webpack.config.dev.js

const path = require('path');
const webpack = require('webpack');
const HtmlWebPackPlugin = require('html-webpack-plugin');
const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin');

module.exports = {
  entry: './src/index.jsx',
  output: {
    path: path.join(__dirname, '/dist'),
    publicPath: '/',
    filename: 'main.js',
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: ['babel-loader'],
      },
      {
        test: /\.css$/,
        use: [
          'style-loader',
          'css-loader',
        ],
      },
    ],
  },
  plugins: [
    new MonacoWebpackPlugin(),
    new HtmlWebPackPlugin({
      template: './src/index.html',
      filename: './index.html',
    }),
    new webpack.DefinePlugin({
      'process.env': {
        'NODE_ENV': "'development'",
      },
    }),
  ],
};