我是express js的初学者，我正在提供一个保存在公用文件夹中的外部html文件index.js。index.html如下所示：
<!DOCTYPE html>
<html lang="en">
<head>
<title>Express new title</title>
</head>
<body>
<h1>Welcome to the new era of express</h1>
</body>
</html>我想做的是在正文中添加一个段落标记。我遵循以下链接：nodejs-如何使用javascript在html文档中插入元素？因此，我使用了节点html解析器库，并尝试在主体中添加p标记。
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
const router = require("./routes");
const fs = require("fs");
const parse = require('node-html-parser').parse;
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', indexRouter);
app.use('/users', usersRouter);
/* this is the end point i am trying to test */
app.use('/hello',async (req,res,next)=>{
const fileLocation = path.join(process.cwd(), "public", "index.html");
try {
let frontend = await fs.readFile(fileLocation, "utf-8", (err,html)=>{
if(err){
throw err;
}
const root = parse(html);
const body = root.querySelector('body');
// body.set_content('<p>Hello testing here</p>');
body.appendChild("<p>Hello</p>");
console.log("state", root.toString());
})
next();
} catch (e) {
res.send(e);
}
})
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
module.exports = app;读取和解析文件的端点是“/hello”。在运行express server并请求终结点时http://localhost:3000/hello，我收到以下错误：typeerror:无法在字符串（paragraphtagopen）hello（ParagraphTagClosed）上创建属性“parentnode”
我不明白这个问题的真正含义。有人能帮我吗？
暂无答案！
目前还没有任何答案，快来回答吧！