await-promise-sequential.js

// Promise.resolve(ids).then(ids => {
//     return ids.reduce((cur, next) => {
//         return cur.then(() => {
//             return doThingThatReturnsPromise(next);
//         });
//     }, Promise.resolve());
// }).then(() => {
//     console.log('all done');
// }).catch(err => {
//     console.error(err);
// });

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

data = [0, 1, 2];

(async function() {

  try {
    let responses = await data.reduce((cur, next) => {
      return cur.then(async function() {
        console.log('start');
        return await sleep(1000);
      });
    }, Promise.resolve());
	  
	console.log('done');
	  
  } catch (err) {
    console.error(err);
  }


}())