fix: Replace request.abort with response.close in HTTP instrumentation

lib/instrumentation/core/http.js

@@ -146,7 +146,7 @@ function wrapEmitWithTransaction(agent, emit, isHTTPS) {
     function instrumentedFinish() {
       // Remove listeners so this doesn't get called twice.
       response.removeListener('finish', instrumentedFinish)
-      request.removeListener('aborted', instrumentedFinish)
+      response.removeListener('close', instrumentedFinish)
 
       // Naming must happen before the segment and transaction are ended,
       // because metrics recording depends on naming's side effects.
@@ -188,7 +188,8 @@ function wrapEmitWithTransaction(agent, emit, isHTTPS) {
       transaction.end()
     }
     response.once('finish', instrumentedFinish)
-    request.once('aborted', instrumentedFinish)
+    // Used to detect if client has prematurely disconnected, which works in all Node.js versions currently supported (14/16/18)
+    response.once('close', instrumentedFinish)
 
     return tracer.bindFunction(emit, segment).apply(this, arguments)
   })

test/versioned/express/client-disconnect.tap.js

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const fork = require('child_process').fork
+const tap = require('tap')
+const helper = require('../../lib/agent_helper')
+const metrics = require('../../lib/metrics_helper')
+
+function generateApp() {
+  const express = require('express')
+  const bodyParser = require('body-parser')
+
+  const app = express()
+  app.use(bodyParser.json())
+
+  app.post('/test', async function controller(req, res) {
+    try {
+      await new Promise((resolve) =>
+        setTimeout(() => {
+          resolve()
+        }, req.body.timeout)
+      )
+
+      res.status(200).send('OK')
+    } catch (err) {
+      res.status(500).send('Err')
+    }
+  })
+
+  return app
+}
+
+tap.test('Client Premature Disconnection', (t) => {
+  t.setTimeout(3000)
+  const agent = helper.instrumentMockedAgent()
+  const server = generateApp().listen(0)
+  const { port } = server.address()
+
+  t.teardown(() => {
+    server.close()
+    helper.unloadAgent(agent)
+  })
+
+  agent.on('transactionFinished', (transaction) => {
+    t.doesNotThrow(function () {
+      metrics.assertSegments(
+        transaction.trace.root,
+        [
+          'WebTransaction/Expressjs/POST//test',
+          [
+            'Nodejs/Middleware/Expressjs/query',
+            'Nodejs/Middleware/Expressjs/expressInit',
+            'Nodejs/Middleware/Expressjs/jsonParser',
+            'Expressjs/Route Path: /test',
+            ['Nodejs/Middleware/Expressjs/controller', ['timers.setTimeout']]
+          ]
+        ],
+        { exact: true }
+      )
+    }, 'should have expected segments')
+
+    t.equal(agent.getTransaction(), null, 'should have ended the transaction')
+    t.end()
+  })
+
+  const forkedRequest = fork(`${__dirname}/helpers/request.js`)
+  forkedRequest.send(port)
+})

test/versioned/express/helpers/request.js

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+// Polyfill till we drop support for Node 14
+const { AbortController } = require('node-abort-controller')
+const axios = require('axios')
+
+process.on('message', (port) => {
+  const controller = new AbortController()
+  axios
+    .post(`http://localhost:${port}/test`, { timeout: 1500 }, { signal: controller.signal })
+    .catch(() => {
+      // eslint-disable-next-line no-process-exit
+      process.exit()
+    })
+
+  setTimeout(() => {
+    controller.abort()
+  }, 100)
+})

test/versioned/express/package.json

@@ -10,13 +10,16 @@
       "dependencies": {
         "express": ">=4.6.0",
         "express-enrouten": "1.1",
-        "ejs": "2.5.9"
+        "ejs": "2.5.9",
+        "axios": "^1.3.3",
+        "node-abort-controller": "^3.1.1"
       },
       "files": [
         "app-use.tap.js",
         "async-error.tap.js",
         "bare-router.tap.js",
         "captures-params.tap.js",
+        "client-disconnect.tap.js",
         "errors.tap.js",
         "express-enrouten.tap.js",
         "ignoring.tap.js",