Is it possible to `filterNotNull` a `MutableStateFlow` and keep returning a `StateFlow` instead of a...

# coroutines

[Javier]

Is it possible to filterNotNull a MutableStateFlow and keep returning a StateFlow instead of a Flow? It is forcing me to add an stateIn to retransform the Flow into StateFlow

[Guillermo Alcantara]

I thought states couldn't be nullable

[Javier]

They can be nullable but I think there is no way to filter the emission of null states without stateIn

[Ian Lake]

The whole point of StateFlow is that it has always has a value. If your upstream MutableStateFlow only emits null, then filterNotNull never emits anything. That's why you need to use stateIn() to either set an initialValue (so that your StateFlow actually has a value ) or use the suspend stateIn that suspends until the first value is emitted

[Javier]

Thank you Ian 🙂

The last words about stateIn is what I was imagining