feat: add `navigationHistory.getEntryAtIndex(int index)` method (#41661)

* feat: add `navigationHistory.getEntryAtIndex(int index)` method (#41577)

* chore: remove code not related to this pr:

* test: fix flaky tests by replacing real urls with data urls

* test: remove hardcoded url

docs/api/navigation-history.md

@@ -0,0 +1,29 @@
+## Class: NavigationHistory
+
+> Manage a list of navigation entries, representing the user's browsing history within the application.
+
+Process: [Main](../glossary.md#main-process)<br />
+_This class is not exported from the `'electron'` module. It is only available as a return value of other methods in the Electron API._
+
+Each navigation entry corresponds to a specific page. The indexing system follows a sequential order, where the first available navigation entry is at index 0, representing the earliest visited page, and the latest navigation entry is at index N, representing the most recent page. Maintaining this ordered list of navigation entries enables seamless navigation both backward and forward through the user's browsing history.
+
+### Instance Methods
+
+#### `navigationHistory.getActiveIndex()`
+
+Returns `Integer` - The index of the current page, from which we would go back/forward or reload.
+
+#### `navigationHistory.getEntryAtIndex(index)`
+
+* `index` Integer
+
+Returns `Object`:
+
+* `url` string - The URL of the navigation entry at the given index.
+* `title` string - The page title of the navigation entry at the given index.
+
+If index is out of bounds (greater than history length or less than 0), null will be returned.
+
+#### `navigationHistory.length()`
+
+Returns `Integer` - History length.

docs/api/web-contents.md

@@ -2200,6 +2200,10 @@ A `Integer` representing the unique ID of this WebContents. Each ID is unique am
 
 A [`Session`](session.md) used by this webContents.
 
+#### `contents.navigationHistory` _Readonly_
+
+A [`NavigationHistory`](navigation-history.md) used by this webContents.
+
 #### `contents.hostWebContents` _Readonly_
 
 A [`WebContents`](web-contents.md) instance that might own this `WebContents`.

filenames.auto.gni

@@ -33,6 +33,7 @@ auto_filenames = {
     "docs/api/message-port-main.md",
     "docs/api/native-image.md",
     "docs/api/native-theme.md",
+    "docs/api/navigation-history.md",
     "docs/api/net-log.md",
     "docs/api/net.md",
     "docs/api/notification.md",

lib/browser/api/web-contents.ts

@@ -518,6 +518,17 @@ WebContents.prototype._init = function () {
     enumerable: true
   });
 
+  // Add navigationHistory property which handles session history,
+  // maintaining a list of navigation entries for backward and forward navigation.
+  Object.defineProperty(this, 'navigationHistory', {
+    value: {
+      getActiveIndex: this._getActiveIndex.bind(this),
+      length: this._historyLength.bind(this),
+      getEntryAtIndex: this._getNavigationEntryAtIndex.bind(this)
+    },
+    writable: false
+  });
+
   // Dispatch IPC messages to the ipc module.
   this.on('-ipc-message' as any, function (this: Electron.WebContents, event: Electron.IpcMainEvent, internal: boolean, channel: string, args: any[]) {
     addSenderToEvent(event, this);

shell/browser/api/electron_api_web_contents.cc

@@ -352,6 +352,20 @@ struct Converter<scoped_refptr<content::DevToolsAgentHost>> {
   }
 };
 
+template <>
+struct Converter<content::NavigationEntry*> {
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
+                                   content::NavigationEntry* entry) {
+    if (!entry) {
+      return v8::Null(isolate);
+    }
+    gin_helper::Dictionary dict(isolate, v8::Object::New(isolate));
+    dict.Set("url", entry->GetURL().spec());
+    dict.Set("title", entry->GetTitleForDisplay());
+    return dict.GetHandle();
+  }
+};
+
 }  // namespace gin
 
 namespace electron::api {
@@ -2533,6 +2547,11 @@ int WebContents::GetActiveIndex() const {
   return web_contents()->GetController().GetCurrentEntryIndex();
 }
 
+content::NavigationEntry* WebContents::GetNavigationEntryAtIndex(
+    int index) const {
+  return web_contents()->GetController().GetEntryAtIndex(index);
+}
+
 void WebContents::ClearHistory() {
   // In some rare cases (normally while there is no real history) we are in a
   // state where we can't prune navigation entries
@@ -4304,9 +4323,11 @@ void WebContents::FillObjectTemplate(v8::Isolate* isolate,
       .SetMethod("goToOffset", &WebContents::GoToOffset)
       .SetMethod("canGoToIndex", &WebContents::CanGoToIndex)
       .SetMethod("goToIndex", &WebContents::GoToIndex)
-      .SetMethod("getActiveIndex", &WebContents::GetActiveIndex)
+      .SetMethod("_getActiveIndex", &WebContents::GetActiveIndex)
+      .SetMethod("_getNavigationEntryAtIndex",
+                 &WebContents::GetNavigationEntryAtIndex)
+      .SetMethod("_historyLength", &WebContents::GetHistoryLength)
       .SetMethod("clearHistory", &WebContents::ClearHistory)
-      .SetMethod("length", &WebContents::GetHistoryLength)
       .SetMethod("isCrashed", &WebContents::IsCrashed)
       .SetMethod("forcefullyCrashRenderer",
                  &WebContents::ForcefullyCrashRenderer)

shell/browser/api/electron_api_web_contents.h

@@ -190,6 +190,7 @@ class WebContents : public ExclusiveAccessContext,
   bool CanGoToIndex(int index) const;
   void GoToIndex(int index);
   int GetActiveIndex() const;
+  content::NavigationEntry* GetNavigationEntryAtIndex(int index) const;
   void ClearHistory();
   int GetHistoryLength() const;
   const std::string GetWebRTCIPHandlingPolicy() const;

spec/api-web-contents-spec.ts

@@ -537,6 +537,79 @@ describe('webContents module', () => {
     });
   });
 
+  describe('navigationHistory', () => {
+    let w: BrowserWindow;
+    const urlPage1 = 'data:text/html,<html><head><script>document.title = "Page 1";</script></head><body></body></html>';
+    const urlPage2 = 'data:text/html,<html><head><script>document.title = "Page 2";</script></head><body></body></html>';
+    const urlPage3 = 'data:text/html,<html><head><script>document.title = "Page 3";</script></head><body></body></html>';
+
+    beforeEach(async () => {
+      w = new BrowserWindow({ show: false });
+    });
+    afterEach(closeAllWindows);
+    describe('navigationHistory.getEntryAtIndex(index) API ', () => {
+      it('should fetch default navigation entry when no urls are loaded', async () => {
+        const result = w.webContents.navigationHistory.getEntryAtIndex(0);
+        expect(result).to.deep.equal({ url: '', title: '' });
+      });
+      it('should fetch navigation entry given a valid index', async () => {
+        await w.loadURL(urlPage1);
+        const result = w.webContents.navigationHistory.getEntryAtIndex(0);
+        expect(result).to.deep.equal({ url: urlPage1, title: 'Page 1' });
+      });
+      it('should return null given an invalid index larger than history length', async () => {
+        await w.loadURL(urlPage1);
+        const result = w.webContents.navigationHistory.getEntryAtIndex(5);
+        expect(result).to.be.null();
+      });
+      it('should return null given an invalid negative index', async () => {
+        await w.loadURL(urlPage1);
+        const result = w.webContents.navigationHistory.getEntryAtIndex(-1);
+        expect(result).to.be.null();
+      });
+    });
+
+    describe('navigationHistory.getActiveIndex() API', () => {
+      it('should return valid active index after a single page visit', async () => {
+        await w.loadURL(urlPage1);
+        expect(w.webContents.navigationHistory.getActiveIndex()).to.equal(0);
+      });
+
+      it('should return valid active index after a multiple page visits', async () => {
+        await w.loadURL(urlPage1);
+        await w.loadURL(urlPage2);
+        await w.loadURL(urlPage3);
+
+        expect(w.webContents.navigationHistory.getActiveIndex()).to.equal(2);
+      });
+
+      it('should return valid active index given no page visits', async () => {
+        expect(w.webContents.navigationHistory.getActiveIndex()).to.equal(0);
+      });
+    });
+
+    describe('navigationHistory.length() API', () => {
+      it('should return valid history length after a single page visit', async () => {
+        await w.loadURL(urlPage1);
+        expect(w.webContents.navigationHistory.length()).to.equal(1);
+      });
+
+      it('should return valid history length after a multiple page visits', async () => {
+        await w.loadURL(urlPage1);
+        await w.loadURL(urlPage2);
+        await w.loadURL(urlPage3);
+
+        expect(w.webContents.navigationHistory.length()).to.equal(3);
+      });
+
+      it('should return valid history length given no page visits', async () => {
+        // Note: Even if no navigation has committed, the history list will always start with an initial navigation entry
+        // Ref: https://source.chromium.org/chromium/chromium/src/+/main:ceontent/public/browser/navigation_controller.h;l=381
+        expect(w.webContents.navigationHistory.length()).to.equal(1);
+      });
+    });
+  });
+
   describe('getFocusedWebContents() API', () => {
     afterEach(closeAllWindows);
 

spec/chromium-spec.ts

@@ -2068,13 +2068,13 @@ describe('chromium features', () => {
         const w = new BrowserWindow({ show: false });
         await w.loadFile(path.join(fixturesPath, 'pages', 'blank.html'));
         // History should have current page by now.
-        expect(w.webContents.length()).to.equal(1);
+        expect(w.webContents.navigationHistory.length()).to.equal(1);
 
         const waitCommit = once(w.webContents, 'navigation-entry-committed');
         w.webContents.executeJavaScript('window.history.pushState({}, "")');
         await waitCommit;
         // Initial page + pushed state.
-        expect(w.webContents.length()).to.equal(2);
+        expect(w.webContents.navigationHistory.length()).to.equal(2);
       });
     });
 
@@ -2102,7 +2102,7 @@ describe('chromium features', () => {
         });
         await w.webContents.mainFrame.frames[0].executeJavaScript('window.history.back()');
         expect(await w.webContents.executeJavaScript('window.history.state')).to.equal(1);
-        expect(w.webContents.getActiveIndex()).to.equal(1);
+        expect(w.webContents.navigationHistory.getActiveIndex()).to.equal(1);
       });
     });
   });

typings/internal-electron.d.ts

@@ -78,9 +78,10 @@ declare namespace Electron {
     _print(options: any, callback?: (success: boolean, failureReason: string) => void): void;
     _getPrintersAsync(): Promise<Electron.PrinterInfo[]>;
     _init(): void;
+    _getNavigationEntryAtIndex(index: number): Electron.EntryAtIndex | null;
+    _getActiveIndex(): number;
+    _historyLength(): number;
     canGoToIndex(index: number): boolean;
-    getActiveIndex(): number;
-    length(): number;
     destroy(): void;
     // <webview>
     attachToIframe(embedderWebContents: Electron.WebContents, embedderFrameId: number): void;