fix: WebSocket Connection Closed crashing from BrowserCriClient

cli/CHANGELOG.md

@@ -1,4 +1,12 @@
 <!-- See the ../guides/writing-the-cypress-changelog.md for details on writing the changelog. -->
+## 13.14.2
+
+_Released 9/10/2024 (PENDING)_
+
+**Bugfixes:**
+
+- Fixed an issue where Cypress could crash with a `WebSocket Connection Closed` error. Fixes [#30100](https://github.com/cypress-io/cypress/issues/30100).
+
 ## 13.14.1
 
 _Released 8/29/2024_

packages/server/lib/browsers/browser-cri-client.ts

@@ -403,7 +403,10 @@ export class BrowserCriClient {
 
     browserCriClient.addExtraTargetClient(targetInfo, extraTargetCriClient)
 
-    await extraTargetCriClient.send('Fetch.enable')
+    await extraTargetCriClient.send('Fetch.enable').catch((err) => {
+      // swallow this error so it doesn't crash Cypress
+      debug('Fetch.enable failed on extra target#%s: %s', targetId, err)
+    })
 
     // we mark extra targets with this header, so that the proxy can recognize
     // where they came from and run only the minimal middleware necessary

packages/server/test/unit/browsers/browser-cri-client_spec.ts

@@ -278,6 +278,20 @@ describe('lib/browsers/browser-cri-client', function () {
       expect(options.browserClient.send).to.be.calledWith('Runtime.runIfWaitingForDebugger', undefined, 'session-id')
     })
 
+    it('does not throw if Fetch.enable on extra target throws', async () => {
+      const extraTargetCriClient = {
+        send: sinon.stub().withArgs('Fetch.enable').rejects('Fetch.enable failed'),
+        on: sinon.stub(),
+      }
+
+      options.CriConstructor.resolves(extraTargetCriClient)
+
+      options.browserClient.send.withArgs('Fetch.enable').resolves()
+      options.browserClient.send.withArgs('Runtime.runIfWaitingForDebugger').resolves()
+
+      expect(BrowserCriClient._onAttachToTarget(options as any)).to.be.fulfilled
+    })
+
     it('adds the service worker fetch event binding', async () => {
       options.event.targetInfo.type = 'service_worker'