webpack.dev.js

const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const webpack = require('webpack');

module.exports = merge(common, {
  mode: 'development',
  devServer: {
    contentBase: './',
    hot: true,
    open: true,
    port: 9000
  },
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader'
        ]
      },
    ]
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin()
  ]
});