Async Task Runner

async-task-runner.js

function processTasks(tasks){
  if(!tasks?.length) return console.log('Finished');
  const [exec, ...rest] = tasks;
  setTimeout(() => {
    exec();
    processTasks(rest);
  });
}

const smallBatch = [
  () => console.log('Small A'),
  () => console.log('Small B'),
  () => console.log('Small C')
];

const regularBatch = new Array(200)
  .fill({})
  .map((item, index) => {
    return function(){ console.log(`Regular ${index}`) };
  });

const bigBatch = new Array(1000)
  .fill({})
  .map((item, index) => {
    return function(){ console.log(`Big ${index}`) };
  });

processTasks(bigBatch);
processTasks(smallBatch);
processTasks(regularBatch);