Feature: ActiveJob Integration and Documentation (#817)

* Add note on Active Job integration for #663

* Implement GlobalID by delegating to object and add documentation.

* Update readme and add missing require statement.

* Actually include the module.

* Create post instead of assuming it exists.

* Add test for #to_global_id.

README.md

@@ -618,6 +618,15 @@ is included in `ActiveRecord::Base` and `Mongoid::Document` by default. If
 you're using another ORM, or want to decorate plain old Ruby objects,
 you can include this module manually.
 
+### Active Job Integration
+
+[Active Job](http://edgeguides.rubyonrails.org/active_job_basics.html) allows you to pass ActiveRecord 
+objects to background tasks directly and performs the necessary serialization and deserialization. In
+order to do this, arguments to a background job must implement [Global ID](https://github.com/rails/globalid).
+Decorated objects implement Global ID by delegating to the object they are decorating. This means
+you can pass decorated objects to background jobs, however, the object won't be decorated when it is
+deserialized.
+
 ## Contributors
 
 Draper was conceived by Jeff Casimir and heavily refined by Steve Klabnik and a

lib/draper/compatibility/global_id.rb

@@ -0,0 +1,22 @@
+module Draper
+  module Compatibility
+    # [Active Job](http://edgeguides.rubyonrails.org/active_job_basics.html) allows you to pass
+    # ActiveRecord objects to background tasks directly and performs the necessary serialization
+    # and deserialization. In order to do this, arguments to a background job must implement
+    # [Global ID](https://github.com/rails/globalid).
+    #
+    # This compatibility patch implements Global ID for decorated objects by delegating to the object
+    # that is decorated. This means you can pass decorated objects to background jobs, but 
+    # the object won't be decorated when it is deserialized. This patch is meant as an intermediate
+    # fix until we can find a way to deserialize the decorated object correctly.
+    module GlobalID
+      extend ActiveSupport::Concern
+
+      included do
+        include ::GlobalID::Identification
+
+        delegate :to_global_id, :to_signed_global_id, to: :object
+      end
+    end
+  end
+end

lib/draper/decorator.rb

@@ -1,6 +1,9 @@
+require 'draper/compatibility/global_id'
+
 module Draper
   class Decorator
     include Draper::ViewHelpers
+    include Draper::Compatibility::GlobalID if defined?(GlobalID)
     extend Draper::Delegation
 
     include ActiveModel::Serialization

spec/dummy/app/jobs/publish_post_job.rb

@@ -0,0 +1,7 @@
+class PublishPostJob < ActiveJob::Base
+  queue_as :default
+
+  def perform(post)
+    post.save!
+  end
+end

spec/dummy/config/environments/test.rb

@@ -28,4 +28,6 @@ Dummy::Application.configure do
   config.active_support.deprecation = :stderr
 
   config.eager_load = false
+
+  config.active_job.queue_adapter = :test
 end

spec/dummy/spec/jobs/publish_post_job_spec.rb

@@ -0,0 +1,9 @@
+RSpec.describe PublishPostJob, type: :job do
+  let(:post) { Post.create.decorate }
+
+  subject(:job) { described_class.perform_later(post) }
+
+  it 'queues the job' do
+    expect { job }.to have_enqueued_job(described_class).with(post.object)
+  end
+end

spec/dummy/spec/models/post_spec.rb

@@ -1,8 +1,15 @@
 require 'spec_helper'
 require 'shared_examples/decoratable'
 
-describe Post do
-  it_behaves_like "a decoratable model"
+RSpec.describe Post do
+  it_behaves_like 'a decoratable model'
 
   it { should be_a ApplicationRecord }
+
+  describe '#to_global_id' do
+    let(:post) { Post.create }
+    subject { post.to_global_id }
+
+    it { is_expected.to eq post.decorate.to_global_id }
+  end
 end