Bug 2002721 - [webdriver-bidi] Make sure that "script.realmCreated" event is sent after a browser element is attached to a browser context. r=jdescottes

lutien · lutien · commit 47a9b982fe0f · 2025-12-05T11:35:54.000Z
Differential Revision: https://phabricator.services.mozilla.com/D274756
diff --git a/remote/webdriver-bidi/modules/root/browsingContext.sys.mjs b/remote/webdriver-bidi/modules/root/browsingContext.sys.mjs
@@ -1980,6 +1980,15 @@ class BrowsingContextModule extends RootBiDiModule {
         "browsingContext.contextCreated",
         browsingContextInfo
       );
+
+      // This is an internal event is used by the script module
+      // to ensure that "script.realmCreated" event is emitted
+      // after "browsingContext.contextCreated".
+      this.messageHandler.emitEvent(
+        "browsingContext._contextCreatedEmitted",
+        { browsingContext },
+        browsingContextInfo
+      );
     }
   };
 
diff --git a/remote/webdriver-bidi/modules/root/script.sys.mjs b/remote/webdriver-bidi/modules/root/script.sys.mjs
@@ -8,6 +8,8 @@ const lazy = {};
 
 ChromeUtils.defineESModuleGetters(lazy, {
   assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  BrowsingContextListener:
+    "chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs",
   ContextDescriptorType:
     "chrome://remote/content/shared/messagehandler/MessageHandler.sys.mjs",
   error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
@@ -63,22 +65,35 @@ const ScriptEvaluateResultType = {
  */
 
 class ScriptModule extends RootBiDiModule {
+  #contextListener;
   #preloadScriptMap;
+  #realmInfoMap;
   #subscribedEvents;
 
   constructor(messageHandler) {
     super(messageHandler);
 
+    this.#contextListener = new lazy.BrowsingContextListener();
+    this.#contextListener.on("attached", this.#onContextAttached);
+
     // Map in which the keys are UUIDs, and the values are structs
     // of the type PreloadScript.
     this.#preloadScriptMap = new Map();
 
+    // Map with browsing contexts as keys and realm info object
+    // as values.
+    this.#realmInfoMap = new WeakMap();
+
     // Set of event names which have active subscriptions.
     this.#subscribedEvents = new Set();
   }
 
   destroy() {
+    this.#contextListener.off("attached", this.#onContextAttached);
+    this.#contextListener.destroy();
+
     this.#preloadScriptMap = null;
+    this.#realmInfoMap = null;
     this.#subscribedEvents = null;
   }
 
@@ -903,24 +918,51 @@ class ScriptModule extends RootBiDiModule {
       .filter(realm => realm.context !== null);
   }
 
+  #hasEventSubscriptionToContextCreated(browsingContext) {
+    const sessionData =
+      this.messageHandler.sessionData.getSessionDataForContext(
+        "browsingContext",
+        "event",
+        browsingContext
+      );
+
+    return sessionData.some(
+      item => item.value === "browsingContext.contextCreated"
+    );
+  }
+
+  #onContextAttached = (eventName, data) => {
+    const { browsingContext } = data;
+    // If there is a subscription for "browsingContext.contextCreated" event,
+    // do not send "script.realmCreated" event yet and
+    // wait until the "browsingContext.contextCreated" event is submitted
+    if (
+      this.#realmInfoMap.has(browsingContext) &&
+      !this.#hasEventSubscriptionToContextCreated(browsingContext)
+    ) {
+      this.#sendDelayedRealmCreatedEvent(browsingContext);
+    }
+  };
+
+  #onContextCreatedSubmitted = (eventName, { browsingContext }) => {
+    if (this.#realmInfoMap.has(browsingContext)) {
+      this.#sendDelayedRealmCreatedEvent(browsingContext);
+    }
+  };
+
   #onRealmCreated = (eventName, { realmInfo }) => {
     // Resolve browsing context to a TabManager id.
     const context = lazy.NavigableManager.getIdForBrowsingContext(
       realmInfo.context
     );
-    const browsingContextId = realmInfo.context.id;
 
-    // Do not emit the event, if the browsing context is gone.
+    // Do not emit the event, if the browsing context is gone or not created yet.
     if (context === null) {
+      // Save the realm info to send it when the browsing context is ready.
+      this.#realmInfoMap.set(realmInfo.context, realmInfo);
       return;
     }
-
-    realmInfo.context = context;
-    this._emitEventForBrowsingContext(
-      browsingContextId,
-      "script.realmCreated",
-      realmInfo
-    );
+    this.#sendRealmCreatedEvent(realmInfo, realmInfo.context, context);
   };
 
   #onRealmDestroyed = (eventName, { realm, context }) => {
@@ -929,25 +971,55 @@ class ScriptModule extends RootBiDiModule {
     });
   };
 
-  #startListingOnRealmCreated() {
+  #sendDelayedRealmCreatedEvent(browsingContext) {
+    const realmInfo = this.#realmInfoMap.get(browsingContext);
+    // Resolve browsing context to a TabManager id.
+    const browsingContextId = lazy.NavigableManager.getIdForBrowsingContext(
+      realmInfo.context
+    );
+    this.#sendRealmCreatedEvent(realmInfo, browsingContext, browsingContextId);
+    this.#realmInfoMap.delete(browsingContext);
+  }
+
+  #sendRealmCreatedEvent(realmInfo, context, browsingContextId) {
+    realmInfo.context = browsingContextId;
+
+    this._emitEventForBrowsingContext(
+      context.id,
+      "script.realmCreated",
+      realmInfo
+    );
+  }
+
+  #startListeningOnRealmCreated() {
     if (!this.#subscribedEvents.has("script.realmCreated")) {
       this.messageHandler.on("realm-created", this.#onRealmCreated);
+      this.messageHandler.on(
+        "browsingContext._contextCreatedEmitted",
+        this.#onContextCreatedSubmitted
+      );
+      this.#contextListener.startListening();
     }
   }
 
-  #stopListingOnRealmCreated() {
+  #stopListeningOnRealmCreated() {
     if (this.#subscribedEvents.has("script.realmCreated")) {
       this.messageHandler.off("realm-created", this.#onRealmCreated);
+      this.messageHandler.off(
+        "browsingContext._contextCreatedEmitted",
+        this.#onContextCreatedSubmitted
+      );
+      this.#contextListener.stopListening();
     }
   }
 
-  #startListingOnRealmDestroyed() {
+  #startListeningOnRealmDestroyed() {
     if (!this.#subscribedEvents.has("script.realmDestroyed")) {
       this.messageHandler.on("realm-destroyed", this.#onRealmDestroyed);
     }
   }
 
-  #stopListingOnRealmDestroyed() {
+  #stopListeningOnRealmDestroyed() {
     if (this.#subscribedEvents.has("script.realmDestroyed")) {
       this.messageHandler.off("realm-destroyed", this.#onRealmDestroyed);
     }
@@ -956,12 +1028,12 @@ class ScriptModule extends RootBiDiModule {
   #subscribeEvent(event) {
     switch (event) {
       case "script.realmCreated": {
-        this.#startListingOnRealmCreated();
+        this.#startListeningOnRealmCreated();
         this.#subscribedEvents.add(event);
         break;
       }
       case "script.realmDestroyed": {
-        this.#startListingOnRealmDestroyed();
+        this.#startListeningOnRealmDestroyed();
         this.#subscribedEvents.add(event);
         break;
       }
@@ -971,12 +1043,12 @@ class ScriptModule extends RootBiDiModule {
   #unsubscribeEvent(event) {
     switch (event) {
       case "script.realmCreated": {
-        this.#stopListingOnRealmCreated();
+        this.#stopListeningOnRealmCreated();
         this.#subscribedEvents.delete(event);
         break;
       }
       case "script.realmDestroyed": {
-        this.#stopListingOnRealmDestroyed();
+        this.#stopListeningOnRealmDestroyed();
         this.#subscribedEvents.delete(event);
         break;
       }
