Update 2017: I would use an async function if the environment supports it: async function readFiles(files) { for(const file of files) { await readFile(file); } }; If you’d like, you can defer reading the files until you need them using an async generator (if your environment supports it): async function* readFiles(files) { for(const file of … Read more
How a promise library decides If it has a .then function – that’s the only standard promise libraries use. The Promises/A+ specification has a notion called thenable which is basically “an object with a then method”. Promises will and should assimilate anything with a then method. All of the promise implementation you’ve mentioned do this. … Read more
Promises are not callbacks. A promise represents the future result of an asynchronous operation. Of course, writing them the way you do, you get little benefit. But if you write them the way they are meant to be used, you can write asynchronous code in a way that resembles synchronous code and is much more … Read more
The deferred antipattern (now explicit-construction anti-pattern) coined by Esailija is a common anti-pattern people who are new to promises make, I’ve made it myself when I first used promises. The problem with the above code is that is fails to utilize the fact that promises chain. Promises can chain with .then and you can return … Read more