Feature #35030

Updated by Go MAEDA 6 months ago

Rails 6.0 or later supports parallel testing. Enabling this feature can reduce the time required for testing and improve development efficiency.
https://guides.rubyonrails.org/testing.html#parallel-testing https://guides.rubyonrails.org/testing.html#parallel-testing-with-threads

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%.

<pre><code class="diff">
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.