statelyai/xstate xstate@6.0.0-alpha.53

on GitHub

Patch Changes

• 010298e: Named guards are now plain predicate functions. A guard receives only the arguments you pass it — the transition args object is no longer injected first. Pass values from context or the event explicitly:

  const machine = createMachine({
    context: { count: 0 },
    guards: {
      // Previously: isAbove: (args, threshold) => args.context.count > threshold
      isAbove: (count: number, threshold: number) => count > threshold,
      isEnabled: () => true
    },
    initial: 'a',
    states: {
      a: {
        on: {
          NEXT: ({ context, guards }) => {
            if (guards.isAbove(context.count, 3) && guards.isEnabled()) {
              return { target: 'b' };
            }
          }
        }
      },
      b: {}
    }
  });

  Exception: guards referenced declaratively from serialized JSON or SCXML machines (guard: { type, params }) are invoked by the runtime and still receive the transition args object first, then params — the runtime is the caller there and has nothing else to pass.

• c405428: Fixed framework adapter snapshot inference in projects that enable exactOptionalPropertyTypes.

  const actor = createActor(machine);
  const count = useSelector(actor, (snapshot) => snapshot.context.count);