babel-minify
An ES6+ aware minifier based on the Babel toolchain (beta)
...When it's possible to only target browsers that support newer ES features, code sizes can be smaller because you don't have to transpile and then minify. When testing, it's recommended to run minifiers for production so less code is sent to end-users vs. in development where it can be an issue for readability when debugging. Options specific to a certain environment are merged into and overwritten non-env specific options.