From 97aaa12be46f211d94559c8dcadc33052c45bac2 Mon Sep 17 00:00:00 2001
From: Simon Knott <info@simonknott.de>
Date: Mon, 7 Oct 2024 18:43:25 +0200
Subject: [PATCH] cherry-pick(#32956): fix(fetch): listener leaks on Socket

Closes https://github.com/microsoft/playwright/issues/32951

`node:http` reuses TCP Sockets under the hood. We weren't cleaning up
our listeners, leading to the `MaxListenersExceededWarning`.

This PR adds cleanup logic. It also raises the warning threshhold, so
that it doesn't trigger until there's 100 concurrent requests over the
same socket.
---
 packages/playwright-core/src/server/fetch.ts | 52 +++++++++++---------
 1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/packages/playwright-core/src/server/fetch.ts b/packages/playwright-core/src/server/fetch.ts
index f07f8c63f343c..9505dab28fded 100644
--- a/packages/playwright-core/src/server/fetch.ts
+++ b/packages/playwright-core/src/server/fetch.ts
@@ -25,7 +25,7 @@ import zlib from 'zlib';
 import type { HTTPCredentials } from '../../types/types';
 import { TimeoutSettings } from '../common/timeoutSettings';
 import { getUserAgent } from '../utils/userAgent';
-import { assert, createGuid, monotonicTime } from '../utils';
+import { assert, createGuid, eventsHelper, monotonicTime, type RegisteredListener } from '../utils';
 import { HttpsProxyAgent, SocksProxyAgent } from '../utilsBundle';
 import { BrowserContext, verifyClientCertificates } from './browserContext';
 import { CookieStore, domainMatches, parseRawCookie } from './cookieStore';
@@ -312,8 +312,11 @@ export abstract class APIRequestContext extends SdkObject {
 
       let securityDetails: har.SecurityDetails | undefined;
 
+      const listeners: RegisteredListener[] = [];
+
       const request = requestConstructor(url, requestOptions as any, async response => {
         const responseAt = monotonicTime();
+
         const notifyRequestFinished = (body?: Buffer) => {
           const endAt = monotonicTime();
           // spec: http://www.softwareishard.com/blog/har-12-spec/#timings
@@ -478,12 +481,13 @@ export abstract class APIRequestContext extends SdkObject {
       });
       request.on('error', reject);
 
-      const disposeListener = () => {
-        reject(new Error('Request context disposed.'));
-        request.destroy();
-      };
-      this.on(APIRequestContext.Events.Dispose, disposeListener);
-      request.on('close', () => this.off(APIRequestContext.Events.Dispose, disposeListener));
+      listeners.push(
+          eventsHelper.addEventListener(this, APIRequestContext.Events.Dispose, () => {
+            reject(new Error('Request context disposed.'));
+            request.destroy();
+          })
+      );
+      request.on('close', () => eventsHelper.removeEventListeners(listeners));
 
       request.on('socket', socket => {
         // happy eyeballs don't emit lookup and connect events, so we use our custom ones
@@ -492,22 +496,24 @@ export abstract class APIRequestContext extends SdkObject {
         tcpConnectionAt = happyEyeBallsTimings.tcpConnectionAt;
 
         // non-happy-eyeballs sockets
-        socket.on('lookup', () => { dnsLookupAt = monotonicTime(); });
-        socket.on('connect', () => { tcpConnectionAt = monotonicTime(); });
-        socket.on('secureConnect', () => {
-          tlsHandshakeAt = monotonicTime();
-
-          if (socket instanceof TLSSocket) {
-            const peerCertificate = socket.getPeerCertificate();
-            securityDetails = {
-              protocol: socket.getProtocol() ?? undefined,
-              subjectName: peerCertificate.subject.CN,
-              validFrom: new Date(peerCertificate.valid_from).getTime() / 1000,
-              validTo: new Date(peerCertificate.valid_to).getTime() / 1000,
-              issuer: peerCertificate.issuer.CN
-            };
-          }
-        });
+        listeners.push(
+            eventsHelper.addEventListener(socket, 'lookup', () => { dnsLookupAt = monotonicTime(); }),
+            eventsHelper.addEventListener(socket, 'connect', () => { tcpConnectionAt = monotonicTime(); }),
+            eventsHelper.addEventListener(socket, 'secureConnect', () => {
+              tlsHandshakeAt = monotonicTime();
+
+              if (socket instanceof TLSSocket) {
+                const peerCertificate = socket.getPeerCertificate();
+                securityDetails = {
+                  protocol: socket.getProtocol() ?? undefined,
+                  subjectName: peerCertificate.subject.CN,
+                  validFrom: new Date(peerCertificate.valid_from).getTime() / 1000,
+                  validTo: new Date(peerCertificate.valid_to).getTime() / 1000,
+                  issuer: peerCertificate.issuer.CN
+                };
+              }
+            }),
+        );
 
         serverIPAddress = socket.remoteAddress;
         serverPort = socket.remotePort;