Possible to provide type for states?

[crishoj]

Similarly to how setup() provides a way to specify types for tags, context and events, is there any way to specify a type for states?

E.g.:

setup({
  types: {
    events: {} as MyEvents,
    context: {} as MyContext,
    tags: {} as MyTags,
    states: {} as MyStates, // 👈 This is what I would like to do
  },
  // ...
})

If I'm not mistaken, the type of states would have to be a union of StateValue, e.g.:

type MyStates = 
  | 'Idle' 
  | 'Starting' 
  | { Running: 'SubStateA' } 
  | { Running: 'SubStateB' }

---

The rationale for this: We have several state machines that observe each other and transition once another machine enters a certain state. I tried obtaining types for the possible states of our machines with this monstrosity:

type MyStates = Parameters<SnapshotFrom<MyActor>['matches']>[0]

But, this leads to circular references in the types.

My idea is that if I could declare possible states in advance (as with tags), I could use this simple non-derived type in referencing locations and ensure type-safety.

[davidkpiano]

cc. @Andarist