Tree-Hugger-JS MCP Server

Instructions

Implementation Reference

• src/index.ts:569-607 (handler)

  The handler function that implements the core logic of the 'find_all_pattern' tool. It searches the current AST for all nodes matching the given pattern using tree-hugger-js's findAll method, applies an optional limit, formats the results, and returns them.

  private async findAllPattern(args: { pattern: string; limit?: number }) {
    if (!this.currentAST) {
      return {
        content: [{
          type: "text",
          text: "No AST loaded. Please use parse_code first.",
        }],
        isError: true,
      };
    }
  
    try {
      const results = this.currentAST.tree.findAll(args.pattern);
      const limitedResults = args.limit ? results.slice(0, args.limit) : results;
      
      const matches = limitedResults.map((node: NodeWrapper) => ({
        type: node.type,
        text: node.text.length > 100 ? node.text.slice(0, 100) + '...' : node.text,
        line: node.line,
        column: node.column,
        name: node.name,
      }));
  
      return {
        content: [{
          type: "text",
          text: `Found ${results.length} matches for pattern "${args.pattern}"${args.limit ? ` (showing first ${limitedResults.length})` : ''}:\n${JSON.stringify(matches, null, 2)}`,
        }],
      };
    } catch (error) {
      return {
        content: [{
          type: "text",
          text: `Error finding pattern: ${error instanceof Error ? error.message : String(error)}`,
        }],
        isError: true,
      };
    }
  }

• src/index.ts:219-232 (schema)

  The input schema definition for the 'find_all_pattern' tool, specifying the required 'pattern' string and optional 'limit' number.

  inputSchema: {
    type: "object",
    properties: {
      pattern: {
        type: "string",
        description: "Pattern to match: 'function', 'call[text*=\"console.log\"]', 'string[text*=\"TODO\"]'"
      },
      limit: {
        type: "number",
        description: "Maximum number of matches to return (default: no limit). Use for large codebases."
      }
    },
    required: ["pattern"],
  },

• src/index.ts:216-233 (registration)

  The tool registration in the ListToolsRequestSchema handler's tools array, including name, description, and input schema.

  {
    name: "find_all_pattern", 
    description: "Find all nodes matching the specified pattern. Use for comprehensive analysis when you need all matches.\n\nExamples:\n• Audit all functions: find_all_pattern('function')\n• Find all TODO comments: find_all_pattern('comment[text*=\"TODO\"]')\n• Security audit: find_all_pattern('call[text*=\"eval\"]')\n• Performance review: find_all_pattern('call[text*=\"console.log\"]') to find debug logs\n• API usage: find_all_pattern('call[text*=\"fetch\"]') to find all API calls\n• React hooks: find_all_pattern('call[text*=\"use\"]') for hooks usage\n• Error patterns: find_all_pattern('string[text*=\"error\"]') for error messages\n• Database queries: find_all_pattern('string[text*=\"SELECT\"]') for SQL\n• Event handlers: find_all_pattern('function[text*=\"onClick\"]')",
    inputSchema: {
      type: "object",
      properties: {
        pattern: {
          type: "string",
          description: "Pattern to match: 'function', 'call[text*=\"console.log\"]', 'string[text*=\"TODO\"]'"
        },
        limit: {
          type: "number",
          description: "Maximum number of matches to return (default: no limit). Use for large codebases."
        }
      },
      required: ["pattern"],
    },
  },

• src/index.ts:419-420 (registration)

  The switch case in the CallToolRequestSchema handler that routes calls to the findAllPattern method.

  case "find_all_pattern":
    return await this.findAllPattern(args as { pattern: string; limit?: number });