec4955f170e95be11
-            for more information.
-          MSG
-          value = type_cast_from_column(column, value)
-        end
-
         _quote(value)
       end
 
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 9c820ce585..2e5af1777c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -43,7 +43,7 @@ module ActiveRecord
       end
 
       # Returns an array of table names defined in the database.
-      def tables(name = nil)
+      def tables
         raise NotImplementedError, "#tables is not implemented"
       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 20fcac8a22..1c3d10c15d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -310,45 +310,36 @@ module ActiveRecord
         show_variable "collation_database"
       end
 
-      def tables(name = nil) # :nodoc:
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          #tables currently returns both tables and views.
-          This behavior is deprecated and will be changed with Rails 5.1 to only return tables.
-          Use #data_sources instead.
-        MSG
+      def tables # :nodoc:
+        sql = "SELECT table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE'"
+        sql << " AND table_schema = #{quote(@config[:database])}"
 
-        if name
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing arguments to #tables is deprecated without replacement.
-          MSG
-        end
+        select_values(sql, "SCHEMA")
+      end
 
-        data_sources
+      def views # :nodoc:
+        select_values("SHOW FULL TABLES WHERE table_type = 'VIEW'", "SCHEMA")
       end
 
-      def data_sources
+      def data_sources # :nodoc:
         sql = "SELECT table_name FROM information_schema.tables "
         sql << "WHERE table_schema = #{quote(@config[:database])}"
 
         select_values(sql, "SCHEMA")
       end
 
-      def truncate(table_name, name = nil)
-        execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
-      end
+      def table_exists?(table_name) # :nodoc:
+        return false unless table_name.present?
 
-      def table_exists?(table_name)
-        # Update lib/active_record/internal_metadata.rb when this gets removed
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          #table_exists? currently checks both tables and views.
-          This behavior is deprecated and will be changed with Rails 5.1 to only check tables.
-          Use #data_source_exists? instead.
-        MSG
+        schema, name = extract_schema_qualified_name(table_name)
 
-        data_source_exists?(table_name)
+        sql = "SELECT table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE'"
+        sql << " AND table_schema = #{quote(schema)} AND table_name = #{quote(name)}"
+
+        select_values(sql, "SCHEMA").any?
       end
 
-      def data_source_exists?(table_name)
+      def data_source_exists?(table_name) # :nodoc:
         return false unless table_name.present?
 
         schema, name = extract_schema_qualified_name(table_name)
@@ -359,10 +350,6 @@ module ActiveRecord
         select_values(sql, "SCHEMA").any?
       end
 
-      def views # :nodoc:
-        select_values("SHOW FULL TABLES WHERE table_type = 'VIEW'", "SCHEMA")
-      end
-
       def view_exists?(view_name) # :nodoc:
         return false unless view_name.present?
 
@@ -374,6 +361,10 @@ module ActiveRecord
         select_values(sql, "SCHEMA").any?
       end
 
+      def truncate(table_name, name = nil)
+        execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
+      end
+
       # Returns an array of indexes for the given table.
       def indexes(table_name, name = nil) #:nodoc:
         indexes = []
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 9e7487b27f..85836fc575 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -71,13 +71,7 @@ module ActiveRecord
         end
 
         # Returns the list of all tables in the schema search path.
-        def tables(name = nil)
-          if name
-            ActiveSupport::Deprecation.warn(<<-MSG.squish)
-              Passing arguments to #tables is deprecated without replacement.
-            MSG
-          end
-
+        def tables
           select_values("SELECT tablename FROM pg_tables WHERE schemaname = ANY(current_schemas(false))", "SCHEMA")
         end
 
@@ -91,40 +85,42 @@ module ActiveRecord
           SQL
         end
 
+        def views # :nodoc:
+          select_values(<<-SQL, "SCHEMA")
+            SELECT c.relname
+            FROM pg_class c
+            LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+            WHERE c.relkind IN ('v','m') -- (v)iew, (m)aterialized view
+            AND n.nspname = ANY (current_schemas(false))
+          SQL
+        end
+
         # Returns true if table exists.
         # If the schema is not specified as part of +name+ then it will only find tables within
         # the current schema search path (regardless of permissions to access tables in other schemas)
         def table_exists?(name)
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            #table_exists? currently checks both tables and views.
-            This behavior is deprecated and will be changed with Rails 5.1 to only check tables.
-            Use #data_source_exists? instead.
-          MSG
-
-          data_source_exists?(name)
-        end
-
-        def data_source_exists?(name)
           name = Utils.extract_schema_qualified_name(name.to_s)
           return false unless name.identifier
 
           select_values(<<-SQL, "SCHEMA").any?
-              SELECT c.relname
-              FROM pg_class c
-              LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
-              WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view
-              AND c.relname = #{quote(name.identifier)}
-              AND n.nspname = #{name.schema ? quote(name.schema) : "ANY (current_schemas(false))"}
+            SELECT tablename
+            FROM pg_tables
+            WHERE tablename = #{quote(name.identifier)}
+            AND schemaname = #{name.schema ? quote(name.schema) : "ANY (current_schemas(false))"}
           SQL
         end
 
-        def views # :nodoc:
-          select_values(<<-SQL, "SCHEMA")
+        def data_source_exists?(name) # :nodoc:
+          name = Utils.extract_schema_qualified_name(name.to_s)
+          return false unless name.identifier
+
+          select_values(<<-SQL, "SCHEMA").any?
             SELECT c.relname
             FROM pg_class c
             LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
-            WHERE c.relkind IN ('v','m') -- (v)iew, (m)aterialized view
-            AND n.nspname = ANY (current_schemas(false))
+            WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view
+            AND c.relname = #{quote(name.identifier)}
+            AND n.nspname = #{name.schema ? quote(name.schema) : "ANY (current_schemas(false))"}
           SQL
         end
 
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index 3a319c4029..4d339b0a8c 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -48,8 +48,6 @@ module ActiveRecord
 
         @data_sources[name] = connection.data_source_exists?(name)
       end
-      alias table_exists? data_source_exists?
-      deprecate table_exists?: "use #data_source_exists? instead"
 
       # Add internal cache for table with +table_name+.
       def add(table_name)
@@ -63,8 +61,6 @@ module ActiveRecord
       def data_sources(name)
         @data_sources[name]
       end
-      alias tables data_sources
-      deprecate tables: "use #data_sources instead"
 
       # Get the columns for a table
       def columns(table_name)
@@ -99,8 +95,6 @@ module ActiveRecord
         @primary_keys.delete name
         @data_sources.delete name
       end
-      alias clear_table_cache! clear_data_source_cache!
-      deprecate clear_table_cache!: "use #clear_data_source_cache! instead"
 
       def marshal_dump
         # if we get current version during initialization, it happens stack over flow.
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index e761b9531a..297e2997a9 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -259,47 +259,34 @@ module ActiveRecord
 
       # SCHEMA STATEMENTS ========================================
 
-      def tables(name = nil) # :nodoc:
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          #tables currently returns both tables and views.
-          This behavior is deprecated and will be changed with Rails 5.1 to only return tables.
-          Use #data_sources instead.
-        MSG
-
-        if name
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing arguments to #tables is deprecated without replacement.
-          MSG
-        end
-
-        data_sources
+      def tables # :nodoc:
+        select_values("SELECT name FROM sqlite_master WHERE type = 'table' AND name <> 'sqlite_sequence'", "SCHEMA")
       end
 
-      def data_sources
+      def data_sources # :nodoc:
         select_values("SELECT name FROM sqlite_master WHERE type IN ('table','view') AND name <> 'sqlite_sequence'", "SCHEMA")
       end
 
-      def table_exists?(table_name)
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          #table_exists? currently checks both tables and views.
-          This behavior is deprecated and will be changed with Rails 5.1 to only check tables.
-          Use #data_source_exists? instead.
-        MSG
-
-        data_source_exists?(table_name)
+      def views # :nodoc:
+        select_values("SELECT name FROM sqlite_master WHERE type = 'view' AND name <> 'sqlite_sequence'", "SCHEMA")
       end
 
-      def data_source_exists?(table_name)
+      def table_exists?(table_name) # :nodoc:
         return false unless table_name.present?
 
-        sql = "SELECT name FROM sqlite_master WHERE type IN ('table','view') AND name <> 'sqlite_sequence'"
+        sql = "SELECT name FROM sqlite_master WHERE type = 'table' AND name <> 'sqlite_sequence'"
         sql << " AND name = #{quote(table_name)}"
 
         select_values(sql, "SCHEMA").any?
       end
 
-      def views # :nodoc:
-        select_values("SELECT name FROM sqlite_master WHERE type = 'view' AND name <> 'sqlite_sequence'", "SCHEMA")
+      def data_source_exists?(table_name) # :nodoc:
+        return false unless table_name.present?
+
+        sql = "SELECT name FROM sqlite_master WHERE type IN ('table','view') AND name <> 'sqlite_sequence'"
+        sql << " AND name = #{quote(table_name)}"
+
+        select_values(sql, "SCHEMA").any?
       end
 
       def view_exists?(view_name) # :nodoc:
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index c812a05101..18fac5af1b 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -95,19 +95,9 @@ module ActiveRecord
   #
   # Wraps the underlying database error as +cause+.
   class StatementInvalid < ActiveRecordError
-    def initialize(message = nil, original_exception = nil)
-      if original_exception
-        ActiveSupport::Deprecation.warn("Passing #original_exception is deprecated and has no effect. " \
-                                        "Exceptions will automatically capture the original exception.", caller)
-      end
-
+    def initialize(message = nil)
       super(message || $!.try(:message))
     end
-
-    def original_exception
-      ActiveSupport::Deprecation.warn("#original_exception is deprecated. Use #cause instead.", caller)
-      cause
-    end
   end
 
   # Defunct wrapper class kept for compatibility.
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 3b4532a3f2..de1b0d63bc 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -862,29 +862,17 @@ module ActiveRecord
       class_attribute :fixture_table_names
       class_attribute :fixture_class_names
       class_attribute :use_transactional_tests
-      class_attribute :use_transactional_fixtures
       class_attribute :use_instantiated_fixtures # true, false, or :no_instances
       class_attribute :pre_loaded_fixtures
       class_attribute :config
 
-      singleton_class.deprecate "use_transactional_fixtures=" => "use use_transactional_tests= instead"
-
       self.fixture_table_names = []
       self.use_instantiated_fixtures = false
       self.pre_loaded_fixtures = false
       self.config = ActiveRecord::Base
 
       self.fixture_class_names = {}
-
-      silence_warnings do
-        define_singleton_method :use_transactional_tests do
-          if use_transactional_fixtures.nil?
-            true
-          else
-            use_transactional_fixtures
-          end
-        end
-      end
+      self.use_transactional_tests = true
     end
 
     module ClassMethods
diff --git a/activerecord/lib/active_record/internal_metadata.rb b/activerecord/lib/active_record/internal_metadata.rb
index 20d61dba67..25ee9d6bfe 100644
--- a/activerecord/lib/active_record/internal_metadata.rb
+++ b/activerecord/lib/active_record/internal_metadata.rb
@@ -23,7 +23,7 @@ module ActiveRecord
       end
 
       def table_exists?
-        ActiveSupport::Deprecation.silence { connection.table_exists?(table_name) }
+        connection.table_exists?(table_name)
       end
 
       # Creates an internal metadata table with columns +key+ and +value+
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index cc6bc17b9d..ed0c81b639 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -522,7 +522,10 @@ module ActiveRecord
     def self.inherited(subclass) # :nodoc:
       super
       if subclass.superclass == Migration
-        subclass.include Compatibility::Legacy
+        raise StandardError, "Directly inheriting from ActiveRecord::Migration is not supported. " \
+          "Please specify the Rails release the migration was written for:\n" \
+          "\n" \
+          "  class #{self.class.name} < ActiveRecord::Migration[4.2]"
       end
     end
 
@@ -1026,12 +1029,10 @@ module ActiveRecord
       end
 
       def get_all_versions(connection = Base.connection)
-        ActiveSupport::Deprecation.silence do
-          if connection.table_exists?(schema_migrations_table_name)
-            SchemaMigration.all.map { |x| x.version.to_i }.sort
-          else
-            []
-          end
+        if connection.table_exists?(schema_migrations_table_name)
+          SchemaMigration.all.map { |x| x.version.to_i }.sort
+        else
+          []
         end
       end
 
diff --git a/activerecord/lib/active_record/migration/compatibility.rb b/activerecord/lib/active_record/migration/compatibility.rb
index 9c357e1604..2904634eb7 100644
--- a/activerecord/lib/active_record/migration/compatibility.rb
+++ b/activerecord/lib/active_record/migration/compatibility.rb
@@ -13,7 +13,27 @@ module ActiveRecord
 
       V5_1 = Current
 
-      module FourTwoShared
+      class V5_0 < V5_1
+        def create_table(table_name, options = {})
+          if adapter_name == "PostgreSQL"
+            if options[:id] == :uuid && !options[:default]
+              options[:default] = "uuid_generate_v4()"
+            end
+          end
+
+          # Since 5.1 Postgres adapter uses bigserial type for primary
+          # keys by default and MySQL uses bigint. This compat layer makes old migrations utilize
+          # serial/int type instead -- the way it used to work before 5.1.
+          if options[:id].blank?
+            options[:id] = :integer
+            options[:auto_increment] = true
+          end
+
+          super
+        end
+      end
+
+      class V4_2 < V5_0
         module TableDefinition
           def references(*, **options)
             options[:index] ||= false
@@ -101,46 +121,6 @@ module ActiveRecord
             index_name
           end
       end
-
-      class V5_0 < V5_1
-        def create_table(table_name, options = {})
-          if adapter_name == "PostgreSQL"
-            if options[:id] == :uuid && !options[:default]
-              options[:default] = "uuid_generate_v4()"
-            end
-          end
-
-          # Since 5.1 Postgres adapter uses bigserial type for primary
-          # keys by default and MySQL uses bigint. This compat layer makes old migrations utilize
-          # serial/int type instead -- the way it used to work before 5.1.
-          if options[:id].blank?
-            options[:id] = :integer
-            options[:auto_increment] = true
-          end
-
-          super
-        end
-      end
-
-      class V4_2 < V5_0
-        # 4.2 is defined as a module because it needs to be shared with
-        # Legacy. When the time comes, V5_0 should be defined straight
-        # in its class.
-        include FourTwoShared
-      end
-
-      module Legacy
-        include FourTwoShared
-
-        def migrate(*)
-          ActiveSupport::Deprecation.warn \
-            "Directly inheriting from ActiveRecord::Migration is deprecated. " \
-            "Please specify the Rails release the migration was written for:\n" \
-            "\n" \
-            "  class #{self.class.name} < ActiveRecord::Migration[4.2]"
-          super
-        end
-      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index e1a3c59f08..f3e81ee1e2 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -878,15 +878,13 @@ module ActiveRecord
         }
 
         if names.length > 1
-          example_options = options.dup
-          example_options[:source] = source_reflection_names.first
-          ActiveSupport::Deprecation.warn \
-            "Ambiguous source reflection for through association. Please " \
-            "specify a :source directive on your declaration like:\n" \
-            "\n" \
-            "  class #{active_record.name} < ActiveRecord::Base\n" \
-            "    #{macro} :#{name}, #{example_options}\n" \
-            "  end"
+          raise AmbiguousSourceReflectionForThroughAssociation.new(
+            active_record.name,
+            macro,
+            name,
+            options,
+            source_reflection_names
+          )
         end
 
         @source_reflection_name = names.first
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 4e941cf2df..a4b5eacfbf 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -446,16 +446,8 @@ module ActiveRecord
     # ==== Examples
     #
     #   Person.where(age: 0..18).destroy_all
-    def destroy_all(conditions = nil)
-      if conditions
-        ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
-          Passing conditions to destroy_all is deprecated and will be removed in Rails 5.1.
-          To achieve the same use where(conditions).destroy_all.
-        MESSAGE
-        where(conditions).destroy_all
-      else
-        records.each(&:destroy).tap { reset }
-      end
+    def destroy_all
+      records.each(&:destroy).tap { reset }
     end
 
     # Destroy an object (or multiple objects) that has the given id. The object is instantiated first,
@@ -503,7 +495,7 @@ module ActiveRecord
     #
     #   Post.limit(100).delete_all
     #   # => ActiveRecord::ActiveRecordError: delete_all doesn't support limit
-    def delete_all(conditions = nil)
+    def delete_all
       invalid_methods = INVALID_METHODS_FOR_DELETE_ALL.select do |method|
         value = get_value(method)
         SINGLE_VALUE_METHODS.include?(method) ? value : value.any?
@@ -512,27 +504,19 @@ module ActiveRecord
         raise ActiveRecordError.new("delete_all doesn't support #{invalid_methods.join(', ')}")
       end
 
-      if conditions
-        ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
-          Passing conditions to delete_all is deprecated and will be removed in Rails 5.1.
-          To achieve the same use where(conditions).delete_all.
-        MESSAGE
-        where(conditions).delete_all
-      else
-        stmt = Arel::DeleteManager.new
-        stmt.from(table)
+      stmt = Arel::DeleteManager.new
+      stmt.from(table)
 
-        if has_join_values?
-          @klass.connection.join_to_delete(stmt, arel, arel_attribute(primary_key))
-        else
-          stmt.wheres = arel.constraints
-        end
+      if has_join_values?
+        @klass.connection.join_to_delete(stmt, arel, arel_attribute(primary_key))
+      else
+        stmt.wheres = arel.constraints
+      end
 
-        affected = @klass.connection.delete(stmt, "SQL", bound_attributes)
+      affected = @klass.connection.delete(stmt, "SQL", bound_attributes)
 
-        reset
-        affected
-      end
+      reset
+      affected
     end
 
     # Deletes the row with a primary key matching the +id+ argument, using a
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 270511bede..dd92f40dee 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -152,14 +152,6 @@ module ActiveRecord
       result = result.reverse_order!
 
       limit ? result.reverse : result.first
-    rescue ActiveRecord::IrreversibleOrderError
-      ActiveSupport::Deprecation.warn(<<-WARNING.squish)
-          Finding a last element by loading the relation when SQL ORDER
-          can not be reversed is deprecated.
-          Rails 5.1 will raise ActiveRecord::IrreversibleOrderError in this case.
-          Please call `to_a.last` if you still want to load the relation.
-      WARNING
-      find_last(limit)
     end
 
     # Same as #last but raises ActiveRecord::RecordNotFound if no record
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index f9f6ff403e..18ae10a652 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -4,7 +4,6 @@ module ActiveRecord
     require "active_record/relation/predicate_builder/association_query_handler"
     require "active_record/relation/predicate_builder/base_handler"
     require "active_record/relation/predicate_builder/basic_object_handler"
-    require "active_record/relation/predicate_builder/class_handler"
     require "active_record/relation/predicate_builder/polymorphic_array_handler"
     require "active_record/relation/predicate_builder/range_handler"
     require "active_record/relation/predicate_builder/relation_handler"
@@ -16,7 +15,6 @@ module ActiveRecord
       @handlers = []
 
       register_handler(BasicObject, BasicObjectHandler.new)
-      register_handler(Class, ClassHandler.new(self))
       register_handler(Base, BaseHandler.new(self))
       register_handler(Range, RangeHandler.new)
       register_handler(RangeHandler::RangeWithBinds, RangeHandler.new)
diff --git a/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb
deleted file mode 100644
index 810937ead6..0000000000
--- a/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb
+++ /dev/null
@@ -1,29 +0,0 @@
-module ActiveRecord
-  class PredicateBuilder
-    class ClassHandler # :nodoc:
-      def initialize(predicate_builder)
-        @predicate_builder = predicate_builder
-      end
-
-      def call(attribute, value)
-        print_deprecation_warning
-        predicate_builder.build(attribute, value.name)
-      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
-
-      private
-
-        def print_deprecation_warning
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing a class as a value in an Active Record query is deprecated and
-            will be removed. Pass a string instead.
-          MSG
-        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 5f5d8ceea3..2d19395191 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -76,7 +76,7 @@ module ActiveRecord
     end
 
     def bound_attributes
-      if limit_value && !string_containing_comma?(limit_value)
+      if limit_value
         limit_bind = Attribute.with_cast_value(
           "LIMIT".freeze,
           connection.sanitize_limit(limit_value),
@@ -243,9 +243,7 @@ module ActiveRecord
     def select(*fields)
       if block_given?
         if fields.any?
-          ActiveSupport::Deprecation.warn(<<-WARNING.squish)
-            When select is called with a block, it ignores other arguments. This behavior is now deprecated and will result in an ArgumentError in Rails 5.1. You can safely remove the arguments to resolve the deprecation warning because they do not have any effect on the output of the call to the select method with a block.
-          WARNING
+          raise ArgumentError, "`select' with block doesn't take arguments."
         end
 
         return super()
@@ -690,13 +688,6 @@ module ActiveRecord
     end
 
     def limit!(value) # :nodoc:
-      if string_containing_comma?(value)
-        # Remove `string_containing_comma?` when removing this deprecation
-        ActiveSupport::Deprecation.warn(<<-WARNING.squish)
-          Passing a string to limit in the form "1,2" is deprecated and will be
-          removed in Rails 5.1. Please call `offset` explicitly instead.
-        WARNING
-      end
       self.limit_value = value
       self
     end
@@ -958,13 +949,7 @@ module ActiveRecord
 
         arel.where(where_clause.ast) unless where_clause.empty?
         arel.having(having_clause.ast) unless having_clause.empty?
-        if limit_value
-          if string_containing_comma?(limit_value)
-            arel.take(connection.sanitize_limit(limit_value))
-          else
-            arel.take(Arel::Nodes::BindParam.new)
-          end
-        end
+        arel.take(Arel::Nodes::BindParam.new) if limit_value
         arel.skip(Arel::Nodes::BindParam.new) if offset_value
         arel.group(*arel_columns(group_values.uniq.reject(&:blank?))) unless group_values.empty?
 
@@ -1192,10 +1177,6 @@ module ActiveRecord
       end
       alias having_clause_factory where_clause_factory
 
-      def string_containing_comma?(value)
-        ::String === value && value.include?(",")
-      end
-
       def default_value_for(name)
         case name
         when :create_with
diff --git a/activerecord/lib/active_record/schema_migration.rb b/activerecord/lib/active_record/schema_migration.rb
index 99b23e5593..5efbcff96a 100644
--- a/activerecord/lib/active_record/schema_migration.rb
+++ b/activerecord/lib/active_record/schema_migration.rb
@@ -17,7 +17,7 @@ module ActiveRecord
       end
 
       def table_exists?
-        ActiveSupport::Deprecation.silence { connection.table_exists?(table_name) }
+        connection.table_exists?(table_name)
       end
 
       def create_table
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index fd215eeb86..6f868b6b7e 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -241,14 +241,6 @@ module ActiveRecord
         ActiveRecord::InternalMetadata[:environment] = ActiveRecord::Migrator.current_environment
       end
 
-      def load_schema_for(*args)
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          This method was renamed to `#load_schema` and will be removed in the future.
-          Use `#load_schema` instead.
-        MSG
-        load_schema(*args)
-      end
-
       def schema_file(format = ActiveRecord::Base.schema_format)
         case format
         when :ruby
diff --git a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
index 8d5ab9bff9..1f756c2979 100644
--- a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
@@ -21,7 +21,7 @@ module ActiveRecord
 
         FileUtils.rm(file)
       rescue Errno::ENOENT => error
-        raise NoDatabaseError.new(error.message, error)
+        raise NoDatabaseError.new(error.message)
       end
 
       def purge
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index f22acd0f77..56b75540e3 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -274,16 +274,6 @@ module ActiveRecord
         set_callback(:rollback_without_transaction_enrollment, :after, *args, &block)
       end
 
-      def raise_in_transactional_callbacks
-        ActiveSupport::Deprecation.warn("ActiveRecord::Base.raise_in_transactional_callbacks is deprecated and will be removed without replacement.")
-        true
-      end
-
-      def raise_in_transactional_callbacks=(value)
-        ActiveSupport::Deprecation.warn("ActiveRecord::Base.raise_in_transactional_callbacks= is deprecated, has no effect and will be removed without replacement.")
-        value
-      end
-
       private
 
         def set_options_for_callbacks!(args, enforced_options = {})