Failed assertion: line 954 pos 14: '_pendingExceptionDetails != null' when Patrol test finishes

[Wreos]

Hello, Guys! I faced the problem that the patrol test hangs with the following error in the flutter logs. Could you help?
patrol: ^2.0.7

Test code

void main() {

  patrolTest(
    'Login as valid user',
    nativeAutomation: true,
    bindingType: BindingType.patrol,
    nativeAutomatorConfig: NativeAutomatorConfig(
      packageName: 'de.app.*',
    ),
        ($) async {
      await app.main();
        await $('Login').tap();
        await $(#loginForm_phoneNumberInput_textField).enterText('+491');
        await $(#sendConfirmationButton).tap();
        await $('Tapped notification with ID: 1').waitUntilVisible();
    },
  );

Test logs

No device specified, using the first one (emulator-5554) • Building apk with entrypoint test_bundle.dart... ✓ Completed building apk with entrypoint test_bundle.dart (51.3s) • Executing tests of apk with entrypoint test_bundle.dart on emulator-5554..

Flutter logs

 00:14 +1: main_test Login as valid user [E]
2023-07-17 17:25:41.737 17398-17506 flutter                 de.*.customerAppDev              I    'package:flutter_test/src/binding.dart': Failed assertion: line 954 pos 14: '_pendingExceptionDetails != null': A test overrode FlutterError.onError but either failed to return it to its original state, or had unexpected additional errors that it could not handle. Typically, this is caused by using expect() before restoring FlutterError.onError.
2023-07-17 17:25:41.745 17398-17506 flutter                 de.*.customerAppDev              I    dart:core-patch/errors_patch.dart 51:61       _AssertionError._doThrowNew
                                                                                                      dart:core-patch/errors_patch.dart 40:5        _AssertionError._throwNew
                                                                                                      package:flutter_test/src/binding.dart 954:14  TestWidgetsFlutterBinding._runTest.handleUncaughtError
                                                                                                      package:flutter_test/src/binding.dart 959:9   TestWidgetsFlutterBinding._runTest.<fn>
                                                                                                      dart:async/zone.dart 1081:14                  _Zone._processUncaughtError
                                                                                                      dart:async/zone.dart 1285:5                   _CustomZone.handleUncaughtError
                                                                                                      dart:async/future_impl.dart 734:16            Future._propagateToListeners
                                                                                                      dart:async/future_impl.dart 592:5             Future._completeError
                                                                                                      dart:async/zone.dart 1423:47                  _rootRunBinary
                                                                                                      dart:async/zone.dart 1315:19                  _CustomZone.runBinary
                                                                                                      dart:async/future_impl.dart 162:22            _FutureListener.handleError
                                                                                                      dart:async/future_impl.dart 796:47            Future._propagateToListeners.handleError
                                                                                                      dart:async/future_impl.dart 817:13            Future._propagateToListeners
                                                                                                      da

UPD
It happens only when test assertion is fail, when assert is true, test passes

[fylyppo]

Hi, check if your app overrides FlutterError.onError.
It could look like:

final oldCallback = FlutterError.onError;
      FlutterError.onError = (details) {
        print('error');
        oldCallback?.call(details);
      };

And if yes, check what happens when you remove it.

[Wreos]

Thanks. Yes, I have. But unfortunately even after I removed it, problem still appearing. The most interesting thing that I am facing with this problem only when assertion in test is failed, element not found for example. If element is visible - everything is fine.

final originalOnError = FlutterError.onError;
  FlutterError.onError = (details) {
    AppLogger.error(details.exception, details.stack, LogTag.flutter);
    FirebaseCrashlytics.instance.recordError(details.exception, details.stack);
    originalOnError?.call(details);
  };
  PlatformDispatcher.instance.onError = (error, stack) {
    AppLogger.error(error, stack, LogTag.flutter);
    FirebaseCrashlytics.instance.recordError(error, stack);
    return false;
  };

[fylyppo]

You see this only if the test is failed because you got some error and onError is overriden.
Maybe you somehow overriding it in one more place. Here you can find the same problem, maybe it'll be helpful for you. Let me know if you found something interesting.

[Wreos]

Thanks, when I handle error in the test using this approach, it shows root of the problem (element is not visible)