Question

I want to write something like:

var list = new List<int>(){1,2,3};
var bigList = new List<int>(){1,2,3,4,5,6,7,8,9};

CollectionAssert.Contains(bigList, list);

I can get an error similar to:

 Expected: collection containing < 1,2,3 >
 But was:  < 1,2,3,4,5,6,7,8,9 >

Is it possible to use the contains method against another collection?

Answer 1

The signature is

   CollectionAssert.Contains (ICollection collection, Object element) 

And it checks if element (singular) is inside collection.
It is not a method to check for sub-lists.

You should probably use:

    CollectionAssert.IsSubsetOf (ICollection subset, ICollection superset)