public async Task Should_save_snapshot_in_snapshot_repository() { //Arrange var snapshotRepository = new Mock <ISnapshotRepository>(); var sut = new SnapshotStore(snapshotRepository.Object, Mock.Of <IEventStoreSerDes>(), Mock.Of <ILogger <SnapshotStore> >()); var snapshot = "snapshot"; var stream = "stream"; //Act await sut.StoreSnapshotAsync(new SnapshotEnvelope(snapshot, 5, stream), It.IsAny <CancellationToken>()); //Assert snapshotRepository.Verify(er => er.StoreSnapshotAsync(stream, It.IsAny <SnapshotDescriptor>(), It.IsAny <CancellationToken>()), Times.Once); }