Reorganize autoloads:

  * A new module (ActiveSupport::Autoload) is provide that extends
    autoloading with new behavior.
  * All autoloads in modules that have extended ActiveSupport::Autoload
    will be eagerly required in threadsafe environments
  * Autoloads can optionally leave off the path if the path is the same
    as full_constant_name.underscore
  * It is possible to specify that a group of autoloads live under an
    additional path. For instance, all of ActionDispatch's middlewares
    are ActionDispatch::MiddlewareName, but they live under 
    "action_dispatch/middlewares/middleware_name"
  * It is possible to specify that a group of autoloads are all found
    at the same path. For instance, a number of exceptions might all
    be declared there.
  * One consequence of this is that testing-related constants are not
    autoloaded. To get the testing helpers for a given component,
    require "component_name/test_case". For instance, "action_controller/test_case".
  * test_help.rb, which is automatically required by a Rails application's
    test helper, requires the test_case.rb for all active components, so
    this change will not be disruptive in existing or new applications.

1 files changed, 80 insertions, 0 deletions

diff --git a/activesupport/test/autoload.rb b/activesupport/test/autoload.rb
new file mode 100644
index 0000000000..5d8026a9ca
--- /dev/null
+++ b/activesupport/test/autoload.rb
@@ -0,0 +1,80 @@
+require 'abstract_unit'
+
+class TestAutoloadModule < ActiveSupport::TestCase
+  include ActiveSupport::Testing::Isolation
+
+  module ::Fixtures
+    extend ActiveSupport::Autoload
+
+    module Autoload
+      extend ActiveSupport::Autoload
+    end
+  end
+
+  test "the autoload module works like normal autoload" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass, "fixtures/autoload/some_class"
+    end
+
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "when specifying an :eager constant it still works like normal autoload by default" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass, "fixtures/autoload/some_class"
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    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 $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "the location of autoloaded constants defaults to :name.underscore" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "the location of :eager autoloaded constants defaults to :name.underscore" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass
+    end
+
+    ActiveSupport::Autoload.eager_autoload!
+    assert $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "a directory for a block of autoloads can be specified" do
+    module ::Fixtures
+      autoload_under "autoload" do
+        autoload :AnotherClass
+      end
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/another_class.rb")
+    assert_nothing_raised { ::Fixtures::AnotherClass }
+  end
+
+  test "a path for a block of autoloads can be specified" do
+    module ::Fixtures
+      autoload_at "fixtures/autoload/another_class" do
+        autoload :AnotherClass
+      end
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/another_class.rb")
+    assert_nothing_raised { ::Fixtures::AnotherClass }
+  end
+end
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