CollectionOrdering.Any: How to specify a comparer?

[fubar-coder]

Hi,

is there a way to specify a comparer for CollectionOrdering.Any?

Example:

class Test {
  public string Text { get; set; }
}

class TestComparer : IComparer<Test>, IEqualityComparer<Test> {
  public int Compare(Test? x, Test? y) => StringComparer.OrdinalIgnoreCase.Compare(x?.Text, y?.Text);
  public int GetHashCode(Test x) => StringComparer.OrdinalIgnoreCase.GetHashCode(x.Text);
  public bool Equals(Test? x, Test? y) => StringComparer.OrdinalIgnoreCase.Equals(x?.Text, y?.Text);
}

Assert.That(
  new Test[] {
    new Test { Text = "a" },
    new Test { Text = "b" }, 
  })
  .IsEquivalentTo([
    new Test { Text = "B" },
    new Test { Text = "a" },
  ],
  new TestComparer(),
  CollectionOrdering.Any);

CollectionOrdering.Any tries to sort the the enumerables first, but doesn't try to cast the equality comparer to an IComparer<Test> and instead uses the default comparer, which results in the following error: Failed to compare two elements in the array..

The only thing that I can do for now is to manually sort the array before passing it to the Assert.

My initial hope was, that it tries to use the equality comparer and a hash set (or two) to determine the differences between the actual and expected sequences.

[thomhurst]

Try upgrading to v0.7.15 and let me know if it fixes things for you 😄

[fubar-coder]

Works as expected, thank you ❤️