为什么要区分Develoment 和 Production
Develoment环境需要开启devServer方便开发,Production环境需要精简sourceMap和对代码进行压缩、
方式一:不同模式用不同配置文件打包
1.安装webpack-merge合并多个配置文件
npm install webpack-merge -d
2.webpack-common.js做公共的配置
const path = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
module.exports = {
entry: {
main: './src/index.js'
},
module: {
rules: [
{
test: /.jpg$/,
use: {
loader: 'file-loader',
options: {
//占位符
name: "[name].[ext]",
outputPath: './img',
limit: 2048
}
}
},
{
test: /.scss$/,
use: [
'style-loader',
{
loader: 'css-loader',
options: {
//通过import引入的scss文件,也走下班2个loader
importLoaders: 2,
//开启模块化
modules: true
}
},
'sass-loader',
'postcss-loader'
]
},
{
test: /.css$/,
use: [
'style-loader',
'css-loader',
'postcss-loader'
]
},
{
test: /.js$/,
exclude: /node_modules/,
loader: 'babel-loader'
}
]
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
}),
new CleanWebpackPlugin()
],
output: {
filename: '[name].js',
path: path.resolve(__dirname, 'dist')
}
}
3.webpack-dev.js做的Develoment 环境的配置
const webpack = require('webpack')
const { merge } = require('webpack-merge')
const commonConfig = require('./webpack-common.js')
const devConfig = {
mode: 'development',
devtool: 'cheap-module-eval-source-map',
devServer: {
contentBase: './dist/',//开启服务器的目录
open: true,//自动打开一个浏览器,
hot: true,
proxy: {
'/api': 'http://localhost:3000'
},
},
optimization: {
usedExports: true
},
plugins: [
new webpack.HotModuleReplacementPlugin()
],
}
module.exports = merge(commonConfig, devConfig)
4.webpack-prod.js做的Production 环境的配置
const { merge } = require('webpack-merge')
const commonConfig = require('./webpack-common.js')
const prodConfig = {
mode: 'production',
devtool: 'cheap-module-source-map',
}
module.exports = merge(commonConfig, prodConfig)
5.pakeage.json 利用不同的打包文件打包
"scripts": {
"dev": "webpack-dev-server --config webpack-dev.js",
"build": "webpack --config webpack-prod.js"
},
"sideEffects": [
"*.css"
]
方式二:不同模式用不同的环境变量打包
1.安装webpack-merge合并多个配置文件
npm install webpack-merge -d
3.webpack-dev.js做的Develoment 环境的配置
const webpack = require('webpack')
// const { merge } = require('webpack-merge')
const commonConfig = require('./webpack-common.js')
const devConfig = {
...
}
module.exports = devConfig
// module.exports = merge(commonConfig, devConfig)
4.webpack-prod.js做的Production 环境的配置
// const { merge } = require('webpack-merge')
const commonConfig = require('./webpack-common.js')
const prodConfig = {
...
}
// module.exports = merge(commonConfig, prodConfig)
module.exports = prodConfig
2.webpack-common.js做公共的配置,并且根据环境变量,到处不同的merge config
...
const { merge } = require('webpack-merge')
const devConfig = require('./webpack-dev.js')
const prodConfig = require('./webpack-prod.js')
const commonConfig = {
...
}
//关键代码
module.exports = function (env) {
if (env && env.production) {
return merge(commonConfig, prodConfig)
} else {
return merge(commonConfig, devConfig)
}
}
5.pakeage.json 不再利用不同的打包文件打包
不再利用不同的打包文件打包,而都是webpack-common.js。build的时候传了环境变量--env.production。
"scripts": {
"dev": "webpack-dev-server --config webpack-common.js",
"build": "webpack --env.production --config webpack-common.js",
"dev-build": "webpack --profile --json > stats.json --config webpack-common.js "
},