vitest-dev/vitest · error · TypeError

vi.unmock() expects a string path, but received a

Error message

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

What it means

Thrown by `vi.unmock(path)` when `path` is not a string. Like `vi.mock`, `vi.unmock` is hoisted and requires a string module specifier so the transformer can register the unmock before imports execute. A non-string path is rejected with a TypeError.

Solutions

1. Pass a string literal specifier: `vi.unmock('./myModule')`.
2. If you need runtime control, use `vi.doUnmock` inside the test (still requires a string).
3. Verify the argument is the specifier, not the imported module object.

Example fix

// before
import * as M from './myModule'
vi.unmock(M)

// after
vi.unmock('./myModule')

function unmockSafe(path) {
  if (typeof path !== 'string') throw new TypeError('vi.unmock requires a string path')
  return vi.unmock(path)
}

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

When it happens

Trigger: Calling `vi.unmock(nonString)`; passing a module namespace object or Promise instead of a path string; using a dynamically computed path that isn't a string.

Common situations: Refactoring that replaces a literal path with a variable; passing the imported binding; misunderstanding the hoisting requirement; copy-paste from `vi.mock` with the wrong argument.

Related errors

• vi.mock() expects a string path, but received a
• vi.doMock() expects a string path, but received a
• vi.doUnmock() expects a string path, but received a
• vi.unmock() expects a string path, but received a
• any() expects to be passed a constructor function. Please…

AI-assisted analysis of vitest-dev/vitest@1fa9837ec2 (2026-08-11). Data as JSON: /api/errors/d089461bdc8a2ed6. Report an issue: GitHub.

Appendix: source

Thrown at packages/vitest/src/integrations/vi.ts:671

      _mocker().queueMock(
        path,
        importer,
        typeof factory === 'function'
          ? () =>
              factory(() =>
                _mocker().importActual(
                  path,
                  importer,
                  _mocker().getMockContext().callstack,
                ),
              )
          : factory,
      )
    },

    unmock(path: string | Promise<unknown>) {
      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?: MockOptions | MockFactoryWithHelper) {
      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'
          ? () =>

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