A lot of APIs produce promises these days. The big one that I always need to promisify is `setTimeout`, but apart from that, I tend to find that if I'm using the `new Promise` API, I'm usually doing something wrong.
With Node APIs, there's a promisified version of pretty much everything. With browser APIs, there's usually a version with promises, and I'm struggling to think of an asynchronous API without promises that hasn't been superseded by something else (e.g. XMLHttpRequest -> fetch). If I'm converting from an event-emitter API to promises, there's usually going to be an impedance mismatch between the expectations of the event-based system and the promise-based system, and I probably need to explore another option.
I agree that any competent JS dev should understand how to create promises "from scratch" like this. But it still should probably be a fairly rare occurrence, and if I see a lot of `new Promise` calls in one place, it's pretty much always a sign that someone doesn't really understand how promises work.
With Node APIs, there's a promisified version of pretty much everything. With browser APIs, there's usually a version with promises, and I'm struggling to think of an asynchronous API without promises that hasn't been superseded by something else (e.g. XMLHttpRequest -> fetch). If I'm converting from an event-emitter API to promises, there's usually going to be an impedance mismatch between the expectations of the event-based system and the promise-based system, and I probably need to explore another option.
I agree that any competent JS dev should understand how to create promises "from scratch" like this. But it still should probably be a fairly rare occurrence, and if I see a lot of `new Promise` calls in one place, it's pretty much always a sign that someone doesn't really understand how promises work.