Node v8.x N-API asynchronous Promise example addon
IMPORTANT!
Node.js will process the fulfillment/conclusion of the Promise in an
asynchronous fashion (compared to "real-time" in JavaScript) because the
fulfillment is added to the event loop's "Promise fulfillment microtask
queue", which is processed immediately after the "nextTick microtask
queue", even when it is fulfilled synchronously in C++.
If this ever becomes UNTRUE, then you would need to utilize an
AsyncWorker (or a similar concept) in order to ensure this
Promise is fulfilled asynchronously.