How to browserify, compile ES6 and minify NodeJS application

It shouldn't be necessary anymore to use a task runner. However, use a neat plugin like babelify from command line as described in its README.md here.

npm install --save-dev browserify babelify babel-preset-es2015

browserify script.js -o bundle.js \
    -t [ babelify --presets es2015 ] 

And add other transforms as needed from here or any where else, e.g. uglify.