Nock

Lifecycle and Network Controls ​

Restore Nock ​

You can restore the HTTP interceptor to the normal unmocked behaviour by calling:

js
nock.restore()

INFO

nock.restore() does not clear the interceptor list. Use nock.cleanAll() if you expect the interceptor list to be empty.

nock.restore() also removes the HTTP interceptor itself and stops any active recording. Run nock.activate() to re-activate it. Without re-activation, Nock will not intercept any calls.

Activate Nock ​

Nock is activated when you import it. Only for cases where it has been deactivated using nock.restore(), you can reactivate the HTTP interceptor to start intercepting HTTP calls using:

js
nock.activate()

Calling nock.activate() while Nock is already active throws Nock already active.

Check Activation State ​

Use nock.isActive() to check whether the HTTP interceptor is currently active:

js
if (!nock.isActive()) {
  nock.activate()
}

Clear Interceptors ​

Use nock.cleanAll() to remove all registered interceptors, including persistent interceptors. This does not restore the HTTP interceptor:

js
nock.cleanAll()

Abort Pending Requests ​

Use nock.abortPendingRequests() to clear the timers Nock uses for delayed replies. Delayed requests that are still waiting do not complete; they are not rejected with an error.

js
nock.abortPendingRequests()

Remove an Interceptor ​

Use nock.removeInterceptor() with an interceptor instance:

js
const interceptor = nock('http://example.org').get('/resource')
interceptor.reply(200, 'OK')
nock.removeInterceptor(interceptor)

You can also pass a request descriptor. method defaults to GET, proto to http, and path to /. Use host for the hostname; include a non-default port in the host value.

js
nock.removeInterceptor({ host: 'localhost', path: '/mockedResource' })

nock.removeInterceptor({
  host: 'localhost',
  path: '/login',
  method: 'POST',
  proto: 'https',
})

nock.removeInterceptor() returns true when the origin has interceptors and false when it has none. Note that it also returns true when the origin has interceptors but none matched the descriptor, so do not rely on the result to confirm a removal. .reply() returns the scope, not the interceptor, so keep the interceptor reference before calling .reply() if you need to remove it later.

Clone a Scope ​

Use scope.clone() to create a new scope with the same base URL and scope options:

js
const scope = nock('http://example.test')
const getScope = scope.get('/').reply(200)
const postScope = scope.clone().post('/').reply(200)

Disable Nock with NOCK_OFF ​

You can bypass Nock completely by setting the NOCK_OFF environment variable to "true" before Nock is imported.

This way you can have your tests hit the real servers just by switching on this environment variable.

sh
NOCK_OFF=true node my_test.js

Control Real Network Requests ​

By default, any requests made to a host that is not mocked will be executed normally. If you want to block these requests, nock allows you to do so.

Disable Network Connections ​

For disabling real http requests.

js
nock.disableNetConnect()

So, if you try to request any host not 'nocked', it will fail with a NetConnectNotAllowedError. Its message includes the host, port, and path.

js
nock.disableNetConnect()
const req = http.get('http://google.com/')
req.on('error', err => {
  console.log(err)
})
// The returned `http.ClientRequest` will emit an error event (or throw if you're not listening for it)
// This code will log a NetConnectNotAllowedError with message:
// Nock: Disallowed net connect for "google.com:80/"

With fetch, the rejection is a TypeError: fetch failed whose cause is the NetConnectNotAllowedError.

Allow Network Connections ​

For enabling any real HTTP requests (the default behavior):

js
nock.enableNetConnect()

You could allow real HTTP requests for certain host names by providing a string or a regular expression for the hostname, or a function that accepts the hostname and returns true or false. A string is converted to a regular expression, so it matches as a substring of host:port:

js
// Using a string
nock.enableNetConnect('amazon.com')

// Or a RegExp
nock.enableNetConnect(/(amazon|github)\.com/)

// Or a Function
nock.enableNetConnect(
  host => host.includes('amazon.com') || host.includes('github.com'),
)

http.get('http://www.amazon.com/')
http.get('http://github.com/')

http.get('http://google.com/')
// This will throw NetConnectNotAllowedError with message:
// Nock: Disallowed net connect for "google.com:80/"

A common use case when testing local endpoints would be to disable all but localhost, then add in additional nocks for external requests:

js
nock.disableNetConnect()
// Allow localhost connections so we can test local routes and mock servers.
nock.enableNetConnect('127.0.0.1')

Reset Network Rules ​

When you're done with the test, you probably want to set everything back to normal:

js
nock.cleanAll()
nock.enableNetConnect()