flutter_gherkin_automated #

Improved flutter gherkin performance and stability

Performance #

Preliminary: integration tests performance vs. development #

Original flutter_gherkin BDD test generator uses integration test bindings only. It takes seconds for each 'Tap button' and etc. Simple feature takes minutes. While such behaviour is appropriate for real world testing it make BDD completely unusable at development stage.

Solution #

Prepare test for each feature in test/bdd/features/ using @GherkinAutomatedTestSuite annotation and AutomatedBindingNoDelay binding:

// file: test/bdd/features/some_feature1.dart
@GherkinAutomatedTestSuite()
void main() {
  AutomatedBindingNoDelay.init();

  group("[Unit]", () {
    some_feature1.main();
  });
}

Combine them all in test/bdd/bdd_test.dart:

// file: test/bdd/bdd_test.dart
void main() {
  AutomatedBindingNoDelay.init();

  group("[Gherkin]", () {
    some_feature1.main();
    some_feature2.main();
  });
}

flutter test vs flutter driver #

I already has 4x speed improvement using custom integration testing bindings and flutter test instead of flutter drive. Also flutter test gives me ability to perform debug and coverage analysis.

flutter test based on automated binding. It is suitable for development. And gives ability to test, debug and coverage of particular features.

flutter drive based on integration binding. It can be invoked sometimes.

I do both on CI server.

I use automated test on development machine for each code change:

# particular feature test
flutter test test/bdd/features/some_feature1.dart
# complete test
flutter test --coverage -j 10)

and for integration test before project release:

flutter drive --driver=test_driver/integration_test_driver.dart \
    --target=integration_test/gherkin_suite_test_fast.dart -d web-server

Results #

I have more than 40X speed improvement on i9:

Stability #

Flutter 2.5.0 Semantics #

In flutter 2.5.0-2.5.2 there is regression. Integration tests occasionally terminate with exceptions like "Parent #24 has child #29 but child #29 is attached to #30..." and etc. Do not try to search root of problem in your code. Very simple widgets can stop working. It is just regression bug in flutter. Flutter 2.6.0 seems to be fixed. Still waiting

Solution #

I provide special @GherkinNoSemanticsTestSuite annotation for integration testing.

//integration_test/gherkin_suite_test.dart
@GherkinNoSemanticsTestSuite()
void main() async {
  await Firebase.initializeApp();
  executeTestSuite(
    FlutterTestConfiguration.DEFAULT(),
    (World world) => app.main(),
  );
}