Core: Handle WebSocket errors so a bad frame can't crash the dev server

code/core/src/core-server/utils/__tests__/server-channel.test.ts

@@ -713,4 +713,13 @@ describe('ServerChannelTransport', () => {
       expect(handleUpgradeSpy).not.toHaveBeenCalled();
     });
   });
+
+  it('does not crash when a socket emits an error', () => {
+    const server = new EventEmitter() as any as Server;
+    const transport = createTransport(server);
+
+    const socket = connectClient(server, transport, 'manager');
+
+    expect(() => socket.emit('error', new Error('Max payload size exceeded'))).not.toThrow();
+  });
 });

code/core/src/core-server/utils/get-server-channel.ts

@@ -125,6 +125,11 @@ export class ServerChannelTransport {
   }
 
   private addClient(ws: WebSocket, role: ChannelClientRole) {
+    ws.on('error', (error) => {
+      // Without a listener, Node crashes on 'error' (e.g. oversized frame). ws closes the socket itself.
+      logger.warn(`WebSocket error on server channel: ${error}`);
+    });
+
     ws.on('message', (raw) => {
       const data = raw.toString();
       const event = typeof data === 'string' && isJSON(data) ? parse(data, {}) : data;