模拟IList的单元测试方法

Question

I'm trying to mock the following method TryGetApns :

    private readonly Func<string, ICommunicationClient> _communicationFactory;

    public CommunicationApiFacade(Func<string, ICommunicationClient> communicationFactory)
    {
        _communicationFactory = communicationFactory;
    }

    public IList<ApnResponse> TryGetApns(string tenant)
    {
        GetApnsResponse response = null;
        try
        {
            var communicationApiClient = _communicationFactory(tenant);
            response = communicationApiClient.JctConfigurationService.GetApns();
        }
        catch (HttpException e)
        {
            ...
        }

        return response?.Apns ?? new List<ApnResponse>();
    }

with the following test:

    private Mock<ICommunicationApiFacade> _communicationApiFacade;

    [SetUp]
    public void SetUp()
    {
        _fixture = new Fixture()
            .Customize(new AutoMoqCustomization());

        _communicationApiFacade = _fixture.Freeze<Mock<ICommunicationApiFacade>>();
    }

    [Test]
    public void RunJctTests_WhenJctIsInAPrivateNetwork_ShouldReturnAPassedTest()
    {
        // Arrange
        var jctApn = _fixture.Create<string>();
        var message = _fixture.Build<JctLoggedIn>()
            .With(x => x.ApnFromDevice, jctApn)
            .Create();

        var response = _fixture.Build<ApnResponse>()
            .With(x => x.IsPrivateApn, true)
            .With(x => x.ApnName, jctApn).Create();

        _communicationApiFacade.Setup(x => x.TryGetApns(string.Empty))
            .Returns(new List<ApnResponse> { response });

        var subject = _fixture.Create<NetworkProviderTestRunner>();

        // Act
        var result = subject.Execute(message);

        // Assert
        Assert.That(result.Result, Is.True);
    }

and this is the NetworkProviderTestRunner class:

    private readonly ICommunicationApiFacade _communicationApi;

    public NetworkProviderTestRunner(ICommunicationApiFacade communicationApi)
    {
        _communicationApi = communicationApi;
    }

    public JctTest Execute(JctLoggedIn message)
    {
        var apns = _communicationApi.TryGetApns(message.Tenant);

        var jctApn = apns.FirstOrDefault(x => x.ApnName == message.ApnFromDevice);

        if (jctApn != null)
        {
            var privateApn = apns.FirstOrDefault(x => x.PublicApnId.Equals(jctApn.Id));
            if (privateApn != null || jctApn.IsPrivateApn)
                return new JctTest { Result = true };
        }
        return new JctTest { Result = false };
    }

JctLoggedIn class:

public class JctLoggedIn : Message
{
    public string Imei { get; set; }
    public string SimCardIdFromDevice { get; set; }
    public string SimCardIdFromStorage { get; set; }
    public string ApnFromDevice { get; set; }
    public string ApnFromStorage { get; set; }
    public string FirmwareFromDevice { get; set; }
    public int DeviceTypeFromStorage { get; set; }
    public int SerialNumber { get; set; }
}

but for some reason I always get back an empty list. I've tried to populate the list in the SetUp and also defining the output there but I's always the same. Any help?

Answer 1

While you could explicitly omit the Tenant property when building the message object, you could also change the Mock setup to this:

_communicationApiFacade.Setup(x => x.TryGetApns(message.Tenant))
    .Returns(new List<ApnResponse> { response });

Answer 2

This line

_communicationApiFacade.Setup(x => x.TryGetApns(string.Empty))
        .Returns(new List<ApnResponse> { response });

is telling the mock to return the list containing response when TryGetApns is called with an empty string for the tenant parameter.

What is the value of message.Tenant after message is created by this line:

var message = _fixture.Build<JctLoggedIn>()
        .With(x => x.ApnFromDevice, jctApn)
        .Create();

If it is not string.empty, your mock will not return the reponse list.

Answer 3

Replace

var response = _fixture.Build<ApnResponse>()
            .With(x => x.IsPrivateApn, true)
            .With(x => x.ApnName, jctApn).Create();

with

var response = _fixture.Build<ApnResponse>()
            .With(x => x.Tenant, String.Empty)
            .With(x => x.IsPrivateApn, true)
            .With(x => x.ApnName, jctApn).Create();

if Tenant is writable.

If the property is writable, AutoFixture will create an object with non-empty value for Tenant without explicitly setting up what you want.