Why or how to use NUnit methods with ICollection<T>

Question

Some of NUnit's Assert methods are overloaded to use ICollection but not ICollection<T> and thus you can't use them.

Is there anyway around this? Heck, am I doing something stupid?

I'm having to drop back to using Assert.AreEqual rather than specialised methods and its making my tests ugly.

Any advice?

Edit:

Thanks for the responses. The That method of NUnit seems interesting so I'll look into it at a later date.

Mark correctly mentioned this, but NUnit Collection Asserts are excellent. I've recently used them on some new tests and found them excellent to work with.

Answer 1

I don't know if this is what you're looking for, but for generic collections instead of using:

Assert.Contains(member, list);

I use:

Assert.That(list.Contains(member));

which I find almost as readable.

Answer 2

ICollection and ICollection<T> are different contracts - one does not inherit the other.

http://msdn.microsoft.com/en-us/library/system.collections.icollection_members.aspx http://msdn.microsoft.com/en-us/library/y2fx0ty0.aspx

If you have a generic collection you can call ToList() on it and get a List<T>, which happens to implement the non-generic ICollection as well. Then use that List in the NUnit Assert method.

Answer 3

There are a set of CollectionAsserts, or you could inherit your test from AssertHelper and use syntax like

Expect(actual, Is.EquivalentTo(expected));

A look at the documentation should give you the syntax for the constraints that apply to collections.

Here's a link (this is version 2.5.2)

N.B. Expect is just shorthand for Assert.That...