vitest-dev/vitest · error · Error

Unsupported framework

Error message

Unsupported framework: ${framework}

What it means

The `vitest-browser` project creator CLI (packages/vitest/src/create/browser/creator.ts) scaffolds a browser component-testing project for a known UI framework. getFrameworkTestPackage maps the framework name to its testing-library/adapter package. An unrecognized framework string falls through the switch to this error.

Solutions

1. Use one of the supported framework names: vue, svelte, react, lit, preact, solid, marko, qwik, or vanilla.
2. Check for typos and case sensitivity in the framework argument.
3. Upgrade Vitest — newer versions may add support for your framework.

Example fix

// before:
npx vitest-browser create --framework angular

// after — use a supported framework or vanilla:
npx vitest-browser create --framework vanilla

const SUPPORTED = ['vue','svelte','react','lit','preact','solid','marko','qwik','vanilla']
if (!SUPPORTED.includes(framework)) {
  throw new Error(`Supported frameworks: ${SUPPORTED.join(', ')}`)
}

function isSupportedFramework(f: string): f is 'vue'|'svelte'|'react'|'lit'|'preact'|'solid'|'marko'|'qwik'|'vanilla' {
  return ['vue','svelte','react','lit','preact','solid','marko','qwik','vanilla'].includes(f)
}

When it happens

Trigger: Passing a framework name not in the supported set (vue, svelte, react, lit, preact, solid, marko, qwik, vanilla) to the browser project creator — e.g. a typo like 'Reat' or an unsupported framework like 'angular'.

Common situations: Typo in the framework argument; using a framework Vitest's browser creator doesn't yet support; outdated Vitest version that predates a newly added framework.

Related errors

• "browser.instances" was set in the config, but the array is…
• Vitest received --browser flag, but no project had a…
• Access denied to " ". See Vite config documentation for…
• All browser instances within a project must use the same…
• aria adapter expects an Element

AI-assisted analysis of vitest-dev/vitest@1fa9837ec2 (2026-08-11). Data as JSON: /api/errors/1986627a4402e163. Report an issue: GitHub.

Appendix: source

Thrown at packages/vitest/src/create/browser/creator.ts:114

      return null
    case 'vue':
      return 'vitest-browser-vue'
    case 'svelte':
      return 'vitest-browser-svelte'
    case 'react':
      return 'vitest-browser-react'
    case 'lit':
      return 'vitest-browser-lit'
    case 'preact':
      return 'vitest-browser-preact'
    case 'solid':
      return '@solidjs/testing-library'
    case 'marko':
      return '@marko/testing-library'
    case 'qwik':
      return 'vitest-browser-qwik'
  }
  throw new Error(`Unsupported framework: ${framework}`)
}

function getFrameworkPluginPackage(framework: string) {
  switch (framework) {
    case 'vue':
      return '@vitejs/plugin-vue'
    case 'svelte':
      return '@sveltejs/vite-plugin-svelte'
    case 'react':
      return '@vitejs/plugin-react'
    case 'preact':
      return '@preact/preset-vite'
    case 'solid':
      return 'vite-plugin-solid'
    case 'marko':
      return '@marko/vite'
    case 'qwik':
      return '@builder.io/qwik/optimizer'

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