Question

我正在进行一个简单的单元测试，在创建课程时，Title字段不能为空。我不得不使用具有UnitOfWork的依赖注入的服务类来测试它。当我调试我的测试时，我收到Can not instantiate proxy of class: ContosoUniversity.Models.CourseRepository的异常错误我调查了错误，但是我无法理解如何修复问题和Assert语句？

Error Message Display Image

CourseRepository

public class CourseRepository : GenericRepository<Course>
{
    public CourseRepository(SchoolContext context)
        : base(context)
    {
    }

的UnitOfWork

public class UnitOfWork : IDisposable, IUnitOfWork
{
    private SchoolContext context = new SchoolContext();
    private GenericRepository<Department> departmentRepository;
    private CourseRepository courseRepository;

    public CourseRepository CourseRepository
    {
        get
        {
            if (this.courseRepository == null)
            {
                this.courseRepository = new CourseRepository(context);
            }
            return courseRepository;
        }
    }

    public virtual CourseRepository GetCourseRepository()
    {
        if (this.courseRepository == null)
        {
            this.courseRepository = new CourseRepository(context);
        }
        return courseRepository;
    }

CourseService

public class CourseService : ICourseService
{
    private IUnitOfWork unitOfWork;

    public CourseService (IUnitOfWork unitOfWork)
    {
        this.unitOfWork = unitOfWork;
    }

    public void Create(Course course)
    {
        unitOfWork.GetCourseRepository().Insert(course);
        unitOfWork.Save();
    }

    public Course GetCourseByID(int id)
    {
        return unitOfWork.GetCourseRepository().GetByID(id);
    }

TestMethod的

[TestMethod]
public void TestMethod1()
{
    var course = new Course
    {
        CourseID = 2210,
        Title = string.Empty,
        Credits = 3,
        DepartmentID = 1
    };

    Mock<CourseRepository> mockRepo = new Mock<CourseRepository>();
    mockRepo.Setup(m => m.GetByID(course.CourseID)).Returns(course);

    var mockUnit = new Mock<IUnitOfWork>();
    mockUnit.Setup(x => x.GetCourseRepository()).Returns(mockRepo.Object);

    var myService = new CourseService(mockUnit.Object);
    myService.Create(course);

    //var error = _modelState["Title"].Errors[0];
    //Assert.AreEqual("The Title field is required.", error.ErrorMessage);

    //mockRepo.Setup(x => x.Insert(course));
}

Answer 1

如果你的类没有无参数构造函数，那么你需要在创建Mock时传递这些参数。在您的情况下，CourseRepository的模拟将创建如下。

CourseRepository

您也可以传递构造函数参数的模拟对象，而不是null。

Answer 2

或者，如果您的类具有内部无参数构造函数，则需要将InternalsVisibleTo属性添加到程序集。

如果是Moq，请添加以下内容：

[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")]

或者这，如果您需要一个强钥匙

[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2,PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")]

Answer 3

在嘲笑时只需使用接口。

Mock<ICourseRepository> mockRepo = new Mock<ICourseRepository>();
mockRepo.Setup(m => m.GetByID(course.CourseID)).Returns(course);

无法实例化类错误的代理

3 个答案: