Moq与任务等待

Question

由于我已将我的WCF方法转换为Async,因此我的单元测试失败了,我无法找出正确的语法来使它们工作.

Cllient代理类

 public interface IClientProxy
{
     Task DoSomething(CredentialDataList credentialData, string store);
}

服务类

  public class CredentialSync : ICredentialSync
{
    private ICredentialRepository _repository;

    private IClientProxy _client;

    public CredentialSync()
    {
        this._repository = new CredentialRepository();
        this._client = new ClientProxy();
    }

    public CredentialSync(ICredentialRepository repository, IClientProxy client)
    {
        this._repository = repository;
        this._client = client;
    }

   public async Task Synchronise(string payrollNumber)
    {
        try
        {
            if (string.IsNullOrEmpty(payrollNumber))
            {
                .... some code
              }
            else
            {
                CredentialDataList credentialData = new CredentialDataList();
                List<CredentialData> credentialList = new List<CredentialData>();

                // fetch the record from the database
                List<GetCredentialData_Result> data = this._repository.GetCredentialData(payrollNumber);
                var pinData = this._repository.GetCredentialPinData(payrollNumber);

                // get the stores for this employee
                var storeList = data.Where(a => a.StoreNumber != null)
                    .GroupBy(a => a.StoreNumber)
                    .Select(x => new Store { StoreNumber = x.Key.ToString() }).ToArray();

                var credential = this.ExtractCredentialData(data, pinData, payrollNumber);

                credentialList.Add(credential);
                credentialData.CredentialList = credentialList;

                foreach (var store in storeList)
                {       
                  //this line causes an Object reference not set to an instance of an object error
                   await  _client.DoSomething(credentialData, store.StoreNumber);

                }
            }
        }
        catch (Exception ex)
        {
            throw new FaultException<Exception>(ex);
        }
    }

测试类

 /// </summary>
[TestClass]
public class SynchTest
{

    private Mock<ICredentialRepository> _mockRepository;
    private Mock<IClientProxy> _mockService;

    [TestInitialize]
    public void Setup()
    {
       ... some setups for repository which work fine
    }

[TestMethod]      
    public async Task SynchroniseData_WithOneEmployee_CallsReplicateService()
    {
        this._mockService = new Mock<IClientProxy>();
        this._mockService.Setup(x=>x.DoSomething(It.IsAny<CredentialDataList>(), It.IsAny<string>()));
        // arrange
        string payrollNumber = "1";
        CredentialSync service = new CredentialSync(this._mockRepository.Object, this._mockService.Object);

        // act
        await service.Synchronise(payrollNumber);

        // assert                 
        this._mockService.VerifyAll();
    }

错误是在何时ClientProxy.DoSomething被调用:

你调用的对象是空的

参数都很好.

如果我将我的ClientProxy.DoSomething方法转换为同步方法(public void DoSomething(...)),代码工作正常,但我确实需要异步调用它

Answer 1

DoSomething返回null而不是返回a Task,因此在等待时会出现异常.您需要指定何时构建它应该返回的模拟Task.

在这种情况下,您似乎可以简单地返回已完成的任务,Task.FromResult因此模拟设置应如下所示:

this._mockService.Setup(...).Returns(Task.FromResult(false));

从下一版本的.Net(4.6)开始,您可以使用 Task.CompletedTask

Answer 2

您可以使用ReturnsAsync减少代码中的混乱程度

this._mockService.Setup(...).ReturnsAsync(false);

这样您就可以删除Task.FromResult部分代码

Answer 3

我认为您需要Task从DoSomething模拟返回

this._mockService.Setup(x => x.DoSomething(It.IsAny<CredentialDataList>(), It.IsAny<string>()))
    .Returns(Task.FromResult<int>(0));