1 files changed, 69 insertions, 0 deletions
diff --git a/devtools/client/inspector/test/browser_inspector_picker-reset-reference.js b/devtools/client/inspector/test/browser_inspector_picker-reset-reference.js
new file mode 100644
index 0000000000..2a9bc39ca6
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+++ b/devtools/client/inspector/test/browser_inspector_picker-reset-reference.js
@@ -0,0 +1,69 @@
+/* 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 the node picker reset its reference for the last hovered node when the user
+// stops picking (See Bug 1736183).
+
+const TEST_URL =
+  "data:text/html;charset=utf8,<h1 id=target>Pick target</h1><h2>ignore me</h2>";
+
+add_task(async () => {
+  const { inspector, toolbox, highlighterTestFront } =
+    await openInspectorForURL(TEST_URL);
+
+  const { waitForHighlighterTypeHidden } = getHighlighterTestHelpers(inspector);
+
+  info(
+    "Start the picker and hover an element to populate the picker hovered node reference"
+  );
+  await startPicker(toolbox);
+  await hoverElement(inspector, "#target");
+  ok(
+    await highlighterTestFront.assertHighlightedNode("#target"),
+    "The highlighter is shown on the expected node"
+  );
+
+  info("Hit Escape to cancel picking");
+  let onHighlighterHidden = waitForHighlighterTypeHidden(
+    inspector.highlighters.TYPES.BOXMODEL
+  );
+  await stopPickerWithEscapeKey(toolbox);
+  await onHighlighterHidden;
+
+  info("And start it again, and hover the same node again");
+  await startPicker(toolbox);
+  await hoverElement(inspector, "#target");
+  ok(
+    await highlighterTestFront.assertHighlightedNode("#target"),
+    "The highlighter is shown on the expected node again"
+  );
+
+  info("Pick the element to stop the picker");
+  onHighlighterHidden = waitForHighlighterTypeHidden(
+    inspector.highlighters.TYPES.BOXMODEL
+  );
+  // nodePicker isPicking property is set to false _after_ picker-node-picked event, so
+  // we need to wait for picker-stopped here.
+  const onPickerStopped = toolbox.nodePicker.once("picker-stopped");
+  await pickElement(inspector, "#target", 5, 5);
+  await onHighlighterHidden;
+  await onPickerStopped;
+
+  info("And start it and hover the same node, again");
+  await startPicker(toolbox);
+  await hoverElement(inspector, "#target");
+  ok(
+    await highlighterTestFront.assertHighlightedNode("#target"),
+    "The highlighter is shown on the expected node again"
+  );
+
+  info("Stop the picker to avoid pending Promise");
+  onHighlighterHidden = waitForHighlighterTypeHidden(
+    inspector.highlighters.TYPES.BOXMODEL
+  );
+  await stopPickerWithEscapeKey(toolbox);
+  await onHighlighterHidden;
+});