A way of accessing objects from functions.

index.ts

// So I realised this was just a candidate fn. Nothing novel about it.

(function () {
   'use strict';
  
  var res = { data: [] };
  
  function check(obj: Object, fn: Function) {
    return fn.call(obj)
  }
  
  function hasNoData() {
    return this.data.length === 0;
  }
   
  if ( hasNoData(res) ) { ... do smth } // this is when hasNoData accepts an arg
  
  if ( check(res, hasNoData) ) { ... do smth } // true
}());