[Bug]: CSFNext `.test` not working with combined exports.

[eidryn]

Describe the bug

When using CSFNext with experimentalTestSyntax=true 'combined' export statements fail to run and break storybook as they do not resolve the AST tree to the underlying variable and the _stories property does not contain the exported story (and therefore __stats cannot be accessed).

export const Primary = meta.story({}) // <= Works fine

const Primary = meta.story({})

export { Primary }; // <= TypeError: Cannot read properties of undefined (reading '__stats')

We use combined exports so that it is easy to check what is exported from a file, especially large ones but this is not compatible with the new .test functionality - though everything else works fine.

Reproduction link

https://stackblitz.com/edit/github-gyecjlwc?file=README.md

Reproduction steps

1. Go to above link
2. Access the Button story and observe working correctly with in-line export, and separate export at EOF
3. Uncomment the Secondary.test() function.
4. Observe storybook breaks

System

│  Storybook Environment Info:
│

│  System:
│  OS: macOS 26.2
│  CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
│  Shell: 5.9 - /bin/zsh
│  Binaries:
│  Node: 24.11.0 - ~/.nvm/versions/node/v24.11.0/bin/node
│  Yarn: 1.22.19 - ~/.yarn/bin/yarn
│  npm: 11.6.1 - ~/.nvm/versions/node/v24.11.0/bin/npm <----- active
│  pnpm: 10.20.0 - ~/Library/pnpm/pnpm
│  Browsers:
│  Chrome: 142.0.7444.60
│  Safari: 26.2
│  npmPackages:
│  @storybook/addon-a11y: 10.1.4 => 10.1.4
│  @storybook/addon-docs: 10.1.4 => 10.1.4
│  @storybook/addon-themes: 10.1.4 => 10.1.4
│  @storybook/addon-vitest: 10.1.4 => 10.1.4
│  @storybook/react-vite: 10.1.4 => 10.1.4
│  eslint-plugin-storybook: 10.1.4 => 10.1.4
│  storybook: 10.1.4 => 10.1.4
│  storybook-addon-tag-badges: 3.0.2 => 3.0.2

Additional context

No response

[dosubot]

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

This is a current limitation in Storybook 10.1.4 when using CSFNext with experimentalTestSyntax=true: the .test method does not work with combined exports (e.g., const Primary = meta.story({}); export { Primary };). The technical reason is that Storybook's AST parser processes .test() calls before it has registered stories exported via combined exports, so the story metadata (_stories) is missing and causes the TypeError you observed. There's a TODO in the codebase acknowledging this limitation, and the .test feature is designed to work with direct (inline) exports only for now (source, discussion).

To avoid this error, use inline exports for any story that needs .test. If you need to share data or mocks across stories, move them to a separate utility file and import them into your story file. There are no configuration changes or workarounds that enable .test with combined exports at this time (example workaround).

If you need help refactoring large files or want migration tips, let me know!

To reply, just mention @dosu.

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