fix: catch websocket error events

WebSockets can throw an error event that has to be captured in
node to prevent application crashing.

This seems to be crashing WebKit Linux on some of the bots with the
`ECONNRESET` error:
- https://github.com/microsoft/playwright/runs/544357239

WS-related `ECONNRESET` error discussion:
- websockets/ws#1256

src/server/chromium.ts

@@ -18,7 +18,7 @@
 import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
-import { helper } from '../helper';
+import { debugError, helper } from '../helper';
 import { CRBrowser } from '../chromium/crBrowser';
 import * as platform from '../platform';
 import * as ws from 'ws';
@@ -269,6 +269,8 @@ function wrapTransportWithWebSocket(transport: ConnectionTransport, port: number
       session.queue!.push(parsedMessage);
     });
 
+    socket.on('error', error => debugError(error));
+
     socket.on('close', (socket as any).__closeListener = () => {
       const session = socketToBrowserSession.get(socket);
       if (!session || !session.sessionId)

src/server/firefox.ts

@@ -25,7 +25,7 @@ import { TimeoutError } from '../errors';
 import { Events } from '../events';
 import { FFBrowser } from '../firefox/ffBrowser';
 import { kBrowserCloseMessageId } from '../firefox/ffConnection';
-import { helper } from '../helper';
+import { debugError, helper } from '../helper';
 import * as platform from '../platform';
 import { BrowserServer } from './browserServer';
 import { BrowserArgOptions, BrowserType, LaunchOptions } from './browserType';
@@ -295,6 +295,8 @@ function wrapTransportWithWebSocket(transport: ConnectionTransport, port: number
         pendingBrowserContextDeletions.set(seqNum, params.browserContextId);
     });
 
+    socket.on('error', error => debugError(error));
+
     socket.on('close', (socket as any).__closeListener = () => {
       for (const [browserContextId, s] of browserContextIds) {
         if (s === socket) {

src/server/webkit.ts

@@ -22,7 +22,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as platform from '../platform';
 import * as os from 'os';
-import { helper } from '../helper';
+import { debugError, helper } from '../helper';
 import { kBrowserCloseMessageId } from '../webkit/wkConnection';
 import { LaunchOptions, BrowserArgOptions, BrowserType } from './browserType';
 import { ConnectionTransport, SequenceNumberMixer } from '../transport';
@@ -276,6 +276,8 @@ function wrapTransportWithWebSocket(transport: ConnectionTransport, port: number
         pendingBrowserContextDeletions.set(seqNum, params.browserContextId);
     });
 
+    socket.on('error', error => debugError(error));
+
     socket.on('close', (socket as any).__closeListener = () => {
       for (const [pageProxyId, s] of pageProxyIds) {
         if (s === socket)