Hello folks, I have a case where I’m collecting a ...

# coroutines

[aballano]

Hello folks, I have a case where I’m collecting a flow to do some operations but on every emission I need to do a side effect and have another different flow to observe until there’s a new value emitted. I was thinking on using flatMapLatest but that would multiply the initial emission every time the internal one emits something + would get delayed, so I though about doing a onEachLatest sort of 🤔 Sharing here for feedback or in case I’m missing something 😬

@ExperimentalCoroutinesApi
public fun <T> Flow<T>.onEachLatest(action: suspend (T) -> Unit): Flow<T> = transformLatest { value ->
    action(value)
    return@transformLatest emit(value)
}

the only real difference with onEach is the transform -> transformLatest but I guess that should work, right?

[Nick Allen]

Simpler: mapLatest { action(it); it }

Avoid side effects unless you are calling a terminal operator. If a Flow is collected twice, your side effects will happen twice.

If you are calling a terminal operator, then consider just using collectLatest and do your side effect there.

[aballano]

thank you @Nick Allen I’ll look into that