Add JUnitSerializer with bidirectional serialization and format conversion support

src/DemaConsulting.TestResults/IO/JUnitSerializer.cs

@@ -0,0 +1,142 @@
+// Copyright(c) 2025 DEMA Consulting
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+using System.Globalization;
+using System.Text;
+using System.Xml.Linq;
+
+namespace DemaConsulting.TestResults.IO;
+
+/// <summary>
+///     JUnit Serializer class
+/// </summary>
+public static class JUnitSerializer
+{
+    /// <summary>
+    ///     Serializes the TestResults object to a JUnit XML file
+    /// </summary>
+    /// <param name="results">Test Results</param>
+    /// <returns>JUnit XML file contents</returns>
+    public static string Serialize(TestResults results)
+    {
+        // Group test results by class name for test suites
+        var testSuites = results.Results
+            .GroupBy(r => r.ClassName)
+            .OrderBy(g => g.Key);
+
+        // Construct the root element
+        var root = new XElement("testsuites",
+            new XAttribute("name", results.Name));
+
+        // Add test suites for each class
+        foreach (var suiteGroup in testSuites)
+        {
+            var className = string.IsNullOrEmpty(suiteGroup.Key) ? "DefaultSuite" : suiteGroup.Key;
+            var suiteTests = suiteGroup.ToList();
+
+            var testSuite = new XElement("testsuite",
+                new XAttribute("name", className),
+                new XAttribute("tests", suiteTests.Count),
+                new XAttribute("failures", suiteTests.Count(t => t.Outcome == TestOutcome.Failed)),
+                new XAttribute("errors", suiteTests.Count(t => t.Outcome == TestOutcome.Error || t.Outcome == TestOutcome.Timeout || t.Outcome == TestOutcome.Aborted)),
+                new XAttribute("skipped", suiteTests.Count(t => !t.Outcome.IsExecuted())),
+                new XAttribute("time", suiteTests.Sum(t => t.Duration.TotalSeconds).ToString("F3", CultureInfo.InvariantCulture)));
+
+            // Add test cases
+            foreach (var test in suiteTests)
+            {
+                var testCase = new XElement("testcase",
+                    new XAttribute("name", test.Name),
+                    new XAttribute("classname", string.IsNullOrEmpty(test.ClassName) ? "DefaultSuite" : test.ClassName),
+                    new XAttribute("time", test.Duration.TotalSeconds.ToString("F3", CultureInfo.InvariantCulture)));
+
+                // Add failure or error information
+                if (test.Outcome == TestOutcome.Failed)
+                {
+                    var failure = new XElement("failure");
+                    if (!string.IsNullOrEmpty(test.ErrorMessage))
+                    {
+                        failure.Add(new XAttribute("message", test.ErrorMessage));
+                    }
+                    if (!string.IsNullOrEmpty(test.ErrorStackTrace))
+                    {
+                        failure.Add(new XCData(test.ErrorStackTrace));
+                    }
+                    testCase.Add(failure);
+                }
+                else if (test.Outcome == TestOutcome.Error || test.Outcome == TestOutcome.Timeout || test.Outcome == TestOutcome.Aborted)
+                {
+                    var error = new XElement("error");
+                    if (!string.IsNullOrEmpty(test.ErrorMessage))
+                    {
+                        error.Add(new XAttribute("message", test.ErrorMessage));
+                    }
+                    if (!string.IsNullOrEmpty(test.ErrorStackTrace))
+                    {
+                        error.Add(new XCData(test.ErrorStackTrace));
+                    }
+                    testCase.Add(error);
+                }
+                else if (!test.Outcome.IsExecuted())
+                {
+                    var skipped = new XElement("skipped");
+                    if (!string.IsNullOrEmpty(test.ErrorMessage))
+                    {
+                        skipped.Add(new XAttribute("message", test.ErrorMessage));
+                    }
+                    testCase.Add(skipped);
+                }
+
+                // Add system output
+                if (!string.IsNullOrEmpty(test.SystemOutput))
+                {
+                    testCase.Add(new XElement("system-out", new XCData(test.SystemOutput)));
+                }
+
+                // Add system error
+                if (!string.IsNullOrEmpty(test.SystemError))
+                {
+                    testCase.Add(new XElement("system-err", new XCData(test.SystemError)));
+                }
+
+                testSuite.Add(testCase);
+            }
+
+            root.Add(testSuite);
+        }
+
+        // Write the XML text
+        var doc = new XDocument(root);
+        var writer = new Utf8StringWriter();
+        doc.Save(writer);
+        return writer.ToString();
+    }
+
+    /// <summary>
+    ///     String writer that uses UTF-8 encoding
+    /// </summary>
+    private sealed class Utf8StringWriter : StringWriter
+    {
+        /// <summary>
+        ///     Gets the UTF-8 encoding
+        /// </summary>
+        public override Encoding Encoding => Encoding.UTF8;
+    }
+}