Testing an assertion

[Andreas Sumerauer]

Is it possible to test an assertion with the flutter test framework?

In particular: Is there a way to make a test pass when an assertion fails (given this is the expected outcome)?

Thanks!

[Jonas Sander]

I'm writing it from memory, but it should go something like this:

bool assertion = false;
assert(() {assertion = true; return true;}())
return assertion;

[Andreas Sumerauer]

Thanks, but that is not what I meant I'm afraid.

It appears that one has to insert a try block within the test body and catch that.

Here is an example:

main()
  test('south > north (must throw AssertionError)', () {
    bool assertionError = false;
    try {
      final LatLngBounds bounds = LatLngBounds(
        southwest: const LatLng(30.0, 20.0),
        northeast: const LatLng(-10.0, 40.0),
      );
    }
    on AssertionError catch (e){
      assertionError = true;
    }
    expect(assertionError, true);
  });
}

It would be nice to have a testAssert function for that specific case (or maybe even better a more general testException).

[Jonas Sander]

You may want to look at this.

https://stackoverflow.com/q/49523786/8121937

You can also specify the Excepetion that should be thrown.

--
You received this message because you are subscribed to a topic in the Google Groups "Flutter Dev" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/flutter-dev/fICU_VEOO7M/unsubscribe.
To unsubscribe from this group and all its topics, send an email to flutter-dev...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Andreas Sumerauer]

Thanks!

That is exaclty what I was looking for.