production.js

production.js

...
const TerserPlugin = require("terser-webpack-plugin");

environment.config.merge({
    devtool: "hidden-source-map",
    optimization: {
        minimizer: [
            new TerserPlugin({
                extractComments: false,
                parallel: true,
                cache: true,
                sourceMap: false,
                terserOptions: {
                    parse: {
                        ecma: 8,
                    },
                    compress: {
                        ecma: 5,
                        warnings: false,
                        comparisons: false,
                    },
                    mangle: {
                        safari10: true,
                    },
                    output: {
                        ecma: 5,
                        comments: false,
                        ascii_only: true,
                    },
                },
            }),
        ],
    },
});
...