1 files changed, 49 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/browser/browser_ext_themes_tab_selected.js b/toolkit/components/extensions/test/browser/browser_ext_themes_tab_selected.js
new file mode 100644
index 0000000000..3dd77ac92c
--- /dev/null
+++ b/toolkit/components/extensions/test/browser/browser_ext_themes_tab_selected.js
@@ -0,0 +1,49 @@
+"use strict";
+
+// This test checks whether applied WebExtension themes that attempt to change
+// the background color of selected tab are applied correctly.
+
+add_task(async function test_tab_background_color_property() {
+  const TAB_BACKGROUND_COLOR = "#9400ff";
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      theme: {
+        colors: {
+          frame: ACCENT_COLOR,
+          tab_background_text: TEXT_COLOR,
+          tab_selected: TAB_BACKGROUND_COLOR,
+        },
+      },
+    },
+  });
+
+  await extension.startup();
+
+  info("Checking selected tab color");
+
+  let openTab = document.querySelector(".tabbrowser-tab[visuallyselected]");
+  let openTabBackground = openTab.querySelector(".tab-background");
+
+  let selectedTab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "about:blank"
+  );
+  let selectedTabBackground = selectedTab.querySelector(".tab-background");
+
+  let openTabColor = window
+    .getComputedStyle(openTabBackground)
+    .getPropertyValue("background-color");
+  let selectedTabColor = window
+    .getComputedStyle(selectedTabBackground)
+    .getPropertyValue("background-color");
+
+  Assert.equal(
+    selectedTabColor,
+    "rgb(" + hexToRGB(TAB_BACKGROUND_COLOR).join(", ") + ")",
+    "Selected tab background color should be set."
+  );
+  Assert.notEqual(openTabColor, selectedTabColor);
+
+  gBrowser.removeTab(selectedTab);
+  await extension.unload();
+});