feat: add excludePatterns to search_files for filtering directories

- Add excludePatterns property to SearchFilesArgsSchema
- Modify searchFiles function to handle path exclusions
- Add minimatch import for glob pattern matching

This change allows excluding specific directories (like node_modules)
from file searches to prevent context window overflow.

Issue: modelcontextprotocol/servers#251

src/filesystem/index.ts

@@ -13,6 +13,7 @@ import os from 'os';
 import { z } from "zod";
 import { zodToJsonSchema } from "zod-to-json-schema";
 import { diffLines, createTwoFilesPatch } from 'diff';
+import minimatch from 'minimatch';
 
 // Command line argument parsing
 const args = process.argv.slice(2);
@@ -134,6 +135,7 @@ const MoveFileArgsSchema = z.object({
 const SearchFilesArgsSchema = z.object({
   path: z.string(),
   pattern: z.string(),
+  excludePatterns: z.array(z.string()).optional().default([])
 });
 
 const GetFileInfoArgsSchema = z.object({
@@ -183,6 +185,7 @@ async function getFileStats(filePath: string): Promise<FileInfo> {
 async function searchFiles(
   rootPath: string,
   pattern: string,
+  excludePatterns: string[] = []
 ): Promise<string[]> {
   const results: string[] = [];
 
@@ -191,11 +194,22 @@ async function searchFiles(
 
     for (const entry of entries) {
       const fullPath = path.join(currentPath, entry.name);
-      
+
       try {
         // Validate each path before processing
         await validatePath(fullPath);
 
+        // Check if path matches any exclude pattern
+        const relativePath = path.relative(rootPath, fullPath);
+        const shouldExclude = excludePatterns.some(pattern => {
+          const globPattern = pattern.startsWith('*') ? pattern : `*/${pattern}/*`;
+          return minimatch(relativePath, globPattern, { dot: true });
+        });
+
+        if (shouldExclude) {
+          continue;
+        }
+
         if (entry.name.toLowerCase().includes(pattern.toLowerCase())) {
           results.push(fullPath);
         }
@@ -574,4 +588,4 @@ async function runServer() {
 runServer().catch((error) => {
   console.error("Fatal error running server:", error);
   process.exit(1);
-});
+});