I expect that will execute sequentially though as opposed to the solution above it.
Your question about Rust futures makes a ton more sense now. This only works because a promise is self-executing / not inert like a Rust Future. Thank you kind stranger! Your async-foo is strong ^_^
IIUC, work to be done for a promise is (typically) placed in the task queue when the promise is created, and will be eligible to start running the next time you get back to the event loop, which is part of what an `await` does.
The asynchronous portion of the work is enqueued when the function is called, but does not start executing until it's scheduled, which can't happen until the current task ends or is blocked by an await. This is useful, as it means a promise can't settle before you've had a chance to add handlers; otherwise you might sometimes get UnhandledPromiseRejections because of an unavoidable race condition.
I said arguably correct because there's nothing stopping the function from doing a portion of the work synchronously, which would mean the work as a whole starts with the function call.