Merge pull request #18325 from rafaelfranca/rm-remove-deprecations

Remove all deprecation code

38 files changed, 174 insertions, 452 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 83224c522c..d1eee8e73e 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,67 @@
+*   Change the behavior of boolean columns to be closer to Ruby's semantics.
+
+    Before this change we had a small set of "truthy", and all others are "falsy".
+
+    Now, we have a small set of "falsy" values and all others are "truthy" matching
+    Ruby's semantics.
+
+    *Rafael Mendonça França*
+
+*   Deprecate `ActiveRecord::Base.errors_in_transactional_callbacks=`.
+
+    *Rafael Mendonça França*
+
+*   Change transaction callbacks to not swallowing errors.
+
+    Before this change any error raised inside a transaction callback are
+    rescued and printed in the logs.
+
+    Now these errors are not rescue anymore and just bubble up, as the other callbacks.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated `sanitize_sql_hash_for_conditions`.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated `Reflection#source_macro`.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated `symbolized_base_class` and `symbolized_sti_name`.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated `ActiveRecord::Base.disable_implicit_join_references=`.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated access to connection specification using a string acessor.
+
+    Now all strings will be handled as a URL.
+
+    *Rafael Mendonça França*
+
+*   Change the default `null` value for `timestamps` to `false`.
+
+    *Rafael Mendonça França*
+
+*   Return an array of pools from `connection_pools`.
+
+    *Rafael Mendonça França*
+
+*   Return a null column from `column_for_attribute` when no column exists.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated `serialized_attributes`.
+
+    *Rafael Mendonça França*
+
+*   Remove deprecated automatic counter caches on `has_many :through`.
+
+    *Rafael Mendonça França*
+
 *   Change the way in which callback chains can be halted.
 
     The preferred method to halt a callback chain from now on is to explicitly
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 7a050ca224..f1e784d771 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,5 +1,3 @@
-require 'active_support/core_ext/string/filters'
-
 module ActiveRecord
   # = Active Record Has Many Through Association
   module Associations
@@ -49,16 +47,7 @@ module ActiveRecord
         end
 
         save_through_record(record)
-        if has_cached_counter? && !through_reflection_updates_counter_cache?
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Automatic updating of counter caches on through associations has been
-            deprecated, and will be removed in Rails 5. Instead, please set the
-            appropriate `counter_cache` options on the `has_many` and `belongs_to`
-            for your associations to #{through_reflection.name}.
-          MSG
 
-          update_counter_in_database(1)
-        end
         record
       end
 
@@ -211,11 +200,6 @@ module ActiveRecord
         def invertible_for?(record)
           false
         end
-
-        def through_reflection_updates_counter_cache?
-          counter_name = cached_counter_attribute_name
-          inverse_updates_counter_named?(counter_name, through_reflection)
-        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb
index a6e1a24360..afcaa5d55a 100644
--- a/activerecord/lib/active_record/associations/preloader/association.rb
+++ b/activerecord/lib/active_record/associations/preloader/association.rb
@@ -104,11 +104,11 @@ module ActiveRecord
         end
 
         def association_key_type
-          @klass.type_for_attribute(association_key_name.to_s).type
+          @klass.column_for_attribute(association_key_name).type
         end
 
         def owner_key_type
-          @model.type_for_attribute(owner_key_name.to_s).type
+          @model.column_for_attribute(owner_key_name).type
         end
 
         def load_slices(slices)
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index b7edac791e..8f165fb1dc 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -192,7 +192,8 @@ module ActiveRecord
       end
 
       # Returns the column object for the named attribute.
-      # Returns nil if the named attribute does not exist.
+      # Returns a +ActiveRecord::ConnectionAdapters::NullColumn+ if the
+      # named attribute does not exist.
       #
       #   class Person < ActiveRecord::Base
       #   end
@@ -202,17 +203,12 @@ module ActiveRecord
       #   # => #<ActiveRecord::ConnectionAdapters::Column:0x007ff4ab083980 @name="name", @sql_type="varchar(255)", @null=true, ...>
       #
       #   person.column_for_attribute(:nothing)
-      #   # => nil
+      #   # => #<ActiveRecord::ConnectionAdapters::NullColumn:0xXXX @name=nil, @sql_type=nil, @cast_type=#<Type::Value>, ...>
       def column_for_attribute(name)
-        column = columns_hash[name.to_s]
-        if column.nil?
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            `#column_for_attribute` will return a null object for non-existent
-            columns in Rails 5. Use `#has_attribute?` if you need to check for
-            an attribute's existence.
-          MSG
+        name = name.to_s
+        columns_hash.fetch(name) do
+          ConnectionAdapters::NullColumn.new(name)
         end
-        column
       end
     end
 
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 20f0936e52..f6ab543015 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -36,19 +36,8 @@ module ActiveRecord
       extend ActiveSupport::Concern
 
       module ClassMethods
-        [:cache_attributes, :cached_attributes, :cache_attribute?].each do |method_name|
-          define_method method_name do |*|
-            cached_attributes_deprecation_warning(method_name)
-            true
-          end
-        end
-
         protected
 
-        def cached_attributes_deprecation_warning(method_name)
-          ActiveSupport::Deprecation.warn "Calling `#{method_name}` is no longer necessary. All attributes are cached."
-        end
-
         if Module.methods_transplantable?
           def define_method_attribute(name)
             method = ReaderMethodCache[name]
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index e5ec5ddca5..d0d8a968c5 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -1,5 +1,3 @@
-require 'active_support/core_ext/string/filters'
-
 module ActiveRecord
   module AttributeMethods
     module Serialization
@@ -51,19 +49,6 @@ module ActiveRecord
             Type::Serialized.new(type, coder)
           end
         end
-
-        def serialized_attributes
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            `serialized_attributes` is deprecated without replacement, and will
-            be removed in Rails 5.0.
-          MSG
-
-          @serialized_attributes ||= Hash[
-            columns.select { |t| t.cast_type.is_a?(Type::Serialized) }.map { |c|
-              [c.name, c.cast_type.coder]
-            }
-          ]
-        end
       end
     end
   end
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 6235745fb2..1371317e3c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -2,7 +2,6 @@ require 'thread'
 require 'thread_safe'
 require 'monitor'
 require 'set'
-require 'active_support/core_ext/string/filters'
 
 module ActiveRecord
   # Raised when a connection could not be obtained within the connection
@@ -517,15 +516,7 @@ module ActiveRecord
       def connection_pool_list
         owner_to_pool.values.compact
       end
-
-      def connection_pools
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          In the next release, this will return the same as `#connection_pool_list`.
-          (An array of pools, rather than a hash mapping specs to pools.)
-        MSG
-
-        Hash[connection_pool_list.map { |pool| [pool.spec, pool] }]
-      end
+      alias :connection_pools :connection_pool_list
 
       def establish_connection(owner, spec)
         @class_to_pool.clear
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 68d8a2cd6a..7eaa89c9a7 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -56,18 +56,6 @@ module ActiveRecord
       end
     end
 
-    module TimestampDefaultDeprecation # :nodoc:
-      def emit_warning_if_null_unspecified(options)
-        return if options.key?(:null)
-
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          `#timestamp` was called without specifying an option for `null`. In Rails 5,
-          this behavior will change to `null: false`. You should manually specify
-         `null: true` to prevent the behavior of your existing migrations from changing.
-        MSG
-      end
-    end
-
     class ReferenceDefinition # :nodoc:
       def initialize(
         name,
@@ -167,8 +155,6 @@ module ActiveRecord
     # The table definitions
     # The Columns are stored as a ColumnDefinition in the +columns+ attribute.
     class TableDefinition
-      include TimestampDefaultDeprecation
-
       # An array of ColumnDefinition objects, representing the column changes
       # that have been defined.
       attr_accessor :indexes
@@ -375,7 +361,9 @@ module ActiveRecord
       #   t.timestamps null: false
       def timestamps(*args)
         options = args.extract_options!
-        emit_warning_if_null_unspecified(options)
+
+        options[:null] = false if options[:null].nil?
+
         column(:created_at, :datetime, options)
         column(:updated_at, :datetime, options)
       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 34d60493ea..0f44c332ae 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -851,14 +851,14 @@ module ActiveRecord
         columns
       end
 
-      include TimestampDefaultDeprecation
       # Adds timestamps (+created_at+ and +updated_at+) columns to +table_name+.
       # Additional options (like <tt>null: false</tt>) are forwarded to #add_column.
       #
       #   add_timestamps(:suppliers, null: false)
       #
       def add_timestamps(table_name, options = {})
-        emit_warning_if_null_unspecified(options)
+        options[:null] = false if options[:null].nil?
+
         add_column table_name, :created_at, :datetime, options
         add_column table_name, :updated_at, :datetime, options
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
index fd666c8c39..f6ef3b0675 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
@@ -69,12 +69,7 @@ module ActiveRecord
       def rollback_records
         ite = records.uniq
         while record = ite.shift
-          begin
-            record.rolledback! full_rollback?
-          rescue => e
-            raise if ActiveRecord::Base.raise_in_transactional_callbacks
-            record.logger.error(e) if record.respond_to?(:logger) && record.logger
-          end
+          record.rolledback! full_rollback?
         end
       ensure
         ite.each do |i|
@@ -89,12 +84,7 @@ module ActiveRecord
       def commit_records
         ite = records.uniq
         while record = ite.shift
-          begin
-            record.committed!
-          rescue => e
-            raise if ActiveRecord::Base.raise_in_transactional_callbacks
-            record.logger.error(e) if record.respond_to?(:logger) && record.logger
-          end
+          record.committed!
         end
       ensure
         ite.each do |i|
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index fa24d9b43f..c3a8bf5c74 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -25,7 +25,6 @@ module ActiveRecord
       autoload :TableDefinition
       autoload :Table
       autoload :AlterTable
-      autoload :TimestampDefaultDeprecation
     end
 
     autoload_at 'active_record/connection_adapters/abstract/connection_pool' do
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 65d8b1a8ab..e74de60a83 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -5,7 +5,6 @@ module ActiveRecord
   module ConnectionAdapters
     # An abstract definition of a column in a table.
     class Column
-      TRUE_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE', 'on', 'ON'].to_set
       FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF'].to_set
 
       module Format
@@ -77,6 +76,12 @@ module ActiveRecord
         [self.class, name, default, cast_type, sql_type, null, default_function]
       end
     end
+
+    class NullColumn < Column
+      def initialize(name)
+        super name, nil, Type::Value.new
+      end
+    end
   end
   # :startdoc:
 end
diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index e54e3199ff..08d46fca96 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -1,5 +1,4 @@
 require 'uri'
-require 'active_support/core_ext/string/filters'
 
 module ActiveRecord
   module ConnectionAdapters
@@ -210,30 +209,12 @@ module ActiveRecord
           when Symbol
             resolve_symbol_connection spec
           when String
-            resolve_string_connection spec
+            resolve_url_connection spec
           when Hash
             resolve_hash_connection spec
           end
         end
 
-        def resolve_string_connection(spec)
-          # Rails has historically accepted a string to mean either
-          # an environment key or a URL spec, so we have deprecated
-          # this ambiguous behaviour and in the future this function
-          # can be removed in favor of resolve_url_connection.
-          if configurations.key?(spec) || spec !~ /:/
-            ActiveSupport::Deprecation.warn(<<-MSG.squish)
-              Passing a string to ActiveRecord::Base.establish_connection for a
-              configuration lookup is deprecated, please pass a symbol
-              (#{spec.to_sym.inspect}) instead.
-            MSG
-
-            resolve_symbol_connection(spec)
-          else
-            resolve_url_connection(spec)
-          end
-        end
-
         # Takes the environment such as +:production+ or +:development+.
         # This requires that the @configurations was initialized with a key that
         # matches.
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 38b2d632d2..5c7c0feeb7 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -87,13 +87,6 @@ module ActiveRecord
 
       mattr_accessor :maintain_test_schema, instance_accessor: false
 
-      def self.disable_implicit_join_references=(value)
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          Implicit join references were removed with Rails 4.1.
-          Make sure to remove this configuration because it does nothing.
-        MSG
-      end
-
       class_attribute :default_connection_handler, instance_writer: false
       class_attribute :find_by_statement_cache
 
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 4732462b05..3c71936c3b 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -768,12 +768,6 @@ module ActiveRecord
 
   end
 
-  #--
-  # Deprecate 'Fixtures' in favor of 'FixtureSet'.
-  #++
-  # :nodoc:
-  Fixtures = ActiveSupport::Deprecation::DeprecatedConstantProxy.new('ActiveRecord::Fixtures', 'ActiveRecord::FixtureSet')
-
   class Fixture #:nodoc:
     include Enumerable
 
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index b91e9ac137..fd1e22349b 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -79,16 +79,6 @@ module ActiveRecord
         :true == (@finder_needs_type_condition ||= descends_from_active_record? ? :false : :true)
       end
 
-      def symbolized_base_class
-        ActiveSupport::Deprecation.warn('`ActiveRecord::Base.symbolized_base_class` is deprecated and will be removed without replacement.')
-        @symbolized_base_class ||= base_class.to_s.to_sym
-      end
-
-      def symbolized_sti_name
-        ActiveSupport::Deprecation.warn('`ActiveRecord::Base.symbolized_sti_name` is deprecated and will be removed without replacement.')
-        @symbolized_sti_name ||= sti_name.present? ? sti_name.to_sym : symbolized_base_class
-      end
-
       # Returns the class descending directly from ActiveRecord::Base, or
       # an abstract class, if any, in the inheritance hierarchy.
       #
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 7696ef13c7..66f2b6b768 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -153,15 +153,6 @@ module ActiveRecord
         JoinKeys.new(foreign_key, active_record_primary_key)
       end
 
-      def source_macro
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          ActiveRecord::Base.source_macro is deprecated and will be removed
-          without replacement.
-        MSG
-
-        macro
-      end
-
       def constraints
         scope_chain.flatten
       end
@@ -763,16 +754,6 @@ module ActiveRecord
         source_reflection.join_keys(association_klass)
       end
 
-      # The macro used by the source association
-      def source_macro
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          ActiveRecord::Base.source_macro is deprecated and will be removed
-          without replacement.
-        MSG
-
-        source_reflection.source_macro
-      end
-
       # A through association is nested if there would be more than one join table
       def nested?
         chain.length > 2
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 4b5f5773a0..95dbd6a77f 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
@@ -1,5 +1,3 @@
-require 'active_support/core_ext/string/filters'
-
 module ActiveRecord
   class PredicateBuilder
     class ArrayHandler # :nodoc:
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index f5aa60a69a..768a72a947 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -72,35 +72,6 @@ module ActiveRecord
         expanded_attrs
       end
 
-      # Sanitizes a hash of attribute/value pairs into SQL conditions for a WHERE clause.
-      #   { name: "foo'bar", group_id: 4 }
-      #     # => "name='foo''bar' and group_id= 4"
-      #   { status: nil, group_id: [1,2,3] }
-      #     # => "status IS NULL and group_id IN (1,2,3)"
-      #   { age: 13..18 }
-      #     # => "age BETWEEN 13 AND 18"
-      #   { 'other_records.id' => 7 }
-      #     # => "`other_records`.`id` = 7"
-      #   { other_records: { id: 7 } }
-      #     # => "`other_records`.`id` = 7"
-      # And for value objects on a composed_of relationship:
-      #   { address: Address.new("123 abc st.", "chicago") }
-      #     # => "address_street='123 abc st.' and address_city='chicago'"
-      def sanitize_sql_hash_for_conditions(attrs, default_table_name = self.table_name)
-        table = Arel::Table.new(table_name).alias(default_table_name)
-        predicate_builder = PredicateBuilder.new(TableMetadata.new(self, table))
-        ActiveSupport::Deprecation.warn(<<-EOWARN)
-sanitize_sql_hash_for_conditions is deprecated, and will be removed in Rails 5.0
-        EOWARN
-        attrs = predicate_builder.resolve_column_aliases(attrs)
-        attrs = expand_hash_conditions_for_aggregates(attrs)
-
-        predicate_builder.build_from_hash(attrs).map { |b|
-          connection.visitor.compile b
-        }.join(' AND ')
-      end
-      alias_method :sanitize_sql_hash, :sanitize_sql_hash_for_conditions
-
       # Sanitizes a hash of attribute/value pairs into SQL conditions for a SET clause.
       #   { status: nil, group_id: 1 }
       #     # => "status = NULL , group_id = 1"
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index 31ca90fb58..1c48196762 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -4,23 +4,10 @@ module ActiveRecord
     extend ActiveSupport::Concern
     #:nodoc:
     ACTIONS = [:create, :destroy, :update]
-    #:nodoc:
-    CALLBACK_WARN_MESSAGE = "Currently, Active Record suppresses errors raised " \
-      "within `after_rollback`/`after_commit` callbacks and only print them to " \
-      "the logs. In the next version, these errors will no longer be suppressed. " \
-      "Instead, the errors will propagate normally just like in other Active " \
-      "Record callbacks.\n" \
-      "\n" \
-      "You can opt into the new behavior and remove this warning by setting:\n" \
-      "\n" \
-      "  config.active_record.raise_in_transactional_callbacks = true\n\n"
 
     included do
       define_callbacks :commit, :rollback,
                        scope: [:kind, :name]
-
-      mattr_accessor :raise_in_transactional_callbacks, instance_writer: false
-      self.raise_in_transactional_callbacks = false
     end
 
     # = Active Record Transactions
@@ -236,9 +223,6 @@ module ActiveRecord
       def after_commit(*args, &block)
         set_options_for_callbacks!(args)
         set_callback(:commit, :after, *args, &block)
-        unless ActiveRecord::Base.raise_in_transactional_callbacks
-          ActiveSupport::Deprecation.warn(CALLBACK_WARN_MESSAGE)
-        end
       end
 
       # This callback is called after a create, update, or destroy are rolled back.
@@ -247,9 +231,16 @@ module ActiveRecord
       def after_rollback(*args, &block)
         set_options_for_callbacks!(args)
         set_callback(:rollback, :after, *args, &block)
-        unless ActiveRecord::Base.raise_in_transactional_callbacks
-          ActiveSupport::Deprecation.warn(CALLBACK_WARN_MESSAGE)
-        end
+      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
diff --git a/activerecord/lib/active_record/type/boolean.rb b/activerecord/lib/active_record/type/boolean.rb
index 978d16d524..2e24afc7c0 100644
--- a/activerecord/lib/active_record/type/boolean.rb
+++ b/activerecord/lib/active_record/type/boolean.rb
@@ -10,19 +10,10 @@ module ActiveRecord
       def cast_value(value)
         if value == ''
           nil
-        elsif ConnectionAdapters::Column::TRUE_VALUES.include?(value)
-          true
-        else
-          if !ConnectionAdapters::Column::FALSE_VALUES.include?(value)
-            ActiveSupport::Deprecation.warn(<<-MSG.squish)
-              You attempted to assign a value which is not explicitly `true` or `false`
-              to a boolean column. Currently this value casts to `false`. This will
-              change to match Ruby's semantics, and will cast to `true` in Rails 5.
-              If you would like to maintain the current behavior, you should
-              explicitly handle the values you would like cast to `false`.
-            MSG
-          end
+        elsif ConnectionAdapters::Column::FALSE_VALUES.include?(value)
           false
+        else
+          true
         end
       end
     end
diff --git a/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb b/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
index f7bf6987c4..fd94a2d038 100644
--- a/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
+++ b/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
@@ -9,7 +9,7 @@ class <%= migration_class_name %> < ActiveRecord::Migration
 <% end -%>
 <% end -%>
 <% if options[:timestamps] %>
-      t.timestamps null: false
+      t.timestamps
 <% end -%>
     end
 <% attributes_with_index.each do |attribute| -%>
diff --git a/activerecord/test/cases/ar_schema_test.rb b/activerecord/test/cases/ar_schema_test.rb
index 025c9fe6f9..f4e8003bc3 100644
--- a/activerecord/test/cases/ar_schema_test.rb
+++ b/activerecord/test/cases/ar_schema_test.rb
@@ -93,69 +93,38 @@ if ActiveRecord::Base.connection.supports_migrations?
       assert_equal "20131219224947", ActiveRecord::SchemaMigration.normalize_migration_number("20131219224947")
     end
 
-    def test_timestamps_without_null_is_deprecated_on_create_table
-      assert_deprecated do
-        ActiveRecord::Schema.define do
-          create_table :has_timestamps do |t|
-            t.timestamps
-          end
+    def test_timestamps_without_null_set_null_to_false_on_create_table
+      ActiveRecord::Schema.define do
+        create_table :has_timestamps do |t|
+          t.timestamps
         end
       end
+
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'created_at' }.null
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'updated_at' }.null
     end
 
-    def test_timestamps_without_null_is_deprecated_on_change_table
-      assert_deprecated do
-        ActiveRecord::Schema.define do
-          create_table :has_timestamps
+    def test_timestamps_without_null_set_null_to_false_on_change_table
+      ActiveRecord::Schema.define do
+        create_table :has_timestamps
 
-          change_table :has_timestamps do |t|
-            t.timestamps
-          end
+        change_table :has_timestamps do |t|
+          t.timestamps default: Time.now
         end
       end
-    end
 
-    def test_timestamps_without_null_is_deprecated_on_add_timestamps
-      assert_deprecated do
-        ActiveRecord::Schema.define do
-          create_table :has_timestamps
-          add_timestamps :has_timestamps
-        end
-      end
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'created_at' }.null
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'updated_at' }.null
     end
 
-    def test_no_deprecation_warning_from_timestamps_on_create_table
-      assert_not_deprecated do
-        ActiveRecord::Schema.define do
-          create_table :has_timestamps do |t|
-            t.timestamps null: true
-          end
-
-          drop_table :has_timestamps
-
-          create_table :has_timestamps do |t|
-            t.timestamps null: false
-          end
-        end
+    def test_timestamps_without_null_set_null_to_false_on_add_timestamps
+      ActiveRecord::Schema.define do
+        create_table :has_timestamps
+        add_timestamps :has_timestamps, default: Time.now
       end
-    end
-
-    def test_no_deprecation_warning_from_timestamps_on_change_table
-      assert_not_deprecated do
-        ActiveRecord::Schema.define do
-          create_table :has_timestamps
-          change_table :has_timestamps do |t|
-            t.timestamps null: true
-          end
 
-          drop_table :has_timestamps
-
-          create_table :has_timestamps
-          change_table :has_timestamps do |t|
-            t.timestamps null: false, default: Time.now
-          end
-        end
-      end
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'created_at' }.null
+      assert !@connection.columns(:has_timestamps).find { |c| c.name == 'updated_at' }.null
     end
   end
 end
diff --git a/activerecord/test/cases/associations/deprecated_counter_cache_on_has_many_through_test.rb b/activerecord/test/cases/associations/deprecated_counter_cache_on_has_many_through_test.rb
deleted file mode 100644
index 48f7ddbe83..0000000000
--- a/activerecord/test/cases/associations/deprecated_counter_cache_on_has_many_through_test.rb
+++ /dev/null
@@ -1,26 +0,0 @@
-require "cases/helper"
-
-class DeprecatedCounterCacheOnHasManyThroughTest < ActiveRecord::TestCase
-  class Post < ActiveRecord::Base
-    has_many :taggings, as: :taggable
-    has_many :tags, through: :taggings
-  end
-
-  class Tagging < ActiveRecord::Base
-    belongs_to :taggable, polymorphic: true
-    belongs_to :tag
-  end
-
-  class Tag < ActiveRecord::Base
-  end
-
-  test "counter caches are updated in the database if the belongs_to association doesn't specify a counter cache" do
-    post = Post.create!(title: 'Hello', body: 'World!')
-    assert_deprecated { post.tags << Tag.create!(name: 'whatever') }
-
-    assert_equal 1, post.tags.size
-    assert_equal 1, post.tags_count
-    assert_equal 1, post.reload.tags.size
-    assert_equal 1, post.reload.tags_count
-  end
-end
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index 731d433706..feb1fca500 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -531,20 +531,6 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     end
   end
 
-  def test_deprecated_cache_attributes
-    assert_deprecated do
-      Topic.cache_attributes :replies_count
-    end
-
-    assert_deprecated do
-      Topic.cached_attributes
-    end
-
-    assert_deprecated do
-      Topic.cache_attribute? :replies_count
-    end
-  end
-
   def test_converted_values_are_returned_after_assignment
     developer = Developer.new(name: 1337, salary: "50000")
 
diff --git a/activerecord/test/cases/connection_adapters/connection_handler_test.rb b/activerecord/test/cases/connection_adapters/connection_handler_test.rb
index 3e33b30144..b72f8ca88c 100644
--- a/activerecord/test/cases/connection_adapters/connection_handler_test.rb
+++ b/activerecord/test/cases/connection_adapters/connection_handler_test.rb
@@ -44,9 +44,7 @@ module ActiveRecord
       end
 
       def test_connection_pools
-        assert_deprecated do
-          assert_equal({ Base.connection_pool.spec => @pool }, @handler.connection_pools)
-        end
+        assert_equal([@pool], @handler.connection_pools)
       end
     end
   end
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 37ad469476..9ee92a3cd2 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
@@ -51,34 +51,6 @@ module ActiveRecord
         assert_equal expected, actual
       end
 
-      def test_resolver_with_database_uri_and_and_current_env_string_key
-        ENV['DATABASE_URL'] = "postgres://localhost/foo"
-        config   = { "default_env" => {  "adapter" => "not_postgres", "database" => "not_foo" } }
-        actual   = assert_deprecated { resolve_spec("default_env", config) }
-        expected = { "adapter"=>"postgresql", "database"=>"foo", "host"=>"localhost" }
-        assert_equal expected, actual
-      end
-
-      def test_resolver_with_database_uri_and_and_current_env_string_key_and_rails_env
-        ENV['DATABASE_URL'] = "postgres://localhost/foo"
-        ENV['RAILS_ENV'] = "foo"
-
-        config   = { "not_production" => {"adapter" => "not_postgres", "database" => "not_foo" } }
-        actual   = assert_deprecated { resolve_spec("foo", config) }
-        expected = { "adapter" => "postgresql", "database" => "foo", "host" => "localhost" }
-        assert_equal expected, actual
-      end
-
-      def test_resolver_with_database_uri_and_and_current_env_string_key_and_rack_env
-        ENV['DATABASE_URL'] = "postgres://localhost/foo"
-        ENV['RACK_ENV'] = "foo"
-
-        config   = { "not_production" => {"adapter" => "not_postgres", "database" => "not_foo" } }
-        actual   = assert_deprecated { resolve_spec("foo", config) }
-        expected = { "adapter" => "postgresql", "database" => "foo", "host" => "localhost" }
-        assert_equal expected, actual
-      end
-
       def test_resolver_with_database_uri_and_known_key
         ENV['DATABASE_URL'] = "postgres://localhost/foo"
         config   = { "production" => { "adapter" => "not_postgres", "database" => "not_foo", "host" => "localhost" } }
@@ -95,16 +67,6 @@ module ActiveRecord
         end
       end
 
-      def test_resolver_with_database_uri_and_unknown_string_key
-        ENV['DATABASE_URL'] = "postgres://localhost/foo"
-        config   = { "not_production" => {  "adapter" => "not_postgres", "database" => "not_foo" } }
-        assert_deprecated do
-          assert_raises AdapterNotSpecified do
-           resolve_spec("production", config)
-          end
-        end
-      end
-
       def test_resolver_with_database_uri_and_supplied_url
         ENV['DATABASE_URL'] = "not-postgres://not-localhost/not_foo"
         config   = { "production" => {  "adapter" => "also_not_postgres", "database" => "also_not_foo" } }
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 98cf60a8c4..5b71bd7e67 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -165,18 +165,6 @@ class DirtyTest < ActiveRecord::TestCase
     assert_equal parrot.name_change, parrot.title_change
   end
 
-  def test_reset_attribute!
-    pirate = Pirate.create!(:catchphrase => 'Yar!')
-    pirate.catchphrase = 'Ahoy!'
-
-    assert_deprecated do
-      pirate.reset_catchphrase!
-    end
-    assert_equal "Yar!", pirate.catchphrase
-    assert_equal Hash.new, pirate.changes
-    assert !pirate.catchphrase_changed?
-  end
-
   def test_restore_attribute!
     pirate = Pirate.create!(:catchphrase => 'Yar!')
     pirate.catchphrase = 'Ahoy!'
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 80ac57ec7c..925491acbd 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -24,9 +24,6 @@ ActiveSupport::Deprecation.debug = true
 # Disable available locale checks to avoid warnings running the test suite.
 I18n.enforce_available_locales = false
 
-# Enable raise errors in after_commit and after_rollback.
-ActiveRecord::Base.raise_in_transactional_callbacks = true
-
 # Connect to the database
 ARTest.connect
 
diff --git a/activerecord/test/cases/migration/change_schema_test.rb b/activerecord/test/cases/migration/change_schema_test.rb
index 337360e97f..b3129a8984 100644
--- a/activerecord/test/cases/migration/change_schema_test.rb
+++ b/activerecord/test/cases/migration/change_schema_test.rb
@@ -195,32 +195,29 @@ module ActiveRecord
       end
 
       def test_create_table_with_timestamps_should_create_datetime_columns
-        # FIXME: Remove the silence when we change the default `null` behavior
-        ActiveSupport::Deprecation.silence do
-          connection.create_table table_name do |t|
-            t.timestamps
-          end
+        connection.create_table table_name do |t|
+          t.timestamps
         end
         created_columns = connection.columns(table_name)
 
         created_at_column = created_columns.detect {|c| c.name == 'created_at' }
         updated_at_column = created_columns.detect {|c| c.name == 'updated_at' }
 
-        assert created_at_column.null
-        assert updated_at_column.null
+        assert !created_at_column.null
+        assert !updated_at_column.null
       end
 
       def test_create_table_with_timestamps_should_create_datetime_columns_with_options
         connection.create_table table_name do |t|
-          t.timestamps :null => false
+          t.timestamps null: true
         end
         created_columns = connection.columns(table_name)
 
         created_at_column = created_columns.detect {|c| c.name == 'created_at' }
         updated_at_column = created_columns.detect {|c| c.name == 'updated_at' }
 
-        assert !created_at_column.null
-        assert !updated_at_column.null
+        assert created_at_column.null
+        assert updated_at_column.null
       end
 
       def test_create_table_without_a_block
diff --git a/activerecord/test/cases/migration/foreign_key_test.rb b/activerecord/test/cases/migration/foreign_key_test.rb
index 51e21528c2..ad35d690bd 100644
--- a/activerecord/test/cases/migration/foreign_key_test.rb
+++ b/activerecord/test/cases/migration/foreign_key_test.rb
@@ -29,7 +29,7 @@ module ActiveRecord
 
       teardown do
         if defined?(@connection)
-          @connection.drop_table "astronauts" if @connection.table_exists? 'astronauts' 
+          @connection.drop_table "astronauts" if @connection.table_exists? 'astronauts'
           @connection.drop_table "rockets" if @connection.table_exists? 'rockets'
         end
       end
@@ -220,6 +220,18 @@ module ActiveRecord
       ensure
         silence_stream($stdout) { migration.migrate(:down) }
       end
+
+      private
+
+      def silence_stream(stream)
+        old_stream = stream.dup
+        stream.reopen(RbConfig::CONFIG['host_os'] =~ /mswin|mingw/ ? 'NUL:' : '/dev/null')
+        stream.sync = true
+        yield
+      ensure
+        stream.reopen(old_stream)
+        old_stream.close
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 3192b797b4..5829ef2100 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -936,4 +936,14 @@ class CopyMigrationsTest < ActiveRecord::TestCase
       end
     end
   end
+
+  def silence_stream(stream)
+    old_stream = stream.dup
+    stream.reopen(RbConfig::CONFIG['host_os'] =~ /mswin|mingw/ ? 'NUL:' : '/dev/null')
+    stream.sync = true
+    yield
+  ensure
+    stream.reopen(old_stream)
+    old_stream.close
+  end
 end
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index e86b892a0a..a2252a836f 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -80,10 +80,24 @@ class ReflectionTest < ActiveRecord::TestCase
     assert_equal :integer, @first.column_for_attribute("id").type
   end
 
-  def test_non_existent_columns_return_nil
-    assert_deprecated do
-      assert_nil @first.column_for_attribute("attribute_that_doesnt_exist")
-    end
+  def test_non_existent_columns_return_null_object
+    column = @first.column_for_attribute("attribute_that_doesnt_exist")
+    assert_instance_of ActiveRecord::ConnectionAdapters::NullColumn, column
+    assert_equal "attribute_that_doesnt_exist", column.name
+    assert_equal nil, column.sql_type
+    assert_equal nil, column.type
+    assert_not column.number?
+    assert_not column.text?
+    assert_not column.binary?
+  end
+
+  def test_non_existent_columns_are_identity_types
+    column = @first.column_for_attribute("attribute_that_doesnt_exist")
+    object = Object.new
+
+    assert_equal object, column.type_cast_from_database(object)
+    assert_equal object, column.type_cast_from_user(object)
+    assert_equal object, column.type_cast_for_database(object)
   end
 
   def test_reflection_klass_for_nested_class_name
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index fb9258c038..2e2c5ee10b 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1382,12 +1382,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal "id", Post.all.primary_key
   end
 
-  def test_disable_implicit_join_references_is_deprecated
-    assert_deprecated do
-      ActiveRecord::Base.disable_implicit_join_references = true
-    end
-  end
-
   def test_ordering_with_extra_spaces
     assert_equal authors(:david), Author.order('id DESC , name DESC').last
   end
diff --git a/activerecord/test/cases/sanitize_test.rb b/activerecord/test/cases/sanitize_test.rb
index f477cf7d92..262e0abc22 100644
--- a/activerecord/test/cases/sanitize_test.rb
+++ b/activerecord/test/cases/sanitize_test.rb
@@ -7,17 +7,6 @@ class SanitizeTest < ActiveRecord::TestCase
   def setup
   end
 
-  def test_sanitize_sql_hash_handles_associations
-    quoted_bambi = ActiveRecord::Base.connection.quote("Bambi")
-    quoted_column_name = ActiveRecord::Base.connection.quote_column_name("name")
-    quoted_table_name = ActiveRecord::Base.connection.quote_table_name("adorable_animals")
-    expected_value = "#{quoted_table_name}.#{quoted_column_name} = #{quoted_bambi}"
-
-    assert_deprecated do
-      assert_equal expected_value, Binary.send(:sanitize_sql_hash, {adorable_animals: {name: 'Bambi'}})
-    end
-  end
-
   def test_sanitize_sql_array_handles_string_interpolation
     quoted_bambi = ActiveRecord::Base.connection.quote_string("Bambi")
     assert_equal "name=#{quoted_bambi}", Binary.send(:sanitize_sql_array, ["name=%s", "Bambi"])
diff --git a/activerecord/test/cases/serialized_attribute_test.rb b/activerecord/test/cases/serialized_attribute_test.rb
index c261a5b1c0..e29f7462c8 100644
--- a/activerecord/test/cases/serialized_attribute_test.rb
+++ b/activerecord/test/cases/serialized_attribute_test.rb
@@ -22,12 +22,6 @@ class SerializedAttributeTest < ActiveRecord::TestCase
     end
   end
 
-  def test_list_of_serialized_attributes
-    assert_deprecated do
-      assert_equal %w(content), Topic.serialized_attributes.keys
-    end
-  end
-
   def test_serialized_attribute
     Topic.serialize("content", MyObject)
 
diff --git a/activerecord/test/cases/transaction_callbacks_test.rb b/activerecord/test/cases/transaction_callbacks_test.rb
index 0f5caa52e3..185fc22e98 100644
--- a/activerecord/test/cases/transaction_callbacks_test.rb
+++ b/activerecord/test/cases/transaction_callbacks_test.rb
@@ -266,47 +266,6 @@ class TransactionCallbacksTest < ActiveRecord::TestCase
     assert_equal 2, @first.rollbacks
   end
 
-  def test_after_transaction_callbacks_should_prevent_callbacks_from_being_called
-    old_transaction_config = ActiveRecord::Base.raise_in_transactional_callbacks
-    ActiveRecord::Base.raise_in_transactional_callbacks = false
-
-    def @first.last_after_transaction_error=(e); @last_transaction_error = e; end
-    def @first.last_after_transaction_error; @last_transaction_error; end
-    @first.after_commit_block{|r| r.last_after_transaction_error = :commit; raise "fail!";}
-    @first.after_rollback_block{|r| r.last_after_transaction_error = :rollback; raise "fail!";}
-
-    second = TopicWithCallbacks.find(3)
-    second.after_commit_block{|r| r.history << :after_commit}
-    second.after_rollback_block{|r| r.history << :after_rollback}
-
-    Topic.transaction do
-      @first.save!
-      second.save!
-    end
-    assert_equal :commit, @first.last_after_transaction_error
-    assert_equal [:after_commit], second.history
-
-    second.history.clear
-    Topic.transaction do
-      @first.save!
-      second.save!
-      raise ActiveRecord::Rollback
-    end
-    assert_equal :rollback, @first.last_after_transaction_error
-    assert_equal [:after_rollback], second.history
-  ensure
-    ActiveRecord::Base.raise_in_transactional_callbacks = old_transaction_config
-  end
-
-  def test_after_commit_should_not_raise_when_raise_in_transactional_callbacks_false
-    old_transaction_config = ActiveRecord::Base.raise_in_transactional_callbacks
-    ActiveRecord::Base.raise_in_transactional_callbacks = false
-    @first.after_commit_block{ fail "boom" }
-    Topic.transaction { @first.save! }
-  ensure
-    ActiveRecord::Base.raise_in_transactional_callbacks = old_transaction_config
-  end
-
   def test_after_commit_callback_should_not_swallow_errors
     @first.after_commit_block{ fail "boom" }
     assert_raises(RuntimeError) do
diff --git a/activerecord/test/cases/types_test.rb b/activerecord/test/cases/types_test.rb
index b0979cbe1f..73e92addfe 100644
--- a/activerecord/test/cases/types_test.rb
+++ b/activerecord/test/cases/types_test.rb
@@ -17,6 +17,10 @@ module ActiveRecord
         assert type.type_cast_from_user('TRUE')
         assert type.type_cast_from_user('on')
         assert type.type_cast_from_user('ON')
+        assert type.type_cast_from_user(' ')
+        assert type.type_cast_from_user("\u3000\r\n")
+        assert type.type_cast_from_user("\u0000")
+        assert type.type_cast_from_user('SOMETHING RANDOM')
 
         # explicitly check for false vs nil
         assert_equal false, type.type_cast_from_user(false)
@@ -28,12 +32,6 @@ module ActiveRecord
         assert_equal false, type.type_cast_from_user('FALSE')
         assert_equal false, type.type_cast_from_user('off')
         assert_equal false, type.type_cast_from_user('OFF')
-        assert_deprecated do
-          assert_equal false, type.type_cast_from_user(' ')
-          assert_equal false, type.type_cast_from_user("\u3000\r\n")
-          assert_equal false, type.type_cast_from_user("\u0000")
-          assert_equal false, type.type_cast_from_user('SOMETHING RANDOM')
-        end
       end
 
       def test_type_cast_float