[Testing] Updated FlakyTestAttribute to allow retries (#27772)

* Updated FlakyTestAttribute to allow retries

* Updated attribute comment based on feedback

* Loggin attempt with TestExecutionContext.CurrentResult

* Avoid static var

* [housekeeping] Automated PR to fix formatting errors on update-flakytestattribute

* Fix build errors

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: jsuarezruiz

src/Controls/tests/TestCases.Shared.Tests/Tests/FlakyTestAttribute.cs

@@ -1,13 +1,90 @@
 using NUnit.Framework;
+using NUnit.Framework.Interfaces;
+using NUnit.Framework.Internal;
+using NUnit.Framework.Internal.Commands;
 
-namespace Microsoft.Maui.TestCases.Tests;
-
-public class FlakyTestAttribute : IgnoreAttribute
+namespace Microsoft.Maui.TestCases.Tests
 {
-	public FlakyTestAttribute() : base(nameof(FlakyTestAttribute))
-	{
-	}
-	public FlakyTestAttribute(string reason) : base(reason)
+	/// <summary>
+	/// Custom NUnit attribute to mark a test as flaky, allowing retries (by default 2).
+	/// If after the retries the test fails, can ignore it.
+	/// Note: This attribute should be used temporarily until the test is changed.
+	/// </summary>  
+	/// <example>
+	/// <code>
+	/// [FlakyTest("Description with details of the test that sometimes fails.", retryCount: 2, ignore: true)]
+	/// </code>
+	/// </example>
+	internal class FlakyTestAttribute : Attribute, IWrapTestMethod, IWrapSetUpTearDown
 	{
+		readonly string _ignoreMessage;
+		readonly int _retryCount;
+		readonly bool _ignore;
+
+		public FlakyTestAttribute(string message, int retryCount = 2, bool ignore = true)
+		{
+			_ignoreMessage = message;
+			_retryCount = retryCount;
+			_ignore = ignore;
+		}
+
+		public ActionTargets Targets => ActionTargets.Suite | ActionTargets.Test;
+
+		public TestCommand Wrap(TestCommand command)
+		{
+			return new CustomRetryCommand(command, _ignoreMessage, _retryCount, _ignore);
+		}
+
+		public class CustomRetryCommand : DelegatingTestCommand
+		{
+			readonly string _ignoreMessage;
+			readonly int _retryCount;
+			readonly bool _ignore;
+
+			int _failedAttempts = 0;
+
+			public CustomRetryCommand(TestCommand innerCommand, string ignoreMessage, int retryCount, bool ignore)
+				: base(innerCommand)
+			{
+				_ignoreMessage = ignoreMessage;
+				_retryCount = retryCount;
+				_ignore = ignore;
+			}
+
+			public override TestResult Execute(TestExecutionContext context)
+			{
+				int count = _retryCount;
+				while (count-- > 0)
+				{
+					context.CurrentResult = innerCommand.Execute(context);
+					var results = context.CurrentResult.ResultState;
+
+					if (results.Equals(ResultState.Error)
+						|| results.Equals(ResultState.Failure)
+						|| results.Equals(ResultState.SetUpError)
+						|| results.Equals(ResultState.SetUpFailure)
+						|| results.Equals(ResultState.TearDownError)
+						|| results.Equals(ResultState.ChildFailure)
+						|| results.Equals(ResultState.Cancelled))
+					{
+						_failedAttempts++;
+						TestExecutionContext.CurrentContext.OutWriter.WriteLine("Test Failed on attempt #" + _failedAttempts);
+					}
+					else
+					{
+						TestExecutionContext.CurrentContext.OutWriter.WriteLine("Test Passed on attempt #" + (_failedAttempts + 1));
+						break;
+					}
+				}
+
+				// If want to ignore and all retry attempts fail, ignore the test with the provided message.
+				if (_ignore && _failedAttempts == _retryCount)
+				{
+					context.CurrentResult.SetResult(ResultState.Ignored, _ignoreMessage);
+				}
+
+				return context.CurrentResult;
+			}
+		}
 	}
 }