webpack.config.js

  const path = require('path');

  module.exports = {
    entry: './src/app.js',
    output: {
      filename: 'bundle.js',
      path: path.resolve(__dirname, 'public')
    },
    module: {
        rules: [
            {
                test: /\.css$/,
                use: [
                'style-loader',
                'css-loader'
                ]
            },
            {  //Here we are including the .scss loader to make it transpale Sass to CSS.
                test: /\.scss$/,
                use: [{
                    loader: "style-loader" // creates style nodes from JS strings
                }, {
                    loader: "css-loader" // translates CSS into CommonJS
                }, {
                    loader: "sass-loader" // compiles Sass to CSS
                }]
            }
        ]
    }
  };