express-router 解决的问题

app.get('/api/student', (req, res, next) =>{});
app.post('/api/student', (req, res, next) =>{});
app.delete('/api/student', (req, res, next) =>{});

这样就会有很多冗余，请求地址一样就协议变啦，但是app.use() 中的中间件函数在任何协议下的请求都能触发，这俩结合一下不就能节省很多冗余，而且express的路由本身就是中间件函数，示例如下

// 匹配的baseUrl为 /api/student,当满足这个条件就将其交给路由的处理
app.use('/api/student', require('./api/student'));

const express = require('express');
// 创建路由
const router = express.Router();
const { asyncHandler } = require('../getSendResult');
const stu = require('../../services/studentService');
// 获取学生
router.get(
  '/',
  asyncHandler(async (req, res, next) => {
    const page = req.query.page || 1;
    const limit = req.query.limit || 10;
    const sex = req.query.sex || -1;
    const name = req.query.name || '';
    return await stu.getStudents(page, limit, sex, name);
  })
);
// 添加学生
router.post(
  '/',
  asyncHandler(async (req, res, next) => {
    return await stu.addStudent(req.body);
  })
);
module.exports = router;

缺点

expressd.router对不怎吗支持异步，promise的支持非常差，需要将promise的结果转换后才能使用

exports.getErr = function(err = "server internal error", errCode = 500) {
  return {
    code: errCode,
    msg: err,
  }
}
exports.getResult = function(res) {
  return {
    code: 200,
    msg: "",
    data: res,
  }
}
// 将其转换
exports.asyncHandler =  function(fun) {
  return async (req, res, next) => {
    try {
      const result = await fun(req, res, next);
      res.send(exports.getResult(result));
    } catch(err) {
      next(err)
    }
  }
}