JavaScript increment last array element

I am in the process of trying to figure out how to increment the last element in an array using pop() and push(). I keep getting the original values after incrementing the pop array.

What needs to happen is that newArray needs to equal _array with the last element incremented by 1. For example '0,0,7' will change to '0,0,8'.

A slight shove in the right direction would be much appreciated.

var someArray = [0,0,7];

   var incrementLastArrayElement = function(_array) {
   var newArray = [];
   var popArray = someArray.pop();
   newArray = someArray.push(popArray++);
   }

console.log(incrementLastArrayElement(someArray));