Refactor code structure for improved readability and maintainability; optimize performance in key functions.

tests/unit/StellaOps.AuditPack.Tests/AuditPackImporterTests.cs

@@ -0,0 +1,79 @@
+namespace StellaOps.AuditPack.Tests;
+
+using StellaOps.AuditPack.Services;
+
+[Trait("Category", "Unit")]
+public class AuditPackImporterTests
+{
+    [Fact]
+    public async Task Import_ValidPack_Succeeds()
+    {
+        // Arrange
+        var archivePath = await CreateTestArchiveAsync();
+        var importer = new AuditPackImporter();
+        var options = new ImportOptions { VerifySignatures = false };
+
+        try
+        {
+            // Act
+            var result = await importer.ImportAsync(archivePath, options);
+
+            // Assert
+            result.Success.Should().BeTrue();
+            result.Pack.Should().NotBeNull();
+            result.IntegrityResult?.IsValid.Should().BeTrue();
+        }
+        finally
+        {
+            if (File.Exists(archivePath))
+                File.Delete(archivePath);
+        }
+    }
+
+    [Fact]
+    public async Task Import_MissingManifest_Fails()
+    {
+        // Arrange
+        var archivePath = Path.Combine(Path.GetTempPath(), "invalid.tar.gz");
+        await CreateEmptyArchiveAsync(archivePath);
+
+        var importer = new AuditPackImporter();
+
+        try
+        {
+            // Act
+            var result = await importer.ImportAsync(archivePath, new ImportOptions());
+
+            // Assert
+            result.Success.Should().BeFalse();
+            result.Errors.Should().Contain(e => e.Contains("Manifest"));
+        }
+        finally
+        {
+            if (File.Exists(archivePath))
+                File.Delete(archivePath);
+        }
+    }
+
+    private static async Task<string> CreateTestArchiveAsync()
+    {
+        // Create a test pack and export it
+        var builder = new AuditPackBuilder();
+        var pack = await builder.BuildAsync(
+            new ScanResult("test-scan"),
+            new AuditPackOptions());
+
+        var archivePath = Path.Combine(Path.GetTempPath(), $"test-{Guid.NewGuid():N}.tar.gz");
+        await builder.ExportAsync(pack, archivePath, new ExportOptions { Sign = false });
+
+        return archivePath;
+    }
+
+    private static async Task CreateEmptyArchiveAsync(string path)
+    {
+        // Create an empty tar.gz
+        using var fs = File.Create(path);
+        using var gz = new System.IO.Compression.GZipStream(fs, System.IO.Compression.CompressionLevel.Fastest);
+        await gz.WriteAsync(new byte[] { 0 });
+    }
+}