public async Task AllConfirmedAsync_ShouldReturnsCorrectCountOfConfirmedSubscribers() { await this.dbContext.Subscribers.AddRangeAsync(new List <Subscriber> { new Subscriber { IsConfirmed = true }, new Subscriber { IsConfirmed = false }, new Subscriber { IsConfirmed = true }, new Subscriber { IsConfirmed = true }, new Subscriber { IsConfirmed = false }, }); await this.dbContext.SaveChangesAsync(); var subscriberService = new SubscriberService(this.dbContext); var result = await subscriberService.AllConfirmedAsync <FakeSubscriber>(); var expectedCount = 3; var actualCount = result.Count(); Assert.Equal(expectedCount, actualCount); }