public async Task AreTwoUsersFriendsAsyncShouldWorkCorrectly() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options; var dbContext = new ApplicationDbContext(options); var friendRepository = new EfDeletableEntityRepository <Friend>(dbContext); var friendRequestRepository = new EfDeletableEntityRepository <FriendRequest>(dbContext); var service = new FriendService(friendRequestRepository, friendRepository); var newFriendShip = new Friend { SenderId = "1", ReceiverId = "2", }; await friendRepository.AddAsync(newFriendShip); await friendRepository.SaveChangesAsync(); var resultTrue = await service.AreTwoUsersFriendsAsync(newFriendShip.SenderId, newFriendShip.ReceiverId); var resultFalse = await service.AreTwoUsersFriendsAsync("4", "3"); Assert.True(resultTrue); Assert.False(resultFalse); }