1 files changed, 67 insertions, 0 deletions
diff --git a/devtools/client/webconsole/test/browser/browser_webconsole_console_group_open_no_scroll.js b/devtools/client/webconsole/test/browser/browser_webconsole_console_group_open_no_scroll.js
new file mode 100644
index 0000000000..c60a7a6303
--- /dev/null
+++ b/devtools/client/webconsole/test/browser/browser_webconsole_console_group_open_no_scroll.js
@@ -0,0 +1,67 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that opening a group does not scroll the console output.
+
+const TEST_URI = `data:text/html,<!DOCTYPE html><meta charset=utf8><script>
+  Array.from({length: 100}, (_, i) => console.log("log-"+i));
+  console.groupCollapsed("GROUP");
+  console.log("in group");
+</script>`;
+
+add_task(async function () {
+  const hud = await openNewTabAndConsole(TEST_URI);
+  const outputScroller = hud.ui.outputScroller;
+
+  // Let's wait until the first message and the group are displayed.
+  await waitFor(() => findConsoleAPIMessage(hud, "log-0"));
+  const groupMessage = await waitFor(() => findConsoleAPIMessage(hud, "GROUP"));
+
+  is(hasVerticalOverflow(outputScroller), true, "output node overflows");
+  is(
+    isScrolledToBottom(outputScroller),
+    true,
+    "output node is scrolled to the bottom"
+  );
+
+  info("Expand the group");
+  groupMessage.querySelector(".arrow").click();
+  await waitFor(() => findConsoleAPIMessage(hud, "in group"));
+
+  is(hasVerticalOverflow(outputScroller), true, "output node overflows");
+  is(
+    isScrolledToBottom(outputScroller),
+    false,
+    "output node isn't scrolled to the bottom anymore"
+  );
+
+  info("Scroll to bottom");
+  outputScroller.scrollTop = outputScroller.scrollHeight;
+  await new Promise(r =>
+    window.requestAnimationFrame(() => TestUtils.executeSoon(r))
+  );
+
+  is(
+    isScrolledToBottom(outputScroller),
+    true,
+    "output node is scrolled to the bottom"
+  );
+
+  info(
+    "Check that adding a message on an open group when scrolled to bottom scrolls " +
+      "to bottom"
+  );
+  const onNewMessage = waitForMessageByType(hud, "new-message", ".console-api");
+  SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    content.console.group("GROUP-2");
+    content.console.log("new-message");
+  });
+  await onNewMessage;
+  is(
+    isScrolledToBottom(outputScroller),
+    true,
+    "output node is scrolled to the bottom after adding message in group"
+  );
+});