1 files changed, 15 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/tests/ui.spec.js b/devtools/client/debugger/src/utils/tests/ui.spec.js
new file mode 100644
index 0000000000..aa091e6798
--- /dev/null
+++ b/devtools/client/debugger/src/utils/tests/ui.spec.js
@@ -0,0 +1,15 @@
+/* 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/>. */
+
+import { isVisible } from "../ui";
+
+describe("ui", () => {
+  it("should return #mount width", () => {
+    if (!document.body) {
+      throw new Error("no document body");
+    }
+    document.body.innerHTML = "<div id='mount'></div>";
+    expect(isVisible()).toBe(false);
+  });
+});