Make ActiveSupport::Autoload local

Previously, ActiveSupport::Autoload was global and reserved
for usage inside Rails. This pull request makes it local,
fixes its test (they were not being run because its file
was named wrongly) and make it part of Rails public API.

activesupport/lib/active_support.rb

@@ -37,7 +37,6 @@ module ActiveSupport
   autoload :LogSubscriber
   autoload :Notifications
 
-  # TODO: Narrow this list down
   eager_autoload do
     autoload :BacktraceCleaner
     autoload :BasicObject
@@ -55,12 +54,12 @@ module ActiveSupport
     autoload :OptionMerger
     autoload :OrderedHash
     autoload :OrderedOptions
-    autoload :Rescuable
     autoload :StringInquirer
     autoload :TaggedLogging
     autoload :XmlMini
   end
 
+  autoload :Rescuable
   autoload :SafeBuffer, "active_support/core_ext/string/output_safety"
   autoload :TestCase
 end

activesupport/lib/active_support/dependencies/autoload.rb

 require "active_support/inflector/methods"
 
 module ActiveSupport
+  # Autoload and eager load conveniences for your library.
+  #
+  # This module allows you to define autoloads based on
+  # Rails conventions (i.e. no need to define the path
+  # it is automatically guessed based on the filename)
+  # and also define a set of constants that needs to be
+  # eager loaded:
+  #
+  #   module MyLib
+  #     extend ActiveSupport::Autoload
+  #
+  #     autoload :Model
+  #
+  #     eager_autoload do
+  #       autoload :Cache
+  #     end
+  #   end
+  #
+  # Then your library can be eager loaded by simply calling:
+  #
+  #   MyLib.eager_load!
+  #
   module Autoload
-    @@autoloads = {}
-    @@under_path = nil
-    @@at_path = nil
-    @@eager_autoload = false
+    def self.extended(base)
+      base.class_eval do
+        @_autoloads = {}
+        @_under_path = nil
+        @_at_path = nil
+        @_eager_autoload = false
+      end
+    end
 
-    def autoload(const_name, path = @@at_path)
+    def autoload(const_name, path = @_at_path)
       unless path
-        full = [name, @@under_path, const_name.to_s, path].compact.join("::")
+        full = [name, @_under_path, const_name.to_s, path].compact.join("::")
         path = Inflector.underscore(full)
       end
 
-      if @@eager_autoload
-        @@autoloads[const_name] = path
+      if @_eager_autoload
+        @_autoloads[const_name] = path
       end
 
       super const_name, path
     end
 
     def autoload_under(path)
-      @@under_path, old_path = path, @@under_path
+      @_under_path, old_path = path, @_under_path
       yield
     ensure
-      @@under_path = old_path
+      @_under_path = old_path
     end
 
     def autoload_at(path)
-      @@at_path, old_path = path, @@at_path
+      @_at_path, old_path = path, @_at_path
       yield
     ensure
-      @@at_path = old_path
+      @_at_path = old_path
     end
 
     def eager_autoload
-      old_eager, @@eager_autoload = @@eager_autoload, true
+      old_eager, @_eager_autoload = @_eager_autoload, true
       yield
     ensure
-      @@eager_autoload = old_eager
+      @_eager_autoload = old_eager
     end
 
-    def self.eager_autoload!
-      @@autoloads.values.each { |file| require file }
+    def eager_load!
+      @_autoloads.values.each { |file| require file }
     end
 
     def autoloads
-      @@autoloads
+      @_autoloads
     end
   end
 end

activesupport/test/autoload.rb → activesupport/test/autoload_test.rb

@@ -28,15 +28,6 @@ module ::Fixtures::Autoload
     assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
   end
 
-  test ":eager constants can be triggered via ActiveSupport::Autoload.eager_autoload!" do
-    module ::Fixtures::Autoload
-      autoload :SomeClass, "fixtures/autoload/some_class"
-    end
-    ActiveSupport::Autoload.eager_autoload!
-    assert $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
-    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
-  end
-
   test "the location of autoloaded constants defaults to :name.underscore" do
     module ::Fixtures::Autoload
       autoload :SomeClass
@@ -51,8 +42,7 @@ module ::Fixtures::Autoload
       autoload :SomeClass
     end
 
-    ActiveSupport::Autoload.eager_autoload!
-    assert $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    ::Fixtures::Autoload.eager_load!
     assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
   end