Promises don't work

[Tiagoperes]

version: 0.2.2+0

the following code never prints "after promise":

async function start() {
    console.log('before promise');
    await Promise.resolve('test');
    console.log('after promise');
}

In the flutter code, I call widget.jsRuntime.enableHandlePromises() and widget.jsRuntime.evaluate("start()");.

"before promise" is successfuly printed, but the execution hangs in the promise, even if it's already fulfilled. "after promise" is never printed.

Tested in Android

[Tiagoperes]

I also tried:

• to remove widget.jsRuntime.enableHandlePromises();
• previous versions of the lib;
• different syntax (new Promise(resolve => resolve('test')))
• to use generators/yield instead of async/await (transpilation with babel)

None of these approaches worked. They kept the same behavior, the execution stucked before "after promise" was printed.

[Tiagoperes]

It does work if I force the use of JavascriptCore, which is weird, because the documentation of QuickJS states that it does support promises and its online demo works fine when I test the async code there.

[abner]

Hi @Tiagoperes. I will check

[cacard]

me too

[PhungVanHoa]

@Tiagoperes you should call executePendingJob

[Tiagoperes]

@Tiagoperes you should call executePendingJob

@PhungVanHoa this wouldn't be viable in realistic scenarios. The example I gave is short and its only purpose is to demonstrate the problem. My real issue comes from the need to use a library that, internally relies in many promises. I have no control over these promises and I dont know when they're created. I shouldn't have to explicitly resolve them. Today, if you use the default implementation of flutter_js, the program hangs everytime a promise is created internally by the js lib, and, as I said, I have no way of knowing when a promise is created, I only have access to the API.

This is not problem for me anymore since I realized I could force JavascriptCore on Android and things would work as expected. But, in any case, I think it should also work with QuickJS.

[abner]

I released some improvements in QuickJS integration and it should work better now.
But you still need to keep the calling the executePendingJobs because QuickJS do added Promises support, but it does not have
a event loop running all the time. It evaluate the scripts you send to it, but to resolve promises you need to keep calling executePendingJobs in a regular interval.

There is not i could do better to help you with it.