[Bug]: Vitest/Test addon does not work if non-ASCII character in path

[Evarin]

Describe the bug

I was trying to use storybook with svelte, and stumbled desperately on the error "No test suite found in file "...Page.stories.svelte".

After seeing #29572, I realized that my path contained a hyphenated character (é) ; removing it solved the problem.

Reproduction link

https://github.com/Evarin/storybook-path-issue

Reproduction steps

1. Go to the above link
2. Install and run npx vitest --project=storybook
3. Observe the errors:

 FAIL   storybook (chromium)  src/stories/Button.stories.svelte [ src/stories/Button.stories.svelte ]
Error: No test suite found in file /mnt/Data/teststorybook/tést/src/stories/Button.stories.svelte
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/3]⎯

 FAIL   storybook (chromium)  src/stories/Header.stories.svelte [ src/stories/Header.stories.svelte ]
Error: No test suite found in file /mnt/Data/teststorybook/tést/src/stories/Header.stories.svelte
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[2/3]⎯

 FAIL   storybook (chromium)  src/stories/Page.stories.svelte [ src/stories/Page.stories.svelte ]
Error: No test suite found in file /mnt/Data/teststorybook/tést/src/stories/Page.stories.svelte

Those errors disappear if you rename "tést" "test"

System

System:
│  OS: Linux 6.8 Linux Mint 22.1 (Xia)
│  CPU: (12) x64 Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz
│  Shell: 5.2.21 - /bin/bash
│  Binaries:
│  Node: 24.5.0 - /usr/local/bin/node
│  npm: 11.5.1 - /usr/local/bin/npm
│  pnpm: 10.14.0 - /home/evarin/.local/share/pnpm/pnpm <----- active
│  Browsers:
│  Firefox: 146.0.1

Additional context

No response

[dosubot]

Hi @Evarin! I'm Dosu and I’m helping the storybook team.

This is a limitation in the current Storybook Vitest/Test addon: paths with non-ASCII (accented) characters can cause test discovery to fail, resulting in "No test suite found" errors. The underlying code uses path normalization utilities like pathe and micromatch, but there is no explicit handling for non-ASCII characters in file or directory names, so path matching can break when such characters are present (source).

There is no official fix or configuration workaround for this as of now. The best workaround is to avoid using non-ASCII characters in your file and directory names for stories and components. Keeping all Storybook, Vitest, and related dependencies up to date is also recommended, as ongoing improvements in path normalization may eventually address this (source).

If support for non-ASCII paths is critical for your project, you may want to follow updates in both the Storybook and Vitest changelogs, and consider raising the issue with the Vitest team as well, since the root cause may involve both tools.

To reply, just mention @dosu.

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