mini-css-extract-plugin不支持webpack-dev-server

Question

当我运行npm run dev mini-css-extract-plugin捆绑时，但当我运行npm run server时，mini-css-extract-plugin不捆绑。

const path = require('path');
const webpack = require('webpack');
const VueLoaderPlugin = require('vue-loader/lib/plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');

module.exports = {
    mode: 'development',

    entry: {
        app: './resources/index.js'
    },

    output: {
        path: path.resolve(__dirname, 'app/assets/js'),
        publicPath: '/assets/js',
      filename: 'app.js'
    },

    devServer: {
        contentBase: path.join(__dirname, 'app'),
        port: 9000,
    },

   module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader'
                }
            },
            {
                test: /\.vue$/,
                loader: 'vue-loader'
            },
            {
                test: /\.scss$/,
                use: [
                    MiniCssExtractPlugin.loader,
                    {
                        loader: 'css-loader',
                        options: {
                            importLoaders: 2,
                            sourceMap: true
                        }
                    },
                    {
                        loader: 'postcss-loader',
                        options: {
                            plugins: () => [
                                require('autoprefixer')
                            ],
                            sourceMap: true
                        }
                    },
                    {
                        loader: 'sass-loader',
                        options: {
                            sourceMap: true
                        }
                    }
                ]
            }
        ]
    },

    optimization: {
        splitChunks: {
            cacheGroups: {
                js: {
                    test: /\.js$/,
                    name: "commons",
                    chunks: "all",
                    minChunks: 7,
                },
                css: {
                    test: /\.(css|sass|scss)$/,
                    name: "commons",
                    chunks: "all",
                    minChunks: 2,
                }
            }
        }
    },

    plugins: [
        new MiniCssExtractPlugin({filename: "../css/[name].css"}),
        new VueLoaderPlugin()
    ],

    resolve: {
        alias: {
            'vue$': 'vue/dist/vue.esm.js'
        },
        extensions: ['*', '.js', '.vue', '.json']
    }
};

和

{
  "name": "second",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "dev": "webpack --mode development",
    "pro": "webpack --mode production",
    "server": "webpack-dev-server",
    "watch": "webpack --watch"
  },
....

webpack-dev-server检测js文件的变化并重新加载页面，js函数正常工作，但当scss文件发生变化时，webpack-dev-server也会检测到这一点，但不会捆绑。

我想知道问题出在哪里？

Answer 1

这是我的webpack.config.js

你可以尝试删除其他css加载器(Sass postcss)，制作一个mvd(最小可行演示)，尝试一下。

希望能对你有所帮助

const path = require('path')
const webpack = require('webpack')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin')
const isDevelopment = process.env.NODE_ENV !== 'production';

module.exports = {
  // change to .tsx if necessary
  entry: {
    app: './src/app.tsx'
  },
  output: {
    filename: '[name].[contenthash].js'
  },
  resolve: {
    alias: {
      assets: path.resolve(__dirname, '../src/assets/'),
    },
    extensions: [".ts", ".tsx", ".js", ".jsx"]
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          isDevelopment ? 'style-loader' : {
            loader: MiniCssExtractPlugin.loader,
            options: {
              // you can specify a publicPath here
              // by default it uses publicPath in webpackOptions.output
              publicPath: '../',
              hmr: isDevelopment,
            },
          },
          {
            loader: 'css-loader',
            options: {
              modules: true
            }
          }
        ]
      },
      {
        // 图片格式正则
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        use: [
          {
            loader: 'url-loader',
            // 配置 url-loader 的可选项
            options: {
              // 限制 图片大小 9KB，小于限制会将图片转换为 base64格式
              limit: 10000,
              // 超出限制，创建的文件格式
              // build/images/[图片名].[hash].[图片格式]
              name: 'images/[name].[hash].[ext]'
            }
          }
        ]
      },
      // changed from { test: /\.jsx?$/, use: { loader: 'babel-loader' }, exclude: /node_modules/ },
      { test: /\.(t|j)sx?$/, use: { loader: 'ts-loader' }, exclude: /node_modules/ },

      // addition - add source-map support
      { enforce: "pre", test: /\.js$/, exclude: /node_modules/, loader: "source-map-loader" }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      template: './src/index.html'
    }),
    new MiniCssExtractPlugin({
      filename: '[name].[contenthash].css',
      chunkFilename: '[id].[contenthash].css',
    }),    
    new webpack.EnvironmentPlugin({
      NODE_ENV: 'development', // use 'development' unless process.env.NODE_ENV is defined
      DEBUG: false
    })    
  ],
  optimization: {
    splitChunks: {
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name: 'vendors',
          chunks: 'all',
        },
      },
    },
  }
}