Suspense

[BigAB]

Is your feature request related to a problem? Please describe.
In order to take advantage of the React suspense component, along with concurrent mode, so that w don't have to include loading: true, and the like, in our state....

Describe the solution you'd like
As always intended but I was waiting until some big announcement about data fetching and suspense at React Conf that never really came, so....

Use Suspense in React by an option called suspense which will default to false at first but may change in the future (breaking change) to default to true

If suspense is set to true, whenever the newState$ observable, returned from the Epic returns undefined, it will throw a promise, that will resolve on the next non-undefined value emitted from new state.

Describe alternatives you've considered
Of course you are free to not opt in (or opt out in the future) to this behaviour and handle your own loading states and spinners, I think the React way is to use the suspense component.