samples/testing_app/README.md

testing_app

A Sample app that shows different types of testing in Flutter.

This particular sample uses the Provider package but any other state management approach would do.

Goals for this sample

Show how to perform:

• Widget Testing,
• Integration Testing,
• Performance Testing, and
• State Management Testing using the Provider package.

How to run tests

• Navigate to the project's root folder using command line and follow the instructions below.

To run tests using only the Flutter SDK:

The Flutter SDK can run unit tests and widget tests in a virtual machine, without the need of a physical device or emulator.

• To run all the test files in the test/ directory in one go, run flutter test.
• To run a particular test file, run flutter test test/<file_path>

To run tests on a physical device/emulator:

• Widget Tests:
  • Run flutter run test/<file_path>
• Integration Tests:
  • Run flutter test integration_test to run all the integration tests with a single command.
  • Alternatively, you can run flutter drive --driver=integration_test/driver.dart --target=integration_test/app_test.dart to run them separately. You can also provide custom driver files with this command.
• Performance Tests:
  • Run flutter drive --driver=integration_test/perf_driver.dart --target=integration_test/perf_test.dart --profile --trace-startup
    • Using a physical device and running performance tests in profile mode is recommended.
    • The --trace-startup option is used to avoid flushing older timeline events when the timeline gets long.
• State Management Tests:
  • For testing state using Flutter Integration Tests
    • Run flutter drive --driver=integration_test/driver.dart --target=integration_test/state_mgmt_test.dart

To generate test coverage report:

• Install the lcov tool:
  • For MacOS, run brew install lcov
  • For Linux, run sudo apt install lcov
• Run tests with coverage:
  • flutter test --coverage
• Convert lcov.info into readable html:
  • Run genhtml coverage/lcov.info -o coverage/index
• Open coverage/index/index.html in your preferred browser.

CI/CD

• Refer .github and the tool directory to see how to test Flutter projects using GitHub Actions.

Note that tools like GitHub Actions can't run tests on a physical device, which is required to run integration tests. Instead, you can use Firebase Test Lab, Codemagic or any platform of your choice to do that.

Questions/issues

If you have a general question about testing in Flutter, the best places to go are:

• Flutter documentation
• StackOverflow

If you run into an issue with the sample itself, please file an issue.