I have a code like this :

array = [...]; //very long array

processArray = function(array) {
  let result =[];
  let Nindex=0;   
  let process = function (){
    // process array (long function) and create result array
    if (Nindex++ < array.length-1) {
      setTimeout(process, 1) //Call recursion
    }
  }
  
  process(); // start processing
  return result
}

resultingArray = processArray (array);

How can I make the function wait all the recursions before returning result ?