In bloc test the add event doesnot work when decodeImageFromList is used inside bloc

Question

Bloc test fails to call an event if we use decodeImageFromList

We had to get the width and height of an image file inside bloc for that we are using decodeImageFromList but after that when we add another event, that event doesn't execute while writing blocTest.

Dummy code:

 Stream<OurState> _mapEventOne(File file) async* {
    final decodedImage =
        await decodeImageFromList(await pickedImage.readAsBytes());
/// This add event is not working
    add(
      EventTwo(
        width: decodedImage.width,
        height: decodedImage.height,
      ),
    );
  }