using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

using System.Xml;

using System.Xml.Linq;

using System.IO;

​

using NUnit.Framework; //NUnit.Framework.AssertionException

​

#nullable enable

​

//https://stackoverflow.com/questions/1123718/format-xml-string-to-print-friendly-xml-string

​

    public static class XmlExtensions

    {

        public static string FormatXml(this string xml, 

                                       bool indent = true, bool newLineOnAttributes = false, string indentChars = "  ", 

                                       ConformanceLevel conformanceLevel = ConformanceLevel.Document, bool ignoreWhitespace = true) => 

            // By default we ignore the incoming whitespace, since the purpose of this method is to reformat the incoming xml.

            xml.FormatXml( new XmlWriterSettings { Indent = indent, NewLineOnAttributes = newLineOnAttributes, IndentChars = indentChars, ConformanceLevel = conformanceLevel }, 

                          new XmlReaderSettings { ConformanceLevel = conformanceLevel, IgnoreWhitespace = ignoreWhitespace });

​

        public static string FormatXml(this string xml, XmlWriterSettings writerSettings, XmlReaderSettings? readerSettings = default)

        {

            using (var textReader = new StringReader(xml))

            using (var xmlReader = XmlReader.Create(textReader, readerSettings ))

            using (var textWriter = new StringWriter())

            {

                using (var xmlWriter = XmlWriter.Create(textWriter, writerSettings))

                    xmlWriter.WriteNode(xmlReader, true);

                return textWriter.ToString();

            }

        }

    }

​

    public class TestClass

    {

        public static void Test()

        {

            foreach (var inXml in GetXml())

            {

                var newXml = inXml.FormatXml(indentChars : "", newLineOnAttributes : false); // Or true, if you prefer

                Console.WriteLine(newXml);

                Assert.IsTrue(XNode.DeepEquals(XDocument.Parse(inXml), XDocument.Parse(newXml)));

                Console.WriteLine();

            }

        }

        static IEnumerable<string> GetXml() => new []

        {

            @"<?xml version='1.0'?><response><error code='1'> Success</error></response>",

            """

            <?xml version='1.0'?>

                        <response>

                                <error code='1'> Success</error>

                </response>

            """,

"""

<?xml version="1.0" encoding="iso-8859-1"?>

    <reportResponse>

      <report>

    <b>Now</b> is the winter of our discontent

Made glorious summer by this sun of York;

And all the clouds that lour'd upon our house

In the deep bosom of the ocean buried.

</report>

    </reportResponse>

""",

        };

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}, {2}, NewLine: {3}).", 

                              System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion,

                              System.Text.Json.JsonSerializer.Serialize(Environment.NewLine));

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​