c# - 如何模拟返回接口(interface)列表的方法

Question

这是我的存储库方法:

    public async Task<IList<IVehicleMake>> GetAllMakes()
    {
        var makes = Context.VehicleMakes.AsQueryable();

        return new List<IVehicleMake>(AutoMapper.Mapper.Map<List<VehicleMake>>(await makes.ToListAsync()));
    }

我知道如何模拟返回具体类型的方法，但正如您所看到的，该方法返回接口(interface)“IVehicleMake”的列表。

是否可以模拟这种方法以及如何模拟？

Answer 1

您可以简单地使用模拟框架，例如 Moq 。这与模拟一个简单的界面没有太大不同。

这里是使用 MS Test 和 Moq 的示例代码

using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;

namespace UnitTestProject1
{
    public class Vehicle{}
    public interface IVehicleMake
    {
        Vehicle Make();
    }
    public interface IVehicleMakeRepository
    {
        Task<IList<IVehicleMake>> GetAllMakes();
    }

    public class MyService
    {
        private readonly IVehicleMakeRepository vehicleMakeRepository;

        public MyService(IVehicleMakeRepository vehicleMakeRepository)
        {
            this.vehicleMakeRepository = vehicleMakeRepository;
        }

        public async Task DoSomething()
        {
            var makes = await vehicleMakeRepository.GetAllMakes();
            foreach (var make in makes)
            {
                var vehicule = make.Make();
            }
        }
    }

    public class MyServiceTest
    {
        [TestClass]
        public class DoSomething
        {
            [TestMethod]
            public async Task Should_CallAllMakersOnce()
            {
                //Arrange
                var mockedMakers = new[] { new Mock<IVehicleMake>(), new Mock<IVehicleMake>(), };
                foreach (var mockedMaker in mockedMakers)
                {
                    mockedMaker.Setup(m => m.Make()).Returns(new Vehicle()).Verifiable();
                }
                var mockedRepository = new Mock<IVehicleMakeRepository>();
                mockedRepository
                    .Setup(m => m.GetAllMakes())
                    .ReturnsAsync(mockedMakers.Select(mm => mm.Object).ToList())
                    .Verifiable();
                var service = new MyService(mockedRepository.Object);
                //Act
                await service.DoSomething();
                //Assert
                mockedRepository.Verify(m => m.GetAllMakes(), Times.Once);
                foreach (var mockedMaker in mockedMakers)
                {
                    mockedMaker.Verify(m => m.Make(), Times.Once);
                }
            }
        }
    }
}