1 files changed, 42 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_open_in_lazy_tab.js b/browser/components/customizableui/test/browser_open_in_lazy_tab.js
new file mode 100644
index 0000000000..c18de67698
--- /dev/null
+++ b/browser/components/customizableui/test/browser_open_in_lazy_tab.js
@@ -0,0 +1,42 @@
+"use strict";
+
+/**
+ * Check that customize mode can be loaded in a lazy tab.
+ */
+add_task(async function open_customize_mode_in_lazy_tab() {
+  let tab = BrowserTestUtils.addTab(gBrowser, "about:blank", {
+    createLazyBrowser: true,
+  });
+  gCustomizeMode.setTab(tab);
+
+  is(tab.linkedPanel, "", "Tab should be lazy");
+
+  let title = gNavigatorBundle.getFormattedString("customizeMode.tabTitle", [
+    document.getElementById("bundle_brand").getString("brandShortName"),
+  ]);
+  is(tab.label, title, "Tab should have correct title");
+
+  let customizePromise = BrowserTestUtils.waitForEvent(
+    gNavToolbox,
+    "customizationready"
+  );
+  gCustomizeMode.enter();
+  await customizePromise;
+
+  is(
+    tab.getAttribute("customizemode"),
+    "true",
+    "Tab should be in customize mode"
+  );
+
+  let customizationContainer = document.getElementById(
+    "customization-container"
+  );
+  is(
+    customizationContainer.hidden,
+    false,
+    "Customization container should be visible"
+  );
+
+  await endCustomizing();
+});