1 files changed, 91 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_913972_currentset_overflow.js b/browser/components/customizableui/test/browser_913972_currentset_overflow.js
new file mode 100644
index 0000000000..fde37e4f3c
--- /dev/null
+++ b/browser/components/customizableui/test/browser_913972_currentset_overflow.js
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+var navbar = document.getElementById(CustomizableUI.AREA_NAVBAR);
+
+registerCleanupFunction(async function asyncCleanup() {
+  await resetCustomization();
+});
+
+// Resize to a small window, resize back, shouldn't affect default state.
+add_task(async function () {
+  let originalWindowWidth = window.outerWidth;
+  ok(
+    !navbar.hasAttribute("overflowing"),
+    "Should start with a non-overflowing toolbar."
+  );
+  ok(CustomizableUI.inDefaultState, "Should start in default state.");
+  let navbarTarget = CustomizableUI.getCustomizationTarget(navbar);
+  let oldChildCount = navbarTarget.childElementCount;
+  window.resizeTo(kForceOverflowWidthPx, window.outerHeight);
+  await TestUtils.waitForCondition(
+    () => navbar.hasAttribute("overflowing"),
+    "Navbar has a overflowing attribute"
+  );
+  ok(navbar.hasAttribute("overflowing"), "Should have an overflowing toolbar.");
+  ok(
+    CustomizableUI.inDefaultState,
+    "Should still be in default state when overflowing."
+  );
+  ok(
+    navbarTarget.childElementCount < oldChildCount,
+    "Should have fewer children."
+  );
+  window.resizeTo(originalWindowWidth, window.outerHeight);
+  await TestUtils.waitForCondition(
+    () => !navbar.hasAttribute("overflowing"),
+    "Navbar does not have an overflowing attribute"
+  );
+  ok(
+    !navbar.hasAttribute("overflowing"),
+    "Should no longer have an overflowing toolbar."
+  );
+  ok(
+    CustomizableUI.inDefaultState,
+    "Should still be in default state now we're no longer overflowing."
+  );
+
+  // Verify actual physical placements match those of the placement array:
+  let placementCounter = 0;
+  let placements = CustomizableUI.getWidgetIdsInArea(
+    CustomizableUI.AREA_NAVBAR
+  );
+  for (let node of navbarTarget.children) {
+    if (node.getAttribute("skipintoolbarset") == "true") {
+      continue;
+    }
+    is(
+      placements[placementCounter++],
+      node.id,
+      "Nodes should match after overflow"
+    );
+  }
+  is(
+    placements.length,
+    placementCounter,
+    "Should have as many nodes as expected"
+  );
+  is(
+    navbarTarget.childElementCount,
+    oldChildCount,
+    "Number of nodes should match"
+  );
+});
+
+// Enter and exit customization mode, check that default state is correct.
+add_task(async function () {
+  ok(CustomizableUI.inDefaultState, "Should start in default state.");
+  await startCustomizing();
+  ok(
+    CustomizableUI.inDefaultState,
+    "Should be in default state in customization mode."
+  );
+  await endCustomizing();
+  ok(
+    CustomizableUI.inDefaultState,
+    "Should be in default state after customization mode."
+  );
+});