NUnit Nested Collection Comparison

Question

Is there something similar to CollectionAssert.AreEquivalent() that works with nested collections?

The following code...

CollectionAssert.AreEquivalent ( 
    new Dictionary<int, Dictionary<int, string>>
    {
        { 1, new Dictionary < int, string > { { 10, "foo" }, { 11, "bar" }, { 12, "spam" } } },
        { 2, new Dictionary < int, string > { { 20, "eggs" }, { 21, "eels" } } },
        { 3, new Dictionary < int, string > { { 30, "hovercraft" } } }
    },
    new Dictionary<int, Dictionary<int, string>>
    {
        { 1, new Dictionary < int, string > { { 10, "foo" }, { 11, "bar" }, { 12, "spam" } } },
        { 2, new Dictionary < int, string > { { 20, "eggs" }, { 21, "eels" } } },
        { 3, new Dictionary < int, string > { { 30, "hovercraft" } } }
    } );

throws this exception...

Expected: equivalent to
    < [1, System.Collections.Generic.Dictionary`2[System.Int32,System.String]],
    [2, System.Collections.Generic.Dictionary`2[System.Int32,System.String]],
    [3, System.Collections.Generic.Dictionary`2[System.Int32,System.String]] >
But was:
    < [1, System.Collections.Generic.Dictionary`2[System.Int32,System.String]],
    [2, System.Collections.Generic.Dictionary`2[System.Int32,System.String]],
    [3, System.Collections.Generic.Dictionary`2[System.Int32,System.String]] >

The following assert passes:

CollectionAssert.AreEquivalent (
    new Dictionary < int, string > { { 10, "foo" }, { 11, "bar" }, { 12, "spam" } },
    new Dictionary < int, string > { { 10, "foo" }, { 11, "bar" }, { 12, "spam" } } );

If I make changes to the expected collection, the assert throws an exception with the entire content of both collections in the message:

Expected: equivalent to < [10, foo], [11, bar], [12, spam] >
But was:  < [10, foo], [11, bar], [12, eggs] >

I'm using NUnit 2.4.7.0.

Answer 1

An old question, but somebody just posted a link to it on nunit-discuss...

The failure is because the version of NUnit used did not support equality comparisons between two dictionaries and fell back on object comparison. Recent releases will not have this problem.