Unity MCP Server

using System; using System.Collections.Generic; using System.IO; using System.Text.RegularExpressions; namespace UnityMcp { /// <summary> /// Parses and evaluates .gitignore patterns. /// Used to prevent MCP from exposing sensitive files. /// </summary> public sealed class GitIgnore { // MARK: Pattern sealed class Pattern { public bool negated; public bool dirOnly; public bool anchored; public Regex regex; public string original; // For debugging } readonly List<Pattern> _patterns = new List<Pattern>(); // MARK: Load public static GitIgnore LoadFromRootGitIgnore(string projectRoot) { var gi = new GitIgnore(); var path = Path.Combine(projectRoot, ".gitignore"); if (!File.Exists(path)) return gi; string[] lines; try { lines = File.ReadAllLines(path); } catch { return gi; } foreach (var raw in lines) { var line = raw.Trim(); if (line.Length == 0) continue; if (line.StartsWith("#", StringComparison.Ordinal)) continue; var original = line; var negated = false; // Handle escaped hash if (line.StartsWith(@"\#", StringComparison.Ordinal)) { line = line.Substring(1); } // Handle negation if (line.StartsWith("!", StringComparison.Ordinal)) { negated = true; line = line.Substring(1); } else if (line.StartsWith(@"\!", StringComparison.Ordinal)) { line = line.Substring(1); } line = line.Trim(); if (line.Length == 0) continue; // Directory-only patterns end with / var dirOnly = line.EndsWith("/", StringComparison.Ordinal); if (dirOnly) { line = line.TrimEnd('/'); } if (line.Length == 0) continue; // Anchored if starts with / or contains / (except trailing which we stripped) var anchored = line.StartsWith("/", StringComparison.Ordinal); if (anchored) { line = line.Substring(1); } // Contains slash means it's a path pattern, not just basename var containsSlash = line.Contains("/"); var regex = BuildRegex(line, anchored || containsSlash); gi._patterns.Add(new Pattern { negated = negated, dirOnly = dirOnly, anchored = anchored || containsSlash, regex = regex, original = original }); } return gi; } // MARK: Match public bool IsIgnored(string relUnix, bool isDirectory) { // Normalize path: forward slashes, no leading/trailing slashes var p = relUnix.Replace("\\", "/").Trim('/'); if (string.IsNullOrEmpty(p)) return false; var ignored = false; for (var i = 0; i < _patterns.Count; i++) { var pat = _patterns[i]; // Directory-only patterns skip files if (pat.dirOnly && !isDirectory) continue; bool matches; if (pat.anchored) { // Anchored patterns match from root matches = pat.regex.IsMatch(p); } else { // Non-anchored patterns can match the full path OR just the basename var basename = Path.GetFileName(p); matches = pat.regex.IsMatch(p) || pat.regex.IsMatch(basename); } if (matches) { ignored = !pat.negated; } } // Also check parent paths - if parent is ignored, children are too // (unless there's a negation pattern) if (!ignored) { var lastSlash = p.LastIndexOf('/'); if (lastSlash > 0) { var parent = p.Substring(0, lastSlash); if (IsIgnored(parent, true)) { // Check if there's a negation that un-ignores this specific path // For simplicity, if parent is ignored, child is ignored ignored = true; } } } return ignored; } // MARK: Regex static Regex BuildRegex(string pattern, bool anchored) { // Convert gitignore glob to regex var regexPattern = GlobToRegex(pattern); string full; if (anchored) { // Must match from start full = "^" + regexPattern + "$"; } else { // Can match anywhere (basename match) or full path full = "^" + regexPattern + "$"; } return new Regex(full, RegexOptions.Compiled); } static string GlobToRegex(string glob) { var sb = new System.Text.StringBuilder(); var i = 0; while (i < glob.Length) { var c = glob[i]; if (c == '*') { // Check for ** if (i + 1 < glob.Length && glob[i + 1] == '*') { // ** matches everything including / // Check if it's /**/ var beforeSlash = (i == 0) || (glob[i - 1] == '/'); var afterSlash = (i + 2 >= glob.Length) || (glob[i + 2] == '/'); if (beforeSlash && afterSlash) { // Matches zero or more directories sb.Append("(?:.*/)?"); i += 2; if (i < glob.Length && glob[i] == '/') i++; // Skip trailing / continue; } else { // Just ** without slashes - match everything sb.Append(".*"); i += 2; continue; } } else { // Single * matches everything except / sb.Append("[^/]*"); i++; } } else if (c == '?') { // ? matches any single char except / sb.Append("[^/]"); i++; } else if (c == '[') { // Character class - find closing ] var end = glob.IndexOf(']', i + 1); if (end > i) { sb.Append(glob.Substring(i, end - i + 1)); i = end + 1; } else { sb.Append(Regex.Escape(c.ToString())); i++; } } else if (c == '/') { sb.Append("/"); i++; } else { // Escape regex special chars sb.Append(Regex.Escape(c.ToString())); i++; } } return sb.ToString(); } // MARK: Debug public string DebugDump() { var sb = new System.Text.StringBuilder(); sb.AppendLine($"Loaded {_patterns.Count} patterns:"); foreach (var p in _patterns) { sb.AppendLine( $" {p.original} -> regex={p.regex}, dirOnly={p.dirOnly}, anchored={p.anchored}, negated={p.negated}"); } return sb.ToString(); } } /// <summary> /// Caches the GitIgnore instance and reloads when .gitignore changes. /// </summary> public static class GitIgnoreCache { static GitIgnore _cached; static DateTime _lastLoadUtc; public static GitIgnore Get() { var path = Path.Combine(ProjectPaths.ProjectRoot, ".gitignore"); DateTime stamp = default; try { if (File.Exists(path)) stamp = File.GetLastWriteTimeUtc(path); } catch { } if (_cached == null || stamp > _lastLoadUtc) { _cached = GitIgnore.LoadFromRootGitIgnore(ProjectPaths.ProjectRoot); _lastLoadUtc = stamp; } return _cached; } } }