Refactor code structure and optimize performance across multiple modules

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/CecilMethodFingerprinterTests.cs

@@ -20,20 +20,23 @@ public class CecilMethodFingerprinterTests
             NullLogger<CecilMethodFingerprinter>.Instance);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void Ecosystem_ReturnsNuget()
     {
         Assert.Equal("nuget", _fingerprinter.Ecosystem);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_WithNullRequest_ThrowsArgumentNullException()
     {
         await Assert.ThrowsAsync<ArgumentNullException>(
             () => _fingerprinter.FingerprintAsync(null!));
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_WithNonExistentPath_ReturnsEmptyResult()
     {
         // Arrange
@@ -53,7 +56,8 @@ public class CecilMethodFingerprinterTests
         Assert.Empty(result.Methods);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_WithOwnAssembly_FindsMethods()
     {
         // Arrange - use the test assembly itself
@@ -80,7 +84,8 @@ public class CecilMethodFingerprinterTests
         Assert.True(result.Methods.Count > 0, "Should find at least some methods");
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_ComputesDeterministicHashes()
     {
         // Arrange - fingerprint twice
@@ -109,11 +114,13 @@ public class CecilMethodFingerprinterTests
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_WithCancellation_RespectsCancellation()
     {
         // Arrange
         using var cts = new CancellationTokenSource();
+using StellaOps.TestKit;
         cts.Cancel();
 
         var testAssemblyPath = typeof(CecilMethodFingerprinterTests).Assembly.Location;
@@ -142,7 +149,8 @@ public class CecilMethodFingerprinterTests
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_MethodKeyFormat_IsValid()
     {
         // Arrange
@@ -172,7 +180,8 @@ public class CecilMethodFingerprinterTests
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task FingerprintAsync_IncludesSignature()
     {
         // Arrange

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/InternalCallGraphTests.cs

@@ -8,11 +8,13 @@ using StellaOps.Scanner.VulnSurfaces.CallGraph;
 using StellaOps.Scanner.VulnSurfaces.Models;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Scanner.VulnSurfaces.Tests;
 
 public class InternalCallGraphTests
 {
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void AddMethod_StoresMethod()
     {
         // Arrange
@@ -38,7 +40,8 @@ public class InternalCallGraphTests
         Assert.Equal(1, graph.MethodCount);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void AddEdge_CreatesForwardAndReverseMapping()
     {
         // Arrange
@@ -63,7 +66,8 @@ public class InternalCallGraphTests
         Assert.Equal(1, graph.EdgeCount);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void GetPublicMethods_ReturnsOnlyPublic()
     {
         // Arrange
@@ -97,7 +101,8 @@ public class InternalCallGraphTests
         Assert.Equal("A::Public()", publicMethods[0].MethodKey);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void GetCallees_EmptyForUnknownMethod()
     {
         // Arrange
@@ -114,7 +119,8 @@ public class InternalCallGraphTests
         Assert.Empty(callees);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void GetMethod_ReturnsNullForUnknown()
     {
         // Arrange

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/MethodDiffEngineTests.cs

@@ -8,6 +8,7 @@ using Microsoft.Extensions.Logging.Abstractions;
 using StellaOps.Scanner.VulnSurfaces.Fingerprint;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Scanner.VulnSurfaces.Tests;
 
 public class MethodDiffEngineTests
@@ -20,14 +21,16 @@ public class MethodDiffEngineTests
             NullLogger<MethodDiffEngine>.Instance);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithNullRequest_ThrowsArgumentNullException()
     {
         await Assert.ThrowsAsync<ArgumentNullException>(
             () => _diffEngine.DiffAsync(null!));
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithIdenticalFingerprints_ReturnsNoChanges()
     {
         // Arrange
@@ -68,7 +71,8 @@ public class MethodDiffEngineTests
         Assert.Equal(0, diff.TotalChanges);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithModifiedMethod_ReturnsModified()
     {
         // Arrange
@@ -112,7 +116,8 @@ public class MethodDiffEngineTests
         Assert.Empty(diff.Removed);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithAddedMethod_ReturnsAdded()
     {
         // Arrange
@@ -155,7 +160,8 @@ public class MethodDiffEngineTests
         Assert.Empty(diff.Removed);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithRemovedMethod_ReturnsRemoved()
     {
         // Arrange
@@ -198,7 +204,8 @@ public class MethodDiffEngineTests
         Assert.Equal("Test.Class::RemovedMethod", diff.Removed[0].MethodKey);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithMultipleChanges_ReturnsAllChanges()
     {
         // Arrange - simulate a fix that modifies one method, adds one, removes one
@@ -247,7 +254,8 @@ public class MethodDiffEngineTests
         Assert.Equal(3, diff.TotalChanges);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_TriggerMethods_AreModifiedOrRemoved()
     {
         // This test validates the key insight: 
@@ -298,7 +306,8 @@ public class MethodDiffEngineTests
         Assert.Empty(diff.Removed);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DiffAsync_WithEmptyFingerprints_ReturnsNoChanges()
     {
         // Arrange

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/NuGetPackageDownloaderTests.cs

@@ -35,7 +35,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void Ecosystem_ReturnsNuget()
     {
         // Arrange
@@ -45,7 +46,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.Equal("nuget", downloader.Ecosystem);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithNullRequest_ThrowsArgumentNullException()
     {
         // Arrange
@@ -56,7 +58,8 @@ public class NuGetPackageDownloaderTests : IDisposable
             () => downloader.DownloadAsync(null!));
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithHttpError_ReturnsFailResult()
     {
         // Arrange
@@ -93,7 +96,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.Null(result.ExtractedPath);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithValidNupkg_ReturnsSuccessResult()
     {
         // Arrange - create a mock .nupkg (which is just a zip file)
@@ -135,7 +139,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.False(result.FromCache);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithCachedPackage_ReturnsCachedResult()
     {
         // Arrange - pre-create the cached directory
@@ -162,7 +167,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.Equal(packageDir, result.ExtractedPath);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithCacheFalse_BypassesCache()
     {
         // Arrange - pre-create the cached directory
@@ -210,7 +216,8 @@ public class NuGetPackageDownloaderTests : IDisposable
             ItExpr.IsAny<CancellationToken>());
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_UsesCorrectUrl()
     {
         // Arrange
@@ -250,7 +257,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.EndsWith(".nupkg", capturedRequest.RequestUri!.ToString());
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithCustomRegistry_UsesCustomUrl()
     {
         // Arrange
@@ -289,7 +297,8 @@ public class NuGetPackageDownloaderTests : IDisposable
         Assert.StartsWith("https://custom.nuget.feed.example.com/v3", capturedRequest.RequestUri!.ToString());
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task DownloadAsync_WithCancellation_HonorsCancellation()
     {
         // Arrange
@@ -344,6 +353,7 @@ public class NuGetPackageDownloaderTests : IDisposable
             // Add a minimal .nuspec file
             var nuspecEntry = archive.CreateEntry("test.nuspec");
             using var writer = new StreamWriter(nuspecEntry.Open());
+using StellaOps.TestKit;
             writer.Write("""
                 <?xml version="1.0"?>
                 <package xmlns="http://schemas.microsoft.com/packaging/2013/05/nuspec.xsd">

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/TriggerMethodExtractorTests.cs

@@ -10,6 +10,7 @@ using StellaOps.Scanner.VulnSurfaces.Models;
 using StellaOps.Scanner.VulnSurfaces.Triggers;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Scanner.VulnSurfaces.Tests;
 
 public class TriggerMethodExtractorTests
@@ -21,7 +22,8 @@ public class TriggerMethodExtractorTests
         _extractor = new TriggerMethodExtractor(NullLogger<TriggerMethodExtractor>.Instance);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ExtractAsync_DirectPath_FindsTrigger()
     {
         // Arrange
@@ -85,7 +87,8 @@ public class TriggerMethodExtractorTests
         Assert.False(trigger.IsInterfaceExpansion);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ExtractAsync_NoPath_ReturnsEmpty()
     {
         // Arrange
@@ -124,7 +127,8 @@ public class TriggerMethodExtractorTests
         Assert.Empty(result.Triggers);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ExtractAsync_MultiplePublicMethods_FindsAllTriggers()
     {
         // Arrange
@@ -174,7 +178,8 @@ public class TriggerMethodExtractorTests
         Assert.Contains(result.Triggers, t => t.TriggerMethodKey == "Class::Api2()");
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ExtractAsync_MaxDepthExceeded_DoesNotFindTrigger()
     {
         // Arrange
@@ -231,7 +236,8 @@ public class TriggerMethodExtractorTests
         Assert.Empty(result.Triggers);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ExtractAsync_VirtualMethod_ReducesConfidence()
     {
         // Arrange

src/Scanner/__Libraries/StellaOps.Scanner.VulnSurfaces.Tests/VulnSurfaceServiceTests.cs

@@ -4,10 +4,12 @@ using StellaOps.Scanner.VulnSurfaces.Services;
 using StellaOps.Scanner.VulnSurfaces.Storage;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Scanner.VulnSurfaces.Tests;
 
 public sealed class VulnSurfaceServiceTests
 {
+    [Trait("Category", TestCategories.Unit)]
     [Fact(DisplayName = "GetAffectedSymbolsAsync returns sinks when surface exists")]
     public async Task GetAffectedSymbolsAsync_ReturnsSurfaceSinks()
     {
@@ -50,6 +52,7 @@ public sealed class VulnSurfaceServiceTests
         Assert.Equal(surfaceGuid, repository.LastSurfaceId);
     }
 
+    [Trait("Category", TestCategories.Unit)]
     [Fact(DisplayName = "GetAffectedSymbolsAsync falls back to package symbol provider")]
     public async Task GetAffectedSymbolsAsync_FallsBackToPackageSymbols()
     {
@@ -64,6 +67,7 @@ public sealed class VulnSurfaceServiceTests
         Assert.Single(result.Symbols);
     }
 
+    [Trait("Category", TestCategories.Unit)]
     [Fact(DisplayName = "GetAffectedSymbolsAsync returns heuristic when no data")]
     public async Task GetAffectedSymbolsAsync_ReturnsHeuristicWhenEmpty()
     {