V8 coverage is 0% with jsdom environment on Windows #31842
Description
Command
test
Is this a regression?
- Yes, this behavior used to work in the previous version
The previous version in which this bug was not present was
No response
Description
Coverage summary shows 0% when running tests with Vitest (environment: jsdom) and V8 coverage provider on version 21.0.0-rc.4. Works correctly with browser environments (e.g., playwright). This problem occurs only on Windows. I haven't encountered this issue in CI pipelines using the official nodejs docker image, nor on other Linux-based operating systems.
Expected behavior: coverage should work with jsdom without requiring a browser.
Minimal Reproduction
Steps to reproduce (see attached minimal reproduction):
- Create project:
npx @angular/[email protected] new coverage-v8-jsdom - Add coverage provider:
npm i -D @vitest/coverage-v8 - Update angular.json test options:
"options": {
"coverage": true
}
-
Run tests:
npm run test
The coverage summary will show 0 for all statements, branches, etc. -
Add browser support:
npm i -D @vitest/browser-playwright -
Update test options in angular.json:
"options": {
"browsers": ["ChromiumHeadless"],
...
}
- Run tests again:
npm run test
The coverage summary will correctly show the coverage.
Note: The attached minimal reproduction should work after npm install and npm run test. If you remove the browsers option from angular.json, coverage will again be incorrect.
Exception or Error
Your Environment
Angular CLI : 21.0.0-rc.4
Angular : 21.0.0-rc.2
Node.js : 22.16.0
Package Manager : npm 10.9.2
Operating System : win32 x64
┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build │ 21.0.0-rc.4 │ ^21.0.0-rc.4 │
│ @angular/cli │ 21.0.0-rc.4 │ ^21.0.0-rc.4 │
│ @angular/common │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/compiler │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/compiler-cli │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/core │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/forms │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/platform-browser │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ @angular/router │ 21.0.0-rc.2 │ ^21.0.0-next.0 │
│ rxjs │ 7.8.2 │ ~7.8.0 │
│ typescript │ 5.9.3 │ ~5.9.2 │
│ vitest │ 4.0.9 │ ^4.0.8 │
└───────────────────────────┴───────────────────┴───────────────────┘
Anything else relevant?
No response