Nock

Passthrough Requests ​

Allow Unmocked Requests on a Mocked Hostname ​

If you need some request on the same host name to be mocked and some others to really go through the HTTP stack, you can use the allowUnmocked option like this:

js
const scope = nock('http://my.existing.service.com', { allowUnmocked: true })
  .get('/my/url')
  .reply(200, 'OK!')

// GET /my/url => receives the mocked response
// GET /other/url => actually makes request to the server

INFO

When { allowUnmocked: true } lets a request reach the real server, no interceptor is removed.

Pass Through Selected Requests ​

For more granular control over which requests should hit the real server, you can use passthrough(). While allowUnmocked lets through any request that doesn't match an interceptor, passthrough() lets you specify exactly which requests go through the HTTP stack.

js
const scope = nock('http://my.existing.service.com')
  .get('/mock')
  .reply(200, { users: ['fake'] })
  .post('/live')
  .passthrough()

// GET /mock => receives the mocked response
// POST /live => actually makes request to the server

You can use passthrough() with query strings, header matching, and other interceptor features:

js
nock('http://my.existing.service.com')
  .get('/api/data')
  .query({ live: 'true' })
  .matchHeader('authorization', /^Bearer /)
  .passthrough()

Like other interceptors, passthrough interceptors are consumed when matched. They work with modifiers like times(), persist(), and optionally():

js
// Passthrough the first 3 requests, then fail
nock('http://example.com').get('/').times(3).passthrough()

// Passthrough indefinitely
nock('http://example.com').persist().get('/').passthrough()

// Don't fail scope.done() if this is never called
nock('http://example.com').get('/maybe').optionally().passthrough()