Which @angular/* package(s) are the source of the bug?
Don't known / other
Is this a regression?
Yes
Description
If you use browser based testing with vitest and enable testcoverage by setting coverage to true as described in the documentation, the tests will now only work on Chromium. Testing on all other browsers will fail with Error: browserContext.newCDPSession: CDP session is only available in Chromium.
Here is a little example project
Just run npm run test-chromium to test with Chromium, which will work and npm run test-firefox to test with Firefox, which will fail.
If you disable coverage in the angular.json, Firefox will work.
So unlike with Karma, it's no loner possible to run tests with multiple Browsers and Coverage enabled.
An alternative is to add the --coverage flag to test-chromium, but with this setup I need to add a command for each browser and can't use the browsers array in the angular.json.
Please provide a link to a minimal reproduction of the bug
No response
Please provide the exception or error you saw
Please provide the environment you discovered this bug in (run ng version)
Angular CLI : 21.2.6
Angular : 21.2.7
Node.js : 24.6.0
Package Manager : npm 11.12.1
Operating System : darwin arm64
┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build │ 21.2.6 │ ^21.2.1 │
│ @angular/cli │ 21.2.6 │ ^21.2.1 │
│ @angular/common │ 21.2.7 │ ^21.2.0 │
│ @angular/compiler │ 21.2.7 │ ^21.2.0 │
│ @angular/compiler-cli │ 21.2.7 │ ^21.2.0 │
│ @angular/core │ 21.2.7 │ ^21.2.0 │
│ @angular/forms │ 21.2.7 │ ^21.2.0 │
│ @angular/platform-browser │ 21.2.7 │ ^21.2.0 │
│ @angular/router │ 21.2.7 │ ^21.2.0 │
│ rxjs │ 7.8.2 │ ~7.8.0 │
│ typescript │ 5.9.3 │ ~5.9.2 │
│ vitest │ 4.1.3 │ ^4.0.8 │
└───────────────────────────┴───────────────────┴───────────────────┘
Anything else?
No response
Which @angular/* package(s) are the source of the bug?
Don't known / other
Is this a regression?
Yes
Description
If you use browser based testing with vitest and enable testcoverage by setting
coveragetotrueas described in the documentation, the tests will now only work on Chromium. Testing on all other browsers will fail withError: browserContext.newCDPSession: CDP session is only available in Chromium.Here is a little example project
Just run
npm run test-chromiumto test with Chromium, which will work andnpm run test-firefoxto test with Firefox, which will fail.If you disable coverage in the
angular.json, Firefox will work.So unlike with Karma, it's no loner possible to run tests with multiple Browsers and Coverage enabled.
An alternative is to add the
--coverageflag totest-chromium, but with this setup I need to add a command for each browser and can't use thebrowsersarray in theangular.json.Please provide a link to a minimal reproduction of the bug
No response
Please provide the exception or error you saw
Please provide the environment you discovered this bug in (run
ng version)Anything else?
No response