vitest-dev/vitest · error · TypeError

vi.unmock() expects a string path, but received a ${typeof p

Error message

vi.unmock() expects a string path, but received a ${typeof path}

What it means

Thrown at packages/mocker/src/browser/hints.ts:85-89 as a TypeError when vi.unmock() receives a non-string first argument. vi.unmock queues removal of a mock by module specifier, so the path must be a string to look up in the registry.

Source

Thrown at packages/mocker/src/browser/hints.ts:86

      const importer = getImporter('mock')
      _mocker().queueMock(
        path,
        importer,
        typeof factory === 'function'
          ? () =>
              factory(() =>
                _mocker().importActual(
                  path,
                  importer,
                ),
              )
          : factory,
      )
    },

    unmock(path: string | Promise<unknown>): void {
      if (typeof path !== 'string') {
        throw new TypeError(
          `vi.unmock() expects a string path, but received a ${typeof path}`,
        )
      }
      _mocker().queueUnmock(path, getImporter('unmock'))
    },

    doMock(path: string | Promise<unknown>, factory?: ModuleMockOptions | ModuleMockFactoryWithHelper): void {
      if (typeof path !== 'string') {
        throw new TypeError(
          `vi.doMock() expects a string path, but received a ${typeof path}`,
        )
      }
      const importer = getImporter('doMock')
      _mocker().queueMock(
        path,
        importer,
        typeof factory === 'function'
          ? () =>

View on GitHub (pinned to d568f8ce37)

Solutions

  1. Pass a string literal module path: vi.unmock('./logger').
  2. Ensure any variable passed is a string at runtime.

Example fix

// before
vi.unmock(config.loggerPath)

// after
vi.unmock('./logger')
Defensive patterns

Strategy: type-guard

Validate before calling

function unmockIfString(path: unknown) {
  if (typeof path !== 'string') {
    throw new TypeError(`vi.unmock requires a string path, got ${typeof path}`)
  }
  vi.unmock(path)
}

Type guard

function isModulePath(path: unknown): path is string {
  return typeof path === 'string' && path.length > 0
}

Prevention

When it happens

Trigger: Calling vi.unmock(undefined), vi.unmock(someVar) with a non-string variable, or vi.unmock(import('./x')) that was not rewritten.

Common situations: Calling unmock with the wrong argument type after refactoring; passing an object/number accidentally; dynamic import not rewritten by transform.

Related errors


AI-assisted analysis of vitest-dev/vitest@d568f8ce37 (2026-08-03). Data as JSON: /data/errors/2c229f575a556f5c.json. Report an issue: GitHub.