Merge pull request modelcontextprotocol#213 from lamemind/main

[FileSystem] directory_tree base implementation

Author: jspahrsummers

src/filesystem/index.ts

@@ -35,7 +35,7 @@ function expandHome(filepath: string): string {
 }
 
 // Store allowed directories in normalized form
-const allowedDirectories = args.map(dir => 
+const allowedDirectories = args.map(dir =>
   normalizePath(path.resolve(expandHome(dir)))
 );
 
@@ -59,7 +59,7 @@ async function validatePath(requestedPath: string): Promise<string> {
   const absolute = path.isAbsolute(expandedPath)
     ? path.resolve(expandedPath)
     : path.resolve(process.cwd(), expandedPath);
-    
+
   const normalizedRequested = normalizePath(absolute);
 
   // Check if path is within allowed directories
@@ -127,6 +127,10 @@ const ListDirectoryArgsSchema = z.object({
   path: z.string(),
 });
 
+const DirectoryTreeArgsSchema = z.object({
+  path: z.string(),
+});
+
 const MoveFileArgsSchema = z.object({
   source: z.string(),
   destination: z.string(),
@@ -237,7 +241,7 @@ function createUnifiedDiff(originalContent: string, newContent: string, filepath
   // Ensure consistent line endings for diff
   const normalizedOriginal = normalizeLineEndings(originalContent);
   const normalizedNew = normalizeLineEndings(newContent);
-  
+
   return createTwoFilesPatch(
     filepath,
     filepath,
@@ -255,33 +259,33 @@ async function applyFileEdits(
 ): Promise<string> {
   // Read file content and normalize line endings
   const content = normalizeLineEndings(await fs.readFile(filePath, 'utf-8'));
-  
+
   // Apply edits sequentially
   let modifiedContent = content;
   for (const edit of edits) {
     const normalizedOld = normalizeLineEndings(edit.oldText);
     const normalizedNew = normalizeLineEndings(edit.newText);
-    
+
     // If exact match exists, use it
     if (modifiedContent.includes(normalizedOld)) {
       modifiedContent = modifiedContent.replace(normalizedOld, normalizedNew);
       continue;
     }
-    
+
     // Otherwise, try line-by-line matching with flexibility for whitespace
     const oldLines = normalizedOld.split('\n');
     const contentLines = modifiedContent.split('\n');
     let matchFound = false;
-    
+
     for (let i = 0; i <= contentLines.length - oldLines.length; i++) {
       const potentialMatch = contentLines.slice(i, i + oldLines.length);
-      
+
       // Compare lines with normalized whitespace
       const isMatch = oldLines.every((oldLine, j) => {
         const contentLine = potentialMatch[j];
         return oldLine.trim() === contentLine.trim();
       });
-      
+
       if (isMatch) {
         // Preserve original indentation of first line
         const originalIndent = contentLines[i].match(/^\s*/)?.[0] || '';
@@ -296,33 +300,33 @@ async function applyFileEdits(
           }
           return line;
         });
-        
+
         contentLines.splice(i, oldLines.length, ...newLines);
         modifiedContent = contentLines.join('\n');
         matchFound = true;
         break;
       }
     }
-    
+
     if (!matchFound) {
       throw new Error(`Could not find exact match for edit:\n${edit.oldText}`);
     }
   }
-  
+
   // Create unified diff
   const diff = createUnifiedDiff(content, modifiedContent, filePath);
-  
+
   // Format diff with appropriate number of backticks
   let numBackticks = 3;
   while (diff.includes('`'.repeat(numBackticks))) {
     numBackticks++;
   }
   const formattedDiff = `${'`'.repeat(numBackticks)}diff\n${diff}${'`'.repeat(numBackticks)}\n\n`;
-  
+
   if (!dryRun) {
     await fs.writeFile(filePath, modifiedContent, 'utf-8');
   }
-  
+
   return formattedDiff;
 }
 
@@ -383,6 +387,15 @@ server.setRequestHandler(ListToolsRequestSchema, async () => {
           "finding specific files within a directory. Only works within allowed directories.",
         inputSchema: zodToJsonSchema(ListDirectoryArgsSchema) as ToolInput,
       },
+      {
+        name: "directory_tree",
+        description:
+            "Get a recursive tree view of files and directories as a JSON structure. " +
+            "Each entry includes 'name', 'type' (file/directory), and 'children' for directories. " +
+            "Files have no children array, while directories always have a children array (which may be empty). " +
+            "The output is formatted with 2-space indentation for readability. Only works within allowed directories.",
+        inputSchema: zodToJsonSchema(DirectoryTreeArgsSchema) as ToolInput,
+      },
       {
         name: "move_file",
         description:
@@ -413,7 +426,7 @@ server.setRequestHandler(ListToolsRequestSchema, async () => {
       },
       {
         name: "list_allowed_directories",
-        description: 
+        description:
           "Returns the list of directories that this server is allowed to access. " +
           "Use this to understand which directories are available before trying to access files.",
         inputSchema: {
@@ -517,6 +530,49 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
         };
       }
 
+        case "directory_tree": {
+            const parsed = DirectoryTreeArgsSchema.safeParse(args);
+            if (!parsed.success) {
+                throw new Error(`Invalid arguments for directory_tree: ${parsed.error}`);
+            }
+
+            interface TreeEntry {
+                name: string;
+                type: 'file' | 'directory';
+                children?: TreeEntry[];
+            }
+
+            async function buildTree(currentPath: string): Promise<TreeEntry[]> {
+                const validPath = await validatePath(currentPath);
+                const entries = await fs.readdir(validPath, {withFileTypes: true});
+                const result: TreeEntry[] = [];
+
+                for (const entry of entries) {
+                    const entryData: TreeEntry = {
+                        name: entry.name,
+                        type: entry.isDirectory() ? 'directory' : 'file'
+                    };
+
+                    if (entry.isDirectory()) {
+                        const subPath = path.join(currentPath, entry.name);
+                        entryData.children = await buildTree(subPath);
+                    }
+
+                    result.push(entryData);
+                }
+
+                return result;
+            }
+
+            const treeData = await buildTree(parsed.data.path);
+            return {
+                content: [{
+                    type: "text",
+                    text: JSON.stringify(treeData, null, 2)
+                }],
+            };
+        }
+
       case "move_file": {
         const parsed = MoveFileArgsSchema.safeParse(args);
         if (!parsed.success) {