fix(server): use setMaxListeners(0) on all internal event emitters (#5283)

src/server/android/android.ts

@@ -119,6 +119,7 @@ export class AndroidDevice extends EventEmitter {
 
   constructor(android: Android, backend: DeviceBackend, model: string) {
     super();
+    this.setMaxListeners(0);
     this._android = android;
     this._backend = backend;
     this.model = model;
@@ -385,6 +386,7 @@ class AndroidBrowser extends EventEmitter {
 
   constructor(device: AndroidDevice, socket: SocketBackend) {
     super();
+    this.setMaxListeners(0);
     this.device = device;
     this._socket = socket;
     this._socket.on('close', () => {

src/server/android/backendAdb.ts

@@ -109,6 +109,7 @@ class BufferedSocketWrapper extends EventEmitter implements SocketBackend {
 
   constructor(command: string, socket: net.Socket) {
     super();
+    this.setMaxListeners(0);
     this._command = command;
     this._socket = socket;
     this._connectPromise = new Promise(f => this._socket.on('connect', f));

src/server/browser.ts

@@ -61,6 +61,7 @@ export abstract class Browser extends EventEmitter {
 
   constructor(options: BrowserOptions) {
     super();
+    this.setMaxListeners(0);
     this.options = options;
   }
 

src/server/browserContext.ts

@@ -123,6 +123,7 @@ export abstract class BrowserContext extends EventEmitter {
 
   constructor(browser: Browser, options: types.BrowserContextOptions, browserContextId: string | undefined) {
     super();
+    this.setMaxListeners(0);
     this._browser = browser;
     this._options = options;
     this._browserContextId = browserContextId;

src/server/chromium/crConnection.ts

@@ -43,6 +43,7 @@ export class CRConnection extends EventEmitter {
 
   constructor(transport: ConnectionTransport, protocolLogger: ProtocolLogger, browserLogsCollector: RecentLogsCollector) {
     super();
+    this.setMaxListeners(0);
     this._transport = transport;
     this._protocolLogger = protocolLogger;
     this._browserLogsCollector = browserLogsCollector;
@@ -139,6 +140,7 @@ export class CRSession extends EventEmitter {
 
   constructor(connection: CRConnection, rootSessionId: string, targetType: string, sessionId: string) {
     super();
+    this.setMaxListeners(0);
     this._connection = connection;
     this._rootSessionId = rootSessionId;
     this._targetType = targetType;

src/server/electron/electron.ts

@@ -65,6 +65,7 @@ export class ElectronApplication extends EventEmitter {
 
   constructor(browser: CRBrowser, nodeConnection: CRConnection) {
     super();
+    this.setMaxListeners(0);
     this._browserContext = browser._defaultContext as CRBrowserContext;
     this._browserContext.on(BrowserContext.Events.Close, () => {
       // Emit application closed after context closed.

src/server/firefox/ffConnection.ts

@@ -49,6 +49,7 @@ export class FFConnection extends EventEmitter {
 
   constructor(transport: ConnectionTransport, protocolLogger: ProtocolLogger, browserLogsCollector: RecentLogsCollector) {
     super();
+    this.setMaxListeners(0);
     this._transport = transport;
     this._protocolLogger = protocolLogger;
     this._browserLogsCollector = browserLogsCollector;
@@ -162,6 +163,7 @@ export class FFSession extends EventEmitter {
 
   constructor(connection: FFConnection, targetType: string, sessionId: string, rawSend: (message: any) => void) {
     super();
+    this.setMaxListeners(0);
     this._callbacks = new Map();
     this._connection = connection;
     this._targetType = targetType;

src/server/network.ts

@@ -355,6 +355,7 @@ export class WebSocket extends EventEmitter {
 
   constructor(url: string) {
     super();
+    this.setMaxListeners(0);
     this._url = url;
   }
 

src/server/page.ts

@@ -508,6 +508,7 @@ export class Worker extends EventEmitter {
 
   constructor(url: string) {
     super();
+    this.setMaxListeners(0);
     this._url = url;
     this._executionContextCallback = () => {};
     this._executionContextPromise = new Promise(x => this._executionContextCallback = x);

src/server/supplements/recorder/recorderApp.ts

@@ -28,11 +28,11 @@ import { DEFAULT_ARGS } from '../../chromium/chromium';
 const readFileAsync = util.promisify(fs.readFile);
 
 export class RecorderApp extends EventEmitter {
-
   private _page: Page;
 
   constructor(page: Page) {
     super();
+    this.setMaxListeners(0);
     this._page = page;
   }
 

src/server/webkit/wkConnection.ts

@@ -111,6 +111,7 @@ export class WKSession extends EventEmitter {
 
   constructor(connection: WKConnection, sessionId: string, errorText: string, rawSend: (message: any) => void) {
     super();
+    this.setMaxListeners(0);
     this.connection = connection;
     this.sessionId = sessionId;
     this._rawSend = rawSend;

test/browsertype-connect.spec.ts

@@ -256,4 +256,18 @@ describe('connect', (suite, { mode }) => {
     const files = fs.readdirSync(videosPath);
     expect(files.some(file => file.endsWith('webm'))).toBe(true);
   });
+
+  it('should be able to connect 20 times to a single server without warnings', async ({browserType, remoteServer, server}) => {
+    let warning = null;
+    const warningHandler = w => warning = w;
+    process.on('warning', warningHandler);
+
+    const browsers = [];
+    for (let i = 0; i < 20; i++)
+      browsers.push(await browserType.connect({ wsEndpoint: remoteServer.wsEndpoint() }));
+    await Promise.all([browsers.map(browser => browser.close())]);
+
+    process.off('warning', warningHandler);
+    expect(warning).toBe(null);
+  });
 });