public async Task AssignUserToTeamWorksCorrectly() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options; var dbContext = new ApplicationDbContext(options); var repository = new EfDeletableEntityRepository <ApplicationUser>(dbContext); var userId = Guid.NewGuid().ToString(); var user = new ApplicationUser() { Id = userId, }; dbContext.Add(user); await dbContext.SaveChangesAsync(); var service = new UsersService(repository); var teamId = Guid.NewGuid().ToString(); await service.AssignUserToTeam(userId, teamId); var result = dbContext.Users.FirstOrDefault(); Assert.Equal(userId, result.Id); Assert.Equal(teamId, result.TeamId); }