[Bug]: Using `expect(string).toMatchSnapShot` throws "Invalid Chai property: toMatchSnapshot"

[hmidmrii]

Describe the bug

When trying to use toMatchSnapshot matcher in the interaction tests it would throw the following error:

Invalid Chai property: toMatchSnapshot

Reproduction link

https://stackblitz.com/edit/github-hx2exbv1?file=src%2FTest.stories.tsx

Reproduction steps

1. Have a story
2. Write an interaction test and use expect(string).toMatchSnapshot(key)

System

System:
    OS: macOS 15.7.1
    CPU: (11) arm64 Apple M3 Pro
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.20.0 - /Users/hamid/.nvm/versions/node/v22.20.0/bin/node
    npm: 10.9.3 - /Users/hamid/.nvm/versions/node/v22.20.0/bin/npm <----- active
  Browsers:
    Safari: 18.6
  npmPackages:
    @storybook/addon-a11y: ^10.0.8 => 10.0.8 
    @storybook/addon-docs: ^10.0.8 => 10.0.8 
    @storybook/addon-vitest: ^10.0.8 => 10.0.8 
    @storybook/addon-webpack5-compiler-swc: ^4.0.2 => 4.0.2 
    @storybook/react-vite: ^10.0.8 => 10.0.8 
    @storybook/react-webpack5: ^10.0.8 => 10.0.8 
    @storybook/test-runner: ^0.24.1 => 0.24.1 
    chromatic: ^12.2.0 => 12.2.0 
    eslint-plugin-storybook: ^10.0.8 => 10.0.8 
    storybook: ^10.0.8 => 10.0.8

Additional context

from the docs I can see that the exported expect from storybook/test when using Vitest addon is derived from Vitest and it's extending the @testing-library/jest-dom matchers, but I'm not sure why this matcher doesn't exist.

KIM that using composible tests works, and not importing expect (with the test.globals option in Vite enabled) or importing it from vitest will fix the issue, but obviously we can't do that since it's recommended to use exported expect from storybook/test

[hmidmrii]

I can see that the expect exported by storybook/test doesn't have the type for toMatchSnapshot, but it's extending the types from jest.Matchers, so if you don't have @types/jest installed, TS compiler would throw an error on the usage of toMatchSnapshot.

I'm not sure if this is intentional or not.

[dosubot]

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

The lack of toMatchSnapshot support in the expect exported by storybook/test is intentional. The Storybook docs and example tests only mention and demonstrate matchers from Vitest and @testing-library/jest-dom, not snapshot testing. The type extension from jest.Matchers is mainly for compatibility, but it doesn't mean all Jest matchers are implemented—so TypeScript may show types for matchers that aren't actually available, leading to confusion if @types/jest is missing or if you try to use unsupported matchers like toMatchSnapshot source.

Snapshot testing is not supported in Storybook interaction tests via @storybook/test. If you need snapshot or visual regression testing, Storybook recommends using Chromatic, or you can use the test runner setup to add custom snapshot matchers, but this is outside the scope of the storybook/test export source source.

If you need to use snapshot testing, consider using Vitest directly or customizing your test runner configuration.

To reply, just mention @dosu.

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[hmidmrii]

But @dosu, why is it not supported? From the docs, I can see that storybook/test exports the same expect from Vitest, but with extra matchers. Vitest has this matcher, so I expected it to be in storybook/test expect.

[dosubot]

storybook/test does not export Vitest's expect directly—it provides a custom, instrumented version that combines Chai assertions with a subset of Jest-style matchers for compatibility with Storybook's Interactions panel and debugging tools. This custom implementation does not include snapshot matchers like toMatchSnapshot, even though Vitest's native expect does. The official docs and examples only mention behavioral matchers (e.g., toBeInTheDocument, toHaveBeenCalled), not snapshot testing, and recommend Chromatic or other visual testing tools for snapshot/visual regression use cases. This design avoids conflicts and ensures stable integration with Storybook's UI and test environments, as shown in the docs and code.

If you need snapshot testing, you can use Vitest directly outside of Storybook interaction tests, or set up custom matchers in the test runner, but this is not supported via storybook/test.

To reply, just mention @dosu.

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[ahayes91]

Related - #32930 to request support for toMatchScreenshot assertion from vitest 😏