feat: do not emit initial navigation events

src/bidiMapper/modules/context/BrowsingContextImpl.ts

@@ -34,6 +34,7 @@ import {assert} from '../../../utils/assert.js';
 import {Deferred} from '../../../utils/Deferred.js';
 import {type LoggerFn, LogType} from '../../../utils/log.js';
 import {inchesFromCm} from '../../../utils/unitConversions.js';
+import {urlMatchesAboutBlank} from '../../../utils/UrlHelpers.js';
 import {uuidv4} from '../../../utils/uuid.js';
 import type {CdpTarget} from '../cdp/CdpTarget.js';
 import type {Realm} from '../script/Realm.js';
@@ -98,6 +99,11 @@ export class BrowsingContextImpl {
   // Set if there is a pending navigation initiated by `BrowsingContext.navigate` command.
   // The promise is resolved when the navigation is finished or rejected when canceled.
   #pendingCommandNavigation: Deferred<void> | undefined;
+  // Flags if the initial navigation to `about:blank` is in progress.
+  #initialNavigation = true;
+  // Flags if the navigation is initiated by `browsingContext.navigate` or
+  // `browsingContext.reload` command.
+  #navigationInitiatedByCommand = false;
 
   #originalOpener?: string;
 
@@ -408,7 +414,6 @@ export class BrowsingContextImpl {
   onTargetInfoChanged(params: Protocol.Target.TargetInfoChangedEvent) {
     this.#url = params.targetInfo.url;
   }
-
   #initListeners() {
     this.#cdpTarget.cdpClient.on('Page.frameNavigated', (params) => {
       if (this.id !== params.frame.id) {
@@ -468,27 +473,34 @@ export class BrowsingContextImpl {
       if (this.id !== params.frameId) {
         return;
       }
-      // Use `pendingNavigationId` if navigation initiated by BiDi
-      // `BrowsingContext.navigate` or generate a new navigation id.
-      this.#navigationId = this.#pendingNavigationId ?? uuidv4();
-      this.#pendingNavigationId = undefined;
-      this.#eventManager.registerEvent(
-        {
-          type: 'event',
-          method: ChromiumBidi.BrowsingContext.EventNames.NavigationStarted,
-          params: {
-            context: this.id,
-            navigation: this.#navigationId,
-            timestamp: BrowsingContextImpl.getTimestamp(),
-            // The URL of the navigation that is currently in progress. Although the URL
-            // is not yet known in case of user-initiated navigations, it is possible to
-            // provide the URL in case of BiDi-initiated navigations.
-            // TODO: provide proper URL in case of user-initiated navigations.
-            url: this.#pendingNavigationUrl ?? 'UNKNOWN',
+
+      if (this.#navigationInitiatedByCommand) {
+        // In case of the navigation is initiated by `browsingContext.navigate` or
+        // `browsingContext.reload` commands, the `Page.frameRequestedNavigation` is not
+        // emitted, which means the `NavigationStarted` is not emitted.
+        // TODO: consider emit it right after the CDP command `navigate` or `reload` is finished.
+
+        // The URL of the navigation that is currently in progress. Although the URL
+        // is not yet known in case of user-initiated navigations, it is possible to
+        // provide the URL in case of BiDi-initiated navigations.
+        // TODO: provide proper URL in case of user-initiated navigations.
+        const url = this.#pendingNavigationUrl ?? 'UNKNOWN';
+        this.#navigationId = this.#pendingNavigationId ?? uuidv4();
+        this.#pendingNavigationId = undefined;
+        this.#eventManager.registerEvent(
+          {
+            type: 'event',
+            method: ChromiumBidi.BrowsingContext.EventNames.NavigationStarted,
+            params: {
+              context: this.id,
+              navigation: this.#navigationId,
+              timestamp: BrowsingContextImpl.getTimestamp(),
+              url,
+            },
           },
-        },
-        this.id,
-      );
+          this.id,
+        );
+      }
     });
 
     // TODO: don't use deprecated `Page.frameScheduledNavigation` event.
@@ -523,7 +535,34 @@ export class BrowsingContextImpl {
           new UnknownErrorException('navigation aborted'),
         );
         this.#pendingCommandNavigation = undefined;
+        this.#navigationInitiatedByCommand = false;
+      }
+      if (!urlMatchesAboutBlank(params.url)) {
+        // If the url does not match about:blank, do not consider it is an initial
+        // navigation and emit all the required events.
+        // https://github.com/GoogleChromeLabs/chromium-bidi/issues/2793.
+        this.#initialNavigation = false;
+      }
+
+      if (!this.#initialNavigation) {
+        // Do not emit the event for the initial navigation to `about:blank`.
+        this.#navigationId = this.#pendingNavigationId ?? uuidv4();
+        this.#pendingNavigationId = undefined;
+        this.#eventManager.registerEvent(
+          {
+            type: 'event',
+            method: ChromiumBidi.BrowsingContext.EventNames.NavigationStarted,
+            params: {
+              context: this.id,
+              navigation: this.#navigationId,
+              timestamp: BrowsingContextImpl.getTimestamp(),
+              url: params.url,
+            },
+          },
+          this.id,
+        );
       }
+
       this.#pendingNavigationUrl = params.url;
     });
 
@@ -558,36 +597,45 @@ export class BrowsingContextImpl {
 
       switch (params.name) {
         case 'DOMContentLoaded':
-          this.#eventManager.registerEvent(
-            {
-              type: 'event',
-              method: ChromiumBidi.BrowsingContext.EventNames.DomContentLoaded,
-              params: {
-                context: this.id,
-                navigation: this.#navigationId,
-                timestamp,
-                url: this.#url,
+          if (!this.#initialNavigation) {
+            // Do not emit for the initial navigation.
+            this.#eventManager.registerEvent(
+              {
+                type: 'event',
+                method:
+                  ChromiumBidi.BrowsingContext.EventNames.DomContentLoaded,
+                params: {
+                  context: this.id,
+                  navigation: this.#navigationId,
+                  timestamp,
+                  url: this.#url,
+                },
               },
-            },
-            this.id,
-          );
+              this.id,
+            );
+          }
           this.#lifecycle.DOMContentLoaded.resolve();
           break;
 
         case 'load':
-          this.#eventManager.registerEvent(
-            {
-              type: 'event',
-              method: ChromiumBidi.BrowsingContext.EventNames.Load,
-              params: {
-                context: this.id,
-                navigation: this.#navigationId,
-                timestamp,
-                url: this.#url,
+          if (!this.#initialNavigation) {
+            // Do not emit for the initial navigation.
+            this.#eventManager.registerEvent(
+              {
+                type: 'event',
+                method: ChromiumBidi.BrowsingContext.EventNames.Load,
+                params: {
+                  context: this.id,
+                  navigation: this.#navigationId,
+                  timestamp,
+                  url: this.#url,
+                },
               },
-            },
-            this.id,
-          );
+              this.id,
+            );
+          }
+          // The initial navigation is finished.
+          this.#initialNavigation = false;
           this.#lifecycle.load.resolve();
           break;
       }
@@ -884,6 +932,7 @@ export class BrowsingContextImpl {
     const navigationId = uuidv4();
     this.#pendingNavigationId = navigationId;
     this.#pendingCommandNavigation = new Deferred<void>();
+    this.#navigationInitiatedByCommand = true;
 
     // Navigate and wait for the result. If the navigation fails, the error event is
     // emitted and the promise is rejected.
@@ -949,6 +998,7 @@ export class BrowsingContextImpl {
 
     // `#pendingCommandNavigation` can be already rejected and set to undefined.
     this.#pendingCommandNavigation?.resolve();
+    this.#navigationInitiatedByCommand = false;
     this.#pendingCommandNavigation = undefined;
     return {
       navigation: navigationId,
@@ -986,6 +1036,8 @@ export class BrowsingContextImpl {
 
     this.#resetLifecycleIfFinished();
 
+    this.#navigationInitiatedByCommand = true;
+
     await this.#cdpTarget.cdpClient.sendCommand('Page.reload', {
       ignoreCache,
     });

src/utils/UrlHelpers.spec.ts

@@ -0,0 +1,89 @@
+/**
+ * Copyright 2024 Google LLC.
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {expect} from 'chai';
+
+import {urlMatchesAboutBlank} from './UrlHelpers.js';
+
+describe('BrowsingContextStorage', () => {
+  describe('urlMatchesAboutBlank', () => {
+    describe('should return true for matching urls', () => {
+      it('"about:blank"', () => {
+        expect(urlMatchesAboutBlank('about:blank')).to.be.true;
+      });
+
+      it('"about:blank?foo=bar"', () => {
+        expect(urlMatchesAboutBlank('about:blank?foo=bar')).to.be.true;
+      });
+
+      it('"about:blank#foo"', () => {
+        expect(urlMatchesAboutBlank('about:blank#foo')).to.be.true;
+      });
+
+      it('"about:Blank"', () => {
+        expect(urlMatchesAboutBlank('about:Blank')).to.be.true;
+      });
+
+      it('empty string', () => {
+        expect(urlMatchesAboutBlank('')).to.be.true;
+      });
+    });
+
+    describe('should return false for not matching urls', () => {
+      it('"http://example.com"', () => {
+        expect(urlMatchesAboutBlank('http://example.com')).to.be.false;
+      });
+
+      it('"about:blanka"', () => {
+        expect(urlMatchesAboutBlank('about:blanka')).to.be.false;
+      });
+
+      it('"about:blank/foo"', () => {
+        expect(urlMatchesAboutBlank('about:blank/foo')).to.be.false;
+      });
+
+      it('"about://blank"', () => {
+        expect(urlMatchesAboutBlank('about://blank')).to.be.false;
+      });
+
+      it('"about: blank"', () => {
+        expect(urlMatchesAboutBlank('about: blank')).to.be.false;
+      });
+
+      it('username and password', () => {
+        expect(urlMatchesAboutBlank('about:username:password@blank')).to.be
+          .false;
+      });
+
+      it('null', () => {
+        expect(urlMatchesAboutBlank(null as any)).to.be.false;
+      });
+
+      it('undefined', () => {
+        expect(urlMatchesAboutBlank(undefined as any)).to.be.false;
+      });
+
+      it('"blob:http://example.com"', () => {
+        expect(urlMatchesAboutBlank('blob:http://example.com')).to.be.false;
+      });
+
+      it('"about:srcdoc"', () => {
+        expect(urlMatchesAboutBlank('about:srcdoc')).to.be.false;
+      });
+    });
+  });
+});

src/utils/UrlHelpers.ts

@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2024 Google LLC.
+ *  Copyright (c) Microsoft Corporation.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+/**
+ * A URL matches about:blank if its scheme is "about", its path contains a single string
+ * "blank", its username and password are the empty string, and its host is null.
+ * https://html.spec.whatwg.org/multipage/urls-and-fetching.html#matches-about:blank
+ * @param {string} url
+ * @return {boolean}
+ */
+export function urlMatchesAboutBlank(url: string): boolean {
+  // An empty string is a special case, and considered to be about:blank.
+  // https://html.spec.whatwg.org/multipage/nav-history-apis.html#window-open-steps
+  if (url === '') {
+    return true;
+  }
+
+  try {
+    const parsedUrl = new URL(url);
+    const schema = parsedUrl.protocol.replace(/:$/, '');
+    return (
+      schema.toLowerCase() === 'about' &&
+      parsedUrl.pathname.toLowerCase() === 'blank' &&
+      parsedUrl.username === '' &&
+      parsedUrl.password === '' &&
+      parsedUrl.host === ''
+    );
+  } catch (err) {
+    // Wrong URL considered do not match about:blank.
+    if (err instanceof TypeError) {
+      return false;
+    }
+    // Re-throw other unexpected errors.
+    throw err;
+  }
+}