synonym for delayWhen as waitFor?

[eliprand]

This is just a suggestion, but delayWhen() could use a synonym (or a rename?) as waitFor() or waitUntil(). For the second time in a couple of years, I had the need to wait for an observable to complete but ignore its return value and instead use the previous value in the pipe(). Something like:

start().pipe(
  delayWhen(()=>ignoreReturn()),  // <-- ignore the return value, but wait for it to complete
  map((x) => doSomethingWith(x))  // <-- x is the return value from start()
)

Both times it took me way too long to figure out that delayWhen() wasn't like delay() and had very little to do with time (which is what I think about when I hear delay). Someone on SO bailed me out today. And it reminded me that a couple of years back, I had created just that,

The above code would read so much better with waitFor():

start().pipe(
  waitFor(()=>ignoreReturn()),
  map((x) => doSomethingWith(x))
)

[Sawtaytoes]

This is my first time seeing delayWhen, but it looks just like delay to me. Once a value comes in, it gets delayed until the notifier$ emits (the return value). Once it emits, that value is passed through the pipeline.

delay does the same thing, but its notifier$ is a fixed timer observable with the time you passed into delay.

This is the same way bufferWhen and others work. There's the prefix or base operator name, then either Time, When, or Until postfixes. It's the same for audit, debounce, sample, and throttle too. Strangely though, delay is actually delayTime based on this naming scheme.

I think naming it waitFor would be extremely confusing considering it's just a delay operator that takes a notifier$ and there's nothing in RxJS that uses that nomenclature.

I'm not saying the RxJS naming scheme is great, I'm saying what you're proposing doesn't fit with it. If you really wanted to alias it, which would confusing to other developers, I'd recommend doing import { delayWhen as waitFor } from 'rxjs/operators' or create your own ./friendlyRxjsOperators.js for this purpose.

[eliprand]

@Sawtaytoes thanks for the feedback. I agree, waitFor() definitely does not fit the naming scheme (I had not done my research about this subject). That's why I had suggested waitUntil().
But even delayUntil() feels more natural to me. delayWhen() implies a condition. In plain english, delay when something happens implies to delay if a condition is true. Therefore, I would expect a predicate as the parameter.
By contrast delay until something happens implies that the delay is always happening, but is lifted once the event is raised. Does that make sense?
Thanks for the idea of centralizing our aliases in a shared file. This will definitely help bring consistency and discoverability to our aliases.