WebPack進階 （環境變量的使用）

隻需要一個common.js檔案通過在package.json中傳遞不同的參數，區分是開發環境還是生産環境。

在 package.json 中：

{
  "name": "haiyang",
  "sideEffects": [
    "*.css"
  ],
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev-build": "webpack --config ./build/webpack.common.js",
    "dev": "webpack-dev-server --config ./build/webpack.common.js",
    "build": "webpack --env.production --config ./build/webpack.common.js" //通過--env.production,把環境變量傳進去
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.2.0",
    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
    "@babel/plugin-transform-runtime": "^7.2.0",
    "@babel/preset-env": "^7.2.0",
    "@babel/preset-react": "^7.0.0",
    "autoprefixer": "^9.3.1",
    "babel-loader": "^8.0.4",
    "clean-webpack-plugin": "^1.0.0",
    "css-loader": "^1.0.1",
    "express": "^4.16.4",
    "file-loader": "^2.0.0",
    "html-webpack-plugin": "^3.2.0",
    "imports-loader": "^0.8.0",
    "mini-css-extract-plugin": "^0.5.0",
    "node-sass": "^4.10.0",
    "optimize-css-assets-webpack-plugin": "^5.0.1",
    "postcss-loader": "^3.0.0",
    "sass-loader": "^7.1.0",
    "style-loader": "^0.23.1",
    "url-loader": "^1.1.2",
    "webpack-cli": "^3.1.2",
    "webpack-dev-middleware": "^3.4.0",
    "webpack-dev-server": "^3.1.10",
    "webpack-merge": "^4.1.5"
  },
  "dependencies": {
    "@babel/polyfill": "^7.0.0",
    "@babel/runtime": "^7.2.0",
    "@babel/runtime-corejs2": "^7.2.0",
    "jquery": "^3.3.1",
    "lodash": "^4.17.11",
    "react": "^16.6.3",
    "react-dom": "^16.6.3",
    "webpack": "^4.25.1"
  }
}
           

在 webpack.common.js 中：

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const webpack = require('webpack');
const merge = require('webpack-merge');
const devConfig = require('./webpack.dev.js');
const prodConfig = require('./webpack.prod.js');
const commonConfig = {
    entry: {
        main: './src/index.js',
    },
    module: {
        rules: [{ 
            test: /\.js$/, 
            exclude: /node_modules/,
            use: [{
                loader: 'babel-loader'
            }, {
                loader: 'imports-loader?this=>window'
            }]
        }, {
            test: /\.(jpg|png|gif)$/,
            use: {
                loader: 'url-loader',
                options: {
                    name: '[name]_[hash].[ext]',
                    outputPath: 'images/',
                    limit: 10240
                }
            } 
        }, {
            test: /\.(eot|ttf|svg)$/,
            use: {
                loader: 'file-loader'
            } 
        }]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: 'src/index.html'
        }), 
        new CleanWebpackPlugin(['dist'], {
            root: path.resolve(__dirname, '../')
        }),
        new webpack.ProvidePlugin({
            $: 'jquery',
            _join: ['lodash', 'join']
        }),
    ],
    optimization: {
        runtimeChunk: {
            name: 'runtime'
        },
        usedExports: true,
        splitChunks: {
      chunks: 'all',
      cacheGroups: {
          vendors: {
              test: /[\\/]node_modules[\\/]/,
              priority: -10,
              name: 'vendors',
          }
      }
    }
    },
    performance: false,
    output: {
        path: path.resolve(__dirname, '../dist')
    }
}

module.exports = (env) => {
    if(env && env.production) {//線上環境
        return merge(commonConfig, prodConfig);
    }else {//開發環境
        return merge(commonConfig, devConfig);
    }
}

           

在 webpack.dev.js 中：

const webpack = require('webpack');

const devConfig = {
    mode: 'development',
    devtool: 'cheap-module-eval-source-map',
    devServer: {
        contentBase: './dist',
        open: true,
        port: 8080,
        hot: true
    },
    module: {
        rules: [{
            test: /\.scss$/,
            use: [
                'style-loader', 
                {
                    loader: 'css-loader',
                    options: {
                        importLoaders: 2
                    }
                },
                'postcss-loader',
                'sass-loader',
                
            ]
        }, {
            test: /\.css$/,
            use: [
                'style-loader',
                'css-loader',
                'postcss-loader'
            ]
        }]
    },
    plugins: [
        new webpack.HotModuleReplacementPlugin()
    ],
    output: {
        filename: '[name].js',
        chunkFilename: '[name].js',
    }
}

module.exports = devConfig;
           

在webpack.prod.js 中：

const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");

const prodConfig = {
    mode: 'production',
    devtool: 'cheap-module-source-map',
    module: {
        rules:[{
            test: /\.scss$/,
            use: [
                MiniCssExtractPlugin.loader, 
                {
                    loader: 'css-loader',
                    options: {
                        importLoaders: 2
                    }
                },
                'postcss-loader',
                'sass-loader',
                
            ]
        }, {
            test: /\.css$/,
            use: [
                MiniCssExtractPlugin.loader,
                'css-loader',
                'postcss-loader'
            ]
        }]
    },
    optimization: {
        minimizer: [new OptimizeCSSAssetsPlugin({})]
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename: '[name].css',
            chunkFilename: '[name].chunk.css'
        })
    ],
    output: {
        filename: '[name].[contenthash].js',
        chunkFilename: '[name].[contenthash].js'
    }
}

module.exports = prodConfig;