webpack.config.js

const webpack = require('webpack');
const path = require('path');
require("@babel/polyfill/noConflict");

const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
const CopyPlugin = require('copy-webpack-plugin');
const isProdEnv = process.env.NODE_ENV === 'production';
const isDevEnv = !isProdEnv;

module.exports = {
    entry: {
        'background': [
            '@babel/polyfill/noConflict',
            './src/background.js'
        ]
    },
    output: {
        filename: '[name].min.js',
        path: path.resolve(__dirname, 'build')
    },
    module: {
        rules: [
            {
                test: /\.m?js$/,
                exclude: /(node_modules|bower_components)/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: [
                            '@babel/preset-env',
                        ]
                    }
                }
            },
        ]
    },
    optimization: {
        minimize: isProdEnv
    },
    plugins: [
        // new UglifyJSPlugin({
        //   sourceMap: isDevEnv,
        //   uglifyOptions: {
        //     mangle: false,
        //   },
        // }),
        new CopyPlugin([
            {from: 'public', to: '.'},
        ]),
    ],
    node: {
        process: true,
        child_process: "empty",
        fs: "empty",
    },
};