[arctek]

It's also unintuitive in the sense that if you are racing you usually want to discard/stop the other Promises that didn't finish in time. But the only real way to do this is to pass through an AbortController down into whatever networking/IO task (and your own code for that matter) is happening to "cancel" it that way. Otherwise you just end up with the result of the fastest Promise and the rest will continue when they get a chance.

[aporetics]

I thought the point of using observables over promises is that they have cancellation, and presumably an implementation of race would cancel any slower request (i.e., handle the abort controller automatically)? Is that not the case?

[arctek]

My comment was just on the standard behavior. Not sure when it comes to observables, probably comes down to how you are implementing it. But in general it's impossible to cancel a hanging Promise, you have to have some kind of signalling mechanism that either throws so it rejects or otherwise resolves the Promise chain.