ES6 + a little more on top of ES5
In short, es2pi is a collection of ES6 polyfills + methods missing even in ES6.
Array.prototype.repeatis missing. You should be able to go like
var a = .repeat(42);
typeof null === nullis welcome but shouldn't we add
num.is(42)is definitely better than
Thanks to ES5, it is now safe to extend
2π is a little bigger than 6, isn't it?