Had a coworker pose this code snippet for me and a...

# coroutines

[baxter]

Had a coworker pose this code snippet for me and ask me what would break if anything. I'd like to see what you all think as well:

override fun getSomeFlow(): Flow<String> =
        localDataFlow
            .onStart {
                // Fire-and-forget, but still tied to the collector's lifecycle.
                CoroutineScope(currentCoroutineContext()).launch {
                    triggerSomePrefetchCaching()
                }
            }
            .map { data ->
                data.toSomeString()
            }

[baxter]

My initial reaction was: "Thanks, I hate it".

Looking at it though, the issues I started to wonder were:
• How would this cancellations from this impact the flow?
• Would exceptions be passes along down flow?
• Would onStart delay completion until all coroutines launched this way have completed (similar to coroutineScope {} being called)?

[Joffrey]

The worst part that immediately freaks me out is the new CoroutineScope for no apparent reason

[baxter]

Yea, that was a "wtf are you doing, dude" reaction from me.

[Casey Brooks]

The theory kinda makes sense, but I definitely think there are safer and clearer ways to do it. For example, using the flow { } builder and launching the prefetch Coroutine in that block.