Fixes #20799

When `#perform_later` is called the locale isn't stored on the
queue, which results in a locale reset when the job is performed.

An example of the problem:

    I18n.locale = 'de'
    HelloJob.perform_now # german message, correct

but

    I18n.locale = 'de'
    HelloJob.perform_later # english message, incorrect

This PR attaches the current I18n.locale to every job during the
serialization process. It is then restored during deserialization
and used to perform the job with the correct locale.

It falls back to the default locale if no serialized locale is
found in order to provide backward compatibility with previously
stored jobs. It is not necessary to clear the queue for the update.

3 files changed, 19 insertions, 1 deletions

diff --git a/activejob/lib/active_job/base.rb b/activejob/lib/active_job/base.rb
index fd49b3fda5..5d7c4cfb91 100644
--- a/activejob/lib/active_job/base.rb
+++ b/activejob/lib/active_job/base.rb
@@ -5,6 +5,7 @@ require 'active_job/enqueuing'
 require 'active_job/execution'
 require 'active_job/callbacks'
 require 'active_job/logging'
+require 'active_job/translation'
 
 module ActiveJob #:nodoc:
   # = Active Job
@@ -60,6 +61,7 @@ module ActiveJob #:nodoc:
     include Execution
     include Callbacks
     include Logging
+    include Translation
 
     ActiveSupport.run_load_hooks(:active_job, self)
   end
diff --git a/activejob/lib/active_job/core.rb b/activejob/lib/active_job/core.rb
index 0528572cd0..eac7279309 100644
--- a/activejob/lib/active_job/core.rb
+++ b/activejob/lib/active_job/core.rb
@@ -20,6 +20,9 @@ module ActiveJob
 
       # ID optionally provided by adapter
       attr_accessor :provider_job_id
+
+      # I18n.locale to be used during the job.
+      attr_accessor :locale
     end
 
     # These methods will be included into any Active Job object, adding
@@ -68,7 +71,8 @@ module ActiveJob
         'job_class'  => self.class.name,
         'job_id'     => job_id,
         'queue_name' => queue_name,
-        'arguments'  => serialize_arguments(arguments)
+        'arguments'  => serialize_arguments(arguments),
+        'locale'     => I18n.locale
       }
     end
 
@@ -96,6 +100,7 @@ module ActiveJob
       self.job_id               = job_data['job_id']
       self.queue_name           = job_data['queue_name']
       self.serialized_arguments = job_data['arguments']
+      self.locale               = job_data['locale'] || I18n.locale
     end
 
     private
diff --git a/activejob/lib/active_job/translation.rb b/activejob/lib/active_job/translation.rb
new file mode 100644
index 0000000000..67e4cf4ab9
--- /dev/null
+++ b/activejob/lib/active_job/translation.rb
@@ -0,0 +1,11 @@
+module ActiveJob
+  module Translation #:nodoc:
+    extend ActiveSupport::Concern
+
+    included do
+      around_perform do |job, block, _|
+        I18n.with_locale(job.locale, &block)
+      end
+    end
+  end
+end