Fix memory leak

[kosratdev]

Fixes a memory leak in the CountrySelectorBase widget, where the CountrySelectorController hasn't been disposed in the dispose method. Also added leak_tracker_flutter_testing to the dev dependencies to automatically track memory leaks.

Closes #30

Checklist

• I have bumped the version in pubspec.yaml
• I have added an entry in changelog.md for the new pubspec version
• (if applicable) I have added "Closes #1234" to this termplate to automatically close related issues.
• (not required if no sensible change has been made eg: Localization) I have added tests that prove my fix is effective or that my feature works.

[cedvdb]

thanks

Also added leak_tracker_flutter_testing to the dev dependencies to automatically track memory leaks.

While reading the documentation, it seems to me that the tests should use testWidgets instead testWidgetsWithLeakTracking, isn't it ? Otherwise does this do anything ?

[kosratdev]

Based on this documentation, leak_tracker_flutter_testing can be enabled for all tests by enabling it in the test executable method, as we did.

Future<void> testExecutable(FutureOr<void> Function() testMain) async {
  LeakTesting.enable();

  await testMain();
}

After that, all the testWidgets will be tracked for not disposed and not GCed objects.

[kosratdev]

Thanks @cedvdb for accepting the PR. Please don't forget to push it to the pub.dev.

[cedvdb]

Thanks ! It was published on pub dev for version 1.0.17