Debugger in vs-code does not stop at breakpoint but elsewhere

[bonham]

Describe the bug

In vanilla project with vue3 + vitest + @testing-library/vue + node 18.18.2 or 20.11.1, setting and debugging breakpoints in vs-code on windows 11 does not work as expected. Debugger stops at wrong location. I am using vue single file components ( aka .vue files )

Seems to be transpiling and/or sourcemap issue.

The issue disappears when removing <style>...</style> section in .vue file

Reproduction

1. Create any vanilla vue project with simple single file component which contains all sections: template / script / style
2. Write a test with @testing-library/vue which is testing this component
3. Set a breakpoint within a .vue file
4. Run the test and watch where debugger stops
   Result: Debugger stops at wrong line
   Expected: Debugger should stop at correct line

Issue goes away when removing <style>...</style> section in .vue file

Example file SimpleComponent.vue

<template>
  <div>Hi {{ name }}</div>
  <div>Good</div>
</template>
<script setup>
import { ref } from 'vue'
const name = ref("Peter")
console.log("Nothing special") // set breakpoint here
</script>
<style>
.useless {
  color: green;
}
</style>

Example simple.spec.js

import { test } from 'vitest'
import { render } from '@testing-library/vue'
import SimpleComponent from './components/SimpleComponent.vue'

test("Component", () => {
  const renderResult = render(SimpleComponent)
  renderResult.findByText("mymessage")
})

Full example vanilla project to clone and reproduce: https://github.com/bonham/vitest-debug-issue-js

System Info

System:
    OS: Windows 11 10.0.22631
    CPU: (16) x64 AMD Ryzen 7 5700X 8-Core Processor
    Memory: 20.77 GB / 31.93 GB
  Binaries:
    Node: 20.11.1 - C:\Program Files\nodejs\node.EXE
    npm: 10.2.4 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Chromium (122.0.2365.80)
    Internet Explorer: 11.0.22621.1
  npmPackages:
    @vitejs/plugin-vue: ^5.0.4 => 5.0.4 
    vite: ^5.1.6 => 5.1.6 
    vitest: ^1.3.1 => 1.3.1

Used Package Manager

npm

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[AriPerkkio]

Can you test if @vitejs/[email protected] works?

This issue has come up before - it's not really Vitest related. I would guess that your breakpoints don't work even when debugging in browser during development.

Related discussions:

• Coverage issue in vue files when upgraded with version 1.1.3 or 1.2.0 #4991
• How to debug compents while running tests in VS code? #2874

[ghiscoding]

This is most often related to bad or missing sourcemaps

[bonham]

Can you test if @vitejs/[email protected] works?

No, it has the same bug.

This issue has come up before - it's not really Vitest related. I would guess that your breakpoints don't work even when debugging in browser during development.

Breakpoints work well in browser. Breakpoints work well starting vite dev server in "Javascript debug terminal". So it's pretty much narrowed down to vitest I'd say.

Related discussions:

* [Coverage issue in vue files when upgraded with version 1.1.3  or 1.2.0 #4991](https://github.com/vitest-dev/vitest/discussions/4991)

^ This is not related to breakpoints

* [How to debug compents while running tests in VS code? #2874](https://github.com/vitest-dev/vitest/discussions/2874)

^ this is describing exactly the same problem.

Source maps are turned on as you can see in my minimalistic example: https://github.com/bonham/vitest-debug-issue-js/blob/main/vite.config.js

[AriPerkkio]

Breakpoints seem to work fine when using Chrome Dev tools:

vitest-5380.mov

[bonham]

Hi @AriPerkkio, yes you are right. I tried the same and also for me breakpoint works well. This is a good workaround.
( I never tried debugging this way before: https://vitest.dev/guide/debugging#node-inspector-e-g-chrome-devtools )

Summary:

• breakpoints work well when using node inspector and chrome devtools
• breakpoints do not work when running vitest in debug mode within vs-code ( I tested on mac and windows )

Idk, but seems not a vitest issue but maybe a vs-code issue ( vue plugin or whatever .... )

[CreativeTechGuy]

Not sure if this is helpful or not, but I can reproduce this issue (in the VS Code debugger) without vue at all, just a plain node app. Disabling coverage when a debugger is attached is a workaround but unfortunate.

[bonham]

Not sure if this is helpful or not, but I can reproduce this issue (in the VS Code debugger) without vue at all, just a plain node app. Disabling coverage when a debugger is attached is a workaround but unfortunate.

with vitest or even without vitest?

[CreativeTechGuy]

@bonham Oh sorry, yes with vitest.

[CreativeTechGuy]

I just tested debugging in VS Code with a node app instrumented with istanbul and esbuild and it works fine with breakpoints being where they should be. So I think there's something in vitest specifically that is causing the problem, I don't think that VS Code is the root problem (although maybe a contributing factor).

[AriPerkkio]

@CreativeTechGuy how can I reproduce this issue? Is it with covearge.provider: 'v8' or covearge.provider: 'istanbul'? Does it work with vitest --inspect-brk?

[CreativeTechGuy]

@AriPerkkio Sorry for the delay, this is gnarly. I couldn't reproduce it starting from an empty repo, but I started deconstructing my massive repo and I was able to get it down to a few dozen lines total across all files. I've put a ton of information and very detailed steps in the repo README. Let me know if you are able to reproduce. I've been able to reproduce it across two computers (Windows 10 & 11) so far so hopefully you can too.

https://github.com/CreativeTechGuy/vitest-coverage-debugger-issue-repro

[MarvinKubus]

Hi @AriPerkkio, yes you are right. I tried the same and also for me breakpoint works well. This is a good workaround. ( I never tried debugging this way before: https://vitest.dev/guide/debugging#node-inspector-e-g-chrome-devtools )

Summary:

• breakpoints work well when using node inspector and chrome devtools
• breakpoints do not work when running vitest in debug mode within vs-code ( I tested on mac and windows )

Idk, but seems not a vitest issue but maybe a vs-code issue ( vue plugin or whatever .... )

We are experiencing this same problem at the moment and for us the workaround going through the Chrome Devtools is also working, but a lot less convenient to use.