Oftentimes I’ll find myself writing some code similar to the following:

loadPuzzle: (state: AppState, action: PayloadAction<string>) => {
      const newPuzzle = GetPuzzleByID(state, action.payload);
      if (newPuzzle == null)
        return console.error(
          "Tried to load a puzzle that doesn't exist on this machine."
        );
      LoadPuzzle(state, newPuzzle);
    }

i.e. I end up with a function someStatefulChange that gets exported as a reducer for the slice, and an internal function SomeStatefulChange that I can re-use elsewhere imported from another file.

Is this reasonable to do? Are there any potential downsides of this? Does anybody have a better way of approaching this? Is this a codesmell? I have no idea.