Function fromTransition

packages/core/src/actors/transition.ts:167–216

(
  transition: (
    snapshot: TContext,
    event: TEvent,
    actorScope: ActorScope<
      TransitionSnapshot<TContext>,
      TEvent,
      TSystem,
      TEmitted
    >
  ) => TContext,
  initialContext:
    | TContext
    | (({
        input,
        self
      }: {
        input: TInput;
        self: TransitionActorRef<TContext, TEvent>;
      }) => TContext) // TODO: type
)

 * @see {@link https://stately.ai/docs/input | Input docs} for more information about how input is passed
 */
export function fromTransition<
  TContext,
  TEvent extends EventObject,
  TSystem extends AnyActorSystem,
  TInput extends NonReducibleUnknown,
  TEmitted extends EventObject = EventObject
>(
  transition: (
    snapshot: TContext,
    event: TEvent,
    actorScope: ActorScope<
      TransitionSnapshot<TContext>,
      TEvent,
      TSystem,
      TEmitted
    >
  ) => TContext,
  initialContext:
    | TContext
    | (({
        input,
        self
      }: {
        input: TInput;
        self: TransitionActorRef<TContext, TEvent>;
      }) => TContext) // TODO: type
): TransitionActorLogic<TContext, TEvent, TInput, TEmitted> {
  return {
    config: transition,
    transition: (snapshot, event, actorScope) => {
      return {
        ...snapshot,
        context: transition(snapshot.context, event, actorScope as any)
      };
    },
    getInitialSnapshot: (_, input) => {
      return {
        status: 'active',
        output: undefined,
        error: undefined,
        context:
          typeof initialContext === 'function'
            ? (initialContext as any)({ input })
            : initialContext
      };
    },
    getPersistedSnapshot: (snapshot) => snapshot,
    restoreSnapshot: (snapshot: any) => snapshot
  };
}