In error messages, name the method that we can't intercept on an instance

[blairconrad]

Inspired by a StackOverflow question.

The questioner had the equivalent of

public interface IHaveAList
{
    IEnumerable<string> GetList();
}

var fake = A.Fake<IHaveAList>();
A.CallTo(() => fake.GetList().Single())
    .Throws(new Exception());

And didn't understand why he was told

FakeItEasy.Configuration.FakeConfigurationException: 
The current proxy generator can not intercept the specified method for the following reason: 
- Extension methods can not be intercepted since they're static.

The thought was the complaint was about GetList, when really it was about Single.

We should say which method (I'd almost hope for something like Enumerable.Single<TSource>(this IEnumerable<TSource> source), but whatever we can get would be great.
We could maybe take a cue from DefaultFakeObjectCallFormatter, which has very advanced formatting rules based on whether the method is a method or a property and so on, but it's concerned with object calls and we only have MethodInfos available where we build the exception message above (in DefaultInterceptionAsserter.AssertThatMethodCanBeInterceptedOnInstance), so we'd need to do a little work for a full-fidelity solution.

[adamralph]

Makes sense to me.

[thomaslevesque]

(I'd almost hope for something like Enumerable.Single<TSource>(this IEnumerable<TSource> source)

We should probably use the CLR format instead (see #1047)

[thomaslevesque]

btw @blairconrad did you intend to omit the namespace? Should it be System.Linq.Enumerable.Single<TSource>(this System.Collections.Generic.IEnumerable<TSource> source) instead? It's a bit verbose (especially when TSource will be replaced with an actual type), but it's more specific.

[thomaslevesque]

Also, if we're going to change this message, what do you think about dropping the two blank lines and two spaces at the beginning of the message? As far as I can tell, they don't bring any benefit.

[blairconrad]

@thomaslevesque, as you say, we should use the CLR format. And namespaces are good.

The whitespace is there to make the exception render pretty when the user makes this error:

FakeConfigurationException: 

  The current proxy generator can not intercept the specified method for the following reason:
    - Non virtual methods can not be intercepted.

(You probably know this, and were still thinking they could be dropped.)

I think this sort of thing is done in multiple places, and if we were going to start reformatting messages, it might be better to take a look at all of them?
(Which I'm not that excited about…)

[thomaslevesque]

(You probably know this, and were still thinking they could be dropped.)

Actually, I didn't realize this. I guess it makes sense, then.

[blairconrad]

This issue was fixed in Release 3.3.0.