Moq，使用 xUnit 框架进行单元测试并测试返回对象的函数

Question

我有一个仓库

public class StudentsPersonalDetailsRepository : IStudentPersonalDetailsRepository
{
    private readonly StudentManagementSystemEntities _studentsDbContext;
    private readonly ILogger _logger;
    public StudentsPersonalDetailsRepository(StudentManagementSystemEntities context, ILogger<IStudentPersonalDetailsRepository> logger)
    {
        _studentsDbContext = context;
        _logger = logger;
    }
    public IQueryable<StudentPersonalDetails> StudentPersonalDetails => _studentsDbContext.StudentPersonalDetails;
    ......
}

在我的服务层，我有一个服务

public class StudentsPersonalDetailsService:IStudentPersonalDetailsService
{
    private readonly IStudentPersonalDetailsRepository _repository;
    private readonly ILogger _logger;
    public StudentsPersonalDetailsService(IStudentPersonalDetailsRepository studentPersonalDetailsRepository,ILogger<StudentsPersonalDetailsService> logger)
    {
        _repository = studentPersonalDetailsRepository;
        _logger = logger;
    }
    ......
    ......
    public StudentModelResponse GetStudentById(int id)
    {
        Domain.Entities.StudentPersonalDetails obj = _repository.StudentPersonalDetails.
                                                    Where(i => i.RollNo == id)
                                                    .Select(i=>new Domain.Entities.StudentPersonalDetails {
                                                        RollNo=i.RollNo,
                                                        FirstName=i.FirstName,
                                                        LastName=i.LastName,
                                                        MailId=i.MailId,
                                                        MiddleName=i.MiddleName,
                                                        DateOfBirth=i.DateOfBirth,
                                                        GenderOfPerson=i.GenderOfPerson
                                                    }).FirstOrDefault();
        StudentModel ob = StudentModel.Translator(obj);
        return new StudentModelResponse { StudentModel=ob};
    }
}

我的测试代码是

namespace StudentUnitTests
{
     public class StudentServiceShould
     {
         [Theory]
         [InlineData(1)]
         public void AbleToRetrieveStudentById(int n)
         {
             var mock = new Mock<IStudentPersonalDetailsRepository>();
             var logger = new Mock<ILogger<StudentsPersonalDetailsService>> ();
             var ob = new StudentsPersonalDetailsService(mock.Object, logger.Object);
         }
     }
}

我需要为 GetStudentById() 编写一个单元测试并检查函数返回的值。

请帮助我如何模拟服务层。

Answer 1

在上面我们有两件事发生在StudentsPersonalDetailsService.GetStudentById()

1. 从存储库中检索学生信息。
2. 根据从存储库检索到的数据创建学生模型

注意：从存储库中读取时看起来有些奇怪。如果存储库中的项目是 StudentPersonalDetails 为什么要创建新实例

我们可以像这样存根检索学生数据

 public class StudentServiceShould
 {
     [Theory]
     [InlineData(1)]
     public void AbleToRetrieveStudentById(int n)
     {
        var students = new []{
          // new Domain.Entities.StudentPersonalDetails for student role 1,
          // new Domain.Entities.StudentPersonalDetails for student role 2,
          // new Domain.Entities.StudentPersonalDetails for student role 3
        };         


         var mock = new Mock<IStudentPersonalDetailsRepository>();
         mock.SetupGet(mk => mk.StudentPersonalDetails).Returns(students.AsQueryable());
         var logger = new Mock<ILogger<StudentsPersonalDetailsService>> ();
         var ob = new StudentsPersonalDetailsService(mock.Object, logger.Object);
     }
 }

创建StudentModel 对象被封装在Translator 中，但由于它是“StudentModel”上的静态方法，我们无法模拟它，必须一次性测试读取和转换。