feat: match sublist indentation when adding a new item (#4433)

* match sublist indentation

* recursively get last node

* fix linting issues

web/src/components/MemoEditor/Editor/index.tsx

 import { last } from "lodash-es";
 import { forwardRef, ReactNode, useCallback, useEffect, useImperativeHandle, useRef, useState } from "react";
 import { markdownServiceClient } from "@/grpcweb";
-import { NodeType, OrderedListItemNode, TaskListItemNode, UnorderedListItemNode } from "@/types/proto/api/v1/markdown_service";
+import { Node, NodeType, OrderedListItemNode, TaskListItemNode, UnorderedListItemNode } from "@/types/proto/api/v1/markdown_service";
 import { cn } from "@/utils";
 import TagSuggestions from "./TagSuggestions";
 
@@ -150,6 +150,20 @@ const Editor = forwardRef(function Editor(props: Props, ref: React.ForwardedRef<
     updateEditorHeight();
   }, []);
 
+  const getLastNode = (nodes: Node[]): Node | undefined => {
+    const lastNode = last(nodes);
+    if (!lastNode) {
+      return undefined;
+    }
+    if (lastNode.type === NodeType.LIST) {
+      const children = lastNode.listNode?.children;
+      if (children) {
+        return getLastNode(children);
+      }
+    }
+    return lastNode;
+  };
+
   const handleEditorKeyDown = async (event: React.KeyboardEvent<HTMLTextAreaElement>) => {
     if (event.key === "Enter" && !isInIME) {
       if (event.shiftKey || event.ctrlKey || event.metaKey || event.altKey) {
@@ -159,7 +173,7 @@ const Editor = forwardRef(function Editor(props: Props, ref: React.ForwardedRef<
       const cursorPosition = editorActions.getCursorPosition();
       const prevContent = editorActions.getContent().substring(0, cursorPosition);
       const { nodes } = await markdownServiceClient.parseMarkdown({ markdown: prevContent });
-      const lastNode = last(last(nodes)?.listNode?.children);
+      const lastNode = getLastNode(nodes);
       if (!lastNode) {
         return;
       }
@@ -171,13 +185,13 @@ const Editor = forwardRef(function Editor(props: Props, ref: React.ForwardedRef<
       let insertText = indentationMatch ? indentationMatch[0] : ""; // Keep the indentation of the previous line
       if (lastNode.type === NodeType.TASK_LIST_ITEM) {
         const { symbol } = lastNode.taskListItemNode as TaskListItemNode;
-        insertText = `${symbol} [ ] `;
+        insertText += `${symbol} [ ] `;
       } else if (lastNode.type === NodeType.UNORDERED_LIST_ITEM) {
         const { symbol } = lastNode.unorderedListItemNode as UnorderedListItemNode;
-        insertText = `${symbol} `;
+        insertText += `${symbol} `;
       } else if (lastNode.type === NodeType.ORDERED_LIST_ITEM) {
         const { number } = lastNode.orderedListItemNode as OrderedListItemNode;
-        insertText = `${Number(number) + 1}. `;
+        insertText += `${Number(number) + 1}. `;
       }
       if (insertText) {
         editorActions.insertText(insertText);