3 files changed, 23 insertions, 2 deletions
diff --git a/activejob/lib/active_job/callbacks.rb b/activejob/lib/active_job/callbacks.rb
index 61317c7cfc..6b82ea6cab 100644
--- a/activejob/lib/active_job/callbacks.rb
+++ b/activejob/lib/active_job/callbacks.rb
@@ -29,6 +29,9 @@ module ActiveJob
     included do
       define_callbacks :perform
       define_callbacks :enqueue
+
+      class_attribute :return_false_on_aborted_enqueue, instance_accessor: false, instance_predicate: false
+      self.return_false_on_aborted_enqueue = false
     end
 
     # These methods will be included into any Active Job object, adding
diff --git a/activejob/lib/active_job/enqueuing.rb b/activejob/lib/active_job/enqueuing.rb
index b5b9f23c00..ce118c1e8a 100644
--- a/activejob/lib/active_job/enqueuing.rb
+++ b/activejob/lib/active_job/enqueuing.rb
@@ -48,14 +48,33 @@ module ActiveJob
       self.scheduled_at = options[:wait_until].to_f if options[:wait_until]
       self.queue_name   = self.class.queue_name_from_part(options[:queue]) if options[:queue]
       self.priority     = options[:priority].to_i if options[:priority]
+      successfully_enqueued = false
+
       run_callbacks :enqueue do
         if scheduled_at
           self.class.queue_adapter.enqueue_at self, scheduled_at
         else
           self.class.queue_adapter.enqueue self
         end
+
+        successfully_enqueued = true
+      end
+
+      if successfully_enqueued
+        self
+      else
+        if self.class.return_false_on_aborted_enqueue
+          false
+        else
+          ActiveSupport::Deprecation.warn(
+            "Rails 6.0 will return false when the enqueing is aborted. Make sure your code doesn't depend on it" \
+            " returning the instance of the job and set `config.active_job.return_false_on_aborted_enqueue = true`" \
+            " to remove the deprecations."
+          )
+
+          self
+        end
       end
-      self
     end
   end
 end
diff --git a/activejob/lib/active_job/test_helper.rb b/activejob/lib/active_job/test_helper.rb
index e0a71f4da8..f03780b91e 100644
--- a/activejob/lib/active_job/test_helper.rb
+++ b/activejob/lib/active_job/test_helper.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require "active_support/core_ext/class/subclasses"
-require "active_support/core_ext/hash/keys"
 
 module ActiveJob
   # Provides helper methods for testing Active Job