从零搭建 Node.js 企业级 Web 服务器（二）：校验

时间 2020-07-23 标签搭建 node.js node 企业 web 服务器校验

理想中的校验

校验就是对输入条件的约束，避免无效的输入引发异常。Web 系统的用户输入主要为编辑与提交各种表单，一方面校验要作在编辑表单字段与提交的时候，另外一方面接收表单的接口也要作足校验行为，经过先后端共同控制输入条件。然而，当前端比后端校验严格时，会直接提升用户编辑信息的门槛。反之，当后端比前端校验严格时，会让辛苦填写的表单仍没法顺利提交。这两种状况都会严重打击用户的信心，其中的关键在于校验规则的先后端一致。css

选择校验模块

基于上述思考，值得期待的校验模块应该具有如下特色：html

逻辑能够跨端复用
精巧，包大小有限
语义清晰
功能全面
足够稳定

综合比较以后，选择 yup 做为校验模块，如今以上一章已完成的工程 host1-tech/nodejs-server-examples - 01-api-and-layering 着手改造，在工程根目录安装 yup：前端

$ yarn add yup  # 本地安装 yup
# ...
info Direct dependencies
└─ yup@0.29.1
# ...

加上后端校验

悉心的读者会发现当前的店铺管理功能对输入是没有限制的，好比设置店铺名为空也会提交成功。如今加上后端校验弥补这一不足：node

$ mkdir src/moulds            # 新建 src/moulds 目录存放校验 schema

$ tree -L 2 -I node_modules   # 展现除了 node_modules 以外的目录内容结构
.
├── Dockerfile
├── package.json
├── public
│   ├── index.html
│   └── index.js
├── src
│   ├── controllers
│   ├── moulds
│   ├── server.js
│   └── services
└── yarn.lock

// src/moulds/ShopForm.js
const Yup = require('yup');

exports.createShopFormSchema = () =>
  Yup.object({
    name: Yup.string()
      .required('店铺名不能为空')
      .min(3, '店铺名至少 3 个字符')
      .max(20, '店铺名不可超过 20 字'),
  });

// src/controllers/shop.js
const { Router } = require('express');
const shopService = require('../services/shop');
+const { createShopFormSchema } = require('../moulds/ShopForm');

class ShopController {
  // ...
  put = async (req, res) => {
    const { shopId } = req.params;
    const { name } = req.query;
+
+    try {
+      await createShopFormSchema().validate({ name });
+    } catch (e) {
+      res.status(400).send({ success: false, message: e.message });
+      return;
+    }
+
    const shopInfo = await this.shopService.modify({
      id: shopId,
      values: { name },
    });

    if (shopInfo) {
      res.send({ success: true, data: shopInfo });
    } else {
      res.status(404).send({ success: false, data: null });
    }
  };
  // ...
}

module.exports = async () => {
  const c = new ShopController();
  return await c.init();
};

这样一来，不规范的输入就被有效的阻止了，效果以下：git

加上前端校验

如今前端也加上校验为用户有效提供错误信息，先借助 rollup 将 yup 搬上浏览器：github

$ yarn add -D rollup @rollup/plugin-node-resolve @rollup/plugin-commonjs rollup-plugin-terser # 本地安装 rollup 及其插件
# ...
info Direct dependencies
├─ @rollup/plugin-commonjs@14.0.0
├─ @rollup/plugin-node-resolve@8.4.0
├─ rollup-plugin-terser@6.1.0
└─ rollup@2.22.2
# ...

// package.json
{
  "name": "02-validate",
  "version": "1.0.0",
  "scripts": {
-    "start": "node src/server.js"
+    "start": "node src/server.js",
+    "build:yup": "rollup node_modules/yup -o src/moulds/yup.js -p @rollup/plugin-node-resolve,@rollup/plugin-commonjs,rollup-plugin-terser -f umd -n 'yup'"
  }
  // ...
}

$ yarn build:yup
# ...
created src/moulds/yup.js in 1.9s

而后补充前端校验逻辑：express

// src/server.js
const express = require('express');
const { resolve } = require('path');
const { promisify } = require('util');
const initControllers = require('./controllers');

const server = express();
const port = parseInt(process.env.PORT || '9000');
const publicDir = resolve('public');
+const mouldsDir = resolve('src/moulds');

async function bootstrap() {
  server.use(express.static(publicDir));
+  server.use('/moulds', express.static(mouldsDir));
  server.use(await initControllers());
  await promisify(server.listen.bind(server, port))();
  console.log(`> Started on port ${port}`);
}

bootstrap();

// public/glue.js
import './moulds/yup.js';

window.require = (k) => window[k];
window.exports = window.moulds = {};

/* public/index.css */
.error {
  color: red;
  font-size: 14px;
}

<!-- public/index.html -->
<html>
  <head>
    <meta charset="utf-8" />
+    <link rel="stylesheet" href="./index.css" />
  </head>
  <body>
    <div id="root"></div>

    <script type="module">
+      import './glue.js';
      import { refreshShopList, bindShopInfoEvents } from './index.js';

      async function bootstrap() {
        await refreshShopList();
        await bindShopInfoEvents();
      }

      bootstrap();
    </script>
  </body>
</html>

// public/index.js
+import './moulds/ShopForm.js';
+const { createShopFormSchema } = window.moulds;
+
export async function refreshShopList() {
  const res = await fetch('/api/shop');
  const { data: shopList } = await res.json();
  const htmlItems = shopList.map(
    ({ id, name }) => `
<li data-shop-id="${id}">
  <div data-type="text">${name}</div>
  <input type="text" placeholder="输入新的店铺名称" />
  <a href="#" data-type="modify">确认修改</a>
  <a href="#" data-type="remove">删除店铺</a>
+  <div class="error"></div>
</li>`
  );
  document.querySelector('#root').innerHTML = `
<h1>店铺列表：</h1>
<ul class="shop-list">${htmlItems.join('')}</ul>`;
}

// ...

export async function modifyShopInfo(e) {
  const shopId = e.target.parentElement.dataset.shopId;
  const name = e.target.parentElement.querySelector('input').value;
+
+  try {
+    await createShopFormSchema().validate({ name });
+  } catch ({ message }) {
+    console.log(message);
+    e.target.parentElement.querySelector('.error').innerHTML = message;
+    return;
+  }
+
  await fetch(`/api/shop/${shopId}?name=${encodeURIComponent(name)}`, {
    method: 'PUT',
  });
  await refreshShopList();
}

看一下效果：json

本章源码