1 files changed, 52 insertions, 0 deletions
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-editor-scroll.js b/devtools/client/debugger/test/mochitest/browser_dbg-editor-scroll.js
new file mode 100644
index 0000000000..50185d7340
--- /dev/null
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-editor-scroll.js
@@ -0,0 +1,52 @@
+/* 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/>. */
+
+// Tests that the editor keeps proper scroll position per document
+// while also moving to the correct location upon pause/breakpoint selection
+
+"use strict";
+
+requestLongerTimeout(2);
+
+add_task(async function () {
+  // This test runs too slowly on linux debug. I'd like to figure out
+  // which is the slowest part of this and make it run faster, but to
+  // fix a frequent failure allow a longer timeout.
+  const dbg = await initDebugger("doc-editor-scroll.html");
+
+  // Set the initial breakpoint.
+  await selectSource(dbg, "simple1.js");
+  await addBreakpoint(dbg, "simple1.js", 26);
+
+  const cm = getCM(dbg);
+
+  info("Open long file, scroll down to line below the fold");
+  await selectSource(dbg, "long.js");
+  cm.scrollTo(0, 600);
+
+  info("Ensure vertical scroll is the same after switching documents");
+  await selectSource(dbg, "simple1.js");
+  is(cm.getScrollInfo().top, 0);
+  await selectSource(dbg, "long.js");
+  is(cm.getScrollInfo().top, 600);
+
+  info("Trigger a pause, click on a frame, ensure the right line is selected");
+  invokeInTab("doNamedEval");
+  await waitForPaused(dbg);
+  findElement(dbg, "frame", 1).focus();
+  await clickElement(dbg, "frame", 1);
+  Assert.notEqual(
+    cm.getScrollInfo().top,
+    0,
+    "frame scrolled down to correct location"
+  );
+
+  info("Navigating while paused, goes to the correct location");
+  await selectSource(dbg, "long.js");
+  is(cm.getScrollInfo().top, 600);
+
+  info("Open new source, ensure it's at 0 scroll");
+  await selectSource(dbg, "frames.js");
+  is(cm.getScrollInfo().top, 0);
+});