fix(networkidle): do not produce networkidle event on errored pages (#13938)

packages/playwright-core/src/server/frames.ts

@@ -85,6 +85,8 @@ type SelectorInFrame = {
   info: SelectorInfo;
 };
 
+const kDummyFrameId = '<dummy>';
+
 export class FrameManager {
   private _page: Page;
   private _frames = new Map<string, Frame>();
@@ -99,6 +101,11 @@ export class FrameManager {
     this._mainFrame = undefined as any as Frame;
   }
 
+  createDummyMainFrameIfNeeded() {
+    if (!this._mainFrame)
+      this.frameAttached(kDummyFrameId, null);
+  }
+
   dispose() {
     for (const frame of this._frames.values())
       frame._stopNetworkIdleTimer();
@@ -468,7 +475,8 @@ export class Frame extends SdkObject {
 
     this._firedLifecycleEvents.add('commit');
     this._subtreeLifecycleEvents.add('commit');
-    this._startNetworkIdleTimer();
+    if (id !== kDummyFrameId)
+      this._startNetworkIdleTimer();
   }
 
   isDetached(): boolean {

packages/playwright-core/src/server/page.ts

@@ -587,8 +587,7 @@ export class Page extends SdkObject {
 
   private _setIsError(error: Error) {
     this._pageIsError = error;
-    if (!this._frameManager.mainFrame())
-      this._frameManager.frameAttached('<dummy>', null);
+    this._frameManager.createDummyMainFrameIfNeeded();
   }
 
   isClosed(): boolean {