webpack.config.js

const path = require('path');
const BundleDeclarationsWebpackPlugin = require('bundle-declarations-webpack-plugin');

module.exports = {
    entry: './temp/src/index.js',
    target: 'web',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'index.js',
        library: {
            type: 'umd',
            name: 'what',
        },
        globalObject: 'globalThis',
    },
    mode: 'production',
    plugins: [
        new BundleDeclarationsWebpackPlugin({
            entry: ['src/index.ts'],
            outFile: 'index.d.ts',
        }),
    ],
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: ['@babel/preset-env'],
                    },
                },
            },
        ],
    },
};