7 files changed, 13 insertions, 73 deletions
diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index 5588699d9b..b86e988841 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,61 +1 @@
-*   Passwords with spaces only allowed in `ActiveModel::SecurePassword`.
-
-    Presence validation can be used to restore old behavior.
-
-    *Yevhene Shemet*
-
-*   Validate options passed to `ActiveModel::Validations.validate`.
-
-    Preventing, in many cases, the simple mistake of using `validate` instead of `validates`.
-
-    *Sonny Michaud*
-
-*   Deprecate `reset_#{attribute}` in favor of `restore_#{attribute}`.
-
-    These methods may cause confusion with the `reset_changes`, which has
-    different behaviour.
-
-    *Rafael Mendonça França*
-
-*   Deprecate `ActiveModel::Dirty#reset_changes` in favor of `#clear_changes_information`.
-
-    Method's name is causing confusion with the `reset_#{attribute}` methods.
-    While `reset_name` sets the value of the name attribute to previous value
-    `reset_changes` only discards the changes.
-
-    *Rafael Mendonça França*
-
-*   Added `restore_attributes` method to `ActiveModel::Dirty` API which restores
-    the value of changed attributes to previous value.
-
-    *Igor G.*
-
-*   Allow proc and symbol as values for `only_integer` of `NumericalityValidator`
-
-    *Robin Mehner*
-
-*   `has_secure_password` now verifies that the given password is less than 72
-    characters if validations are enabled.
-
-    Fixes #14591.
-
-    *Akshay Vishnoi*
-
-*   Remove deprecated `Validator#setup` without replacement.
-
-    See #10716.
-
-    *Kuldeep Aggarwal*
-
-*   Add plural and singular form for length validator's default messages.
-
-    *Abd ar-Rahman Hamid*
-
-*   Introduce `validate` as an alias for `valid?`.
-
-    This is more intuitive when you want to run validations but don't care about
-    the return value.
-
-    *Henrik Nyh*
-
-Please check [4-1-stable](https://github.com/rails/rails/blob/4-1-stable/activemodel/CHANGELOG.md) for previous changes.
+Please check [4-2-stable](https://github.com/rails/rails/blob/4-2-stable/activemodel/CHANGELOG.md) for previous changes.
diff --git a/activemodel/activemodel.gemspec b/activemodel/activemodel.gemspec
index 36e565f692..73600b83fb 100644
--- a/activemodel/activemodel.gemspec
+++ b/activemodel/activemodel.gemspec
@@ -7,7 +7,7 @@ Gem::Specification.new do |s|
   s.summary     = 'A toolkit for building modeling frameworks (part of Rails).'
   s.description = 'A toolkit for building modeling frameworks like Active Record. Rich support for attributes, callbacks, validations, serialization, internationalization, and testing.'
 
-  s.required_ruby_version = '>= 1.9.3'
+  s.required_ruby_version = '>= 2.1.0'
 
   s.license = 'MIT'
 
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index ae185694ca..4e389c8692 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -255,7 +255,7 @@ module ActiveModel
       end
 
       # Remove changes information for the provided attributes.
-      def clear_attribute_changes(attributes)
+      def clear_attribute_changes(attributes) # :doc:
         attributes_changed_by_setter.except!(*attributes)
       end
   end
diff --git a/activemodel/lib/active_model/gem_version.rb b/activemodel/lib/active_model/gem_version.rb
index 932fe3e5a9..2403242ce6 100644
--- a/activemodel/lib/active_model/gem_version.rb
+++ b/activemodel/lib/active_model/gem_version.rb
@@ -5,10 +5,10 @@ module ActiveModel
   end
 
   module VERSION
-    MAJOR = 4
-    MINOR = 2
+    MAJOR = 5
+    MINOR = 0
     TINY  = 0
-    PRE   = "beta4"
+    PRE   = "alpha"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end
diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index 77f2a64b11..b66dbf1afe 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -130,10 +130,10 @@ module ActiveModel
       #
       #   json = { person: { name: 'bob', age: 22, awesome:true } }.to_json
       #   person = Person.new
-      #   person.from_json(json) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
-      #   person.name            # => "bob"
-      #   person.age             # => 22
-      #   person.awesome         # => true
+      #   person.from_json(json, true) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
+      #   person.name                  # => "bob"
+      #   person.age                   # => 22
+      #   person.awesome               # => true
       def from_json(json, include_root=include_root_in_json)
         hash = ActiveSupport::JSON.decode(json)
         hash = hash.values.first if include_root
diff --git a/activemodel/test/cases/validations/numericality_validation_test.rb b/activemodel/test/cases/validations/numericality_validation_test.rb
index 3834d327ea..12a22f9c40 100644
--- a/activemodel/test/cases/validations/numericality_validation_test.rb
+++ b/activemodel/test/cases/validations/numericality_validation_test.rb
@@ -59,7 +59,7 @@ class NumericalityValidationTest < ActiveModel::TestCase
 
   def test_validates_numericality_of_with_integer_only_and_proc_as_value
     Topic.send(:define_method, :allow_only_integers?, lambda { false })
-    Topic.validates_numericality_of :approved, only_integer: Proc.new {|topic| topic.allow_only_integers? }
+    Topic.validates_numericality_of :approved, only_integer: Proc.new(&:allow_only_integers?)
 
     invalid!(NIL + BLANK + JUNK)
     valid!(FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
@@ -130,7 +130,7 @@ class NumericalityValidationTest < ActiveModel::TestCase
 
   def test_validates_numericality_with_proc
     Topic.send(:define_method, :min_approved, lambda { 5 })
-    Topic.validates_numericality_of :approved, greater_than_or_equal_to: Proc.new {|topic| topic.min_approved }
+    Topic.validates_numericality_of :approved, greater_than_or_equal_to: Proc.new(&:min_approved)
 
     invalid!([3, 4])
     valid!([5, 6])
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index de71bb6f42..98e0266d7e 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -282,7 +282,7 @@ class ValidationsTest < ActiveModel::TestCase
       ActiveModel::Validations::FormatValidator,
       ActiveModel::Validations::LengthValidator,
       ActiveModel::Validations::PresenceValidator
-    ], validators.map { |v| v.class }.sort_by { |c| c.to_s }
+    ], validators.map(&:class).sort_by(&:to_s)
   end
 
   def test_list_of_validators_will_be_empty_when_empty