Hey, I saw a lot of "Reasons not to use GlobalScope" but what are the alternatives when you can't re...

# compose

[Cicero]

Hey, I saw a lot of "Reasons not to use GlobalScope" but what are the alternatives when you can't reach a scope? Do I always need to pass down an activity reference?

I have a singleton watching network state and pushing this state as it changes into a singleton flow.

The way I need to handle some of this processing will always require a thread but it's not guaranteed I will have short access to a scope.

What is your solution? What is our community default solution?

[Big Chungus]

You can create your own coroutine scope with CoroutineScope() factory function and close it when no longer needed

[Big Chungus]

Works like a charm on js https://github.com/mpetuska/template-kmp-library/blob/master/test/src/jsMain/kotlin/runBlockingTest.kt

[Cicero]

fun CoroutineScope.launch(
    context: CoroutineContext = EmptyCoroutineContext,
    // ...
): Job

From https://elizarov.medium.com/coroutine-context-and-scope-c8b255d59055

?

[Cicero]

Ok, but then how do I close? Does the run blocking already resolves the issue automagically?

[Big Chungus]

Scope normally closes itself when all jobs complete, but you can also close it manually

[Cicero]

Ok, thanks man, I will hit that hint you gave me

[Cicero]

Hopefully this will save from all my references to GlobalScope

[Cicero]

❤️

[Big Chungus]

Good luck!

[Cicero]

Didn't really solve my problem, I'm still trying to get around the issue

[Cicero]

I need to emit a flow from a place I wouldn't have conventional access to a context.

Should I just create a global reference to my activities context?

[Big Chungus]

Well global custom CoroutineScope is still better than GlobalScope, because you can close it whenever you want without having to worry about it being used by some of the libs

[Cicero]

But how do I create a scope when there is no scope?

[Cicero]

The only reason I'm using Global is to avoid hoisting trough 5 layers just to ask for a scope

[Cicero]

fun dismissFeedback() {
    runBlockingTest{
        NetworkFeedback.feedback.emit(Finish)
    }
}

fun runBlockingTest(test: suspend CoroutineScope.() -> Unit) =
    CoroutineScope(EmptyCoroutineContext).produce<Unit>(block = test)

fun networkRequestTrigger() {
    runBlockingTest{
        NetworkFeedback.feedback.emit(Request)
    }
}

[Cicero]

❤️

[Cicero]

A question o elbow grease

[Cicero]

But now I'm curious if this is the best approach 🙂

[Big Chungus]

Not sure if it's the best, but definitely better than GlobalScope

[Big Chungus]

Might be good to reuse your custom scope between tests, tho

[Cicero]

Awesome, this is satisfactory