Follow-up cleanup for FixturesTestTrait (#7281)

Author: Youssef1313

src/Adapter/MSTestAdapter.PlatformServices/EngineConstants.cs

@@ -35,11 +35,6 @@ internal static class EngineConstants
     /// </summary>
     internal const string AssemblyFixturesHierarchyClassName = "[Assembly]";
 
-    /// <summary>
-    /// Discover fixtures or not.
-    /// </summary>
-    internal const string FixturesTestTrait = "FixturesTrait";
-
     /// <summary>
     /// Assembly initialize.
     /// </summary>

src/Adapter/MSTestAdapter.PlatformServices/Execution/ClassCleanupManager.cs

@@ -14,9 +14,8 @@ internal sealed class ClassCleanupManager
 
     public ClassCleanupManager(IEnumerable<UnitTestElement> testsToRun)
     {
-        IEnumerable<UnitTestElement> runnableTests = testsToRun.Where(t => t.Traits is null || !t.Traits.Any(t => t.Name == EngineConstants.FixturesTestTrait));
         _remainingTestCountsByClass =
-            new(runnableTests.GroupBy(t => t.TestMethod.FullClassName)
+            new(testsToRun.GroupBy(t => t.TestMethod.FullClassName)
                 .ToDictionary(
                     g => g.Key,
                     g => g.Count()));

src/Adapter/MSTestAdapter.PlatformServices/Execution/TestExecutionManager.cs

@@ -251,12 +251,6 @@ private static bool MatchTestFilter(ITestCaseFilterExpression? filterExpression,
         if (filterExpression != null
             && !filterExpression.MatchTestCase(test, p => testMethodFilter.PropertyValueProvider(test, p)))
         {
-            // If this is a fixture test, return true. Fixture tests are not filtered out and are always available for the status.
-            if (test.Traits.Any(t => t.Name == EngineConstants.FixturesTestTrait))
-            {
-                return true;
-            }
-
             // Skip test if not fitting filter criteria.
             return false;
         }