Nock

Common issues ​

"No match for response" when using got with error responses

Got automatically retries failed requests twice. That means if you have a test which mocks a 4xx or 5xx response, got will immediately reissue it. At that point, the mock will have been consumed and the second request will error out with Nock: No match for request.

The same is true for .replyWithError().

Adding { retry: 0 } to the got invocations will disable retrying, e.g.:

js
await got('http://example.test/', { retry: 0 })

If you need to do this in all your tests, you can create a module got_client.js which exports a custom got instance:

js
import got from 'got'

export default got.extend({ retry: 0 })

This is how it's handled in Nock itself (see #1523).

Requests made by ES Modules are not intercepted ​

When an ES module imports request with a namespaced import like import * as http from "node:http", and the module is imported before nock, requests made by this module are not intercepted. You can fix this by telling Node to preload nock using the --import=nock CLI option or setting the NODE_OPTIONS=--import=nock environment variable.

Axios ​

To use Nock with Axios, you may need to configure Axios to use the Node adapter as in the example below:

js
import axios from 'axios'
import nock from 'nock'
import test from 'ava' // You can use any test framework.

// If you are using jsdom, axios will default to using the XHR adapter which
// can't be intercepted by nock. So, configure axios to use the node adapter.
//
// References:
// https://github.com/axios/axios/pull/5277

axios.defaults.adapter = 'http'

test('can fetch test response', async t => {
  // Set up the mock request.
  const scope = nock('http://localhost')
    .get('/test')
    .reply(200, 'test response')

  // Make the request. Note that the hostname must match exactly what is passed
  // to `nock()`. Alternatively you can set `axios.defaults.host = 'http://localhost'`
  // and run `axios.get('/test')`.
  await axios.get('http://localhost/test')

  // Assert that the expected request was made.
  scope.done()
})

For Nock + Axios + Jest to work, you'll have to also adapt your jest.config.js, like so:

js
const config = {
  moduleNameMapper: {
    // Force CommonJS build for http adapter to be available.
    // via https://github.com/axios/axios/issues/5101#issuecomment-1276572468
    '^axios$': require.resolve('axios'),
  },
}

Memory issues with Jest ​

Memory issues can be avoided by calling nock.restore() after each test suite.
One of the core principles of Jest is that it runs tests in isolation. It does this by manipulating the modules cache of Node in a way that conflicts with how Nock monkey patches the builtin http and https modules. Related issue with more details.