Add ability to capture output for failed tests.

Author: oyanushkevich

Allure.Xunit/AllureXunitConfiguration.cs

@@ -12,6 +12,8 @@ namespace Allure.Xunit
     internal class AllureXunitConfiguration : AllureConfiguration
     {
         public string XunitRunnerReporter { get; set; } = "auto";
+        
+        public bool CaptureFailedTestOutput { get; set; } = false;
 
         [JsonConstructor]
         protected AllureXunitConfiguration(

Allure.Xunit/AllureXunitHelper.cs

@@ -33,10 +33,16 @@ internal static void StartAllureTestCase(
                 testResult ?? CreateTestResultByTest(test)
             );
 
-        internal static void ApplyTestFailure(IFailureInformation failure)
+        internal static void ApplyTestFailure(ITestFailed failure)
         {
             var trace = string.Join("\n", failure.StackTraces);
             var message = string.Join("\n", failure.Messages);
+
+            if (AllureXunitConfiguration.CurrentConfig.CaptureFailedTestOutput)
+            {
+                message = string.Concat(message, "\n", failure.Output);
+            }
+
             var status = failure.ExceptionTypes.Any(
                 exceptionType => !exceptionType.StartsWith("Xunit.Sdk.")
             ) ? Status.broken : Status.failed;