IDictionary.ContainsKey assertion case sensitivity issue.

[voicu-matei]

[TestMethod]
public void ReproTest()
{
IDictionary<string, string> dictionary = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
{
{"name", "name description"}
};

        //The following 2 lines assert the same and should both pass
        dictionary.ContainsKey("NaMe").Should().BeTrue(); //passes
        dictionary.Should().ContainKey("NaMe"); //fails
    }

[dennisdoomen]

Hmm, it seems we're not relying on the dictionary's own equality algorithms then...

[voicu-matei]

I took a quick look at the code and it seems that indeed the dictionary's EqualityComparer is not used.

[voicu-matei]

I'm trying to fix it myself, but it's not possible to retrieve the Comparer from an IDictionary<K,V>.

GenericDictionaryAssertions.cs line 334.

var missingKeys = expectedKeys.Except(Subject.Keys);

could become

var missingKeys = expectedKeys.Except(Subject.Keys);

var dictionarySubject = Subject as Dictionary<TKey, TValue>;
if (dictionarySubject != null)
{
missingKeys = expectedKeys.Except(Subject.Keys, dictionarySubject.Comparer);
}

But this solves only the Dictionary problem.
Stuff like ConcurrentDictionary<,> will still not work as this is a different impl of IDictionary<,>. Still trying to find a generic way to fix this.
I also notice that the sources are linked from the 3.5 to the 4.0 project, so I cannot include System.Collections.Concurrent to test for ConcurrentDictionary.

[voicu-matei]

Reflection on Subject.GetType() and check for a public property of type IEqualityComparer of TKey ?
Could work.

[voicu-matei]

GenericDictionaryAssertions.cs line 334.

var missingKeys = expectedKeys.Except(Subject.Keys);

becomes:

var missingKeys = expectedKeys.Except(Subject.Keys);

var comparerPropertyInfo = Subject.GetType().GetProperties(BindingFlags.Public)
.FirstOrDefault(p => p.PropertyType == typeof(IEqualityComparer));

if(comparerPropertyInfo != null)
{
var comparer = (IEqualityComparer)comparerPropertyInfo.GetValue(Subject, null);
missingKeys = expectedKeys.Except(Subject.Keys, comparer);
}

Do you agree?

[voicu-matei]

Still no good for ConcurrentDictionary because that one does not expose the IEqualityComparer publicly. Would need to look for private fields of that type also.

Pfiu....

[dennisdoomen]

Maybe we should just rewrite that code to use the ContainsKey() method of the dictionary. That'll use whatever the dictionary uses internally.

[voicu-matei]

Ahaaa, indeed.

var missingKeys = expectedKeys.Except(Subject.Keys);
//becomes
var missingKeys = expectedKeys.Where(key => !Subject.ContainsKey(key));

This is the obvious way. What was I thinking!?!
Thanks!

[dennisdoomen]

Don't worry. I'm looking at it from a large distance so my mind is not clouded by the interiors of a dictionary :-)

[dennisdoomen]

Fixed by pull request #61.