let objA = testObj(dateProp: "Mar 13, 2018")
let objB = testObj(dateProp: "Apr 13, 2018")
let objC = testObj(dateProp: "Apr 12, 2018")
let objD = testObj(dateProp: "")

let arr: [testObj] = [objA, objB, objC]

let sortedArr = arr.sorted(by: { DateHandler.shared.convertStringToDate(string: $0.dateProp)?.compare(DateHandler.shared.convertStringToDate(string: $1.dateProp)!) == .orderedDescending })

print(sortedArr)