From 8a3eb1105cc754734b97070deb1694fe73202c41 Mon Sep 17 00:00:00 2001
From: Mo <mo@standardnotes.com>
Date: Fri, 6 Sep 2024 10:38:39 -0500
Subject: [PATCH] Fix issue where cmd/ctrl + left arrow after a tab character
 would cause exception (#6588)

---
 packages/lexical-code/src/CodeHighlighter.ts  |  2 ++
 .../__tests__/e2e/Tab.spec.mjs                | 29 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/packages/lexical-code/src/CodeHighlighter.ts b/packages/lexical-code/src/CodeHighlighter.ts
index e4a4f626f28..dd721b03e9a 100644
--- a/packages/lexical-code/src/CodeHighlighter.ts
+++ b/packages/lexical-code/src/CodeHighlighter.ts
@@ -773,7 +773,9 @@ function $handleMoveTo(
   const focusNode = focus.getNode();
   const isMoveToStart = type === MOVE_TO_START;
 
+  // Ensure the selection is within the codeblock
   if (
+    !$isSelectionInCode(selection) ||
     !($isCodeHighlightNode(anchorNode) || $isTabNode(anchorNode)) ||
     !($isCodeHighlightNode(focusNode) || $isTabNode(focusNode))
   ) {
diff --git a/packages/lexical-playground/__tests__/e2e/Tab.spec.mjs b/packages/lexical-playground/__tests__/e2e/Tab.spec.mjs
index abbfd5c316c..118e39536d4 100644
--- a/packages/lexical-playground/__tests__/e2e/Tab.spec.mjs
+++ b/packages/lexical-playground/__tests__/e2e/Tab.spec.mjs
@@ -8,9 +8,11 @@
 
 import {
   assertHTML,
+  assertSelection,
   focusEditor,
   html,
   initialize,
+  keyDownCtrlOrMeta,
   test,
 } from '../utils/index.mjs';
 
@@ -114,5 +116,32 @@ test.describe('Tab', () => {
       `,
     );
   });
+
+  test('can go to start of line after a tab character', async ({
+    page,
+    isPlainText,
+  }) => {
+    test.skip(isPlainText);
+    await focusEditor(page);
+
+    await page.keyboard.type('Foo');
+    await page.keyboard.press('Tab');
+
+    page.on('pageerror', (error) => {
+      throw new Error(`Uncaught exception: ${error.message}`);
+    });
+
+    // Press ctrl + left arrow key to go to start of line
+    await keyDownCtrlOrMeta(page);
+    await page.keyboard.press('ArrowLeft');
+
+    // ensure cursor is now at beginning of line
+    await assertSelection(page, {
+      anchorOffset: 0,
+      anchorPath: [0, 0, 0],
+      focusOffset: 0,
+      focusPath: [0, 0, 0],
+    });
+  });
 });
 /* eslint-enable sort-keys-fix/sort-keys-fix */