Sequential Promises

promise.js

function go(id) {
    return new Promise((resolve, reject) => {
        console.log('promise entered', id);
        const rnd = Math.random() * 500;
        setTimeout(() => {
            resolve('resolved');
        }, rnd);
    });
}

let deferred = Promise.resolve();
for (let i = 0; i < 10; i++) {
    deferred = deferred.then(r => {
        return go(i);
    });
}
deferred.then(() => console.log('complete'));