Cancellable Test Resources

A test can hold onto resources that don't stop when the test stops. A fetch, a child process, a file stream, a polling loop: none of those notice when Vitest has cancelled the test, and the worker has to sit there waiting for them to finish on their own. Vitest cancels a test when it exceeds its timeout, when another test fails under --bail, or when someone presses Ctrl+C in the terminal.

The test context provides a signal 3.2.0+ that fires in all of those cases. Pass it to anything that accepts an AbortSignal and the resource is released when Vitest cancels.

Pattern

import { test } from 'vitest'

test('stop request when test times out', async ({ signal }) => {
  await fetch('/heavy-resource', { signal })
}, 2000)

If the request hasn't completed within 2 seconds, fetch rejects with AbortError instead of the test hanging until the operation finishes.

Other Web APIs that accept an AbortSignal

• fetch
• addEventListener, where passing { signal } removes the listener on abort
• ReadableStream.pipeTo
• Node.js APIs like fs.readFile, child_process.spawn, and setTimeout or setInterval, all of which accept { signal }
• Any custom code that calls signal.throwIfAborted() or listens for 'abort'

Forwarding the signal

Wire the test's signal into your own helpers so cancellation propagates all the way down:

async function pollUntilReady(url: string, signal: AbortSignal) {
  while (!signal.aborted) {
    const res = await fetch(url, { signal })
    if (res.ok) {
      return
    }
    await new Promise(r => setTimeout(r, 200))
  }
  signal.throwIfAborted()
}

test('worker becomes ready', async ({ signal }) => {
  await pollUntilReady('http://localhost:4000/health', signal)
}, 5000)

See also

• signal in Test Context
• bail
• testTimeout