webpack.dev.js

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

module.exports = merge(common, {
  mode: 'development',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: '[name].js',
    publicPath: '/',
  },
  module: {
    rules: [
      {
        test: /\.(sa|sc|c)ss$/,
        use: ['style-loader', 'css-loader', 'sass-loader'],
      },
      {
        test: /\.(png|svg|jpe?g|gif|mp3|ttf)$/i,
        use: {
          loader: 'file-loader',
          options: {
            name: 'assets/[name].[ext]',
          },
        },
      },
    ],
  },
  devtool: 'inline-source-map',
  devServer: {
    // contentBase
    static: {
      directory: './dist',
    },
    port: 3000,
    // hotOnly
    hot: 'only',
  },
});