From 89df4f2e0cb25334e7bf4349d9ca01637591334c Mon Sep 17 00:00:00 2001
From: Lucas Mansur <lucas.mansur2@gmail.com>
Date: Wed, 11 Sep 2019 21:20:09 -0300
Subject: [PATCH] Stop queue_name_prefix from being global

Changes in `queue_name_prefix` no longer affects unrelated jobs.
---
 activejob/CHANGELOG.md                    |  4 ++++
 activejob/lib/active_job/queue_name.rb    |  2 +-
 activejob/test/cases/queue_naming_test.rb | 19 +++++++++++++++++++
 activejob/test/jobs/prefixed_job.rb       |  7 +++++++
 guides/source/active_job_basics.md        | 13 +++++++++++++
 5 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 activejob/test/jobs/prefixed_job.rb

diff --git a/activejob/CHANGELOG.md b/activejob/CHANGELOG.md
index 0976e0d6dc..b4ffb8153e 100644
--- a/activejob/CHANGELOG.md
+++ b/activejob/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Changes in `queue_name_prefix` of a job no longer affects all other jobs. Fixes #37084.
+
+    *Lucas Mansur*
+
 *   Allow `Class` and `Module` instances to be serialized.
 
     *Kevin Deisz*
diff --git a/activejob/lib/active_job/queue_name.rb b/activejob/lib/active_job/queue_name.rb
index a718397db4..4c028502f4 100644
--- a/activejob/lib/active_job/queue_name.rb
+++ b/activejob/lib/active_job/queue_name.rb
@@ -6,7 +6,6 @@ module ActiveJob
 
     # Includes the ability to override the default queue name and prefix.
     module ClassMethods
-      mattr_accessor :queue_name_prefix
       mattr_accessor :default_queue_name, default: "default"
 
       # Specifies the name of the queue to process the job on.
@@ -56,6 +55,7 @@ module ActiveJob
     included do
       class_attribute :queue_name, instance_accessor: false, default: -> { self.class.default_queue_name }
       class_attribute :queue_name_delimiter, instance_accessor: false, default: "_"
+      class_attribute :queue_name_prefix
     end
 
     # Returns the name of the queue the job will be run on.
diff --git a/activejob/test/cases/queue_naming_test.rb b/activejob/test/cases/queue_naming_test.rb
index 4b43c7c3c5..2b83a72d5c 100644
--- a/activejob/test/cases/queue_naming_test.rb
+++ b/activejob/test/cases/queue_naming_test.rb
@@ -2,6 +2,7 @@
 
 require "helper"
 require "jobs/hello_job"
+require "jobs/prefixed_job"
 require "jobs/logging_job"
 require "jobs/nested_job"
 
@@ -124,6 +125,24 @@ class QueueNamingTest < ActiveSupport::TestCase
     end
   end
 
+  test "can change queue_name_prefix in a job class definition without affecting other jobs" do
+    assert_equal "production", PrefixedJob.queue_name_prefix
+    assert_nil HelloJob.queue_name_prefix
+  end
+
+  test "can change queue_name_prefix in a job class without affecting other jobs" do
+    original_prefix = PrefixedJob.queue_name_prefix
+
+    begin
+      PrefixedJob.queue_name_prefix = "staging"
+
+      assert_equal "staging", PrefixedJob.queue_name_prefix
+      assert_nil HelloJob.queue_name_prefix
+    ensure
+      PrefixedJob.queue_name_prefix = original_prefix
+    end
+  end
+
   test "uses queue passed to #set" do
     job = HelloJob.set(queue: :some_queue).perform_later
     assert_equal "some_queue", job.queue_name
diff --git a/activejob/test/jobs/prefixed_job.rb b/activejob/test/jobs/prefixed_job.rb
new file mode 100644
index 0000000000..23d7e46ce9
--- /dev/null
+++ b/activejob/test/jobs/prefixed_job.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class PrefixedJob < ActiveJob::Base
+  self.queue_name_prefix = "production"
+
+  def perform; end
+end
diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md
index c88b281410..9af55c3a31 100644
--- a/guides/source/active_job_basics.md
+++ b/guides/source/active_job_basics.md
@@ -202,6 +202,19 @@ end
 # on your staging environment
 ```
 
+You can also configure the prefix on a per job basis.
+
+```ruby
+class GuestsCleanupJob < ApplicationJob
+  queue_as :low_priority
+  self.queue_name_prefix = nil
+  #....
+end
+
+# Now your job's queue won't be prefixed, overriding what
+# was configured in `config.active_job.queue_name_prefix`.
+```
+
 The default queue name prefix delimiter is '\_'.  This can be changed by setting
 `config.active_job.queue_name_delimiter` in `application.rb`: