9 files changed, 80 insertions, 15 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index af70a81414..4c3eded38a 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,10 +1,25 @@
+*   Add `Date#prev_occurring` and `Date#next_occurring` to return specified next/previous occurring day of week.
+
+    *Shota Iguchi*
+
+*   Add default option to class_attribute. Before:
+
+        class_attribute :settings
+        self.settings = {}
+
+    Now:
+
+        class_attribute :settings, default: {}
+
+    *DHH*
+
 *   `#singularize` and `#pluralize` now respect uncountables for the specified locale.
 
     *Eilis Hamilton*
 
-*   Add ActiveSupport::CurrentAttributes to provide a thread-isolated attributes singleton.
+*   Add `ActiveSupport::CurrentAttributes` to provide a thread-isolated attributes singleton.
     Primary use case is keeping all the per-request attributes easily available to the whole system.
-    
+
     *DHH*
 
 *   Fix implicit coercion calculations with scalars and durations
diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb
index d771cab68b..ddfa91a342 100644
--- a/activesupport/lib/active_support/callbacks.rb
+++ b/activesupport/lib/active_support/callbacks.rb
@@ -62,8 +62,7 @@ module ActiveSupport
 
     included do
       extend ActiveSupport::DescendantsTracker
-      class_attribute :__callbacks, instance_writer: false
-      self.__callbacks ||= {}
+      class_attribute :__callbacks, instance_writer: false, default: {}
     end
 
     CALLBACK_FILTER_TYPES = [:before, :after, :around]
diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb
index ba422f9071..8caddcd5c3 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute.rb
@@ -68,11 +68,16 @@ class Class
   #   object.setting = false  # => NoMethodError
   #
   # To opt out of both instance methods, pass <tt>instance_accessor: false</tt>.
+  #
+  # To set a default value for the attribute, pass <tt>default:</tt>, like so:
+  #
+  #   class_attribute :settings, default: {}
   def class_attribute(*attrs)
     options = attrs.extract_options!
-    instance_reader = options.fetch(:instance_accessor, true) && options.fetch(:instance_reader, true)
-    instance_writer = options.fetch(:instance_accessor, true) && options.fetch(:instance_writer, true)
+    instance_reader    = options.fetch(:instance_accessor, true) && options.fetch(:instance_reader, true)
+    instance_writer    = options.fetch(:instance_accessor, true) && options.fetch(:instance_writer, true)
     instance_predicate = options.fetch(:instance_predicate, true)
+    default_value      = options.fetch(:default, nil)
 
     attrs.each do |name|
       remove_possible_singleton_method(name)
@@ -123,6 +128,10 @@ class Class
         remove_possible_method "#{name}="
         attr_writer name
       end
+
+      unless default_value.nil?
+        self.send("#{name}=", default_value)
+      end
     end
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
index f2ba7fdda5..e2e1d3e359 100644
--- a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
@@ -320,6 +320,22 @@ module DateAndTime
       beginning_of_year..end_of_year
     end
 
+    # Returns specific next occurring day of week
+    def next_occurring(day_of_week)
+      current_day_number = wday != 0 ? wday - 1 : 6
+      from_now = DAYS_INTO_WEEK.fetch(day_of_week) - current_day_number
+      from_now += 7 unless from_now > 0
+      since(from_now.days)
+    end
+
+    # Returns specific previous occurring day of week
+    def prev_occurring(day_of_week)
+      current_day_number = wday != 0 ? wday - 1 : 6
+      ago = current_day_number - DAYS_INTO_WEEK.fetch(day_of_week)
+      ago += 7 unless ago > 0
+      ago(ago.days)
+    end
+
     private
       def first_hour(date_or_time)
         date_or_time.acts_like?(:time) ? date_or_time.beginning_of_day : date_or_time
diff --git a/activesupport/lib/active_support/reloader.rb b/activesupport/lib/active_support/reloader.rb
index 121c621751..9558146201 100644
--- a/activesupport/lib/active_support/reloader.rb
+++ b/activesupport/lib/active_support/reloader.rb
@@ -69,11 +69,8 @@ module ActiveSupport
       end
     end
 
-    class_attribute :executor
-    class_attribute :check
-
-    self.executor = Executor
-    self.check = lambda { false }
+    class_attribute :executor, default: Executor
+    class_attribute :check, default: lambda { false }
 
     def self.check! # :nodoc:
       @should_reload ||= check.call
diff --git a/activesupport/lib/active_support/rescuable.rb b/activesupport/lib/active_support/rescuable.rb
index 12ec8bf1b8..826832ba7d 100644
--- a/activesupport/lib/active_support/rescuable.rb
+++ b/activesupport/lib/active_support/rescuable.rb
@@ -8,8 +8,7 @@ module ActiveSupport
     extend Concern
 
     included do
-      class_attribute :rescue_handlers
-      self.rescue_handlers = []
+      class_attribute :rescue_handlers, default: []
     end
 
     module ClassMethods
diff --git a/activesupport/lib/active_support/testing/assertions.rb b/activesupport/lib/active_support/testing/assertions.rb
index 28cf2953bf..28e1df8870 100644
--- a/activesupport/lib/active_support/testing/assertions.rb
+++ b/activesupport/lib/active_support/testing/assertions.rb
@@ -167,7 +167,7 @@ module ActiveSupport
         retval
       end
 
-      # Assertion that the result of evaluating an expression is changed before
+      # Assertion that the result of evaluating an expression is not changed before
       # and after invoking the passed in block.
       #
       #   assert_no_changes 'Status.all_good?' do
diff --git a/activesupport/test/core_ext/class/attribute_test.rb b/activesupport/test/core_ext/class/attribute_test.rb
index 5a9ec78cc1..f16043c612 100644
--- a/activesupport/test/core_ext/class/attribute_test.rb
+++ b/activesupport/test/core_ext/class/attribute_test.rb
@@ -3,7 +3,11 @@ require "active_support/core_ext/class/attribute"
 
 class ClassAttributeTest < ActiveSupport::TestCase
   def setup
-    @klass = Class.new { class_attribute :setting }
+    @klass = Class.new do
+      class_attribute :setting
+      class_attribute :timeout, default: 5
+    end
+
     @sub = Class.new(@klass)
   end
 
@@ -12,6 +16,10 @@ class ClassAttributeTest < ActiveSupport::TestCase
     assert_nil @sub.setting
   end
 
+  test "custom default" do
+    assert_equal 5, @klass.timeout
+  end
+
   test "inheritable" do
     @klass.setting = 1
     assert_equal 1, @sub.setting
diff --git a/activesupport/test/core_ext/date_time_ext_test.rb b/activesupport/test/core_ext/date_time_ext_test.rb
index be7c14e9b4..276fa2bfd3 100644
--- a/activesupport/test/core_ext/date_time_ext_test.rb
+++ b/activesupport/test/core_ext/date_time_ext_test.rb
@@ -28,6 +28,28 @@ class DateTimeExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
+  def test_next_occur
+    datetime = DateTime.new(2016, 9, 24, 0, 0) # saturday
+    assert_equal datetime.next_occurring(:monday), datetime.since(2.days)
+    assert_equal datetime.next_occurring(:tuesday), datetime.since(3.days)
+    assert_equal datetime.next_occurring(:wednesday), datetime.since(4.days)
+    assert_equal datetime.next_occurring(:thursday), datetime.since(5.days)
+    assert_equal datetime.next_occurring(:friday), datetime.since(6.days)
+    assert_equal datetime.next_occurring(:saturday), datetime.since(1.week)
+    assert_equal datetime.next_occurring(:sunday), datetime.since(1.day)
+  end
+
+  def test_prev_occur
+    datetime = DateTime.new(2016, 9, 24, 0, 0) # saturday
+    assert_equal datetime.prev_occurring(:monday), datetime.ago(5.days)
+    assert_equal datetime.prev_occurring(:tuesday), datetime.ago(4.days)
+    assert_equal datetime.prev_occurring(:wednesday), datetime.ago(3.days)
+    assert_equal datetime.prev_occurring(:thursday), datetime.ago(2.days)
+    assert_equal datetime.prev_occurring(:friday), datetime.ago(1.day)
+    assert_equal datetime.prev_occurring(:saturday), datetime.ago(1.week)
+    assert_equal datetime.prev_occurring(:sunday), datetime.ago(6.days)
+  end
+
   def test_readable_inspect
     datetime = DateTime.new(2005, 2, 21, 14, 30, 0)
     assert_equal "Mon, 21 Feb 2005 14:30:00 +0000", datetime.readable_inspect