waitFor() function

Subscribes to an actor ref and waits for its emitted value to satisfy a predicate, and then resolves with that value. Will throw if the desired state is not reached after a timeout (defaults to 10 seconds).

Signature:

export declare function waitFor<TActorRef extends ActorRef<any, any>>(actorRef: TActorRef, predicate: (emitted: SnapshotFrom<TActorRef>) => boolean, options?: Partial<WaitForOptions>): Promise<SnapshotFrom<TActorRef>>;

Parameters

Parameter	Type	Description
actorRef	TActorRef	The actor ref to subscribe to
predicate	(emitted: SnapshotFrom<TActorRef>) => boolean	Determines if a value matches the condition to wait for
options	Partial<WaitForOptions>	(Optional)

Returns:

Promise<SnapshotFrom<TActorRef>>

A promise that eventually resolves to the emitted value that matches the condition

Example

const state = await waitFor(someService, state => {
  return state.hasTag('loaded');
});

state.hasTag('loaded'); // true