toMatchScreenshot cannot find currentTest

[djrenren]

Describe the bug

I'm attempting to use vitest's new toMatchScreenshot() matcher to test storybook stories.
After invoking storybook's composeStory function, the test context seems to get lost. It's likely that storybook is mucking with something global that's breaking something inside vitest but I couldn't find it on my own since I'm not very familiar with how browser mode works under the hood.

Reproduction

The minimal repro looks like this:

import { expect, test } from 'vitest'
import { render } from 'vitest-browser-react'
import { composeStory } from '@storybook/react-vite'
import meta, { ExampleStory } from './HelloWorld.stories.tsx'

const Example = composeStory(ExampleStory, meta)

test('renders name', async () => {
  const screen = await render(<div data-testid="story"><Example /></div>);
  await expect(screen.getByTestId('story')).toMatchScreenshot()
})

and the error looks like:

but I've made a runnable project here which is a minimal change on top of the npx vitest init browser: https://github.com/djrenren/vitestScreenshotTestFailure.

Just run npm run test:browser

System Info

System:
    OS: macOS 15.6.1
    CPU: (14) arm64 Apple M3 Max
    Memory: 1000.64 MB / 36.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.16.0 - /Users/john/.nvm/versions/node/v22.16.0/bin/node
    npm: 10.9.2 - /Users/john/.nvm/versions/node/v22.16.0/bin/npm
    pnpm: 10.18.3 - /Users/john/.nvm/versions/node/v22.16.0/bin/pnpm
    bun: 1.1.29 - /Users/john/.bun/bin/bun
    Deno: 1.41.3 - /Users/john/.deno/bin/deno
  Browsers:
    Brave Browser: 141.1.83.120
    Chrome: 141.0.7390.123
    Firefox: 144.0
    Firefox Developer Edition: 132.0
    Safari: 18.6
    Safari Technology Preview: 18.4
  npmPackages:
    @vitejs/plugin-react: ^5.1.0 => 5.1.0 
    @vitest/browser-playwright: ^4.0.4 => 4.0.4 
    vitest: ^4.0.4 => 4.0.4 
    vitest-browser-react: ^2.0.2 => 2.0.2

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.

[macarie]

Thanks for the report!

Yes, it looks like the context is getting lost. We're planning to address this on our side, but it requires some internal changes, so we don’t have an exact timeline yet. We’ll update this issue once there’s progress.

[yannbf]

Hey there @macarie! After a bit of investigating I found the culprit.
If any code imports from storybook/test (doesn't matter what), this code executes:
https://github.com/storybookjs/storybook/blob/492430d1e1cec2878c225c724c2ee3e963728de3/code/core/src/test/expect.ts#L142

That side effect occurs because our imports end up importing that file @storybook/react -> .. many imports .. -> storybook/test

@kasperpeulen has context on the need for that code, in fact we might need to revisit it now that Vitest 4 is out.
I'm afraid this is all I can do at the moment, but it seems like something that this warrants a fix on our end.

[macarie]

Thanks for the investigation @yannbf! While that might indeed be triggering it, I think there's a bigger underlying issue, as this happens even when extracting expect from the test context. What storybook/test does might've just surfaced a bug within the assertion library.

I'll spend some more time debugging to see if I can find the cause and a potential fix.

[shannonmoeller]

Ran into the same issue. Looking forward to a fix!

[Geloosa]

Running into the same without Storybook, just in pure Vitest tests with the playwright browser provider.

[macarie]

Running into the same without Storybook

Can you provide a reproduction for this, @Geloosa?