关于c＃：FakeItEasy，伪造一个来自子类的父母虚拟方法

FakeItEasy, Fake a parents virtual method from the child class

我试图在没有成功的情况下(使用FakeItEasy)从孩子那里伪造对家长公共虚拟验证方法的调用。我有一个基类，它为类似的命令类验证简单命令(为了简单起见，我减少了代码)：

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public class CanSetSettings<TSettings> : IValidationhandler<TSettings> where TSettings : ISetting
{
protected readonly IFooRepository Repository;
protected List<ValidationResult> Results;

public CanSetSettings(IFooRepository repository)
{
if (Repository== null)
throw new ArgumentNullException("IFooRepository","IFooRepository is needed to validate the command.");

repository = repository;
Results = new List<ValidationResult>();
}

public virtual ICollection<ValidationResult> Validate(TSettings settings)
{
if (settings == null)
{
Results.Add(new ValidationResult("Settings","The command to validate cannot be missing."));
return Results;
}

if (Repository.Query(settings.Location) == null)
Results.Add(new ValidationResult("Location","No Location was found for your settings."));

return Results;
}

然后我有从这个基类继承的子类，然后通过重写Validate(简化了我的代码)来实现它们的特定逻辑。

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我在单元测试中尝试过这种方法，它只配置对子类的方法调用，而不能配置父类。如何配置fake来调用子类和伪造父基类方法？谢谢您。

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var _repository = A.Fake<IFooRepository>();
var _validator = A.Fake<CanSetSpecificSetting>(opt => opt.WithArgumentsForConstructor(new object[] { _repository }));

A.CallTo(() => _validator.Validate(_cmd)).CallsBaseMethod().Once();

_validator.Validate(_cmd);

// this passes, but only because it knows about the child call
A.CallTo(() => _validator.Validate(_cmd)).MustHaveHappened(Repeated.Exactly.Once);

相关讨论

不，我不认为你能轻易地做你想做的事，用假货。我甚至认为你不应该那样做。

但是，通过将基调用封装到子类中的模板方法中，可以实现类似的功能。只需更改CanSetSpecificSetting，如下所示：

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public class CanSetSpecificSetting : CanSetSettings<SetSpecificSettings>, IValidationhandler<SetSpecificSettings>
{
public CanSetSpecificSetting (IFooRepository repo)
: base(repo)
{ }

public override ICollection<ValidationResult> Validate(SetSpecificSettings command)
{
BaseValidate(command); // << Instead of calling base.Validate(command).

// ... other logic here

return results;
}

// This is the template method. You MUST declare it as virtual.
protected virtual ICollection<ValidationResult> BaseValidate(SetSpecificSettings command)
{
return base.Validate(command);
}
}

然后像这样更改测试：

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var _repository = A.Fake<IFooRepository>();
var _validator = A.Fake<CanSetSpecificSetting>(opt => opt.WithArgumentsForConstructor(new object[] { _repository }));

A.CallTo(() => _validator.Validate(_cmd)).CallsBaseMethod().Once();

// *** ADD THIS LINE *** must configure it this way because the template method is protected - we don't want to make it public!
A.CallTo(_validator).WhereMethod(x => x.Name =="BaseValidate").Returns("whatever-you-want-to-return");

_validator.Validate(_cmd);

A.CallTo(() => _validator.Validate(_cmd)).MustHaveHappened(Repeated.Exactly.Once);

再说一遍，这很难看。我能想象的唯一的情况是，这样做是可以的，将测试添加到您打算(并且将)尽快重构的一些遗留代码中。

希望它有帮助。