Make sure global test store is created before all integration tests by prepending EnsureDefaultStore. This should fix the issue with mutation test neutral failures probably caused by parallel workers using different DB transactions.

Author: dysk

apps/rails_application/test/test_helper.rb

@@ -5,6 +5,28 @@
 
 ActiveJob::Base.logger = Logger.new(nil)
 
+# Shared test store UUID for parallel mutant workers
+DEFAULT_TEST_STORE_ID = "00000000-0000-4000-8000-000000000001"
+
+# Global hook to ensure default store exists before ANY test runs
+# This runs once per test process, after DB is prepared but before tests start
+module EnsureDefaultStore
+  def before_setup
+    unless defined?(@@default_store_created)
+      ActiveRecord::Base.connection.execute(<<-SQL)
+        INSERT INTO admin_stores (id, name, created_at, updated_at)
+        VALUES ('#{DEFAULT_TEST_STORE_ID}', 'Default Test Store', NOW(), NOW())
+        ON CONFLICT (id) DO NOTHING
+      SQL
+      @@default_store_created = true
+    end
+    super
+  end
+end
+
+# Prepend to all integration tests
+ActionDispatch::IntegrationTest.prepend(EnsureDefaultStore)
+
 class InMemoryTestCase < ActiveSupport::TestCase
 
   def before_setup
@@ -130,9 +152,6 @@ def payment_released
 end
 
 class InMemoryRESIntegrationTestCase < ActionDispatch::IntegrationTest
-  # Shared test store UUID - used by all parallel workers to avoid transaction isolation issues
-  DEFAULT_TEST_STORE_ID = "00000000-0000-4000-8000-000000000001"
-
   def before_setup
     result = super
     @previous_event_store = Rails.configuration.event_store
@@ -141,7 +160,7 @@ def before_setup
     Rails.configuration.command_bus = Arkency::CommandBus.new
 
     Configuration.new.call(Rails.configuration.event_store, Rails.configuration.command_bus)
-    @default_store_id = ensure_default_store
+    @default_store_id = DEFAULT_TEST_STORE_ID
     result
   end
 
@@ -237,17 +256,6 @@ def run_command(command)
     Rails.configuration.command_bus.call(command)
   end
 
-  def ensure_default_store
-    # Create default test store directly in DB, outside of transaction
-    # This ensures it's visible to all parallel mutant workers
-    ActiveRecord::Base.connection.execute(<<-SQL)
-      INSERT INTO admin_stores (id, name, created_at, updated_at)
-      VALUES ('#{DEFAULT_TEST_STORE_ID}', 'Default Test Store', NOW(), NOW())
-      ON CONFLICT (id) DO NOTHING
-    SQL
-    DEFAULT_TEST_STORE_ID
-  end
-
   def register_store(name)
     # For "Default Store", return the shared test store ID
     return DEFAULT_TEST_STORE_ID if name == "Default Store" || name == "Default Test Store"