Bug 1773977 - Add missing implementation for WindowBase.getHighlightedTabs(). r=mkmelin.

Differential Revision: https://phabricator.services.mozilla.com/D151724

mail/components/extensions/parent/ext-mail.js

@@ -1314,6 +1314,16 @@ class Window extends WindowBase {
     yield tabManager.getWrapper(this.window);
   }
 
+  /**
+   * Returns an iterator of TabBase objects for the highlighted tab in this
+   * window. This is an alias for the active tab.
+   *
+   * @returns {Iterator<TabBase>}
+   */
+  *getHighlightedTabs() {
+    yield this.activeTab;
+  }
+
   /** Retrieves the active tab in this window */
   get activeTab() {
     let { tabManager } = this.extension;

mail/components/extensions/test/browser/browser_ext_tabs_query.js

@@ -59,6 +59,24 @@ add_task(async function testQuery() {
           "Id of mail tab is correct"
         );
 
+        // Query for active tab.
+        tabs = await browser.tabs.query({ active: true });
+        browser.test.assertEq(1, tabs.length, "Found one mail tab");
+        browser.test.assertEq(
+          contentTab.id,
+          tabs[0].id,
+          "Id of mail tab is correct"
+        );
+
+        // Query for highlighted tab.
+        tabs = await browser.tabs.query({ highlighted: true });
+        browser.test.assertEq(1, tabs.length, "Found one mail tab");
+        browser.test.assertEq(
+          contentTab.id,
+          tabs[0].id,
+          "Id of mail tab is correct"
+        );
+
         await browser.tabs.remove(contentTab.id);
         browser.test.notifyPass();
       },