Feature #35030

Allow parallel testing

Added by Go MAEDA 7 days ago. Updated 6 days ago.

Status:ClosedStart date:
Priority:NormalDue date:
Assignee:Go MAEDA% Done:


Category:Rails support
Target version:5.0.0


Rails 6.0 or later supports parallel testing. Enabling this feature can reduce the time required for testing and improve development efficiency.

By applying the following patch and run the test suite with PARALLEL_WORKERS=6 environment variable in my environment, the time required to run the test suite was reduced to about 30%.

diff --git a/test/test_helper.rb b/test/test_helper.rb
index 10f4f6e35..95b877d44 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -53,6 +53,8 @@ class ActionView::TestCase

 class ActiveSupport::TestCase
+  parallelize(workers: 1)
   include ActionDispatch::TestProcess

   self.use_transactional_tests = true

The reason why the number of workers is set to 1 is that parallel testing causes some errors in system test.

35030.patch Magnifier (907 Bytes) Go MAEDA, 2021-04-06 02:19

Associated revisions

Revision 20920
Added by Go MAEDA 6 days ago

Allow parallel testing (#35030).

Patch by Go MAEDA.


#1 Updated by Go MAEDA 6 days ago

  • File 35030.patchMagnifier added
  • Subject changed from Enable parallel testing to Allow parallel testing
  • Target version set to 5.0.0

Setting the target version to 5.0.0.

#2 Updated by Go MAEDA 6 days ago

  • Status changed from New to Closed
  • Assignee set to Go MAEDA
  • Resolution set to Fixed

Committed the change.

Now you can run tests in parallel by setting PARALLEL_WORKERS environment variable.

PARALLEL_WORKERS=8 bin/rails test

#3 Updated by Go MAEDA 6 days ago

  • Description updated (diff)

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