Support mixed nested lists (#39)

src/lib/editor/mixedLists.ts

@@ -0,0 +1,27 @@
+import type { Node as ProseMirrorNode, Schema } from '@tiptap/pm/model';
+
+export type MixedListName = 'bulletList' | 'taskList';
+
+export function convertListNode(
+  schema: Schema,
+  listNode: ProseMirrorNode,
+  targetListName: MixedListName,
+): ProseMirrorNode | null {
+  if (
+    (listNode.type.name !== 'bulletList' && listNode.type.name !== 'taskList') ||
+    listNode.type.name === targetListName
+  ) {
+    return null;
+  }
+
+  const targetListType = schema.nodes[targetListName];
+  const targetItemType = schema.nodes[targetListName === 'taskList' ? 'taskItem' : 'listItem'];
+  if (!targetListType || !targetItemType) return null;
+
+  const itemAttrs = targetListName === 'taskList' ? { checked: false } : null;
+  const convertedItems = listNode.content.content.map((item) =>
+    targetItemType.create(itemAttrs, item.content, item.marks)
+  );
+
+  return targetListType.create(null, convertedItems, listNode.marks);
+}