bluebird Converting a callback API to promises.
Remarks
Promises have state, they start as pending and can settle to:
- fulfilled meaning that the computation completed successfully.
- rejected meaning that the computation failed.
Promise returning functions should never throw, they should return rejections instead. Throwing from a promise returning function will force you to use both a } catch { and a .catch. People using promisified APIs do not expect promises to throw. If you're not sure how async APIs work in JS - please see this answer first.
