Debugger does not step into correct function

[bpasero]

Steps:

• run from main
• open src/vs/workbench/services/editor/test/browser/editorService.test.ts
• add a breakpoint into here
• right click "Debug Test" in here
• step into await openEditor(untypedEditor)

=> 🐛 you end up in a weird place

[bpasero]

Since this makes me stop wanting to use debug in VSCode, marking as important selfhosting blocker.

[bpasero]

I think this may reproduce in devtools too, so lowering severity.

[connor4312]

I can reproduce this consistently as well. It seems to be a "vanilla" behavior of the version of V8 in Electron. I don't think this is feasible to correct for in the debugger, we'd need to do source analysis and manually set a breakpoint where the function exists (and that will fail if TS doesn't know where the function is declared).

However, I don't reproduce it when running the test in real (modern) Chrome. With the introduction of test run configurations in #127096 (comment), I'll have an option to run unit tests in browser to avoid this issue.

cc @deepak1556 fyi. You can close this if you don't plan to take any action here (other than pulling in Electron updates)

[deepak1556]

@connor4312 which version of chrome did you test with ? Also what are the minimal steps to test this on the web, I can bisect the chrome CL that fixed it and if its minimal will backport to our current version.

[connor4312]

I tested with Chrome 91, by:

1. Modify line 149 in test/unit/browser/index.js to read const browser = await playwright[browserType].launch({ headless: !Boolean(argv.debug), devtools: Boolean(argv.debug) }); (open the devtools)
2. Add a debugger; statement before the openEditor line so you pause there
3. yarn test-browser --browser chromium --run .\out\vs\workbench\services\editor\test\browser\editorGroupsService.test.ts --debug
4. Try to step into the openEditor line that Ben showed

[deepak1556]

@connor4312 the issue does not repro in chromium 89 (current runtime of vscode insiders), can you confirm if my steps are correct recording.gif.zip

You can download version 89 from https://commondatastorage.googleapis.com/chromium-browser-snapshots/Mac/843806/chrome-mac.zip

[connor4312]

Okay, sorry, it actually works with stepping, just not breakpoints. Updated instructions:

1. Add a debugger; statement before the openEditor line so you pause there
2. yarn test-browser --browser chromium --run .\out\vs\workbench\services\editor\test\browser\editorGroupsService.test.ts --debug
3. After you hit the debugger, add a breakpoint on the next line
4. Continue
5. Step in
6. Land in the wrong place

The bad news is that, with these fixed instructions, I can also reproduce it on modern Chrome 🙁

[connor4312]

I opened a bug for this here: https://bugs.chromium.org/p/chromium/issues/detail?id=1227841

[deepak1556]

Great, thanks!

[piyushsoni]

Just FYI, the Chromium bug has been closed as they want a reproducible test case inside Chromium and not in VS Code.