webpack.config.js

const path = require("path"),
	webpack = require("webpack"),
	package = require("./package.json"),
	MiniCssExtractPlugin = require('mini-css-extract-plugin'),
	OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin'),
	buildMode = "production"; // 'development' or 'production'

module.exports = {
	mode: buildMode,
	entry: {
		kamadatepicker: ["./src/kamadatepicker.js"]
	},
	output: {
		filename: "[name].min.js",
		path: path.resolve(__dirname, "dist")
	},
	plugins: getPlugins(),
	module: {
		rules: [
			{
				test: /\.scss$/,
				exclude: /node_modules/,
				use: [
					{
						loader: MiniCssExtractPlugin.loader,
						options: {
							hmr: buildMode === 'development',
						},
					},
					'css-loader',
					'sass-loader',
				]
			},
			{
				test: /\.js$/,
				use: {
					loader: "babel-loader",
					query: {
						presets: ["@babel/preset-env"]
					}
				}
			}
		]
	}
};

function getPlugins() {
	let plugins = [new MiniCssExtractPlugin({ filename: "kamadatepicker.min.css" })];

	if (buildMode === "production") {
		plugins.push(new webpack.BannerPlugin(`${package.name} - version ${package.version}`));
		plugins.push(new OptimizeCssAssetsPlugin());
	}
	else if (buildMode === "development") {
		plugins.push(
			new webpack.BannerPlugin({ banner: "/* @ sourceURL=[name].js */", raw: true })
		);
	}

	return plugins;
}