fix: Skip inaccessible directories during file search (Fixes CLIENT-K6)

src/Cellm.Tests/Unit/Tools/IgnoreInaccessibleDirectoryInfoWrapperTests.cs

@@ -0,0 +1,84 @@
+using System.IO;
+using System.Linq;
+using Cellm.Tools.FileSearch;
+using Microsoft.Extensions.FileSystemGlobbing;
+using Microsoft.Extensions.FileSystemGlobbing.Abstractions;
+using Xunit;
+
+namespace Cellm.Tests.Unit.Tools;
+
+public class IgnoreInaccessibleDirectoryInfoWrapperTests
+{
+    [Fact]
+    public void EnumerateFileSystemInfos_ReturnsFilesInAccessibleDirectory()
+    {
+        var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        Directory.CreateDirectory(tempDir);
+
+        try
+        {
+            File.WriteAllText(Path.Combine(tempDir, "test.txt"), "hello");
+
+            var wrapper = new IgnoreInaccessibleDirectoryInfoWrapper(new DirectoryInfo(tempDir));
+            var entries = wrapper.EnumerateFileSystemInfos().ToList();
+
+            Assert.Single(entries);
+            Assert.Equal("test.txt", entries[0].Name);
+        }
+        finally
+        {
+            Directory.Delete(tempDir, true);
+        }
+    }
+
+    [Fact]
+    public void EnumerateFileSystemInfos_SkipsInaccessibleDirectories()
+    {
+        // C:\ProgramData contains junction points (Application Data, Desktop, etc.)
+        // that throw when enumerated with the stock DirectoryInfoWrapper.
+        var programData = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData);
+
+        // Stock wrapper throws on problematic junction points:
+        // - IOException when recursive junctions cause path-too-long
+        // - UnauthorizedAccessException when junctions deny access
+        var stockWrapper = new DirectoryInfoWrapper(new DirectoryInfo(programData));
+        var ex = Record.Exception(() =>
+            new Matcher().AddInclude("**/*").Execute(stockWrapper).Files.ToList());
+        Assert.True(ex is IOException or UnauthorizedAccessException,
+            $"Expected IOException or UnauthorizedAccessException, got {ex?.GetType().Name}: {ex?.Message}");
+
+        // Our wrapper skips them
+        var safeWrapper = new IgnoreInaccessibleDirectoryInfoWrapper(new DirectoryInfo(programData));
+        var result = new Matcher().AddInclude("**/*").Execute(safeWrapper);
+
+        // ProgramData has files, so we should get matches without throwing
+        Assert.True(result.HasMatches);
+    }
+
+    [Fact]
+    public void Execute_WithMatcher_ReturnsMatchingFiles()
+    {
+        var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        var subDir = Path.Combine(tempDir, "sub");
+        Directory.CreateDirectory(subDir);
+
+        try
+        {
+            File.WriteAllText(Path.Combine(subDir, "match.cs"), "code");
+            File.WriteAllText(Path.Combine(subDir, "skip.txt"), "text");
+
+            var matcher = new Matcher();
+            matcher.AddInclude("**/*.cs");
+
+            var result = matcher.Execute(new IgnoreInaccessibleDirectoryInfoWrapper(new DirectoryInfo(tempDir)));
+
+            Assert.True(result.HasMatches);
+            Assert.Single(result.Files);
+            Assert.EndsWith("match.cs", result.Files.First().Path);
+        }
+        finally
+        {
+            Directory.Delete(tempDir, true);
+        }
+    }
+}

src/Cellm/Tools/FileSearch/FileSearchRequestHandler.cs

@@ -10,7 +10,8 @@ public Task<FileSearchResponse> Handle(FileSearchRequest request, CancellationTo
         var matcher = new Matcher();
         matcher.AddIncludePatterns(request.IncludePatterns);
         matcher.AddExcludePatterns(request.ExcludePatterns ?? []);
-        var fileNames = matcher.GetResultsInFullPath(request.RootPath);
+        var result = matcher.Execute(new IgnoreInaccessibleDirectoryInfoWrapper(new DirectoryInfo(request.RootPath)));
+        var fileNames = result.Files.Select(x => Path.GetFullPath(Path.Combine(request.RootPath, x.Path)));
 
         return Task.FromResult(new FileSearchResponse(fileNames.ToList()));
     }

src/Cellm/Tools/FileSearch/IgnoreInaccessibleDirectoryInfoWrapper.cs

@@ -0,0 +1,32 @@
+using Microsoft.Extensions.FileSystemGlobbing.Abstractions;
+
+namespace Cellm.Tools.FileSearch;
+
+internal class IgnoreInaccessibleDirectoryInfoWrapper(DirectoryInfo directoryInfo) : DirectoryInfoBase
+{
+    public override string Name => directoryInfo.Name;
+
+    public override string FullName => directoryInfo.FullName;
+
+    public override DirectoryInfoBase? ParentDirectory =>
+        directoryInfo.Parent is not null ? new IgnoreInaccessibleDirectoryInfoWrapper(directoryInfo.Parent) : null;
+
+    public override IEnumerable<FileSystemInfoBase> EnumerateFileSystemInfos()
+    {
+        var options = new EnumerationOptions { IgnoreInaccessible = true };
+
+        foreach (var info in directoryInfo.EnumerateFileSystemInfos("*", options))
+        {
+            if (info is DirectoryInfo dir)
+                yield return new IgnoreInaccessibleDirectoryInfoWrapper(dir);
+            else if (info is FileInfo file)
+                yield return new FileInfoWrapper(file);
+        }
+    }
+
+    public override DirectoryInfoBase GetDirectory(string path) =>
+        new IgnoreInaccessibleDirectoryInfoWrapper(new DirectoryInfo(Path.Combine(directoryInfo.FullName, path)));
+
+    public override FileInfoBase GetFile(string path) =>
+        new FileInfoWrapper(new FileInfo(Path.Combine(directoryInfo.FullName, path)));
+}