Promises series queue

series-promise.js

'use strict';

let p = (v) => {
    return new Promise((resolve, reject) => {
        setTimeout(resolve, 1000)
    }).then(() => v)
}

[1, 2, 3, 4, 5].reduce((seq, curr) => {
    return seq.then(() => p(curr)).then(console.log)
}, Promise.resolve())