creating a function with a given name and arity in ES5 vs. ES2015

create-function-with-given-arity.js

var apply = Function.prototype.call.bind(Function.prototype.apply);

function createFunctionES5(name, arity, behaviour) {
  var params = Array.apply(null, Array(arity)).map(function (x, p) { return "p" + p; }).join(",");
  var code = "return function " + name + "(" + params + ") { return apply(f, this, arguments); }";
  return Function("apply", "f", code)(apply, behaviour);
}

var define = Object.defineProperty.bind(Object);

function createFunctionES2015(name, arity, behaviour) {
  function f(){ return apply(behaviour, this, arguments); };
  define(f, "name", { value: name, writable: false, enumerable: false, configurable: true });
  define(f, "length", { value: arity, writable: false, enumerable: false, configurable: true });
  return f;
}

Oh neat! Should help with currying