1 files changed, 54 insertions, 0 deletions
diff --git a/devtools/client/webconsole/test/browser/browser_jsterm_autocomplete_accept_no_scroll.js b/devtools/client/webconsole/test/browser/browser_jsterm_autocomplete_accept_no_scroll.js
new file mode 100644
index 0000000000..cfdb17d8da
--- /dev/null
+++ b/devtools/client/webconsole/test/browser/browser_jsterm_autocomplete_accept_no_scroll.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that the accepting an autocompletion does not scroll the input.
+
+const TEST_URI = `data:text/html;charset=utf-8,<!DOCTYPE html>
+  <script>
+    /* Create a prototype-less object so popup does not contain native
+     * Object prototype properties.
+     */
+    window.foobar = Object.create(null, Object.getOwnPropertyDescriptors({
+      item0: "value0",
+      item1: "value1",
+    }));
+  </script>`;
+
+add_task(async function () {
+  const hud = await openNewTabAndConsole(TEST_URI);
+  const { jsterm, ui } = hud;
+  const { autocompletePopup: popup } = jsterm;
+
+  info("Insert multiple new lines so the input overflows");
+  const onPopUpOpen = popup.once("popup-opened");
+  const lines = "\n".repeat(200);
+  setInputValue(hud, lines);
+
+  info("Fire the autocompletion popup");
+  EventUtils.sendString("window.foobar.");
+
+  await onPopUpOpen;
+  const scrollableEl = ui.window.document.querySelector(".CodeMirror-scroll");
+
+  Assert.greater(scrollableEl.scrollTop, 0, "The input overflows");
+  const scrollTop = scrollableEl.scrollTop;
+
+  info("Hit Enter to accept the autocompletion");
+  const onPopupClose = popup.once("popup-closed");
+  EventUtils.synthesizeKey("KEY_Enter");
+  await onPopupClose;
+
+  ok(!popup.isOpen, "popup is not open after KEY_Enter");
+  is(
+    getInputValue(hud),
+    lines + "window.foobar.item0",
+    "completion was successful after KEY_Enter"
+  );
+  is(
+    scrollableEl.scrollTop,
+    scrollTop,
+    "The scrolling position stayed the same when accepting the completion"
+  );
+});