1592969 - Captured stack trace doesn't show async separator anymore

Status: VERIFIED FIXED

(DevTools :: Console, defect, P2)

Description

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Consider the following code:

function resolveAfter2Seconds() {
  return new Promise((resolve) => {
    setTimeout(() => {
      console.trace();
      resolve();
    }, 2000);
  });
}

async function waitForData() {
  await resolveAfter2Seconds();
}

STR:

1. Load the scrip within a page
2. Select the Console panel
3. Execute waitForData() in the command line.

The Console panel should show stack trace composed from sync and async frames. Those should be separated by an async message explaining what async op happend.

See the attached screenshot showing how it was working before.

Honza

Comment 1

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Attachment: image.png

Comment 2

[Jan Honza Odvarko [:Honza] (always need-info? me)]

@Brian: do you know what could be the problem here? It was working before no?

Honza

Comment 3

[Cristian Fogel [:cfogel]]

Pushlog: URL

Mozregression points to 1500098.

Comment 4

[Brian Hackett [Laid off!]]

(In reply to Jan Honza Odvarko [:Honza] (always need-info? me) from comment #2)

@Brian: do you know what could be the problem here? It was working before no?

I don't, I'm not familiar with how the console deals with async stacks.

Comment 5

[:Harald Kirschner :digitarald]

Nicolas, maybe you have an idea on how this regressed?

Comment 6

[Nicolas Chevobbe [:nchevobbe]]

Looking at it right now.
Offender should be Bug 1390768, where we started using SmartTrace, which is based on the debugger Frames component, which does not handle async separator.

I'm looking at a case where the debugger should show such separator, would you have one? or maybe we don't want to show the separator in the call stack panel of the debugger?

Comment 7

[:Harald Kirschner :digitarald]

We also want to show async captured stacks in Debugger in bug 1142571, so landing something that adds the separator back for both panels would be great but could be also handled in the other bug as follow up for Debugger.

Comment 8

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1592969 - Show async separator in Frame component. r=davidwalsh.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d59c3470584a
Show async separator in Frame component. r=davidwalsh.

Comment 10

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/d59c3470584a

Comment 11

[:Harald Kirschner :digitarald]

Hi Janet, it would be great to call this out on the console pages: https://developer.mozilla.org/en-US/docs/Tools/Web_Console/Console_messages

Comment 12

[Cristian Fogel [:cfogel]]

Attachment: 72.png

Verfiied the fix with with 72.0a1 (2019-11-08).
However on, 72.0b4 the returned information appears to still be incomplete.

Is the patch limited to the Nightly branch?

Comment 13

[Nicolas Chevobbe [:nchevobbe]]

Cristian, it needs javascript.options.asyncstack pref to be set to true

Comment 14

[Cristian Fogel [:cfogel]]

Thank you for the info. It does indeed appear, plus some additional evaluations on Windows OS.
Marking the bug as verified based on the previous comment (re-verified with 72.0b4).

Comment 15

[Janet Swisher]

Doc changes are managed in https://github.com/mdn/sprints/issues/2468

Comment 16

[Janet Swisher]

Added section and screenshot about async traces: https://developer.mozilla.org/en-US/docs/Tools/Web_Console/Console_messages#Async_stack_frames