From fdedc078f93292449dbad14295982c006c5ab877 Mon Sep 17 00:00:00 2001
From: Tobias Svensson <tob@tobiassvensson.co.uk>
Date: Tue, 17 Sep 2013 16:48:08 +0100
Subject: [PATCH] Add SubclassTracking module.

---
 lib/sidetiq/subclass_tracking.rb | 20 ++++++++++++++++++++
 test/test_subclass_tracking.rb   | 22 ++++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 lib/sidetiq/subclass_tracking.rb
 create mode 100644 test/test_subclass_tracking.rb

diff --git a/lib/sidetiq/subclass_tracking.rb b/lib/sidetiq/subclass_tracking.rb
new file mode 100644
index 0000000..07e18b7
--- /dev/null
+++ b/lib/sidetiq/subclass_tracking.rb
@@ -0,0 +1,20 @@
+module Sidetiq
+  module SubclassTracking
+    def subclasses(deep = false)
+      @subclasses ||= []
+
+      if deep
+        @subclasses.inject([]) do |all, subclass|
+          (all << subclass) + subclass.subclasses(true)
+        end
+      else
+        @subclasses
+      end
+    end
+
+    def inherited(klass)
+      super
+      subclasses << klass
+    end
+  end
+end
diff --git a/test/test_subclass_tracking.rb b/test/test_subclass_tracking.rb
new file mode 100644
index 0000000..b718d7c
--- /dev/null
+++ b/test/test_subclass_tracking.rb
@@ -0,0 +1,22 @@
+require_relative 'helper'
+
+class TestSubclassTracking < Sidetiq::TestCase
+  class Foo
+    extend Sidetiq::SubclassTracking
+  end
+
+  class Bar < Foo
+  end
+
+  class Baz < Bar
+  end
+
+  def test_subclasses_non_recursive
+    assert_equal [Bar], Foo.subclasses
+  end
+
+  def test_subclasses_recursive
+    assert_equal [Bar, Baz], Foo.subclasses(true)
+  end
+end
+