perform.js

Pass callbacks

//by Denys Pysmennyi

function perform() {
  //TODO implement
}

perform(20, function(value) {
  console.log(value) // 20
  var param = 1;
  console.log(param); // 1
  return param;
})
.then('a', 'b', function(a, b, param) {
  console.log(++param); // 2
  return param;
})
.then(function(param) { // param === 2
  console.log(++param); // 3
  return param;
});

// one of the solutions
function perform(...args1) {
	var func1 = args1.pop()
	var result = func1.apply(this, args1)
	return {
		then: function (...args2) {
			var func2 = args2.pop()
			return perform.apply(this, [...args2, result, func2])
		}
	}
}