1 files changed, 63 insertions, 0 deletions
diff --git a/devtools/client/inspector/grids/test/browser_grids_grid-list-on-mutation-element-removed.js b/devtools/client/inspector/grids/test/browser_grids_grid-list-on-mutation-element-removed.js
new file mode 100644
index 0000000000..7a60759071
--- /dev/null
+++ b/devtools/client/inspector/grids/test/browser_grids_grid-list-on-mutation-element-removed.js
@@ -0,0 +1,63 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Tests that the grid item is removed from the grid list when the grid container is
+// removed from the page.
+
+const TEST_URI = `
+  <style type='text/css'>
+    #grid {
+      display: grid;
+    }
+  </style>
+  <div id="grid">
+    <div id="cell1">cell1</div>
+    <div id="cell2">cell2</div>
+  </div>
+`;
+
+add_task(async function () {
+  await addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
+  const { inspector, gridInspector } = await openLayoutView();
+  const { document: doc } = gridInspector;
+  const { highlighters, store } = inspector;
+
+  await selectNode("#grid", inspector);
+  const gridList = doc.getElementById("grid-list");
+  const checkbox = gridList.children[0].querySelector("input");
+
+  info("Checking the initial state of the Grid Inspector.");
+  is(gridList.childNodes.length, 1, "One grid container is listed.");
+  ok(!highlighters.gridHighlighters.size, "No CSS grid highlighter is shown.");
+
+  info("Toggling ON the CSS grid highlighter from the layout panel.");
+  const onHighlighterShown = highlighters.once("grid-highlighter-shown");
+  let onCheckboxChange = waitUntilState(
+    store,
+    state => state.grids.length == 1 && state.grids[0].highlighted
+  );
+  checkbox.click();
+  await onHighlighterShown;
+  await onCheckboxChange;
+
+  info("Checking the CSS grid highlighter is created.");
+  is(highlighters.gridHighlighters.size, 1, "CSS grid highlighter is shown.");
+
+  info("Removing the #grid container in the content page.");
+  const onHighlighterHidden = highlighters.once("grid-highlighter-hidden");
+  onCheckboxChange = waitUntilState(store, state => !state.grids.length);
+  SpecialPowers.spawn(gBrowser.selectedBrowser, [], () =>
+    content.document.getElementById("grid").remove()
+  );
+  await onHighlighterHidden;
+  await onCheckboxChange;
+
+  info("Checking the CSS grid highlighter is not shown.");
+  ok(!highlighters.gridHighlighters.size, "No CSS grid highlighter is shown.");
+  const noGridList = doc.querySelector(
+    "#layout-grid-section .devtools-sidepanel-no-result"
+  );
+  ok(noGridList, "The message no grid containers is displayed.");
+});