[JS][bidi] Impelments functionality to retrieve all top-level browsing contexts

Author: harsha509

javascript/node/selenium-webdriver/bidi/browsingContext.js

@@ -154,6 +154,32 @@ class BrowsingContext {
     return new BrowsingContextInfo(result['context'], result['url'], result['children'], result['parent'])
   }
 
+  /**
+   * @returns {Promise<Array<BrowsingContextInfo>>} A Promise that resolves to an array of BrowsingContextInfo objects representing the top-level browsing contexts.
+   */
+  async getTopLevelContexts() {
+    const params = {
+      method: 'browsingContext.getTree',
+      params: {},
+    }
+
+    let result = await this.bidi.send(params)
+    if ('error' in result) {
+      throw Error(result['error'])
+    }
+
+    const contexts = result['result']['contexts'];
+    const browsingContexts = contexts.map(context => {
+      return new BrowsingContextInfo(
+        context['id'],
+        context['url'],
+        context['children'],
+        context['parent']
+      );
+    });
+    return browsingContexts;
+  }
+
   /**
    * Closes the browsing context
    * @returns {Promise<void>}

javascript/node/selenium-webdriver/test/bidi/browsingcontext_test.js

@@ -447,7 +447,18 @@ suite(
 
         const devicePixelRatio = await driver.executeScript('return window.devicePixelRatio;')
         assert.equal(devicePixelRatio, 5)
-      })
+      });
+
+      it('Get All Top level browsing contexts', async ()=> {
+        const id = await driver.getWindowHandle()
+        const window1 = await BrowsingContext(driver, {
+          browsingContextId: id,
+        });
+        const window2 = await BrowsingContext(driver, {type: 'window'});
+
+        const res = await window1.getTopLevelContexts();
+        assert.equal(res.length, 2);
+      });
     })
   },
   { browsers: [Browser.FIREFOX] },