build.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

const webpack = require('webpack');
function webpackErrorHandler(err, stats){
	if (err) {
		console.error(err.stack || err);
		if (err.details) {
			console.error(err.details);
		}
		process.exit(1);
	}
	const info = stats.toJson();
	if (stats.hasErrors()) {
		console.error(info.errors);
		process.exit(1);
	}
	if (stats.hasWarnings()) {
		console.warn(info.warnings);
	}
}

webpack({
	mode: 'production',
	target: "node",
	entry: {
		index: __dirname + '/data/index.js',
	},
	output: {
		path: __dirname,
		filename: 'gendata.temp.js',
		library: 'gendata',
		libraryTarget: 'umd',
	},
	optimization: {
		minimize: false,
	},
}, (err, stats) => {
	webpackErrorHandler(err, stats);
	var gendata = require('./gendata.temp').default();
	webpack({
		mode: 'production',
		entry: {
			preload: './app/preload.js',
			index: './app/index.js',
		},
		output: {
			path: __dirname,
			filename: '[name].min.js',
		},
		module: {
			rules: [
				{
					test: /(\.jsx|\.js)$/,
					use: {
						loader: "babel-loader",
						options: {
						  presets: ["@babel/preset-env"]
						}
					},
					exclude: /node_modules/
				},
				{
				  test: /\.less$/,
				  use: [
					{
					  loader:"raw-loader"
					},
					{
					  loader:"postcss-loader",
					  options: {
						postcssOptions:{
						  plugins: {
							'cssnano': {}
						  }
						}
					  }
					},
					{
					  loader:"less-loader"
					}
				  ]
				}
			],
		},
		plugins: [
			new HtmlWebpackPlugin({
			  filename: path.resolve(__dirname,'index.html'),
			  template: path.resolve(__dirname,'app/index.ejs'),
			  inject: false
			}),
			new HtmlWebpackPlugin({
			  filename: path.resolve(__dirname,'kanji-reading.html'),
			  template: path.resolve(__dirname,'app/index.ejs'),
			  inject: false,
			  meta:{
				fromLocal:true
			  }
			}),
			new webpack.DefinePlugin({
				'READINGS_DATA': '\"'+gendata.r+'\"',
				'VARIANTS_DATA': '\"'+gendata.v+'\"'
			}),
		],
	}, webpackErrorHandler);
});