Use AS::Reloader to support reloading in ActiveJob

activejob/CHANGELOG.md

+*   Enable class reloading prior to job dispatch, and ensure Active Record
+    connections are returned to the pool when jobs are run in separate threads.
+
+    *Matthew Draper*
+
 *   Tune the async adapter for low-footprint dev/test usage. Use a single
     thread pool for all queues and limit to 0 to #CPU total threads, down from
     2 to 10*#CPU per queue.

activejob/lib/active_job/callbacks.rb

@@ -17,6 +17,11 @@ module Callbacks
     extend  ActiveSupport::Concern
     include ActiveSupport::Callbacks
 
+    class << self
+      include ActiveSupport::Callbacks
+      define_callbacks :execute
+    end
+
     included do
       define_callbacks :perform
       define_callbacks :enqueue

activejob/lib/active_job/execution.rb

@@ -17,8 +17,10 @@ def perform_now(*args)
       end
 
       def execute(job_data) #:nodoc:
-        job = deserialize(job_data)
-        job.perform_now
+        ActiveJob::Callbacks.run_callbacks(:execute) do
+          job = deserialize(job_data)
+          job.perform_now
+        end
       end
     end
 

activejob/lib/active_job/railtie.rb

@@ -19,5 +19,14 @@ class Railtie < Rails::Railtie # :nodoc:
       end
     end
 
+    initializer "active_job.set_reloader_hook" do |app|
+      ActiveSupport.on_load(:active_job) do
+        ActiveJob::Callbacks.singleton_class.set_callback(:execute, :around, prepend: true) do |_, inner|
+          app.reloader.wrap do
+            inner.call
+          end
+        end
+      end
+    end
   end
 end