chore: detect document open for inspector (#9901)

To be used later for other global event listeners.

packages/playwright-core/src/server/injected/injectedScript.ts

@@ -67,6 +67,7 @@ export class InjectedScript {
   _evaluator: SelectorEvaluatorImpl;
   private _stableRafCount: number;
   private _browserName: string;
+  onGlobalListenersRemoved = new Set<() => void>();
 
   constructor(stableRafCount: number, browserName: string, customEngines: { name: string, engine: SelectorEngine}[]) {
     this._evaluator = new SelectorEvaluatorImpl(new Map());
@@ -95,6 +96,8 @@ export class InjectedScript {
 
     this._stableRafCount = stableRafCount;
     this._browserName = browserName;
+
+    this._setupGlobalListenersRemovalDetection();
   }
 
   eval(expression: string): any {
@@ -769,6 +772,31 @@ export class InjectedScript {
     return error;
   }
 
+  private _setupGlobalListenersRemovalDetection() {
+    const customEventName = '__playwright_global_listeners_check__';
+
+    let seenEvent = false;
+    const handleCustomEvent = () => seenEvent = true;
+    window.addEventListener(customEventName, handleCustomEvent);
+
+    new MutationObserver(entries => {
+      const newDocumentElement = entries.some(entry => Array.from(entry.addedNodes).includes(document.documentElement));
+      if (!newDocumentElement)
+        return;
+
+      // New documentElement - let's check whether listeners are still here.
+      seenEvent = false;
+      window.dispatchEvent(new CustomEvent(customEventName));
+      if (seenEvent)
+        return;
+
+      // Listener did not fire. Reattach the listener and notify.
+      window.addEventListener(customEventName, handleCustomEvent);
+      for (const callback of this.onGlobalListenersRemoved)
+        callback();
+    }).observe(document, { childList: true });
+  }
+
   expect(progress: InjectedScriptProgress, element: Element, options: FrameExpectParams, elements: Element[]): { matches: boolean, received?: any } {
     const injected = progress.injectedScript;
     const expression = options.expression;

packages/playwright-core/src/server/supplements/injected/recorder.ts

@@ -116,17 +116,14 @@ export class Recorder {
     this._glassPaneShadow.appendChild(styleElement);
 
     this._refreshListenersIfNeeded();
-    setInterval(() => {
+    injectedScript.onGlobalListenersRemoved.add(() => this._refreshListenersIfNeeded());
-      this._refreshListenersIfNeeded();
+
-      if (params.isUnderTest && !(this as any)._reportedReadyForTest) {
-        (this as any)._reportedReadyForTest = true;
-        console.error('Recorder script ready for test');
-      }
-    }, 500);
     globalThis._playwrightRefreshOverlay = () => {
       this._pollRecorderMode().catch(e => console.log(e)); // eslint-disable-line no-console
     };
     globalThis._playwrightRefreshOverlay();
+    if (params.isUnderTest)
+      console.error('Recorder script ready for test');
   }
 
   private _refreshListenersIfNeeded() {