Fix bugs, remove dead code, upgrade to net8.0, add unit tests

src/AssemblyCrawler.Tests/AssemblyCrawler.Tests.csproj

@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="xunit" Version="2.5.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\AssemblyCrawler\AssemblyCrawler.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+</Project>

src/AssemblyCrawler.Tests/AssemblyExtensionTests.cs

@@ -0,0 +1,67 @@
+using AssemblyCrawler;
+using System.IO;
+
+namespace AssemblyCrawler.Tests;
+
+public class AssemblyExtensionTests : IDisposable
+{
+    private readonly string _tempDir;
+
+    public AssemblyExtensionTests()
+    {
+        _tempDir = Path.Combine(Path.GetTempPath(), "AssemblyExtensionTests_" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(_tempDir);
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_tempDir))
+            Directory.Delete(_tempDir, recursive: true);
+    }
+
+    // IsManagedAssembly uses FName (lowercased), so copy the DLL with a lowercase filename
+    private FileInfo GetManagedDllFileInfo()
+    {
+        string location = typeof(AssemblyExtensionTests).Assembly.Location;
+        string lowercaseName = Path.GetFileName(location).ToLowerInvariant();
+        string dest = Path.Combine(_tempDir, lowercaseName);
+        File.Copy(location, dest, overwrite: true);
+        return new FileInfo(dest);
+    }
+
+    [Fact]
+    public void IsManagedAssembly_ManagedDll_ReturnsTrue()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.True(assemblyInfo.IsManagedAssembly());
+    }
+
+    [Fact]
+    public void IsManagedAssembly_NonManagedFile_ReturnsFalse()
+    {
+        var tempFile = Path.Combine(_tempDir, "notmanaged.dll");
+        File.WriteAllBytes(tempFile, new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 });
+        var fileInfo = new FileInfo(tempFile);
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.False(assemblyInfo.IsManagedAssembly());
+    }
+
+    [Fact]
+    public void SortByHashCode_GroupsIdenticalAssembliesTogether()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var a1 = new AssemblyInfo(fileInfo);
+        var a2 = new AssemblyInfo(fileInfo);
+        var a3 = new AssemblyInfo(fileInfo);
+
+        var list = new List<AssemblyInfo> { a1, a2, a3 };
+        var sorted = list.SortByHashCode();
+
+        // All three should have the same hash code and be in the same group
+        Assert.Single(sorted);
+        Assert.Equal(3, sorted.Values.First().Count);
+    }
+}

src/AssemblyCrawler.Tests/AssemblyInfoTests.cs

@@ -0,0 +1,89 @@
+using AssemblyCrawler;
+using System.IO;
+using System.Reflection;
+
+namespace AssemblyCrawler.Tests;
+
+public class AssemblyInfoTests : IDisposable
+{
+    private readonly string _tempDir;
+
+    public AssemblyInfoTests()
+    {
+        _tempDir = Path.Combine(Path.GetTempPath(), "AssemblyInfoTests_" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(_tempDir);
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_tempDir))
+            Directory.Delete(_tempDir, recursive: true);
+    }
+
+    // IsManagedAssembly uses FName (lowercased), so copy the DLL with a lowercase filename
+    private FileInfo GetManagedDllFileInfo()
+    {
+        string location = typeof(AssemblyInfoTests).Assembly.Location;
+        string lowercaseName = Path.GetFileName(location).ToLowerInvariant();
+        string dest = Path.Combine(_tempDir, lowercaseName);
+        File.Copy(location, dest, overwrite: true);
+        return new FileInfo(dest);
+    }
+
+    [Fact]
+    public void Constructor_ManagedDll_PopulatesFName()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.Equal(fileInfo.Name.ToLowerInvariant(), assemblyInfo.FName.Value);
+    }
+
+    [Fact]
+    public void Constructor_ManagedDll_IsManaged_ReturnsTrue()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.True(assemblyInfo.IsManaged.Value);
+    }
+
+    [Fact]
+    public void Constructor_ManagedDll_AName_IsNotEmpty()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.NotEmpty(assemblyInfo.AName.Value);
+    }
+
+    [Fact]
+    public void Constructor_ManagedDll_AssemblyVersion_IsNotNull()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.NotNull(assemblyInfo.AssemblyVersion.Value);
+    }
+
+    [Fact]
+    public void Constructor_NonManagedBinary_IsManaged_ReturnsFalse()
+    {
+        var tempFile = Path.Combine(_tempDir, "notadll.dll");
+        File.WriteAllBytes(tempFile, new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 });
+        var fileInfo = new FileInfo(tempFile);
+        var assemblyInfo = new AssemblyInfo(fileInfo);
+
+        Assert.False(assemblyInfo.IsManaged.Value);
+    }
+
+    [Fact]
+    public void GetHashCode_SameAssembly_ReturnsConsistentValue()
+    {
+        var fileInfo = GetManagedDllFileInfo();
+        var assemblyInfo1 = new AssemblyInfo(fileInfo);
+        var assemblyInfo2 = new AssemblyInfo(fileInfo);
+
+        Assert.Equal(assemblyInfo1.GetHashCode(), assemblyInfo2.GetHashCode());
+    }
+}

src/AssemblyCrawler.Tests/CrawlerTests.cs

@@ -0,0 +1,102 @@
+using AssemblyCrawler;
+using System.IO;
+
+namespace AssemblyCrawler.Tests;
+
+public class CrawlerTests : IDisposable
+{
+    private readonly string _tempDir;
+
+    public CrawlerTests()
+    {
+        _tempDir = Path.Combine(Path.GetTempPath(), "CrawlerTests_" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(_tempDir);
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_tempDir))
+            Directory.Delete(_tempDir, recursive: true);
+    }
+
+    private void CopyTestDllToDir(string dir, string fileName)
+    {
+        string sourceDll = typeof(CrawlerTests).Assembly.Location;
+        // Use lowercase filename to match FName.Value (which lowercases the name)
+        File.Copy(sourceDll, Path.Combine(dir, fileName.ToLowerInvariant()), overwrite: true);
+    }
+
+    [Fact]
+    public void Crawl_ValidDirectory_PopulatesAssemblyListAndCounts()
+    {
+        CopyTestDllToDir(_tempDir, "test1.dll");
+        CopyTestDllToDir(_tempDir, "test2.dll");
+
+        var crawler = new Crawler(_tempDir);
+        crawler.Crawl();
+
+        Assert.True(crawler.TotalFileCount >= 2);
+        Assert.True(crawler.TotalAssemblyCount >= 2);
+        Assert.True(crawler.AssemblyList.Count >= 2);
+    }
+
+    [Fact]
+    public void Crawl_CalledTwice_DoesNotReCrawl()
+    {
+        CopyTestDllToDir(_tempDir, "test1.dll");
+
+        var crawler = new Crawler(_tempDir);
+        crawler.Crawl();
+        int countAfterFirstCrawl = crawler.TotalAssemblyCount;
+
+        // Copy another DLL to the dir between crawls (shouldn't be picked up)
+        CopyTestDllToDir(_tempDir, "test2.dll");
+        crawler.Crawl();
+
+        Assert.Equal(countAfterFirstCrawl, crawler.TotalAssemblyCount);
+    }
+
+    [Fact]
+    public void Sort_BeforeCrawl_DoesNotCrash()
+    {
+        var crawler = new Crawler(_tempDir);
+
+        // Should print "Must parse directory first." but not throw
+        var exception = Record.Exception(() => crawler.Sort());
+        Assert.Null(exception);
+    }
+
+    [Fact]
+    public void Sort_AfterCrawl_SeparatesManagedAndUnmanaged()
+    {
+        CopyTestDllToDir(_tempDir, "managed1.dll");
+        CopyTestDllToDir(_tempDir, "managed2.dll");
+
+        // Create a non-managed binary file
+        var nonManagedPath = Path.Combine(_tempDir, "native.dll");
+        File.WriteAllBytes(nonManagedPath, new byte[128]);
+
+        var crawler = new Crawler(_tempDir);
+        crawler.Crawl();
+        crawler.Sort();
+
+        // AllAssemblies contains assemblies with duplicates (>1 copy)
+        // AllManagedAssemblies is the filtered managed subset
+        // Both should be valid without exception
+        Assert.NotNull(crawler.AllAssemblies);
+        Assert.NotNull(crawler.AllManagedAssemblies);
+    }
+
+    [Fact]
+    public void CrawlDirectory_IgnoresResourceDlls()
+    {
+        CopyTestDllToDir(_tempDir, "regular.dll");
+        CopyTestDllToDir(_tempDir, "resources.resources.dll");
+
+        var crawler = new Crawler(_tempDir);
+        crawler.Crawl();
+
+        // The .resources.dll should be ignored; only regular.dll counted
+        Assert.Equal(1, crawler.TotalAssemblyCount);
+    }
+}

src/AssemblyCrawler.Tests/StringExtensionTests.cs

@@ -0,0 +1,30 @@
+using AssemblyCrawler;
+
+namespace AssemblyCrawler.Tests;
+
+public class StringExtensionTests
+{
+    [Fact]
+    public void GetStableHashCode_SameInput_ReturnsSameValue()
+    {
+        var hash1 = "hello".GetStableHashCode();
+        var hash2 = "hello".GetStableHashCode();
+        Assert.Equal(hash1, hash2);
+    }
+
+    [Fact]
+    public void GetStableHashCode_DifferentInputs_ReturnsDifferentValues()
+    {
+        var hash1 = "hello".GetStableHashCode();
+        var hash2 = "world".GetStableHashCode();
+        Assert.NotEqual(hash1, hash2);
+    }
+
+    [Fact]
+    public void GetStableHashCode_EmptyString_ReturnsConsistentValue()
+    {
+        var hash1 = "".GetStableHashCode();
+        var hash2 = "".GetStableHashCode();
+        Assert.Equal(hash1, hash2);
+    }
+}

src/AssemblyCrawler.sln

@@ -5,6 +5,8 @@ VisualStudioVersion = 17.2.32630.192
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AssemblyCrawler", "AssemblyCrawler\AssemblyCrawler.csproj", "{F4896D2F-EC6F-426D-9321-F874423D7DE5}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AssemblyCrawler.Tests", "AssemblyCrawler.Tests\AssemblyCrawler.Tests.csproj", "{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -15,6 +17,10 @@ Global
 		{F4896D2F-EC6F-426D-9321-F874423D7DE5}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{F4896D2F-EC6F-426D-9321-F874423D7DE5}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F4896D2F-EC6F-426D-9321-F874423D7DE5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE