如何在ASP.net MVC中正确测试具有数据库调用的控制器

Question

我正在研究ASP.net MVC 3.0应用程序.我使用的MSTest一起Moq进行单元测试.我已经为我的控制器编写了所有测试方法并运行了那些测试,结果很成功.

现在,我怀疑我是否已经正确地进行了单元测试.因为,几乎我的大多数控制器操作都包含数据库调用.

我不嘲笑他们,我只是嘲笑Session和Request使用Moq的对象.

是否真的有必要模拟数据库调用,因为单元测试意味着测试单个代码单元？我认为带有数据库调用的单元测试控制器违反了上述声明.

如果是这样,任何人都可以解释我如何模拟数据库调用吗？我没有使用任何实体框架.

Updated2:

[httppost]
  public void AjaxSave(Model m)
{
   m.update(); // Database call
}

Answer 1

您应该提取使数据库调用成为单独对象的代码(请参阅单一责任原则).例如,你有控制器

public class PersonController : Controller
{
     public ActionResult Index()
     { 
         var connectionString = 
             ConfigurationManager.ConnectionStrings["foo"].ConnectionString;
         using(var connection = new SqlConnection(connectionString))
         {
             string sql = "SELECT Name FROM People";
             var command = connection.CreateCommand(sql);
             var reader = command.ExecuteReader();
             List<Person> people = new List<Person>();
             while(reader.Read())
             {
                 Person p = new Person();
                 p.Name = reader["Name"].ToString();
                 people.Add(p);
             }

             return View(people);
         }
     }
}

将数据访问代码提取到单独的类(通常称为存储库的类):

public class PersonRepository : IPersonRepository
{
     public List<Person> GetAllPeople()
     {
         var connectionString = 
             ConfigurationManager.ConnectionStrings["foo"].ConnectionString;
         using(var connection = new SqlConnection(connectionString))
         {
             string sql = "SELECT Name FROM People";
             var command = connection.CreateCommand(sql);
             var reader = command.ExecuteReader();
             List<Person> people = new List<Person>();
             while(reader.Read())
             {
                 Person p = new Person();
                 p.Name = reader["Name"].ToString();
                 people.Add(p);
             }

             return people;
         }
     }
}

正如您已经注意到的那样,我声明了抽象,这是由数据访问类实现的:

public interface IPersonRepository
{
    List<Person> GetAllPeople();
    // other data access API will go here
}

让控制器依赖于这种抽象(这很重要 - 抽象很容易被模拟):

public class PersonController : Controller
{
     private IPersonRepository _personRepository;

     public PersonController(IPersonRepository personRepository)
     {
         _personRepository = personRepository;
     }

     public ActionResult Index()
     { 
         var people = _personRepository.GetAllPeople();
         return View(people);             
     }
}

然后将存储库实现注入控制器(.NET中的依赖注入)并模拟它以进行测试:

var repositoryMock = new Mock<IPersonRepository>();
var people = new List<People>(); // provide some sample list 
repositoryMock.Setup(r => r.GetAllPeople()).Return(people);
var controller = new PersonController(repositoryMock.Object);

var result = (ViewResult)controller.Index();
// Assert here
Assert.AreEqual(result.ViewName, "Index");
Assert.AreEqual(result.Model, people);
repositoryMock.VerifyAll();