rails new

THOR_MERGE=vimdiff bundle exec rails new -d mysql --skip-action-mailbox
  --skip-action-text --skip-active-job --skip-active-storage
  --skip-action-cable --skip-hotwire --skip-jbuilder --skip-bootsnap
  --skip-bundle .

test/test_helper.rb

@@ -0,0 +1,13 @@
+ENV["RAILS_ENV"] ||= "test"
+require_relative "../config/environment"
+require "rails/test_help"
+
+class ActiveSupport::TestCase
+  # Run tests in parallel with specified workers
+  parallelize(workers: :number_of_processors)
+
+  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
+  fixtures :all
+
+  # Add more helper methods to be used by all tests here...
+end