fix(playback): consistently check for destroyed attribute (#2152)

Node, as of 14.1, started migrating the Client Request terminology from
`aborted` to `destroyed`. In order to supported our current Node version
support, 10.x+, we need to check both flags. Nock was already doing this
in the router, but not during playback.

lib/common.js

@@ -673,6 +673,34 @@ function removeAllTimers() {
   clearTimer(clearImmediate, immediates)
 }
 
+/**
+ * Check if the Client Request has been cancelled.
+ *
+ * Until Node 14 is the minimum, we need to look at both flags to see if the request has been cancelled.
+ * The two flags have the same purpose, but the Node maintainers are migrating from `abort(ed)` to
+ * `destroy(ed)` terminology, to be more consistent with `stream.Writable`.
+ * In Node 14.x+, Calling `abort()` will set both `aborted` and `destroyed` to true, however,
+ * calling `destroy()` will only set `destroyed` to true.
+ * Falling back on checking if the socket is destroyed to cover the case of Node <14.x where
+ * `destroy()` is called, but `destroyed` is undefined.
+ *
+ * Node Client Request history:
+ * - `request.abort()`: Added in: v0.3.8, Deprecated since: v14.1.0, v13.14.0
+ * - `request.aborted`: Added in: v0.11.14, Became a boolean instead of a timestamp: v11.0.0, Not deprecated (yet)
+ * - `request.destroy()`: Added in: v0.3.0
+ * - `request.destroyed`: Added in: v14.1.0, v13.14.0
+ *
+ * @param {ClientRequest} req
+ * @returns {boolean}
+ */
+function isRequestDestroyed(req) {
+  return !!(
+    req.destroyed === true ||
+    req.aborted ||
+    (req.socket && req.socket.destroyed)
+  )
+}
+
 module.exports = {
   contentEncoding,
   dataEqual,
@@ -686,6 +714,7 @@ module.exports = {
   isContentEncoded,
   isJSONContent,
   isPlainObject,
+  isRequestDestroyed,
   isStream,
   isUtf8Representable,
   mapValue,

lib/intercepted_request_router.js

@@ -103,8 +103,7 @@ class InterceptedRequestRouter {
   connectSocket() {
     const { req, socket } = this
 
-    // Until Node 14 is the minimum, we need to look at both flags to see if the request has been cancelled.
-    if (req.destroyed || req.aborted) {
+    if (common.isRequestDestroyed(req)) {
       return
     }
 
@@ -250,8 +249,7 @@ class InterceptedRequestRouter {
       return
     }
 
-    // Until Node 14 is the minimum, we need to look at both flags to see if the request has been cancelled.
-    if (!req.destroyed && !req.aborted && !playbackStarted) {
+    if (!common.isRequestDestroyed(req) && !playbackStarted) {
       this.startPlayback()
     }
   }

lib/playback_interceptor.js

@@ -293,7 +293,7 @@ function playbackInterceptor({
     const { delayBodyInMs, delayConnectionInMs } = interceptor
 
     function respond() {
-      if (req.aborted) {
+      if (common.isRequestDestroyed(req)) {
         return
       }
 
@@ -318,7 +318,7 @@ function playbackInterceptor({
   // correct events are emitted first ('socket', 'finish') and any aborts in the in the queue or
   // called during a 'finish' listener can be called.
   common.setImmediate(() => {
-    if (!req.aborted) {
+    if (!common.isRequestDestroyed(req)) {
       start()
     }
   })

tests/test_destroy.js

@@ -34,4 +34,20 @@ describe('`res.destroy()`', () => {
         expect.fail('should not emit error')
       })
   })
+
+  it('should not emit an response if destroyed first', done => {
+    nock('http://example.test').get('/').reply()
+
+    const req = http
+      .get('http://example.test/', () => {
+        expect.fail('should not emit a response')
+      })
+      .on('error', () => {}) // listen for error so "socket hang up" doesn't bubble
+      .on('socket', () => {
+        setImmediate(() => req.destroy())
+      })
+
+    // give the `setImmediate` calls enough time to cycle.
+    setTimeout(() => done(), 10)
+  })
 })

tests/test_nock_off.js

@@ -30,7 +30,9 @@ describe('NOCK_OFF env var', () => {
       .get('/')
       .reply(200, 'mock')
 
-    const { body } = await got(origin, { ca: httpsServer.ca })
+    const { body } = await got(origin, {
+      https: { certificateAuthority: httpsServer.ca },
+    })
     expect(body).to.equal(responseBody)
     scope.done()
   })