auto-bind-methods.js

var d  = require('es5-ext/object/descriptor');  // soon just require('d');

var Foo = function () {};

Object.defineProperties(Foo.prototype, d.binder({
  someFn: d(function () {
    return this.whatever();
  })
}));

var foo = new Foo();

// On first foo.someFn access: `foo.someFn = foo.someFn.bind(foo); return foo.someFn` happens
otherObj.on('bar', foo.someFn);