nock · markgmilner · Mar 23, 2023
diff --git a/README.md b/README.md
@@ -19,81 +19,83 @@ For instance, if a module performs HTTP requests to a CouchDB server or makes HT
 
 <!-- toc -->
 
-- [How does it work?](#how-does-it-work)
-- [Install](#install)
-  - [Node version support](#node-version-support)
-- [Usage](#usage)
-  - [READ THIS! - About interceptors](#read-this---about-interceptors)
-  - [Specifying hostname](#specifying-hostname)
-  - [Specifying path](#specifying-path)
-  - [Specifying request body](#specifying-request-body)
-  - [Specifying request query string](#specifying-request-query-string)
-  - [Specifying replies](#specifying-replies)
-    - [Access original request and headers](#access-original-request-and-headers)
-    - [Replying with errors](#replying-with-errors)
-  - [Specifying headers](#specifying-headers)
-    - [Header field names are case-insensitive](#header-field-names-are-case-insensitive)
-    - [Specifying Request Headers](#specifying-request-headers)
-    - [Specifying Reply Headers](#specifying-reply-headers)
-    - [Default Reply Headers](#default-reply-headers)
-    - [Including Content-Length Header Automatically](#including-content-length-header-automatically)
-    - [Including Date Header Automatically](#including-date-header-automatically)
-  - [HTTP Verbs](#http-verbs)
-  - [Support for HTTP and HTTPS](#support-for-http-and-https)
-  - [Non-standard ports](#non-standard-ports)
-  - [Repeat response n times](#repeat-response-n-times)
-  - [Delay the response](#delay-the-response)
-    - [Delay the connection](#delay-the-connection)
-      - [Technical Details](#technical-details)
-    - [Delay the response body](#delay-the-response-body)
-      - [Technical Details](#technical-details-1)
-  - [Chaining](#chaining)
-  - [Scope filtering](#scope-filtering)
-  - [Conditional scope filtering](#conditional-scope-filtering)
-  - [Path filtering](#path-filtering)
-  - [Request Body filtering](#request-body-filtering)
-  - [Request Headers Matching](#request-headers-matching)
-  - [Optional Requests](#optional-requests)
-  - [Allow **unmocked** requests on a mocked hostname](#allow-unmocked-requests-on-a-mocked-hostname)
-- [Expectations](#expectations)
-  - [.isDone()](#isdone)
-  - [.cleanAll()](#cleanall)
-  - [.abortPendingRequests()](#abortpendingrequests)
-  - [.persist()](#persist)
-  - [.pendingMocks()](#pendingmocks)
-  - [.activeMocks()](#activemocks)
-  - [.isActive()](#isactive)
-- [Restoring](#restoring)
-- [Activating](#activating)
-- [Turning Nock Off (experimental!)](#turning-nock-off-experimental)
-- [Enable/Disable real HTTP requests](#enabledisable-real-http-requests)
-  - [Disabling requests](#disabling-requests)
-  - [Enabling requests](#enabling-requests)
-  - [Resetting NetConnect](#resetting-netconnect)
-- [Recording](#recording)
-  - [`dont_print` option](#dont_print-option)
-  - [`output_objects` option](#output_objects-option)
-  - [`enable_reqheaders_recording` option](#enable_reqheaders_recording-option)
-  - [`logging` option](#logging-option)
-  - [`use_separator` option](#use_separator-option)
-  - [.removeInterceptor()](#removeinterceptor)
-- [Events](#events)
-  - [Global no match event](#global-no-match-event)
-- [Nock Back](#nock-back)
-  - [Setup](#setup)
-    - [Options](#options)
-  - [Usage](#usage-1)
-    - [Options](#options-1)
-      - [Example](#example)
-  - [Modes](#modes)
-- [Common issues](#common-issues)
-  - [Axios](#axios)
-  - [Memory issues with Jest](#memory-issues-with-jest)
-- [Debugging](#debugging)
-- [Contributing](#contributing)
-- [Contributors](#contributors)
-- [Sponsors](#sponsors)
-- [License](#license)
+- [Nock](#nock)
+  - [How does it work?](#how-does-it-work)
+  - [Install](#install)
+    - [Node version support](#node-version-support)
+  - [Usage](#usage)
+    - [READ THIS! - About interceptors](#read-this---about-interceptors)
+    - [Specifying hostname](#specifying-hostname)
+    - [Specifying path](#specifying-path)
+    - [Specifying request body](#specifying-request-body)
+    - [Specifying request query string](#specifying-request-query-string)
+    - [Specifying replies](#specifying-replies)
+      - [Access original request and headers](#access-original-request-and-headers)
+      - [Replying with errors](#replying-with-errors)
+    - [Specifying headers](#specifying-headers)
+      - [Header field names are case-insensitive](#header-field-names-are-case-insensitive)
+      - [Specifying Request Headers](#specifying-request-headers)
+      - [Specifying Reply Headers](#specifying-reply-headers)
+      - [Default Reply Headers](#default-reply-headers)
+      - [Including Content-Length Header Automatically](#including-content-length-header-automatically)
+      - [Including Date Header Automatically](#including-date-header-automatically)
+    - [HTTP Verbs](#http-verbs)
+    - [Support for HTTP and HTTPS](#support-for-http-and-https)
+    - [Non-standard ports](#non-standard-ports)
+    - [Repeat response n times](#repeat-response-n-times)
+    - [Delay the response](#delay-the-response)
+      - [Delay the connection](#delay-the-connection)
+        - [Technical Details](#technical-details)
+      - [Delay the response body](#delay-the-response-body)
+        - [Technical Details](#technical-details-1)
+    - [Chaining](#chaining)
+    - [Scope filtering](#scope-filtering)
+    - [Conditional scope filtering](#conditional-scope-filtering)
+    - [Path filtering](#path-filtering)
+    - [Request Body filtering](#request-body-filtering)
+    - [Request Headers Matching](#request-headers-matching)
+    - [Optional Requests](#optional-requests)
+    - [Allow **unmocked** requests on a mocked hostname](#allow-unmocked-requests-on-a-mocked-hostname)
+  - [Expectations](#expectations)
+    - [.isDone()](#isdone)
+    - [.cleanAll()](#cleanall)
+    - [.abortPendingRequests()](#abortpendingrequests)
+    - [.persist()](#persist)
+    - [.pendingMocks()](#pendingmocks)
+    - [.activeMocks()](#activemocks)
+    - [.isActive()](#isactive)
+  - [Restoring](#restoring)
+  - [Activating](#activating)
+  - [Turning Nock Off (experimental!)](#turning-nock-off-experimental)
+  - [Enable/Disable real HTTP requests](#enabledisable-real-http-requests)
+    - [Disabling requests](#disabling-requests)
+    - [Enabling requests](#enabling-requests)
+    - [Resetting NetConnect](#resetting-netconnect)
+  - [Recording](#recording)
+    - [`dont_print` option](#dont_print-option)
+    - [`allow_mocked` option](#allow_mocked-option)
+    - [`output_objects` option](#output_objects-option)
+    - [`enable_reqheaders_recording` option](#enable_reqheaders_recording-option)
+    - [`logging` option](#logging-option)
+    - [`use_separator` option](#use_separator-option)
+    - [.removeInterceptor()](#removeinterceptor)
+  - [Events](#events)
+    - [Global no match event](#global-no-match-event)
+  - [Nock Back](#nock-back)
+    - [Setup](#setup)
+      - [Options](#options)
+    - [Usage](#usage-1)
+      - [Options](#options-1)
+        - [Example](#example)
+    - [Modes](#modes)
+  - [Common issues](#common-issues)
+    - [Axios](#axios)
+    - [Memory issues with Jest](#memory-issues-with-jest)
+  - [Debugging](#debugging)
+  - [Contributing](#contributing)
+  - [Contributors](#contributors)
+  - [Sponsors](#sponsors)
+  - [License](#license)
 
 <!-- tocstop -->
 
@@ -1185,8 +1187,6 @@ Recording relies on intercepting real requests and responses and then persisting
 
 In order to stop recording you should call `nock.restore()` and recording will stop.
 
-**ATTENTION!:** when recording is enabled, nock does no validation, nor will any mocks be enabled. Please be sure to turn off recording before attempting to use any mocks in your tests.
-
 ### `dont_print` option
 
 If you just want to capture the generated code into a var as an array you can use:
@@ -1205,6 +1205,29 @@ Copy and paste that code into your tests, customize at will, and you're done! Yo
 
 (Remember that you should do this one test at a time).
 
+### `allow_mocked` option
+
+By default, when recording is enabled, nock does no validation, nor will any mocks be enabled. Please be sure to turn off recording before attempting to use any mocks in your tests.
+
+If you want to intercept and return recorded responses for some requests, you can use:
+
+```js
+nock.recorder.rec({
+  allow_mocked: true,
+  dont_print: true,
+})
+nock('http://example.com')
+  .get('/resource')
+  .reply(200, 'override')
+// Http request to 'http://example.com/resource'
+// Http request to 'http://example.com/resource2'
+const nockCalls = nock.recorder.play()
+```
+
+The `nockCalls` var will only record the non-mocked http requests (i.e. `/resource2`). Calls to matched mocked requests will return the mocked response and will not be recorded.
+
+This is useful when you want your tests to use specific responses for certain requests but to record the rest.
+
 ### `output_objects` option
 
 In case you want to generate the code yourself or use the test data in some other way, you can pass the `output_objects` option to `rec`:

diff --git a/lib/intercept.js b/lib/intercept.js
@@ -437,6 +437,7 @@ module.exports = {
   addInterceptor,
   remove,
   removeAll,
+  interceptorsFor,
   removeInterceptor,
   isOn,
   activate,
@@ -446,6 +447,7 @@ module.exports = {
   activeMocks,
   enableNetConnect,
   disableNetConnect,
+  overrideClientRequest,
   restoreOverriddenClientRequest,
   abortPendingRequests: common.removeAllTimers,
 }
diff --git a/lib/recorder.js b/lib/recorder.js
@@ -1,11 +1,12 @@
 'use strict'
 
 const debug = require('debug')('nock.recorder')
+const http = require('http')
 const querystring = require('querystring')
 const { inspect } = require('util')
 
 const common = require('./common')
-const { restoreOverriddenClientRequest } = require('./intercept')
+const { restoreOverriddenClientRequest, interceptorsFor, isOn, overrideClientRequest } = require('./intercept')
 
 const SEPARATOR = '\n<<<<<<-- cut here -->>>>>>\n'
 let recordingInProgress = false
@@ -166,6 +167,7 @@ function generateRequestAndResponse({
 let currentRecordingId = 0
 
 const defaultRecordOptions = {
+  allow_mocked: false,
   dont_print: false,
   enable_reqheaders_recording: false,
   logging: console.log, // eslint-disable-line no-console
@@ -198,6 +200,7 @@ function record(recOptions) {
   debug('start recording', thisRecordingId, recOptions)
 
   const {
+    allow_mocked: allowMocked,
     dont_print: dontPrint,
     enable_reqheaders_recording: enableReqHeadersRecording,
     logging,
@@ -211,8 +214,14 @@ function record(recOptions) {
   //  NOTE: This is hacky as hell but it keeps the backward compatibility *and* allows correct
   //    behavior in the face of other modules also overriding ClientRequest.
   common.restoreOverriddenRequests()
-  //  We restore ClientRequest as it messes with recording of modules that also override ClientRequest (e.g. xhr2)
-  restoreOverriddenClientRequest()
+
+  if (allowMocked) {
+    //  We override the client request so we can intercept and return recording when matched.
+    overrideClientRequest();
+  } else {
+    //  We restore ClientRequest as it messes with recording of modules that also override ClientRequest (e.g. xhr2)
+    restoreOverriddenClientRequest()
+  }
 
   //  We override the requests so that we can save information on them before executing.
   common.overrideRequests(function (proto, overriddenRequest, rawArgs) {
@@ -227,6 +236,21 @@ function record(recOptions) {
     }
     options._recording = true
 
+    //  If we allow mocks in recording mode and the request matches, return the
+    //  recorded reply.
+    if (isOn() && allowMocked) {
+      options.proto = proto
+
+      const interceptors = interceptorsFor(options)
+
+      if (interceptors && interceptors.some(interceptor => interceptor.matchOrigin(options))) {
+        debug(thisRecordingId, 'matched mocked request')
+        //  NOTE: Since we already overrode the http.ClientRequest we are in
+        //    fact constructing our own OverriddenClientRequest.
+        return new http.ClientRequest(options, callback)
+      }
+    }
+
     const req = overriddenRequest(options, function (res) {
       debug(thisRecordingId, 'intercepting', proto, 'request to record')
 

diff --git a/tests/test_recorder.js b/tests/test_recorder.js
@@ -1261,4 +1261,46 @@ describe('Recorder', () => {
       req.end()
     })
   })
+
+  it('allows mocks', async () => {
+    const exampleText = '<html><body>example</body></html>'
+    const exampleTextOverride = '<html><body>example override</body></html>'
+
+    const { origin } = await servers.startHttpServer((request, response) => {
+      switch (require('url').parse(request.url).pathname) {
+        case '/abc':
+          response.write(exampleText)
+          break
+        case '/xyz':
+          response.write(exampleText)
+          break
+      }
+      response.end()
+    })
+
+    nock.restore()
+    nock.recorder.clear()
+    expect(nock.recorder.play()).to.be.empty()
+
+    nock.recorder.rec({
+      allow_mocked: true,
+      dont_print: true,
+      output_objects: true,
+    })
+
+    // Override /xyz to return a different response.
+    nock(origin).get('/xyz').reply(200, exampleTextOverride)
+    expect(nock.activeMocks()).to.have.lengthOf(1)
+
+    const response1 = await got(`${origin}/abc`)
+    expect(response1.body).to.equal(exampleText)
+
+    const response2 = await got(`${origin}/xyz`)
+    expect(response2.body).to.equal(exampleTextOverride)
+
+    // Expect only the non-overridden request to be recorded.
+    const recorded = nock.recorder.play()
+    expect(recorded).to.have.lengthOf(1)
+    expect(recorded[0].path).to.equal('/abc');
+  })
 })
diff --git a/types/index.d.ts b/types/index.d.ts
@@ -220,6 +220,7 @@ declare namespace nock {
   }
 
   interface RecorderOptions {
+    allow_mocked?: boolean
     dont_print?: boolean
     output_objects?: boolean
     enable_reqheaders_recording?: boolean