invokePromise.ts

type Arguments<TContext> = {
  name: string;
  successTarget: string;
  id?: string;
  successActions?: string[];
  errorActions?: string[];
  otherDoneTargets?: TransitionConfig<TContext, DoneInvokeEvent<$YesReallyAny>>[];
  errorTarget?: string;
  errorPredicate?: (_ctx: unknown, e: DoneInvokeEvent<$YesReallyAny>) => boolean;
};
/**
 * This provides a simple invoked promise pattern. You specify a service name
 * and where you want the machine to transition to on success
 *
 * It works out of the box for Promises that resolve to a boolean indicating success/failure
 *
 * onDone will transition to the errorTarget if the errorPredicate is true, otherwise the success target
 * onError always transitions to the errorTarget
 *
 * @param args
 * @param args.name name of the service definition to invoke
 * @param args.successTarget target to transition to for a successful invocation
 * @param args.successActions actions to run on successful invocation
 * @param args.errorActions actions to run on failed invocation
 * @param args.otherDoneTargets if you need to cater for more conditional transition targets add them here
 * @param [args.errorTarget="error"] - target to transition to for onError or a promise that fails the errorPredicate, defaults to "error"
 * @param args.errorPredicate returns true if promise resolved to error, defaults to checking if resolved to false
 */
export function invokePromise<TContext, TEvent extends EventObject>({
  name,
  successTarget,
  id,
  successActions = [],
  errorActions = [],
  otherDoneTargets = [],
  errorTarget = "error",
  errorPredicate = (_ctx: unknown, e: DoneInvokeEvent<$YesReallyAny>) => e.data === false,
}: Arguments<TContext>): InvokeConfig<TContext, TEvent> {
  return {
    id: id ?? name,
    src: name,
    onDone: [
      { target: errorTarget, cond: errorPredicate, actions: errorActions },
      ...otherDoneTargets,
      { target: successTarget, actions: successActions },
    ],
    onError: { target: errorTarget, actions: errorActions },
  };
}