Simple Webpack 4 Compile SCSS to CSS config with autoprefix and minify

package.json

{
  "name": "my-project",
  "version": "1.0.0",
  "description": "Simple and JS SCSS complie with autoprefix and minify",
  "scripts": {
    "build": "webpack",
    "watch": "webpack --watch"
  },
  "devDependencies": {
    "autoprefixer": "^9.0.0",
    "breakpoint-sass": "^2.7.1",
    "css-loader": "^2.0.0",
    "cssnano": "^4.0.5",
    "node-sass": "^4.9.0",
    "mini-css-extract-plugin": "^0.5.0",
    "postcss-loader": "^3.0.0",
    "sass-loader": "^7.0.1",
    "style-loader": "^0.23.1",
    "webpack": "^4.6.0",
    "webpack-cli": "^3.0.0"
  },
  "dependencies": {
  }
}

webpack.config.js

const path = require('path');
const autoprefixer = require('autoprefixer');
const cssnano = require('cssnano');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");

// Hard code this to production but can be adapted to accept args to change env.
const mode = 'development';

module.exports = {
  mode,
  watch:true,

  output: {
    // Webpack will create js files even though they are not used
    filename: '../js/app.js',
    chunkFilename: '[name].[chunkhash].chunk.js',
    // Where the CSS is saved to
    path: path.resolve(__dirname, 'css') 
  },

  resolve: {
    extensions: ['.css', '.scss'],
    alias: {
      // Provides ability to include node_modules with ~
      '~': path.resolve(process.cwd(), 'src'),
    },
  },

  entry: [
    // Will create "styles.css" in "css" dir.
    './src/index.js',
    './src/app.scss',
  ],

  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          // Extract and save the final CSS.
          MiniCssExtractPlugin.loader,
          // Load the CSS, set url = false to prevent following urls to fonts and images.
          { loader: "css-loader", options: { url: false, importLoaders: 1 } },
          // Add browser prefixes and minify CSS.
          { loader: 'postcss-loader', options: { plugins: [autoprefixer(), cssnano()] }},
          // Load the SCSS/SASS
          { loader: 'sass-loader' },
        ],
      },
    ],
  },

  plugins: [
    // Define the filename pattern for CSS.
    new MiniCssExtractPlugin({
      filename: 'app.css',
      chunkFilename: '[id].css',
    })
  ]
}