Promise sequence or waterfall

promiseSequence.js

const first = () => Promise.resolve('this');
const second = res => Promise.resolve(`${res} is`);
const third = res => Promise.resolve(`${res} a sequence`);

const somePromises = [
     first,
     second,
     third
];

// Execute a list of Promise return functions in series
const promiseSequence = promiseList => 
     promiseList.reduce((acc, curr) => acc.then(curr), Promise.resolve());

promiseSequence(somePromises).then(res => console.log("yep:", res));

// result: yep: this is a sequence