1 files changed, 59 insertions, 0 deletions
diff --git a/devtools/client/webconsole/test/browser/browser_webconsole_object_inspector_scroll.js b/devtools/client/webconsole/test/browser/browser_webconsole_object_inspector_scroll.js
new file mode 100644
index 0000000000..f4c52b2903
--- /dev/null
+++ b/devtools/client/webconsole/test/browser/browser_webconsole_object_inspector_scroll.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that expanding an objectInspector node doesn't alter the output scroll position.
+const TEST_URI =
+  "data:text/html;charset=utf8,<!DOCTYPE html>test Object Inspector";
+
+add_task(async function () {
+  const hud = await openNewTabAndConsole(TEST_URI);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    content.wrappedJSObject.console.log(
+      "oi-test",
+      content.wrappedJSObject.Math
+    );
+  });
+
+  const node = await waitFor(() => findConsoleAPIMessage(hud, "oi-test"));
+  const objectInspector = node.querySelector(".tree");
+
+  let onOiMutation = waitForNodeMutation(objectInspector, {
+    childList: true,
+  });
+
+  info("Expanding the object inspector");
+  objectInspector.querySelector(".arrow").click();
+  await onOiMutation;
+
+  const nodes = objectInspector.querySelectorAll(".node");
+  const lastNode = nodes[nodes.length - 1];
+
+  info("Scroll the last node of the ObjectInspector into view");
+  lastNode.scrollIntoView();
+
+  const outputContainer = hud.ui.outputNode.querySelector(".webconsole-output");
+  ok(hasVerticalOverflow(outputContainer), "There is a vertical overflow");
+  const scrollTop = outputContainer.scrollTop;
+
+  onOiMutation = waitForNodeMutation(objectInspector, {
+    childList: true,
+  });
+
+  info("Expand the last node");
+  const view = lastNode.ownerDocument.defaultView;
+  EventUtils.synthesizeMouseAtCenter(lastNode, {}, view);
+  await onOiMutation;
+
+  is(
+    scrollTop,
+    outputContainer.scrollTop,
+    "Scroll position did not changed when expanding a node"
+  );
+});
+
+function hasVerticalOverflow(container) {
+  return container.scrollHeight > container.clientHeight;
+}