No test suite found

[akornatskyy]

Describe the bug

The issue relates only to VsCode Claude extension, with Vitest version 4 (with default pool or when set to forks or threads).

It works as expected with version 3.

A workaround for version 4 is to set pool to: vmThreads, vmForks or typescript.

Reproduction

run tests from VsCode Claude extension.

System Info

Windows 11, node 25, vitest 4.0.16

Used Package Manager

npm

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[github-actions]

Hello @akornatskyy. Please provide a minimal reproduction using a GitHub repository or StackBlitz (you can also use examples). Issues marked with needs reproduction will be closed if they have no activity within 3 days.

[akornatskyy]

@sheremet-va : run tests from VsCode Claude extension.