Mock GetType() Metod

[alamandra007]

I'm new to RM and I was Just wondering how to mock the GetType()
metod, let's say for SqlConnection class. Could you help me please?

Cheers,
alamandra007

[Ayende Rahien]

You can do that only with remoting mocks, which are not always suitable.
What is the scenario that you are after?

[alamandra007]

Suppose I've got got method SomeMethod inside tested class, looking
like

void SomeMethod(object c)
{
if (c.GetType() == typeof(SqlConnection))
{
// ..some code that wan't invoke but should
}
}

I need the code inside brackets to invoke, but it won't. Unless I mock
the GetType method, while the code of SomeMethod can not be modified.
Is it possible?

[Patrick Steele]

I think you'd rather do:

if(c is IDbConnection)
{
...

[alamandra007]

I said that I can not modify SomeMethod method.

[Patrick Steele]

Oops. Sorry, missed that.

[alamandra007]

That's ok:) Nobody's perfect!

[alamandra007]

I get the InvalidOperationException with message "Can set only a
single return value or exception to throw or delegate to execute on
the same method call", when i try to mock the method at line

Expect.Call(this.Target.GetType()).Return(this.GetType());

where this.Target is a mocked SqlConnection instance.

[Ayende Rahien]

That is because GetType() cannot be mocked using normal mocks.
You can use remoting mocks, but I _STRONGLY ADVICE_ you to avoid this.

The code that you have at the moment should be changed, and the tests are showing you this.

[Owen Evans]

I would agree on Ayende's point really do advise avoid. Ask why you are testing a class you cannot modify (you stated you can't modify the call to gettype) and instead try and abstract away the code that is fixed and use an adapter or factory facade so that you can just remove the test reliance on untestable code

my 2 cents

O

[alamandra007]

While I'm still not convinced, why remoting mocks are such a bad idea,
could you please briefly describe the reasons for not using them?

[Ayende Rahien]

The need to mock GetType() is a bad idea.

On 3/13/08, alamandra007 <alaman...@gmail.com> wrote:

[alamandra007]

OK, I think I'm starting to understand your point of view:D

[alamandra007]

Mock frameworks should be as transparent as they can only be. This has
some serious cosequences. But that's my point of view.