在我们开发的过程中，我们会使用webpack-dev-server实现自动刷新，webpack-dev-server会把编译后的文件全部保存在内存里，而不会写入到文件目录内。但当我们的开发是前端和后端在一个项目里的时候就不行了。我们可以使用webpack结合express实现自动编译刷新
配置webpack
首先就是配置webpack的配置。新建一个webpack.config.js文件
const path = require('path') const webpack = require('webpack') var hotMiddlewareScript = 'webpack-hot-middleware/client' module.exports = { entry: { main: ['./src/main.js', hotMiddlewareScript] }, mode: 'development', output: { path: path.resolve(__dirname, 'public'), filename: 'js/[name].js', publicPath: 'https://www.jb51.net/' }, resolve: { extensions: ['.js'] }, plugins: [ new webpack.optimize.OccurrenceOrderPlugin(), new webpack.HotModuleReplacementPlugin(), new webpack.NoEmitOnErrorsPlugin() ] }
我们这里需要关注的是，每个entry后都要增加一个hotMiddlewareScript，还有就是增加3个插件
首先新建一个webpack.middleware文件，这里我们需要用到webpack-dev-middleware和 webpack-hot-middleware两个中间件。
const webpack = require('webpack') const webpackDevMiddleware = require('webpack-dev-middleware') const webpackHotMiddleware = require('webpack-hot-middleware') const webpackConfig = require('./webpack.config') module.exports = app => { let compiler = webpack(webpackConfig) app.use(webpackDevMiddleware(compiler, { publicPath: 'https://www.jb51.net/', stats: { colors: true, chunks: false } })) app.use(webpackHotMiddleware(compiler)) }
注意：webpack-dev-middleware和webpack-hot-middleware的静态资源服务仅仅用于开发环境。到了生产环境，应该使用express.static()。
下面编写express代码
const express = require('express') const bodyParser = require('body-parser') const {resolve} = require('path') const webpackMiddleware=require('./webpack.middleware') const router = express.Router() const app=express() const port = process.env.PORT || 3000 webpackMiddleware(app) app.use(express.static(resolve(__dirname,'./public'))) app.use(bodyParser.json()) app.use(bodyParser.urlencoded({ extended: true })) // ...代码 app.use(router) app.listen(port, () => { console.log(`Server listening on :${port}, Ctrl+C to stop`) })
这样，我们在开发的时候，前端和后端都在同一个服务里运行了