/**
* Error Handling Module
*
* This module provides custom error classes and error handling utilities
* for the n8n MCP Server.
*/
import { McpError as SdkMcpError } from '@modelcontextprotocol/sdk/types.js';
import { ErrorCode } from './error-codes.js';
// Re-export McpError from SDK
export { McpError } from '@modelcontextprotocol/sdk/types.js';
// Re-export ErrorCode enum
export { ErrorCode } from './error-codes.js';
/**
* n8n API Error class for handling errors from the n8n API
*/
export class N8nApiError extends SdkMcpError {
constructor(message: string, statusCode?: number, details?: unknown) {
// Map HTTP status codes to appropriate MCP error codes
let errorCode = ErrorCode.InternalError;
if (statusCode) {
if (statusCode === 401 || statusCode === 403) {
errorCode = ErrorCode.AuthenticationError;
} else if (statusCode === 404) {
errorCode = ErrorCode.NotFoundError;
} else if (statusCode >= 400 && statusCode < 500) {
errorCode = ErrorCode.InvalidRequest;
}
}
super(errorCode, formatErrorMessage(message, statusCode, details));
}
}
/**
* Format an error message with status code and details
*/
function formatErrorMessage(message: string, statusCode?: number, details?: unknown): string {
let formattedMessage = message;
if (statusCode) {
formattedMessage += ` (Status: ${statusCode})`;
}
if (details) {
try {
const detailsStr = typeof details === 'string'
? details
: JSON.stringify(details, null, 2);
formattedMessage += `\nDetails: ${detailsStr}`;
} catch (error) {
// Ignore JSON stringification errors
}
}
return formattedMessage;
}
/**
* Safely parse JSON response from n8n API
*
* @param text Text to parse as JSON
* @returns Parsed JSON object or null if parsing fails
*/
export function safeJsonParse(text: string): any {
try {
return JSON.parse(text);
} catch (error) {
return null;
}
}
/**
* Handle axios errors and convert them to N8nApiError
*
* @param error Error object from axios
* @param defaultMessage Default error message
* @returns N8nApiError with appropriate details
*/
export function handleAxiosError(error: any, defaultMessage = 'n8n API request failed'): N8nApiError {
// Handle axios error responses
if (error.response) {
const statusCode = error.response.status;
const responseData = error.response.data;
let errorMessage = defaultMessage;
if (responseData && responseData.message) {
errorMessage = responseData.message;
}
return new N8nApiError(errorMessage, statusCode, responseData);
}
// Handle request errors (e.g., network issues)
if (error.request) {
return new N8nApiError(
'Network error connecting to n8n API',
undefined,
error.message
);
}
// Handle other errors
return new N8nApiError(error.message || defaultMessage);
}
/**
* Extract a readable error message from an error object
*
* @param error Error object
* @returns Readable error message
*/
export function getErrorMessage(error: unknown): string {
if (error instanceof Error) {
return error.message;
}
if (typeof error === 'string') {
return error;
}
try {
return JSON.stringify(error);
} catch {
return 'Unknown error';
}
}
