vitest-dev/vitest · warning · Error

Cannot find environment for

Error message

Cannot find environment for ${testFilePath}

What it means

getModuleGraph resolves the Vite DevEnvironment for a test file: it uses the explicitly passed viteEnvironment, else the __vitest__ environment when experimental.viteModuleRunner is false, else getTestFileEnvironment(project, file, browser). If none of these yields an environment, it throws 'Cannot find environment for <file>'. This runs when the UI/API requests the module graph for a file.

Solutions

1. Verify browser config (test.browser.enabled with a valid headless provider) if the file is a browser test.
2. If experimental.viteModuleRunner is false, ensure the __vitest__ environment is registered in the Vite config.
3. Check that test.environmentName / per-project environment is one Vite knows about.
4. Restart Vitest after changing environment config so the project's environments map is rebuilt.

Example fix

// before: browser tests but no browser environment registered
export default defineConfig({ test: { browser: { enabled: true } } })

// after
export default defineConfig({
  test: { browser: { enabled: true, instances: [{ browser: 'chromium' }] }, projects: [...] }
})

const env = viteEnvironment
  ? project.vite.environments[viteEnvironment]
  : getTestFileEnvironment(project, file, browser)
if (!env) throw new Error('no Vite environment registered for ' + file)

function hasEnvironment(project, name) {
  return Boolean(project.vite.environments[name])
}

When it happens

Trigger: A request for a module graph (e.g. clicking a file in the Vitest UI, or the API) for a test file whose Vite environment is not registered. Common when browser.enabled but no browser environment is configured, or viteModuleRunner:false is set without the __vitest__ environment being available.

Common situations: Opening the Vitest UI for a project with browser testing misconfigured, a custom Vite environment that is not registered for the file's environment name, or a stale project state after toggling experimental flags.

Related errors

• Failed to import test file
• Not called in the browser
• stackblitz environment does not support the
• The environment was not defined in the Vite config.
• The VM environment was not defined in the Vite config. This…

AI-assisted analysis of vitest-dev/vitest@1fa9837ec2 (2026-08-11). Data as JSON: /api/errors/9ec1b923fca0d906. Report an issue: GitHub.

Appendix: source

Thrown at packages/vitest/src/utils/graph.ts:31

  const externalized = new Set<string>()
  const inlined = new Set<string>()

  const project = ctx.getProjectByName(projectName)
  const browser = project.config.browser.enabled

  let environment: DevEnvironment | undefined

  if (viteEnvironment) {
    environment = project.vite.environments[viteEnvironment]
  }
  else {
    environment = project.config.experimental.viteModuleRunner === false
      ? project.vite.environments.__vitest__
      : getTestFileEnvironment(project, testFilePath, browser)
  }

  if (!environment) {
    throw new Error(`Cannot find environment for ${testFilePath}`)
  }
  const seen = new Map<EnvironmentModuleNode, string>()

  function get(mod?: EnvironmentModuleNode) {
    if (!mod || !mod.id) {
      return
    }
    if (
      mod.id === '\0vitest/browser'
      // the export helper is injected in all vue files
      // so the module graph becomes too bouncy
      || mod.id.includes('plugin-vue:export-helper')
    ) {
      return
    }
    if (seen.has(mod)) {
      return seen.get(mod)
    }

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