github-repos-manager-mcp/src/utils/response-formatter.cjs

Model Context Protocol (MCP) server that enables your MCP client (e.g., Claude Desktop, Cline, Roo Code, Cursor, Windsurf, etc.) to interact with GitHub repositories using your GitHub personal access token.

/**
 * Utility to format handler responses for MCP compatibility
 */

/**
 * Converts a handler response to MCP format
 * @param {Object} response - The response from a handler
 * @param {boolean} response.success - Whether the operation was successful
 * @param {*} response.data - The data returned by the operation
 * @param {string} response.message - A message about the operation
 * @param {string} response.error - Error details if any
 * @returns {Object} MCP-formatted response
 */
function formatHandlerResponse(response) {
  if (!response || typeof response !== 'object') {
    return {
      content: [{ type: "text", text: "Invalid response format" }],
      isError: true
    };
  }

  // If already in MCP format, return as-is
  if (response.content && Array.isArray(response.content)) {
    return response;
  }

  // Handle error responses
  if (response.success === false || response.error) {
    return {
      content: [{ 
        type: "text", 
        text: response.message || response.error || "Operation failed" 
      }],
      isError: true
    };
  }

  // Handle success responses
  if (response.success === true) {
    let text = "";
    
    if (response.message) {
      text = response.message;
    }
    
    if (response.data) {
      if (typeof response.data === 'string') {
        text = text ? `${text}\n\n${response.data}` : response.data;
      } else if (Array.isArray(response.data)) {
        // Format arrays more nicely
        if (response.data.length === 0) {
          text = text ? `${text}\n\nNo items found.` : "No items found.";
        } else {
          const formattedItems = response.data.map((item, index) => {
            if (typeof item === 'object' && item !== null) {
              // Format objects in arrays
              const keys = Object.keys(item);
              const formatted = keys.map(key => `  ${key}: ${JSON.stringify(item[key])}`).join('\n');
              return `[${index + 1}]\n${formatted}`;
            }
            return `[${index + 1}] ${JSON.stringify(item)}`;
          }).join('\n\n');
          text = text ? `${text}\n\n${formattedItems}` : formattedItems;
        }
      } else if (typeof response.data === 'object') {
        // Format objects more nicely
        const formatted = Object.entries(response.data)
          .map(([key, value]) => `${key}: ${JSON.stringify(value, null, 2)}`)
          .join('\n');
        text = text ? `${text}\n\n${formatted}` : formatted;
      }
    }
    
    if (!text) {
      text = "Operation completed successfully";
    }
    
    return {
      content: [{ type: "text", text }]
    };
  }

  // Default case - try to format whatever we have
  return {
    content: [{ 
      type: "text", 
      text: JSON.stringify(response, null, 2) 
    }]
  };
}

module.exports = {
  formatHandlerResponse
};