1 files changed, 65 insertions, 0 deletions
diff --git a/devtools/client/inspector/grids/test/browser_grids_grid-outline-highlight-cell.js b/devtools/client/inspector/grids/test/browser_grids_grid-outline-highlight-cell.js
new file mode 100644
index 0000000000..0f5f329f9b
--- /dev/null
+++ b/devtools/client/inspector/grids/test/browser_grids_grid-outline-highlight-cell.js
@@ -0,0 +1,65 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Tests that the grid cell is highlighted when hovering over the grid outline of a
+// grid cell.
+
+const TEST_URI = `
+  <style type='text/css'>
+    #grid {
+      display: grid;
+    }
+  </style>
+  <div id="grid">
+    <div id="cella">Cell A</div>
+    <div id="cellb">Cell B</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 { store } = inspector;
+  const HIGHLIGHTER_TYPE = inspector.highlighters.TYPES.GRID;
+  const { waitForHighlighterTypeShown } = getHighlighterTestHelpers(inspector);
+
+  const gridList = doc.getElementById("grid-list");
+  const checkbox = gridList.children[0].querySelector("input");
+
+  info("Toggling ON the CSS grid highlighter from the layout panel.");
+  const onHighlighterShown = waitForHighlighterTypeShown(HIGHLIGHTER_TYPE);
+  const onGridOutlineRendered = waitForDOM(doc, "#grid-cell-group rect", 2);
+  const onCheckboxChange = waitUntilState(
+    store,
+    state => state.grids.length == 1 && state.grids[0].highlighted
+  );
+  checkbox.click();
+
+  info("Wait for checkbox to change");
+  await onCheckboxChange;
+
+  info("Wait for highlighter to be shown");
+  await onHighlighterShown;
+
+  info("Wait for outline to be rendered");
+  await onGridOutlineRendered;
+
+  info("Hovering over grid cell A in the grid outline.");
+  const onCellAHighlight = waitForHighlighterTypeShown(HIGHLIGHTER_TYPE);
+
+  synthesizeMouseOverOnGridCell(doc, 0);
+
+  const { options } = await onCellAHighlight;
+
+  info("Checking show grid cell options are correct.");
+  const { showGridCell } = options;
+  const { gridFragmentIndex, rowNumber, columnNumber } = showGridCell;
+
+  is(gridFragmentIndex, "0", "Should be the first grid fragment index.");
+  is(rowNumber, "1", "Should be the first grid row.");
+  is(columnNumber, "1", "Should be the first grid column.");
+});