DDC async* bug

[vsmenon]

The following test prints:

Hello, World!
Hello, World!
Hello, World!
[hello]

in the VM and dart2js, but prints nothing DDC.

import 'dart:async';

  Stream<String> testStream(String test) async* {
    try {
      await testFunction();
      yield test;
    } catch (e) {
      yield test;
      print('Hello, World!');
      print('Hello, World!');
      print('Hello, World!');
    }
  }

  Future<String> testFunction() async {
    await testFunctio2();
    return "";
  }

  Future<String> testFunctio2() async {
    throw Exception("test");
  }

void main() async {
  var stream = testStream("hello");
  print(await stream.toList());
}

[vsmenon]

@Markzipan - can you take a look when you get a chance?

[Onein]

Any update on this, since the original issue in the flutter repo is already closed?

[Markzipan]

I haven't had the time to look at this yet, but this issue is still reproducible on DDC. We could escalate if it's blocking.

[Onein]

Thanks for the response. No, it's not blocking I just wanted to know if there is any progress because the original issue is closed now. It's just an annoying bug, because you can't really use the ddc in case you work a lot with streams, like I do.

[phamnhuvu-dev]

This bug is very critical when all our business logic is using stream then it is not working on the web platform

[Markzipan]

We have a fix in the works for this issue that's been toiling behind other priorities. I've revived the fix, so this issue may be resolved soon.

[phamnhuvu-dev]

@Markzipan But when I run the web with the release option, the problem is gone.

[Markzipan]

The debug and release compilers are different on the web; this issue only exists for the debug compiler. We plan on resolving async disparities between our various backends soon (tm).

[vari]

Is there any update on the fix for this issue?

[Markzipan]

I have a patch for this issue in the works, but it's dredged up a couple other timing-related code issues. I'll try to get the patch in and work on a more holistic fix later.