Merge branch 'master' into adequaterecord

* master: (108 commits)
  make tests pass on Ruby 2.2
  Use Sqlite3 adapter in examples
  use the body proxy to freeze headers
  just ask the response for the commit status, we do not need to ask the jar
  only write the jar if the response isn't committed
  Fix a grammatical error in the i18n guide [ci skip]
  use method_defined? to check whether or not a method is defined
  Enhance docs for update_attribute [ci-skip]
  Change usec to 0 on tests that compare seconds
  Unit test for mysql quote time usec
  Changelog entry for mysql56 microseconds
  Test microsecond on mysql 5.6
  MySQL 5.6 and later supports microsecond precision in datetime.
  [ci skip] Add documentation for original_fullpath.
  Remove mocking on save, when not necessary
  comment why we are modifying global state. [ci skip]
  `change_table` supports `citext`. Follow up to #12523.
  Removed unnecessary command "application"
  register OID for PostgreSQL citex datatype [Troy Kruthoff & Lachlan Sylvester]
  Fixes STI when 2+ levels deep.
  ...

13 files changed, 229 insertions, 138 deletions

diff --git a/activemodel/README.rdoc b/activemodel/README.rdoc
index 4c00755532..500be2a04a 100644
--- a/activemodel/README.rdoc
+++ b/activemodel/README.rdoc
@@ -49,7 +49,8 @@ behavior out of the box:
         send("#{attr}=", nil)
       end
     end
-
+  
+    person = Person.new
     person.clear_name
     person.clear_age
 
@@ -78,7 +79,21 @@ behavior out of the box:
     class Person
       include ActiveModel::Dirty
 
-      attr_accessor :name
+      define_attribute_methods :name
+
+      def name
+        @name
+      end
+
+      def name=(val)
+        name_will_change! unless val == @name
+        @name = val
+      end
+
+      def save
+        # do persistence work
+        changes_applied
+      end
     end
 
     person = Person.new
@@ -88,6 +103,7 @@ behavior out of the box:
     person.changed?         # => true
     person.changed          # => ['name']
     person.changes          # => { 'name' => [nil, 'bob'] }
+    person.save
     person.name = 'robert'
     person.save
     person.previous_changes # => {'name' => ['bob, 'robert']}
@@ -116,7 +132,10 @@ behavior out of the box:
         "Name"
       end
     end
-
+  
+    person = Person.new
+    person.name = nil
+    person.validate!
     person.errors.full_messages
     # => ["Name cannot be nil"]
 
@@ -180,41 +199,41 @@ behavior out of the box:
 
 * Validation support
 
-   class Person
-     include ActiveModel::Validations
+    class Person
+      include ActiveModel::Validations
 
-     attr_accessor :first_name, :last_name
+      attr_accessor :first_name, :last_name
 
-     validates_each :first_name, :last_name do |record, attr, value|
-       record.errors.add attr, 'starts with z.' if value.to_s[0] == ?z
-     end
-   end
+      validates_each :first_name, :last_name do |record, attr, value|
+        record.errors.add attr, 'starts with z.' if value.to_s[0] == ?z
+      end
+    end
 
-   person = Person.new
-   person.first_name = 'zoolander'
-   person.valid?  # => false
+    person = Person.new
+    person.first_name = 'zoolander'
+    person.valid?  # => false
 
   {Learn more}[link:classes/ActiveModel/Validations.html]
 
 * Custom validators
+  
+    class HasNameValidator < ActiveModel::Validator
+      def validate(record)
+        record.errors[:name] = "must exist" if record.name.blank?
+      end
+    end
+
+    class ValidatorPerson
+      include ActiveModel::Validations
+      validates_with HasNameValidator
+      attr_accessor :name
+    end
 
-   class ValidatorPerson
-     include ActiveModel::Validations
-     validates_with HasNameValidator
-     attr_accessor :name
-   end
-
-   class HasNameValidator < ActiveModel::Validator
-     def validate(record)
-       record.errors[:name] = "must exist" if record.name.blank?
-     end
-   end
-
-   p = ValidatorPerson.new
-   p.valid?                  # =>  false
-   p.errors.full_messages    # => ["Name must exist"]
-   p.name = "Bob"
-   p.valid?                  # =>  true
+    p = ValidatorPerson.new
+    p.valid?                  # =>  false
+    p.errors.full_messages    # => ["Name must exist"]
+    p.name = "Bob"
+    p.valid?                  # =>  true
 
   {Learn more}[link:classes/ActiveModel/Validator.html]
 
diff --git a/activemodel/lib/active_model/gem_version.rb b/activemodel/lib/active_model/gem_version.rb
new file mode 100644
index 0000000000..964b24398d
--- /dev/null
+++ b/activemodel/lib/active_model/gem_version.rb
@@ -0,0 +1,15 @@
+module ActiveModel
+  # Returns the version of the currently loaded ActiveModel as a <tt>Gem::Version</tt>
+  def self.gem_version
+    Gem::Version.new VERSION::STRING
+  end
+
+  module VERSION
+    MAJOR = 4
+    MINOR = 2
+    TINY  = 0
+    PRE   = "alpha"
+
+    STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
+  end
+end
diff --git a/activemodel/lib/active_model/version.rb b/activemodel/lib/active_model/version.rb
index 5c9d2bc6bc..b1f9082ea7 100644
--- a/activemodel/lib/active_model/version.rb
+++ b/activemodel/lib/active_model/version.rb
@@ -1,11 +1,8 @@
+require_relative 'gem_version'
+
 module ActiveModel
-  # Returns the version of the currently loaded ActiveModel as a Gem::Version
+  # Returns the version of the currently loaded ActiveModel as a <tt>Gem::Version</tt>
   def self.version
-    Gem::Version.new "4.2.0.alpha"
-  end
-
-  module VERSION #:nodoc:
-    MAJOR, MINOR, TINY, PRE = ActiveModel.version.segments
-    STRING = ActiveModel.version.to_s
+    gem_version
   end
 end
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index e9cb5ccc96..e81b7ac424 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -104,10 +104,14 @@ class AttributeMethodsTest < ActiveModel::TestCase
   end
 
   test '#define_attribute_method generates attribute method' do
-    ModelWithAttributes.define_attribute_method(:foo)
+    begin
+      ModelWithAttributes.define_attribute_method(:foo)
 
-    assert_respond_to ModelWithAttributes.new, :foo
-    assert_equal "value of foo", ModelWithAttributes.new.foo
+      assert_respond_to ModelWithAttributes.new, :foo
+      assert_equal "value of foo", ModelWithAttributes.new.foo
+    ensure
+      ModelWithAttributes.undefine_attribute_methods
+    end
   end
 
   test '#define_attribute_method does not generate attribute method if already defined in attribute module' do
@@ -134,24 +138,36 @@ class AttributeMethodsTest < ActiveModel::TestCase
   end
 
   test '#define_attribute_method generates attribute method with invalid identifier characters' do
-    ModelWithWeirdNamesAttributes.define_attribute_method(:'a?b')
+    begin
+      ModelWithWeirdNamesAttributes.define_attribute_method(:'a?b')
 
-    assert_respond_to ModelWithWeirdNamesAttributes.new, :'a?b'
-    assert_equal "value of a?b", ModelWithWeirdNamesAttributes.new.send('a?b')
+      assert_respond_to ModelWithWeirdNamesAttributes.new, :'a?b'
+      assert_equal "value of a?b", ModelWithWeirdNamesAttributes.new.send('a?b')
+    ensure
+      ModelWithWeirdNamesAttributes.undefine_attribute_methods
+    end
   end
 
   test '#define_attribute_methods works passing multiple arguments' do
-    ModelWithAttributes.define_attribute_methods(:foo, :baz)
+    begin
+      ModelWithAttributes.define_attribute_methods(:foo, :baz)
 
-    assert_equal "value of foo", ModelWithAttributes.new.foo
-    assert_equal "value of baz", ModelWithAttributes.new.baz
+      assert_equal "value of foo", ModelWithAttributes.new.foo
+      assert_equal "value of baz", ModelWithAttributes.new.baz
+    ensure
+      ModelWithAttributes.undefine_attribute_methods
+    end
   end
 
   test '#define_attribute_methods generates attribute methods' do
-    ModelWithAttributes.define_attribute_methods(:foo)
+    begin
+      ModelWithAttributes.define_attribute_methods(:foo)
 
-    assert_respond_to ModelWithAttributes.new, :foo
-    assert_equal "value of foo", ModelWithAttributes.new.foo
+      assert_respond_to ModelWithAttributes.new, :foo
+      assert_equal "value of foo", ModelWithAttributes.new.foo
+    ensure
+      ModelWithAttributes.undefine_attribute_methods
+    end
   end
 
   test '#alias_attribute generates attribute_aliases lookup hash' do
@@ -164,26 +180,38 @@ class AttributeMethodsTest < ActiveModel::TestCase
   end
 
   test '#define_attribute_methods generates attribute methods with spaces in their names' do
-    ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')
+    begin
+      ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')
 
-    assert_respond_to ModelWithAttributesWithSpaces.new, :'foo bar'
-    assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.send(:'foo bar')
+      assert_respond_to ModelWithAttributesWithSpaces.new, :'foo bar'
+      assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.send(:'foo bar')
+    ensure
+      ModelWithAttributesWithSpaces.undefine_attribute_methods
+    end
   end
 
   test '#alias_attribute works with attributes with spaces in their names' do
-    ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')
-    ModelWithAttributesWithSpaces.alias_attribute(:'foo_bar', :'foo bar')
+    begin
+      ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')
+      ModelWithAttributesWithSpaces.alias_attribute(:'foo_bar', :'foo bar')
 
-    assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.foo_bar
+      assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.foo_bar
+    ensure
+      ModelWithAttributesWithSpaces.undefine_attribute_methods
+    end
   end
 
   test '#alias_attribute works with attributes named as a ruby keyword' do
-    ModelWithRubyKeywordNamedAttributes.define_attribute_methods([:begin, :end])
-    ModelWithRubyKeywordNamedAttributes.alias_attribute(:from, :begin)
-    ModelWithRubyKeywordNamedAttributes.alias_attribute(:to, :end)
-
-    assert_equal "value of begin", ModelWithRubyKeywordNamedAttributes.new.from
-    assert_equal "value of end", ModelWithRubyKeywordNamedAttributes.new.to
+    begin
+      ModelWithRubyKeywordNamedAttributes.define_attribute_methods([:begin, :end])
+      ModelWithRubyKeywordNamedAttributes.alias_attribute(:from, :begin)
+      ModelWithRubyKeywordNamedAttributes.alias_attribute(:to, :end)
+
+      assert_equal "value of begin", ModelWithRubyKeywordNamedAttributes.new.from
+      assert_equal "value of end", ModelWithRubyKeywordNamedAttributes.new.to
+    ensure
+      ModelWithRubyKeywordNamedAttributes.undefine_attribute_methods
+    end
   end
 
   test '#undefine_attribute_methods removes attribute methods' do
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index def28578f8..42d0365521 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -82,6 +82,13 @@ class ErrorsTest < ActiveModel::TestCase
     assert_equal({ foo: "omg" }, errors.messages)
   end
 
+  test "error access is indifferent" do
+    errors = ActiveModel::Errors.new(self)
+    errors[:foo] = "omg"
+
+    assert_equal ["omg"], errors["foo"]
+  end
+
   test "values returns an array of messages" do
     errors = ActiveModel::Errors.new(self)
     errors.set(:foo, "omg")
diff --git a/activemodel/test/cases/secure_password_test.rb b/activemodel/test/cases/secure_password_test.rb
index 82fd291064..bcd1e04a0f 100644
--- a/activemodel/test/cases/secure_password_test.rb
+++ b/activemodel/test/cases/secure_password_test.rb
@@ -4,6 +4,8 @@ require 'models/visitor'
 
 class SecurePasswordTest < ActiveModel::TestCase
   setup do
+    # Used only to speed up tests
+    @original_min_cost = ActiveModel::SecurePassword.min_cost
     ActiveModel::SecurePassword.min_cost = true
 
     @user = User.new
@@ -15,7 +17,7 @@ class SecurePasswordTest < ActiveModel::TestCase
   end
 
   teardown do
-    ActiveModel::SecurePassword.min_cost = false
+    ActiveModel::SecurePassword.min_cost = @original_min_cost
   end
 
   test "create and updating without validations" do
@@ -147,7 +149,7 @@ class SecurePasswordTest < ActiveModel::TestCase
   test "setting a nil password should clear an existing password" do
     @existing_user.password = nil
     assert_equal nil, @existing_user.password_digest
-  end  
+  end
 
   test "authenticate" do
     @user.password = "secret"
@@ -164,11 +166,16 @@ class SecurePasswordTest < ActiveModel::TestCase
   end
 
   test "Password digest cost honors bcrypt cost attribute when min_cost is false" do
-    ActiveModel::SecurePassword.min_cost = false
-    BCrypt::Engine.cost = 5
-
-    @user.password = "secret"
-    assert_equal BCrypt::Engine.cost, @user.password_digest.cost
+    begin
+      original_bcrypt_cost = BCrypt::Engine.cost
+      ActiveModel::SecurePassword.min_cost = false
+      BCrypt::Engine.cost = 5
+
+      @user.password = "secret"
+      assert_equal BCrypt::Engine.cost, @user.password_digest.cost
+    ensure
+      BCrypt::Engine.cost = original_bcrypt_cost
+    end
   end
 
   test "Password digest cost can be set to bcrypt min cost to speed up tests" do
diff --git a/activemodel/test/cases/serializers/json_serialization_test.rb b/activemodel/test/cases/serializers/json_serialization_test.rb
index bc185c737f..60414a6570 100644
--- a/activemodel/test/cases/serializers/json_serialization_test.rb
+++ b/activemodel/test/cases/serializers/json_serialization_test.rb
@@ -30,11 +30,6 @@ class JsonSerializationTest < ActiveModel::TestCase
     @contact.preferences = { 'shows' => 'anime' }
   end
 
-  def teardown
-    # set to the default value
-    Contact.include_root_in_json = false
-  end
-
   test "should not include root in json (class method)" do
     json = @contact.to_json
 
@@ -47,19 +42,25 @@ class JsonSerializationTest < ActiveModel::TestCase
   end
 
   test "should include root in json if include_root_in_json is true" do
-    Contact.include_root_in_json = true
-    json = @contact.to_json
-
-    assert_match %r{^\{"contact":\{}, json
-    assert_match %r{"name":"Konata Izumi"}, json
-    assert_match %r{"age":16}, json
-    assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
-    assert_match %r{"awesome":true}, json
-    assert_match %r{"preferences":\{"shows":"anime"\}}, json
+    begin
+      original_include_root_in_json = Contact.include_root_in_json
+      Contact.include_root_in_json = true
+      json = @contact.to_json
+
+      assert_match %r{^\{"contact":\{}, json
+      assert_match %r{"name":"Konata Izumi"}, json
+      assert_match %r{"age":16}, json
+      assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
+      assert_match %r{"awesome":true}, json
+      assert_match %r{"preferences":\{"shows":"anime"\}}, json
+    ensure
+      Contact.include_root_in_json = original_include_root_in_json
+    end
   end
 
   test "should include root in json (option) even if the default is set to false" do
     json = @contact.to_json(root: true)
+
     assert_match %r{^\{"contact":\{}, json
   end
 
@@ -145,13 +146,18 @@ class JsonSerializationTest < ActiveModel::TestCase
   end
 
   test "as_json should return a hash if include_root_in_json is true" do
-    Contact.include_root_in_json = true
-    json = @contact.as_json
-
-    assert_kind_of Hash, json
-    assert_kind_of Hash, json['contact']
-    %w(name age created_at awesome preferences).each do |field|
-      assert_equal @contact.send(field), json['contact'][field]
+    begin
+      original_include_root_in_json = Contact.include_root_in_json
+      Contact.include_root_in_json = true
+      json = @contact.as_json
+
+      assert_kind_of Hash, json
+      assert_kind_of Hash, json['contact']
+      %w(name age created_at awesome preferences).each do |field|
+        assert_equal @contact.send(field), json['contact'][field]
+      end
+    ensure
+      Contact.include_root_in_json = original_include_root_in_json
     end
   end
 
diff --git a/activemodel/test/cases/serializers/xml_serialization_test.rb b/activemodel/test/cases/serializers/xml_serialization_test.rb
index 11ee17bb27..73f316d5e0 100644
--- a/activemodel/test/cases/serializers/xml_serialization_test.rb
+++ b/activemodel/test/cases/serializers/xml_serialization_test.rb
@@ -57,48 +57,48 @@ class XmlSerializationTest < ActiveModel::TestCase
   end
 
   test "should serialize default root" do
-    @xml = @contact.to_xml
-    assert_match %r{^<contact>},  @xml
-    assert_match %r{</contact>$}, @xml
+    xml = @contact.to_xml
+    assert_match %r{^<contact>},  xml
+    assert_match %r{</contact>$}, xml
   end
 
   test "should serialize namespaced root" do
-    @xml = Admin::Contact.new(@contact.attributes).to_xml
-    assert_match %r{^<contact>},  @xml
-    assert_match %r{</contact>$}, @xml
+    xml = Admin::Contact.new(@contact.attributes).to_xml
+    assert_match %r{^<contact>},  xml
+    assert_match %r{</contact>$}, xml
   end
 
   test "should serialize default root with namespace" do
-    @xml = @contact.to_xml namespace: "http://xml.rubyonrails.org/contact"
-    assert_match %r{^<contact xmlns="http://xml.rubyonrails.org/contact">}, @xml
-    assert_match %r{</contact>$}, @xml
+    xml = @contact.to_xml namespace: "http://xml.rubyonrails.org/contact"
+    assert_match %r{^<contact xmlns="http://xml.rubyonrails.org/contact">}, xml
+    assert_match %r{</contact>$}, xml
   end
 
   test "should serialize custom root" do
-    @xml = @contact.to_xml root: 'xml_contact'
-    assert_match %r{^<xml-contact>},  @xml
-    assert_match %r{</xml-contact>$}, @xml
+    xml = @contact.to_xml root: 'xml_contact'
+    assert_match %r{^<xml-contact>},  xml
+    assert_match %r{</xml-contact>$}, xml
   end
 
   test "should allow undasherized tags" do
-    @xml = @contact.to_xml root: 'xml_contact', dasherize: false
-    assert_match %r{^<xml_contact>},  @xml
-    assert_match %r{</xml_contact>$}, @xml
-    assert_match %r{<created_at},     @xml
+    xml = @contact.to_xml root: 'xml_contact', dasherize: false
+    assert_match %r{^<xml_contact>},  xml
+    assert_match %r{</xml_contact>$}, xml
+    assert_match %r{<created_at},     xml
   end
 
   test "should allow camelized tags" do
-    @xml = @contact.to_xml root: 'xml_contact', camelize: true
-    assert_match %r{^<XmlContact>},  @xml
-    assert_match %r{</XmlContact>$}, @xml
-    assert_match %r{<CreatedAt},     @xml
+    xml = @contact.to_xml root: 'xml_contact', camelize: true
+    assert_match %r{^<XmlContact>},  xml
+    assert_match %r{</XmlContact>$}, xml
+    assert_match %r{<CreatedAt},     xml
   end
 
   test "should allow lower-camelized tags" do
-    @xml = @contact.to_xml root: 'xml_contact', camelize: :lower
-    assert_match %r{^<xmlContact>},  @xml
-    assert_match %r{</xmlContact>$}, @xml
-    assert_match %r{<createdAt},     @xml
+    xml = @contact.to_xml root: 'xml_contact', camelize: :lower
+    assert_match %r{^<xmlContact>},  xml
+    assert_match %r{</xmlContact>$}, xml
+    assert_match %r{<createdAt},     xml
   end
 
   test "should use serializable hash" do
@@ -106,22 +106,22 @@ class XmlSerializationTest < ActiveModel::TestCase
     @contact.name = 'aaron stack'
     @contact.age = 25
 
-    @xml = @contact.to_xml
-    assert_match %r{<name>aaron stack</name>}, @xml
-    assert_match %r{<age type="integer">25</age>}, @xml
-    assert_no_match %r{<awesome>}, @xml
+    xml = @contact.to_xml
+    assert_match %r{<name>aaron stack</name>}, xml
+    assert_match %r{<age type="integer">25</age>}, xml
+    assert_no_match %r{<awesome>}, xml
   end
 
   test "should allow skipped types" do
-    @xml = @contact.to_xml skip_types: true
-    assert_match %r{<age>25</age>}, @xml
+    xml = @contact.to_xml skip_types: true
+    assert_match %r{<age>25</age>}, xml
   end
 
   test "should include yielded additions" do
-    @xml = @contact.to_xml do |xml|
+    xml = @contact.to_xml do |xml|
       xml.creator "David"
     end
-    assert_match %r{<creator>David</creator>}, @xml
+    assert_match %r{<creator>David</creator>}, xml
   end
 
   test "should serialize string" do
@@ -162,7 +162,7 @@ class XmlSerializationTest < ActiveModel::TestCase
     assert_match %r{<nationality>unknown</nationality>}, xml
   end
 
-  test 'should supply serializable to second proc argument' do
+  test "should supply serializable to second proc argument" do
     proc = Proc.new { |options, record| options[:builder].tag!('name-reverse', record.name.reverse) }
     xml = @contact.to_xml(procs: [ proc ])
     assert_match %r{<name-reverse>kcats noraa</name-reverse>}, xml
diff --git a/activemodel/test/cases/translation_test.rb b/activemodel/test/cases/translation_test.rb
index deb4e1ed0a..cedc812ec7 100644
--- a/activemodel/test/cases/translation_test.rb
+++ b/activemodel/test/cases/translation_test.rb
@@ -7,6 +7,10 @@ class ActiveModelI18nTests < ActiveModel::TestCase
     I18n.backend = I18n::Backend::Simple.new
   end
 
+  def teardown
+    I18n.backend.reload!
+  end
+
   def test_translated_model_attributes
     I18n.backend.store_translations 'en', activemodel: { attributes: { person: { name: 'person name attribute' } } }
     assert_equal 'person name attribute', Person.human_attribute_name('name')
diff --git a/activemodel/test/cases/validations/confirmation_validation_test.rb b/activemodel/test/cases/validations/confirmation_validation_test.rb
index 4957ba5d0a..65a2a1eb49 100644
--- a/activemodel/test/cases/validations/confirmation_validation_test.rb
+++ b/activemodel/test/cases/validations/confirmation_validation_test.rb
@@ -53,22 +53,25 @@ class ConfirmationValidationTest < ActiveModel::TestCase
   end
 
   def test_title_confirmation_with_i18n_attribute
-    @old_load_path, @old_backend = I18n.load_path.dup, I18n.backend
-    I18n.load_path.clear
-    I18n.backend = I18n::Backend::Simple.new
-    I18n.backend.store_translations('en', {
-      errors: { messages: { confirmation: "doesn't match %{attribute}" } },
-      activemodel: { attributes: { topic: { title: 'Test Title'} } }
-    })
-
-    Topic.validates_confirmation_of(:title)
-
-    t = Topic.new("title" => "We should be confirmed","title_confirmation" => "")
-    assert t.invalid?
-    assert_equal ["doesn't match Test Title"], t.errors[:title_confirmation]
-
-    I18n.load_path.replace @old_load_path
-    I18n.backend = @old_backend
+    begin
+      @old_load_path, @old_backend = I18n.load_path.dup, I18n.backend
+      I18n.load_path.clear
+      I18n.backend = I18n::Backend::Simple.new
+      I18n.backend.store_translations('en', {
+        errors: { messages: { confirmation: "doesn't match %{attribute}" } },
+        activemodel: { attributes: { topic: { title: 'Test Title'} } }
+      })
+
+      Topic.validates_confirmation_of(:title)
+
+      t = Topic.new("title" => "We should be confirmed","title_confirmation" => "")
+      assert t.invalid?
+      assert_equal ["doesn't match Test Title"], t.errors[:title_confirmation]
+    ensure
+      I18n.load_path.replace @old_load_path
+      I18n.backend = @old_backend
+      I18n.backend.reload!
+    end
   end
 
   test "does not override confirmation reader if present" do
diff --git a/activemodel/test/cases/validations/i18n_validation_test.rb b/activemodel/test/cases/validations/i18n_validation_test.rb
index d10010537e..96084a32ba 100644
--- a/activemodel/test/cases/validations/i18n_validation_test.rb
+++ b/activemodel/test/cases/validations/i18n_validation_test.rb
@@ -19,6 +19,7 @@ class I18nValidationTest < ActiveModel::TestCase
     Person.clear_validators!
     I18n.load_path.replace @old_load_path
     I18n.backend = @old_backend
+    I18n.backend.reload!
   end
 
   def test_full_message_encoding
diff --git a/activemodel/test/cases/validations/numericality_validation_test.rb b/activemodel/test/cases/validations/numericality_validation_test.rb
index f77cf47fb7..e1657407cf 100644
--- a/activemodel/test/cases/validations/numericality_validation_test.rb
+++ b/activemodel/test/cases/validations/numericality_validation_test.rb
@@ -119,6 +119,7 @@ class NumericalityValidationTest < ActiveModel::TestCase
 
     invalid!([3, 4])
     valid!([5, 6])
+  ensure
     Topic.send(:remove_method, :min_approved)
   end
 
@@ -128,6 +129,7 @@ class NumericalityValidationTest < ActiveModel::TestCase
 
     invalid!([6])
     valid!([4, 5])
+  ensure
     Topic.send(:remove_method, :max_approved)
   end
 
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index cfce8fb8e6..4ea5670d32 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -139,6 +139,8 @@ class ValidationsTest < ActiveModel::TestCase
     assert_equal 4, hits
     assert_equal %w(gotcha gotcha), t.errors[:title]
     assert_equal %w(gotcha gotcha), t.errors[:content]
+  ensure
+    CustomReader.clear_validators!
   end
 
   def test_validate_block