Mocking multiple Interfaces in one mock?

[Malte Finsterwalder]

Hi,

Is it possible to create a single mock object, that mocks multiple interfaces?

mock(First.class, Second.class) is obviously not supported.

Greetings,
Malte

[Patricio Arvizu]

You can use MockSettings.extraInterfaces(java.lang.Class<?>...
interfaces)

http://mockito.googlecode.com/svn/branches/1.8.0/javadoc/org/mockito/MockSettings.html

On 23 sep, 04:24, Malte Finsterwalder <ma...@finsterwalder.name>
wrote:

[Malte Finsterwalder]

2009/9/23 Malte Finsterwalder <ma...@finsterwalder.name>:

> Is it possible to create a single mock object, that mocks multiple interfaces?
>
> mock(First.class, Second.class) is obviously not supported.

I found a very simple solution: Create a new interface that extends
all the interfaces to mock:

public interface MockInterface extends First, Second {}
mock(MockInterface.class)

Greetings,
Malte

[Graham Allan]

That's one of the alternatives discussed here:
http://code.google.com/p/mockito/issues/detail?id=51

Summary from that is your suggestion will work, but some find it slightly ugly
and would prefer to use a method. Added advantage with the method call is
consistency.

Regards,
Graham

[Malte Finsterwalder]

Doesn't the multiple Interface mocking idea have a more fundamental problem:

m = mock(First.class, Second.class)

What type does variable m have?

Greetings,
Malte


2009/10/1 Graham Allan <grundl...@googlemail.com>:

[Joe Kearney]

The following declaration let's this work:

<T> T mock(Class<? extends T> ... classes) { ... }

This will allow the following junk to compile, but that doesn't matter.

Object mock = mock(String.class, Number.class, Comparable.class);

So, roughly speaking, your m will have type capture-of<? extends First & Second>. This is well defined only where at most one of the classes array is a class, obviously.

Joe

2009/10/1 Malte Finsterwalder <ma...@finsterwalder.name>

[Malte Finsterwalder]

Joe Kearney wrote:
> The following declaration let's this work:
>
> <T> T mock(Class<? extends T> ... classes) { ... }
>
>
> This will allow the following junk to compile, but that doesn't matter.
>
> Object mock = mock(String.class, Number.class, Comparable.class);
>
>
> So, roughly speaking, your m will have type capture-of<? extends First &
> Second>. This is well defined only where at most one of the classes
> array is a class, obviously.

Can I actually define this as the type of my variable?
If not, the creation of a mock for several interfaces doesn't help,
because I can't access it other than Object.

Greetings,
Malte

[szczepiq]

>Doesn't the multiple Interface mocking idea have a more fundamental problem:
>m = mock(First.class, Second.class)

The first class / interface wins. This is how you use it:

Foo foo = mock(Foo.class, withSettings().extraInterfaces(Bar.class, Baz.class));

Obviously Bar and Baz must be interfaces. Foo can be a class or interface.

Before using this feature make sure your code is clean & simple. In
general you should not be needing this... maybe the code should be
refactored so it is easy & simple to test?

Cheers,
Szczepan Faber

[Joe Kearney]

Oh I see, fair point. No, you'd just get Object. You can't even define methods to perform this for fixed numbers of arguments:
<T1, T2, T3, Ret extends T1 & T2 & T3> Ret mock(Class<T1> t1, Class<T2> t2, Class<T3> t3) { ... }
since you can't specify additional bounds when T1 is a type parameter.

I take it back, this probably isn't as useful as I'd hoped.

Thanks,
Joe

2009/10/1 Malte Finsterwalder <ma...@finsterwalder.name>

[szczepiq]

Hi,

(sorry for late answer but this email was marked as spam)

Yes you can do it with 1.8.1, check out docs for overloaded mock() method.

Cheers,
Szczepan