Vitest error the coverage report (Unable to lookup source)

[wfpaisa]

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

In the "This experimental unit testing" mode, when using coverage, the HTML coverage report does not display properly.

Minimal Reproduction

Steps:

1. Install Angular 20

2. Enable Vitest: https://angular.dev/guide/testing/unit-tests#

3. Run: ng test --code-coverage

4. In the auto-generated folder: dist/test-out/[path]/coverage/index.html

Exception or Error

Unable to lookup source: /home/projects/angular/a20-vitest/dist/test-out/b3051492-863d-46fc-bc29-87425336cca6/src/app/app.ts (ENOENT: no such file or directory, open '/home/projects/angular/a20-vitest/dist/test-out/b3051492-863d-46fc-bc29-87425336cca6/src/app/app.ts')
Error: Unable to lookup source: /home/projects/angular/a20-vitest/dist/test-out/b3051492-863d-46fc-bc29-87425336cca6/src/app/app.ts (ENOENT: no such file or directory, open '/home/projects/angular/a20-vitest/dist/test-out/b3051492-863d-46fc-bc29-87425336cca6/src/app/app.ts')
    at Context.defaultSourceLookup [as sourceFinder] (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/context.js:17:15)
    at Context.getSource (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/context.js:71:21)
    at annotateSourceCode (/home/projects/angular/a20-vitest/node_modules/istanbul-reports/lib/html/annotator.js:249:40)
    at HtmlReport.onDetail (/home/projects/angular/a20-vitest/node_modules/istanbul-reports/lib/html/index.js:414:33)
    at Visitor.value (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/tree.js:38:38)
    at ReportNode.visit (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/tree.js:88:21)
    at /home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/tree.js:92:19
    at Array.forEach ()
    at ReportNode.visit (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/tree.js:91:28)
    at ReportTree.visit (/home/projects/angular/a20-vitest/node_modules/istanbul-lib-report/lib/tree.js:127:24)

Your Environment

Angular CLI: 20.0.1
Node: 22.16.0
Package Manager: npm 10.9.2
OS: linux x64

Anything else relevant?

No response

[william-uribe-puntoscolombia]

Yes, I confirm it happens to me, is there any solution? In my company, coverage is required to go to production, and this limits me to using Angular 20 with Vitest."