fix: correct conversion of checklists

Fixes #255

src/examples/basics.tsx

@@ -128,10 +128,31 @@ const listsMarkdown = `
 * [x] Walk the dog
 * [ ] Watch movie
 * [ ] Have dinner with family
+
+... an all empty list
+
+* [ ] Walk the dog
+* [ ] Watch movie
+* [ ] Have dinner with family
 `
 
 export function Lists() {
-  return <MDXEditor markdown={listsMarkdown} plugins={[listsPlugin()]} />
+  return (
+    <MDXEditor
+      markdown={listsMarkdown}
+      plugins={[
+        listsPlugin(),
+        diffSourcePlugin(),
+        toolbarPlugin({
+          toolbarContents: () => (
+            <DiffSourceToggleWrapper>
+              <UndoRedo />
+            </DiffSourceToggleWrapper>
+          )
+        })
+      ]}
+    />
+  )
 }
 
 export function Table() {

src/plugins/lists/MdastListItemVisitor.ts

@@ -1,10 +1,11 @@
-import { $createListItemNode } from '@lexical/list'
+import { $createListItemNode, ListNode } from '@lexical/list'
 import * as Mdast from 'mdast'
 import { MdastImportVisitor } from '../../importMarkdownToLexical'
 
 export const MdastListItemVisitor: MdastImportVisitor<Mdast.ListItem> = {
   testNode: 'listItem',
-  visitNode({ mdastNode, actions }) {
-    actions.addAndStepInto($createListItemNode(mdastNode.checked ?? undefined))
+  visitNode({ mdastNode, actions, lexicalParent }) {
+    const isChecked = (lexicalParent as ListNode).getListType() === 'check' ? mdastNode.checked ?? false : undefined
+    actions.addAndStepInto($createListItemNode(isChecked))
   }
 }