let someArray = [1, 2]
let chunkSize = 10
let chunks = chunk(someArray, chunkSize)

const chunk = (a, l) => a.length === 0 ? [] : [a.slice(0, l)].concat(chunk(a.slice(l), l));

let batches = chunk(myArray, 10)
for(let batch of batches){
  await Promise.all(batch.map(async(item) => {
    await doSomeAsyncStuffForEachItemInBatch(item);
  }));
})