验证函数调用中是否传递了正确的方法

时间:2012-02-22 16:23:11

标签: c# unit-testing delegates rhino-mocks

我的测试类在其构造函数中使用了2个对象,一个数据加载器和一个使用数据加载器返回的数据的类。

数据加载器接口有两个函数,LoadCompanies()和LoadEmployees(),它们都接受一个int参数并返回一个IEnumerable。

如何验证测试中的方法是否将LoadCompanies()和NOT LoadEmployees()传递到数据使用者类中?

这是我的代码:

[TestFixture]
public class TestingFunctionalParameters_UT
{
    [Test]
    public void Correct_Loader_Method_is_Used()
    {
        const int userId = 1;
        var companies = new[] { "c1", "c2" };
        var dataLoader = MockRepository.GenerateMock<ITestDataLoader>();
        var dataConsumer = MockRepository.GenerateMock<IDataConsumerClass>();

        var testObject = new TestClass(dataLoader, dataConsumer);

        dataConsumer.Expect(fc => fc.LoadIt(Arg<Func<IEnumerable<string>>>.Is.TypeOf)).Return(true);

        //TODO: validate that correct dataloader function was called...
        //dataLoader.Expect(dl => dl.LoadCompanies(userId)).Return(companies);

        var result = testObject.Run(userId);

        Assert.That(result, Is.True);
        dataLoader.VerifyAllExpectations();
        dataConsumer.VerifyAllExpectations();
    }
}

public class TestClass
{
    private readonly ITestDataLoader dataLoader;
    private readonly IDataConsumerClass funcClass;

    public TestClass(ITestDataLoader dataLoader, IDataConsumerClass funcClass)
    {
        this.dataLoader = dataLoader;
        this.funcClass = funcClass;
    }

    public bool Run(int userId)
    {
        Func<IEnumerable<string>> loadFn = () => dataLoader.LoadCompanies(userId);
        return funcClass.LoadIt(loadFn);
    }
}

public interface ITestDataLoader
{
    IEnumerable<string> LoadCompanies(int userId);
    IEnumerable<string> LoadEmployees(int userId);
}

public interface IDataConsumerClass
{
    bool LoadIt(Func<IEnumerable<string>> load);
}

2 个答案:

答案 0 :(得分:1)

您可以创建公司和员工类

class Company
{
    public Company(string name)
    {
        Name = name;
    }

    public string Name { get; private set; }

    public override string ToString()
    {
        return Name;
    }
}

对员工执行相同操作,然后像这样定义您的界面

public interface ITestDataLoader   
{   
    IEnumerable<Company> LoadCompanies(int userId);   
    IEnumerable<Employee> LoadEmployees(int userId);   
}

现在公司和员工不能再混淆了。


编辑:

如果你有很多这样的案例,你可以创建一个公共基类

class NamedItem
{
    public NamedItem(string name)
    {
        Name = name;
    }

    public string Name { get; private set; }

    public override string ToString()
    {
        return Name;
    }
}

class Company : NamedItem
{
    public Company(string name)
        : base(name)
    {
    }
}

class Employee : NamedItem
{
    public Employee (string name)
        : base(name)
    {
    }
}

答案 1 :(得分:0)

编辑:我假设您的示例是简化示例,并且您的实际实现是尝试测试委托注入模式)

也许你可以这样写你的测试? (编辑实际编译

[Test]
public void Correct_Loader_Method_is_Used()
{
    const int userId = 1;
    var companies = new[] { "c1", "c2" };
    var dataLoader = MockRepository.GenerateMock<ITestDataLoader>();
    var dataConsumer = MockRepository.GenerateMock<IDataConsumerClass>();

    var testObject = new TestClass(dataLoader, dataConsumer);

    dataConsumer.Expect(fc => fc.LoadIt(Arg<Func<IEnumerable<string>>>.Matches(x => x().Any()))).Return(true);

    //validate that correct dataloader function was called...
    dataLoader.Expect(dl => dl.LoadCompanies(userId)).Return(companies);
    // Fails if you uncomment this line
    //dataLoader.Expect(dl => dl.LoadEmployees(userId)).Return(companies);

    var result = testObject.Run(userId);

    Assert.That(result, Is.True);
    dataLoader.VerifyAllExpectations();
    dataConsumer.VerifyAllExpectations();
}

基本上Matches()约束会尝试执行该方法,如果它试图调用LoadEmployees(),RhinoMocks会抱怨,因为它没有定义的模拟。

更新:处理Action<T>代表

这可能不太健壮,但对于Action<T> s:

public interface IDataConsumerClass
{
    bool LoadIt(Func<IEnumerable<string>> load);
    bool ExecuteIt<T>(Action<T> execute);
}

//...

dataConsumer.Expect(fc => fc.ExecuteIt(Arg<Action<int>>.Matches(x => ActionWrapper(x, userId)))).Return(true);

//...

private bool ActionWrapper<T>(Action<T> action, T arg)
{
    action(arg);
    return true;
}
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