how do you guys test suspendCancellableCorourtine.

# coroutines

[rkeazor]

how do you guys test suspendCancellableCorourtine.

[Dominaezzz]

Test?

[rkeazor]

as in . is it possible to test what is captured by the continuation

[gildor]

Why do you need this? just run suspend function and test result

[rkeazor]

hmm let me give you an example

[rkeazor]

lets say you have a function like this
fun getUser: User { suspendCancellableCoroutine<User> { cont -> addCallback( object : Callback { override onSuccess(user: User) { if (user != null) cont.resume(user) else cancel (Exception ("No User Found")

[rkeazor]

sorry for the psuedoCode. now as you can see , how will you test the onSuccessMethod here

[rkeazor]

the onSuccesss method has two test paths

[Dominaezzz]

Call getUser add trigger the callback for both paths in your tests then.

[rkeazor]

so what about the continuation than? for instance you could use argumentCapture to capture the what is captured in the callback. but you also need a instance of the continuation so you can verify cont.resume is called?

[Dominaezzz]

Hmm, I don't think you're testing suspendCancellableCoroutine then. You're testing that onSuccess is called.

[Dominaezzz]

Also to check if cont.resume is called, check that the lines of code after suspendCancellableCoroutine are executed.

[gildor]

Not sure why do you need argument capturer here, test this function with controlled callback (depends on implementation of addCallback)

[rkeazor]

@Dominaezzz the only issue with that ,if what con.resume is the only thing inside the if state

[rkeazor]

@gildor than how would you write a test for that block of code

[gildor]

Return null to onSuccess, check that suspend function throws exception

[gildor]

It would be easier to discuss with some self-contained code sample

[rkeazor]

ahh i see what you guys are saying

[rkeazor]

as in just make sure onSuccess returns the right thing

[rkeazor]

that makes sense actually

[rkeazor]

@gildor No need I get what your saying. just do what needs to be done to trigger the callback and see if the suspend function returns the write value

[rkeazor]

i was thinking about invocation testing . but that makes alot of sense. Thanks guys!!