[lexical-markdown] Bug Fix: nest heading inside quote when typing > # SOME HEADER

packages/lexical-markdown/src/MarkdownTransformers.ts

@@ -37,6 +37,7 @@ import {
   $createTextNode,
   $findMatchingParent,
   $getState,
+  $isParagraphNode,
   $setState,
   createState,
   ElementNode,
@@ -241,7 +242,12 @@ const createBlockNode = (
   return (parentNode, children, match, isImport) => {
     const node = createNode(match);
     node.append(...children);
-    parentNode.replace(node);
+    if (!isImport && !$isParagraphNode(parentNode)) {
+      parentNode.clear();
+      parentNode.append(node);
+    } else {
+      parentNode.replace(node);
+    }
     if (!isImport) {
       node.select(0, 0);
     }

packages/lexical-markdown/src/__tests__/unit/MarkdownTransformers.test.ts

@@ -10,7 +10,11 @@ import {buildEditorFromExtensions} from '@lexical/extension';
 import {$createLinkNode, $isLinkNode, LinkExtension} from '@lexical/link';
 import {ListExtension} from '@lexical/list';
 import {registerMarkdownShortcuts} from '@lexical/markdown';
-import {RichTextExtension} from '@lexical/rich-text';
+import {
+  $isHeadingNode,
+  $isQuoteNode,
+  RichTextExtension,
+} from '@lexical/rich-text';
 import {
   $createParagraphNode,
   $createTextNode,
@@ -156,3 +160,19 @@ describe('LINK', () => {
     });
   });
 });
+
+describe('BLOCK QUOTE + HEADING', () => {
+  test('typing "> # SOME HEADER" creates a heading inside a quote (issue #7407)', () => {
+    const editor = buildEditorFromExtensions([MarkdownShortcutTestExtension]);
+    typeMarkdown(editor, '> # SOME HEADER');
+    editor.read(() => {
+      const root = $getRoot();
+      const firstChild = root.getFirstChildOrThrow();
+      assert($isQuoteNode(firstChild), 'Root child must be a QuoteNode');
+      const quoteChild = firstChild.getFirstChildOrThrow();
+      assert($isHeadingNode(quoteChild), 'Quote child must be a HeadingNode');
+      expect(quoteChild.getTag()).toBe('h1');
+      expect(quoteChild.getTextContent()).toBe('SOME HEADER');
+    });
+  });
+});