1 files changed, 51 insertions, 0 deletions
diff --git a/devtools/client/inspector/test/browser_inspector_highlighter-cssgrid_02.js b/devtools/client/inspector/test/browser_inspector_highlighter-cssgrid_02.js
new file mode 100644
index 0000000000..2fabf9b34b
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+++ b/devtools/client/inspector/test/browser_inspector_highlighter-cssgrid_02.js
@@ -0,0 +1,51 @@
+/* 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";
+
+// Test that grid layouts without items don't cause grid highlighter errors.
+
+const TEST_URL = `
+  <style type='text/css'>
+    .grid {
+      display: grid;
+      grid-template-columns: 20px 20px;
+      grid-gap: 15px;
+    }
+  </style>
+  <div class="grid"></div>
+`;
+
+const HIGHLIGHTER_TYPE = "CssGridHighlighter";
+
+add_task(async function () {
+  const { inspector, highlighterTestFront } = await openInspectorForURL(
+    "data:text/html;charset=utf-8," + encodeURIComponent(TEST_URL)
+  );
+  const front = inspector.inspectorFront;
+  const highlighter = await front.getHighlighterByType(HIGHLIGHTER_TYPE);
+
+  info("Try to show the highlighter on the grid container");
+  const node = await getNodeFront(".grid", inspector);
+  await highlighter.show(node);
+
+  let hidden = await highlighterTestFront.getHighlighterNodeAttribute(
+    "css-grid-canvas",
+    "hidden",
+    highlighter
+  );
+  ok(!hidden, "The highlighter is visible");
+
+  info("Hiding the highlighter");
+  await highlighter.hide();
+
+  hidden = await highlighterTestFront.getHighlighterNodeAttribute(
+    "css-grid-canvas",
+    "hidden",
+    highlighter
+  );
+  ok(hidden, "The highlighter is hidden");
+
+  await highlighter.finalize();
+});