Subscriber

useFPReducer optionally accepts a third function argument. We’ll call it a dispatchSubscriber. Anytime an action handler calls dispatch with a given argument, dispatchSubscriber will be called with the same argument. This is meant to be a patch on the fact that there is no baked-in way to monitor dispatch calls from vanilla React hooks. Please note that dispatchSubscriber does not subscribe to the dispatch function that useFPReducer returns. It will only be called inside of action handlers. Please note also that, because the second and third arguments to useFPReducer are both functions, positionality matters. If you would like to pass in a subscriber function, but not a DependencyCreator function, you will need to pass null as the second argument, i.e.

useFPReducer({DO_THING: doerOfThing}, null, subscriber)