Vscode: TS/JS: rejected promise not handled within 1 second

[bpasero]

• VSCode Version: latest insiders
• OS Version: macOS

Steps to Reproduce:

1. open any TS or JS file

=>

/cc fyi @dbaeumer (might be TS lint or JS lint update related?) though I also see this when running out of sources without extensions and I only see it since maybe a couple of days.

[CoenraadS]

I have also seen this message, it caused my pull request build to fail I think:

https://travis-ci.org/Microsoft/vscode/jobs/181022070#L2924

[joaomoreno]

I just spent 30 minutes thinking this was me, and I still don't know where it comes from. 😠 I kept refreshing the workbench, while a JS file was open and saw it always.

We need two fixes here:

• Fix the rejected promise problem
• Improve this specific error reporting to be able to catch the culprit...

[jrieken]

This message means that a promise got rejected and no-one has attached a reject-handler to it.

[joaomoreno]

Yeah but where does it come from? Could we somehow do a better job figuring that out?

[jrieken]

Comes from here: https://github.com/Microsoft/vscode/blob/master/src/vs/workbench/node/extensionHostProcess.ts#L66

[joaomoreno]

Yesterday I spent quite some time trying to figure out if my new git code was the culprit. Having found this out, I figured it wasn't. @bpasero suspects it is somewhere in TypeScript code. Yet, no one knows for sure, it is speculation.

Rephrasing my previous question: can we, as Code, provide a better message to indicate where that promise came from?

[jrieken]

No, you cannot and that is in the nature of a promise/async code. In contrast to throwing an error a promise can be rejected anytime without a meaningful stack trace. Worst, that in this case the promise is rejected without a reason

[jrieken]

And then a very complex search revealed this: Promise.reject<void>(null)