public void DoesExistsByIdWorks() { var options = new DbContextOptionsBuilder <MDManagementDbContext>() .UseInMemoryDatabase(databaseName: "testDb") .Options; using (var dbContext = new MDManagementDbContext(options)) { IJobTitleDataService service = new JobTittleDataServie(dbContext); service.CreateJobTitile("CEO"); var result = service.Exists(1); Assert.IsTrue(result); } }