From 91461dc7a9f0aa879cfff503ea2fdb9a71e0277e Mon Sep 17 00:00:00 2001
From: Abdelkader Boudih <terminale@gmail.com>
Date: Sun, 18 May 2014 20:59:12 +0000
Subject: [PATCH] Lazy-load adapters, fixes #6

---
 lib/active_job/base.rb                        | 23 +++++++++++---
 lib/active_job/errors.rb                      | 12 +++++++
 lib/active_job/job_wrappers/resque_wrapper.rb |  2 +-
 test/adapters/inline.rb                       |  1 +
 test/adapters/resque.rb                       |  2 +-
 test/adapters/sidekiq.rb                      |  2 +-
 test/adapters/sucker_punch.rb                 |  2 +-
 test/cases/adapter_test.rb                    | 31 +++++++++++++++++++
 8 files changed, 67 insertions(+), 8 deletions(-)
 create mode 100644 lib/active_job/errors.rb
 create mode 100644 test/cases/adapter_test.rb

diff --git a/lib/active_job/base.rb b/lib/active_job/base.rb
index 6cce770466..f39dba6f5f 100644
--- a/lib/active_job/base.rb
+++ b/lib/active_job/base.rb
@@ -1,9 +1,9 @@
+require 'active_job/errors'
 require 'active_job/queue_adapters/inline_adapter'
-require 'active_job/queue_adapters/resque_adapter'
-require 'active_job/queue_adapters/sidekiq_adapter'
-require 'active_job/queue_adapters/sucker_punch_adapter'
+require 'active_support/core_ext/string/inflections'
 
 module ActiveJob
+
   class Base
     cattr_accessor(:queue_adapter)   { ActiveJob::QueueAdapters::InlineAdapter }
     cattr_accessor(:queue_base_name) { "active_jobs" }
@@ -13,10 +13,25 @@ class << self
       def enqueue(*args)
         queue_adapter.queue self, *args
       end
-      
+
       def queue_as(part_name)
         self.queue_name = "#{queue_base_name}_#{part_name}"
       end
+
+      def adapter=(adapter_name)
+        adapter_name = adapter_name.to_s
+        unless %w(inline resque sidekiq sucker_punch).include?(adapter_name)
+          fail ActiveJob::NotImplementedError
+        end
+
+        begin
+          require_relative "queue_adapters/#{adapter_name}_adapter"
+          ActiveJob::Base.queue_adapter = "ActiveJob::QueueAdapters::#{adapter_name.camelize}Adapter".constantize
+        rescue
+          fail ActiveJob::Error.new("#{adapter_name} is missing")
+        end
+      end
     end
+
   end
 end
\ No newline at end of file
diff --git a/lib/active_job/errors.rb b/lib/active_job/errors.rb
new file mode 100644
index 0000000000..4fc3be6878
--- /dev/null
+++ b/lib/active_job/errors.rb
@@ -0,0 +1,12 @@
+module ActiveJob
+
+  class NotImplementedError < ::NotImplementedError #:nodoc:
+  end
+
+  class Error < ::StandardError #:nodoc:
+    def initialize(message = nil)
+      super(message)
+    end
+  end
+
+end
\ No newline at end of file
diff --git a/lib/active_job/job_wrappers/resque_wrapper.rb b/lib/active_job/job_wrappers/resque_wrapper.rb
index 0db9cf144f..cbeee4fb1b 100644
--- a/lib/active_job/job_wrappers/resque_wrapper.rb
+++ b/lib/active_job/job_wrappers/resque_wrapper.rb
@@ -2,7 +2,7 @@
 
 require 'active_support/core_ext/enumerable'
 require 'active_support/core_ext/array/access'
-require 'active_support/core_ext/string/inflections'
+
 
 
 module ActiveJob
diff --git a/test/adapters/inline.rb b/test/adapters/inline.rb
index e69de29bb2..131dd029b3 100644
--- a/test/adapters/inline.rb
+++ b/test/adapters/inline.rb
@@ -0,0 +1 @@
+ActiveJob::Base.adapter = :inline
\ No newline at end of file
diff --git a/test/adapters/resque.rb b/test/adapters/resque.rb
index 7431d2d742..6e11f864c2 100644
--- a/test/adapters/resque.rb
+++ b/test/adapters/resque.rb
@@ -1,2 +1,2 @@
-ActiveJob::Base.queue_adapter = ActiveJob::QueueAdapters::ResqueAdapter
+ActiveJob::Base.adapter = :resque
 Resque.inline = true
diff --git a/test/adapters/sidekiq.rb b/test/adapters/sidekiq.rb
index 74ce808d55..55153d0bc6 100644
--- a/test/adapters/sidekiq.rb
+++ b/test/adapters/sidekiq.rb
@@ -1,2 +1,2 @@
 require 'sidekiq/testing/inline'
-ActiveJob::Base.queue_adapter = ActiveJob::QueueAdapters::SidekiqAdapter
+ActiveJob::Base.adapter = :sidekiq
diff --git a/test/adapters/sucker_punch.rb b/test/adapters/sucker_punch.rb
index a373552262..8ce9a902b6 100644
--- a/test/adapters/sucker_punch.rb
+++ b/test/adapters/sucker_punch.rb
@@ -1,2 +1,2 @@
 require 'sucker_punch/testing/inline'
-ActiveJob::Base.queue_adapter = ActiveJob::QueueAdapters::SuckerPunchAdapter
+ActiveJob::Base.adapter = :sucker_punch
diff --git a/test/cases/adapter_test.rb b/test/cases/adapter_test.rb
new file mode 100644
index 0000000000..eac92fb27d
--- /dev/null
+++ b/test/cases/adapter_test.rb
@@ -0,0 +1,31 @@
+require 'helper'
+
+class AdapterTest < ActiveSupport::TestCase
+  def setup
+    @old_adapter = ActiveJob::Base.queue_adapter
+  end
+
+  test 'should load inline adapter' do
+    ActiveJob::Base.adapter = :inline
+    assert_equal ActiveJob::QueueAdapters::InlineAdapter, ActiveJob::Base.queue_adapter
+  end
+
+  test 'should load resque adapter' do
+    ActiveJob::Base.adapter = :resque
+    assert_equal ActiveJob::QueueAdapters::ResqueAdapter, ActiveJob::Base.queue_adapter
+  end
+
+  test 'should load sidekiq adapter' do
+    ActiveJob::Base.adapter = :sidekiq
+    assert_equal ActiveJob::QueueAdapters::SidekiqAdapter, ActiveJob::Base.queue_adapter
+  end
+
+  test 'should load sucker punch adapter' do
+    ActiveJob::Base.adapter = :sucker_punch
+    assert_equal ActiveJob::QueueAdapters::SuckerPunchAdapter, ActiveJob::Base.queue_adapter
+  end
+
+  def teardown
+    ActiveJob::Base.queue_adapter = @old_adapter
+  end
+end