1 files changed, 44 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_exit_background_customize_mode.js b/browser/components/customizableui/test/browser_exit_background_customize_mode.js
new file mode 100644
index 0000000000..b89efef582
--- /dev/null
+++ b/browser/components/customizableui/test/browser_exit_background_customize_mode.js
@@ -0,0 +1,44 @@
+"use strict";
+
+/**
+ * Tests that if customize mode is currently attached to a background
+ * tab, and that tab browses to a new location, that customize mode
+ * is detached from that tab.
+ */
+add_task(async function test_exit_background_customize_mode() {
+  let nonCustomizingTab = gBrowser.selectedTab;
+
+  Assert.equal(
+    gBrowser.tabContainer.querySelector("tab[customizemode=true]"),
+    null,
+    "Should not have a tab marked as being the customize tab now."
+  );
+
+  await startCustomizing();
+  is(gBrowser.tabs.length, 2, "Should have 2 tabs");
+
+  let custTab = gBrowser.selectedTab;
+
+  let finishedCustomizing = BrowserTestUtils.waitForEvent(
+    gNavToolbox,
+    "aftercustomization"
+  );
+  await BrowserTestUtils.switchTab(gBrowser, nonCustomizingTab);
+  await finishedCustomizing;
+
+  let newURL = "http://example.com/";
+  BrowserTestUtils.loadURIString(custTab.linkedBrowser, newURL);
+  await BrowserTestUtils.browserLoaded(custTab.linkedBrowser, false, newURL);
+
+  Assert.equal(
+    gBrowser.tabContainer.querySelector("tab[customizemode=true]"),
+    null,
+    "Should not have a tab marked as being the customize tab now."
+  );
+
+  await startCustomizing();
+  is(gBrowser.tabs.length, 3, "Should have 3 tabs now");
+
+  await endCustomizing();
+  BrowserTestUtils.removeTab(custTab);
+});