Removing Duplicate Nodes from Xml using C#

LINQ to XML makes this reasonably easy if some assumptions are met:

• There are no elements with "triple duplication" e.g. <TestData><TestData><TestData>. I'm sure it's feasible to work around that, but it's trickier.
• We don't need to worry about non-element children (e.g. where TestData has text content as well as the nested TestData element)
• We don't need to worry about attributes

In that case, it's just a matter of checking that there's exactly one child element, and that it's got the same name as the parent element... then replace it.

Here's some code to do exactly that:

using System;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main(string[] args)
    {
        var doc = XDocument.Load("test.xml");
        var replacements = doc.Descendants()
            .Select(GetReplacementForParent)
            .Where(r => r != null)
            .ToList();
        foreach (var replacement in replacements)
        {
            replacement.Parent.ReplaceWith(replacement);
        }
        Console.WriteLine(doc);
    }

    static XElement GetReplacementForParent(XElement element)
    {
        var child = element.Elements(element.Name).FirstOrDefault();
        // TODO: Use a more efficient approach for counting children, maybe.
        // TODO: Check for non-element content? Check for attributes?
        return child != null && element.Elements().Count() == 1
            ? child : null;
    }
}