懒人配置webpack

npm install npm@latest -g 

mkdir webpack-demo && cd webpack-demo
npm init -y
npm install webpack webpack-cli --save-dev

npm install --save-dev babel-loader babel-core babel-preset-env

npm install sass-loader node-sass --save-dev
npm install style-loader css-loader --save-dev

npx webpack --config webpack.config.js

npm install webpack-dev-server --save-dev

//config some code in package.json file 
"scripts": {
  "start:dev": "webpack-dev-server"
}

and in the shell to run 
npm run start:dev

//config hot update 
https://webpack.js.org/guides/hot-module-replacement/

--------------
webpack.config.js file conofigure
/* === dont forget to import scss to main.js file === */
/* ===> import './main.scss'; <=== */

var path = require("path");

module.exports = {
  entry: "./main.js",
  output: {
    path: path.resolve(__dirname, "dist"),
    filename: "bundle.js",
    publicPath: "/dist"
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        use: {
          loader: "babel-loader",
          options: { presets: ["es2015"] }
        }
      },
      {
        test: /\.scss$/,
        use: [
          {
            loader: "style-loader" // creates style nodes from JS strings
          },
          {
            loader: "css-loader" // translates CSS into CommonJS
          },
          {
            loader: "sass-loader" // compiles Sass to CSS
          }
        ]
      }
    ]
  }
};

hot module replacement: