feat: support "CONNECT", socket-based interception

package.json

@@ -122,6 +122,7 @@
     "follow-redirects": "^1.15.1",
     "got": "^11.8.3",
     "happy-dom": "^12.10.3",
+    "hpagent": "^1.2.0",
     "jest": "^27.4.3",
     "node-fetch": "2.6.7",
     "rimraf": "^3.0.2",

proxy.js

@@ -0,0 +1,64 @@
+const http = require('node:http')
+const net = require('node:net')
+const { URL } = require('node:url')
+
+// Create an HTTP tunneling proxy
+const proxy = http.createServer((req, res) => {
+  res.writeHead(200, { 'Content-Type': 'text/plain' })
+  res.end('okay')
+})
+proxy.on('connect', (req, clientSocket, head) => {
+  console.log('\n\nproxy.on(connect)', req.method, req.url, {
+    clientSocket,
+    head: head.toString('utf8'),
+  })
+
+  // Connect to an origin server
+  const { port, hostname } = new URL(`http://${req.url}`)
+  const serverSocket = net.connect(port || 80, hostname, () => {
+    clientSocket.write(
+      'HTTP/1.1 200 Connection Established\r\n' +
+        'Proxy-agent: Node.js-Proxy\r\n' +
+        '\r\n'
+    )
+    serverSocket.write(head)
+    serverSocket.pipe(clientSocket)
+    clientSocket.pipe(serverSocket)
+  })
+})
+
+// Now that proxy is running
+proxy.listen(1337, '127.0.0.1', () => {
+  // Make a request to a tunneling proxy
+  const options = {
+    port: 1337,
+    host: '127.0.0.1',
+    method: 'CONNECT',
+    path: 'www.google.com:80',
+  }
+
+  const req = http.request(options)
+  console.log('req.end()')
+  req.end()
+
+  req.on('connect', (res, socket, head) => {
+    console.log('============='.repeat(10))
+    console.log('\n\n req.on(connect)')
+    console.group({ res, socket, head: head.toString('utf8') })
+    console.log(res.statusCode, res.statusMessage)
+
+    // Make a request over an HTTP tunnel
+    socket.write(
+      'GET / HTTP/1.1\r\n' +
+        'Host: www.google.com:80\r\n' +
+        'Connection: close\r\n' +
+        '\r\n'
+    )
+    socket.on('data', (chunk) => {
+      console.log('incoming chunk...')
+    })
+    socket.on('end', () => {
+      proxy.close()
+    })
+  })
+})

src/interceptors/ClientRequest/NodeClientRequest.ts

@@ -1,4 +1,5 @@
 import { ClientRequest, IncomingMessage } from 'http'
+import { Duplex } from 'stream'
 import type { Logger } from '@open-draft/logger'
 import { until } from '@open-draft/until'
 import { DeferredPromise } from '@open-draft/deferred-promise'
@@ -577,6 +578,25 @@ export class NodeClientRequest extends ClientRequest {
       this.terminate()
 
       this.logger.info('request complete!')
+
+      if (this.method === 'CONNECT') {
+        console.warn('SHOULD EMIT CONNECT', typeof this.response)
+
+        const head = Buffer.from('')
+
+        const socket = new Duplex({
+          read() {},
+          write(chunk, encoding, callback) {
+            console.log(
+              'CONNECT event Duplex write:\n',
+              `== START ==\n${chunk.toString('utf8')}== END ==`
+            )
+            callback()
+          },
+        })
+
+        this.emit('connect', this.response, socket, head)
+      }
     })
   }
 

src/interceptors/ClientRequest/utils/createRequest.ts

@@ -1,4 +1,5 @@
 import type { NodeClientRequest } from '../NodeClientRequest'
+import { FORBIDDEN_REQUEST_METHODS } from '../../../utils/fetchUtils'
 
 /**
  * Creates a Fetch API `Request` instance from the given `http.ClientRequest`.
@@ -26,7 +27,9 @@ export function createRequest(clientRequest: NodeClientRequest): Request {
    * @see https://github.com/mswjs/interceptors/issues/438
    */
   if (clientRequest.url.username || clientRequest.url.password) {
-    const auth = `${clientRequest.url.username || ''}:${clientRequest.url.password || ''}`
+    const auth = `${clientRequest.url.username || ''}:${
+      clientRequest.url.password || ''
+    }`
     headers.set('Authorization', `Basic ${btoa(auth)}`)
 
     // Remove the credentials from the URL since you cannot
@@ -37,13 +40,20 @@ export function createRequest(clientRequest: NodeClientRequest): Request {
 
   const method = clientRequest.method || 'GET'
 
-  return new Request(clientRequest.url, {
-    method,
+  const fetchRequest = new Request(clientRequest.url, {
+    method: FORBIDDEN_REQUEST_METHODS.includes(method)
+      ? `UNSAFE-${method}`
+      : method,
     headers,
     credentials: 'same-origin',
-    body:
-      method === 'HEAD' || method === 'GET'
-        ? null
-        : clientRequest.requestBuffer,
+    body: ['HEAD', 'GET'].includes(method) ? null : clientRequest.requestBuffer,
   })
+
+  if (fetchRequest.method.startsWith('UNSAFE-')) {
+    Object.defineProperty(fetchRequest, 'method', {
+      value: fetchRequest.method.replace('UNSAFE-', ''),
+    })
+  }
+
+  return fetchRequest
 }

src/interceptors/ClientRequest/utils/createResponse.test.ts

@@ -2,7 +2,7 @@ import { it, expect } from 'vitest'
 import { Socket } from 'net'
 import * as http from 'http'
 import { createResponse } from './createResponse'
-import { responseStatusCodesWithoutBody } from '../../../utils/responseUtils'
+import { RESPONSE_STATUS_CODES_WITHOUT_BODY } from '../../../utils/fetchUtils'
 
 it('creates a fetch api response from http incoming message', async () => {
   const message = new http.IncomingMessage(new Socket())
@@ -22,7 +22,7 @@ it('creates a fetch api response from http incoming message', async () => {
   expect(await response.json()).toEqual({ firstName: 'John' })
 })
 
-it.each(responseStatusCodesWithoutBody)(
+it.each(RESPONSE_STATUS_CODES_WITHOUT_BODY)(
   'ignores message body for %i response status',
   (responseStatus) => {
     const message = new http.IncomingMessage(new Socket())

src/interceptors/ClientRequest/utils/createResponse.ts

@@ -1,12 +1,12 @@
 import type { IncomingHttpHeaders, IncomingMessage } from 'http'
-import { responseStatusCodesWithoutBody } from '../../../utils/responseUtils'
+import { RESPONSE_STATUS_CODES_WITHOUT_BODY } from '../../../utils/fetchUtils'
 
 /**
  * Creates a Fetch API `Response` instance from the given
  * `http.IncomingMessage` instance.
  */
 export function createResponse(message: IncomingMessage): Response {
-  const responseBodyOrNull = responseStatusCodesWithoutBody.includes(
+  const responseBodyOrNull = RESPONSE_STATUS_CODES_WITHOUT_BODY.includes(
     message.statusCode || 200
   )
     ? null