time-based-processing.js

const processDataArray = (dataArray, finishCallback) => {
 // take a new copy of array
 const todo = dataArray.concat();
 // to store each processed data
 let result = [];
 // timer function
 const timedProcessing = () => {
   const start = +new Date();
   do {
     // process each data item and store it's result
     const singleResult = processSingleData(todo.shift());
     result.push(singleResult);
     // check if todo has something to process and the time difference must not be greater than 50
   } while (todo.length > 0 && +new Date() - start < 50);
 
   // check for remaining items to process
   if (todo.length > 0) {
     setTimeout(timedProcessing, 25);
   } else {
     // finished with all the items, initiate finish callback
     finishCallback(result);
   }
 };
 setTimeout(timedProcessing, 25);
};



const processSingleData = data => {
 // process data
 return processedData;
};