public async Task ContainPostShouldReturnTrue() { Employer employer = new Employer(); employer.JobPosts.Add(new JobPost() { Id = 1 }); var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(databaseName: "EmployerContainPostTestDb").Options; var dbContext = new ApplicationDbContext(options); dbContext.Employers.Add(employer); await dbContext.SaveChangesAsync(); var repository = new EfDeletableEntityRepository <Employer>(dbContext); var service = new EmployerService(repository, null); Assert.True(service.ContaintPost(1, 1)); }