IEnumerable<T> collections aren't enumerated for comparison.

[martaver]

Given:

public IEnumerable<int> GetInts() 
{
    yield return 1;
    yield return 2;
    yield return 3;
}

and the test:

GetInts().ShouldLookLike(new [] { 1, 2, 3, 4 });

The test should throw an exception, but doesn't.