Bug 1775141 - [webdriver-bidi] Send live "browsingContext.contextCreated" events with "about:blank" as URL. r=webdriver-reviewers,jdescottes

Differential Revision: https://phabricator.services.mozilla.com/D151321

remote/shared/listeners/BrowsingContextListener.jsm

@@ -20,6 +20,8 @@ XPCOMUtils.defineLazyModuleGetters(lazy, {
 const OBSERVER_TOPIC_ATTACHED = "browsing-context-attached";
 const OBSERVER_TOPIC_DISCARDED = "browsing-context-discarded";
 
+const OBSERVER_TOPIC_SET_EMBEDDER = "browsing-context-did-set-embedder";
+
 /**
  * The BrowsingContextListener can be used to listen for notifications coming
  * from browsing contexts that get attached or discarded.
@@ -47,6 +49,7 @@ const OBSERVER_TOPIC_DISCARDED = "browsing-context-discarded";
  */
 class BrowsingContextListener {
   #listening;
+  #topContextsToAttach;
 
   /**
    * Create a new BrowsingContextListener instance.
@@ -54,6 +57,11 @@ class BrowsingContextListener {
   constructor() {
     lazy.EventEmitter.decorate(this);
 
+    // A map that temporarily holds attached top-level browsing contexts until
+    // their embedder element is set, which is required to successfully
+    // retrieve a unique id for the content browser by the TabManager.
+    this.#topContextsToAttach = new Map();
+
     this.#listening = false;
   }
 
@@ -64,11 +72,33 @@ class BrowsingContextListener {
   observe(subject, topic, data) {
     switch (topic) {
       case OBSERVER_TOPIC_ATTACHED:
+        // Delay emitting the event for top-level browsing contexts until
+        // the embedder element has been set.
+        if (!subject.parent) {
+          this.#topContextsToAttach.set(subject, data);
+          return;
+        }
+
         this.emit("attached", { browsingContext: subject, why: data });
         break;
+
       case OBSERVER_TOPIC_DISCARDED:
+        // Remove a recently attached top-level browsing context if it's
+        // immediately discarded.
+        if (this.#topContextsToAttach.has(subject)) {
+          this.#topContextsToAttach.delete(subject);
+        }
+
         this.emit("discarded", { browsingContext: subject, why: data });
         break;
+
+      case OBSERVER_TOPIC_SET_EMBEDDER:
+        const why = this.#topContextsToAttach.get(subject);
+        if (why !== undefined) {
+          this.emit("attached", { browsingContext: subject, why });
+          this.#topContextsToAttach.delete(subject);
+        }
+        break;
     }
   }
 
@@ -79,6 +109,7 @@ class BrowsingContextListener {
 
     Services.obs.addObserver(this, OBSERVER_TOPIC_ATTACHED);
     Services.obs.addObserver(this, OBSERVER_TOPIC_DISCARDED);
+    Services.obs.addObserver(this, OBSERVER_TOPIC_SET_EMBEDDER);
 
     this.#listening = true;
   }
@@ -90,6 +121,9 @@ class BrowsingContextListener {
 
     Services.obs.removeObserver(this, OBSERVER_TOPIC_ATTACHED);
     Services.obs.removeObserver(this, OBSERVER_TOPIC_DISCARDED);
+    Services.obs.removeObserver(this, OBSERVER_TOPIC_SET_EMBEDDER);
+
+    this.#topContextsToAttach.clear();
 
     this.#listening = false;
   }

remote/shared/listeners/test/browser/browser_BrowsingContextListener.js

@@ -28,6 +28,32 @@ add_task(async function test_attachedOnNewTab() {
   gBrowser.removeTab(tab);
 });
 
+add_task(async function test_attachedValidEmbedderElement() {
+  const listener = new BrowsingContextListener();
+
+  let hasEmbedderElement = false;
+  listener.on(
+    "attached",
+    (evtName, { browsingContext }) => {
+      hasEmbedderElement = !!browsingContext.embedderElement;
+    },
+    { once: true }
+  );
+
+  listener.startListening();
+
+  const tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  ok(
+    hasEmbedderElement,
+    "Attached browsing context has a valid embedder element"
+  );
+
+  listener.stopListening();
+  gBrowser.removeTab(tab);
+});
+
 add_task(async function test_discardedOnCloseTab() {
   const listener = new BrowsingContextListener();
   const discarded = listener.once("discarded");

remote/webdriver-bidi/modules/root/browsingContext.jsm

@@ -514,11 +514,6 @@ class BrowsingContextModule extends Module {
       return;
     }
 
-    // Wait until navigation starts, so that an active document is attached.
-    await lazy.waitForInitialNavigationCompleted(browsingContext.webProgress, {
-      resolveWhenStarted: true,
-    });
-
     const contextInfo = this.#getBrowsingContextInfo(browsingContext, {
       maxDepth: 0,
     });

testing/web-platform/meta/webdriver/tests/bidi/browsing_context/context_created/context_created.py.ini

@@ -1,20 +1,11 @@
 [context_created.py]
   disabled:
     if os == "android": https://bugzilla.mozilla.org/show_bug.cgi?id=1506782
-  expected:
-    if (os == "win") and not debug and (processor == "x86_64"): [OK, TIMEOUT]
-  [test_navigate_creates_iframes]
-    expected:
-      if debug and (os == "linux") and fission and not swgl: [FAIL, PASS]
-      FAIL
-
-  [test_navigate_creates_nested_iframes]
-    expected:
-      if debug and (os == "linux") and not swgl: [FAIL, PASS]
-      FAIL
 
   [test_evaluate_window_open_without_url]
+    bug: 1770754
     expected: FAIL
 
   [test_evaluate_window_open_with_url]
+    bug: 1770754
     expected: FAIL