test: add integration tests for NotDiscoverableAttribute

TUnit.TestProject/NotDiscoverableTests.cs

@@ -0,0 +1,40 @@
+namespace TUnit.TestProject;
+
+public class NotDiscoverableTests
+{
+    [Test]
+    [NotDiscoverable]
+    public void Test_WithNotDiscoverable_ShouldNotAppearInDiscovery()
+    {
+        // This test should execute but not appear in test explorer
+    }
+
+    [Test]
+    [NotDiscoverable("Infrastructure test")]
+    public void Test_WithNotDiscoverableAndReason_ShouldNotAppearInDiscovery()
+    {
+        // This test should execute but not appear in test explorer
+    }
+
+    [Test]
+    public void Test_WithoutNotDiscoverable_ShouldAppearInDiscovery()
+    {
+        // This test should appear normally in test explorer
+    }
+}
+
+[NotDiscoverable]
+public class NotDiscoverableClassTests
+{
+    [Test]
+    public void Test_InNotDiscoverableClass_ShouldNotAppearInDiscovery()
+    {
+        // All tests in this class should be hidden from discovery
+    }
+
+    [Test]
+    public void AnotherTest_InNotDiscoverableClass_ShouldNotAppearInDiscovery()
+    {
+        // All tests in this class should be hidden from discovery
+    }
+}