logger.ts•3.89 kB
export enum LogLevel {
ERROR = 0,
WARN = 1,
INFO = 2,
DEBUG = 3,
}
export interface LoggerConfig {
level: LogLevel;
prefix?: string;
timestamp?: boolean;
}
export class Logger {
private config: LoggerConfig;
private static instance: Logger;
private useFileLogging = false;
private fileStream: any = null;
// Cache environment variables for performance
private readonly isStdio = process.env.MCP_MODE === 'stdio';
private readonly isDisabled = process.env.DISABLE_CONSOLE_OUTPUT === 'true';
private readonly isHttp = process.env.MCP_MODE === 'http';
private readonly isTest = process.env.NODE_ENV === 'test' || process.env.TEST_ENVIRONMENT === 'true';
constructor(config?: Partial<LoggerConfig>) {
this.config = {
level: LogLevel.INFO,
prefix: 'n8n-mcp',
timestamp: true,
...config,
};
}
static getInstance(config?: Partial<LoggerConfig>): Logger {
if (!Logger.instance) {
Logger.instance = new Logger(config);
}
return Logger.instance;
}
private formatMessage(level: string, message: string): string {
const parts: string[] = [];
if (this.config.timestamp) {
parts.push(`[${new Date().toISOString()}]`);
}
if (this.config.prefix) {
parts.push(`[${this.config.prefix}]`);
}
parts.push(`[${level}]`);
parts.push(message);
return parts.join(' ');
}
private log(level: LogLevel, levelName: string, message: string, ...args: any[]): void {
// Allow ERROR level logs through in more cases for debugging
const allowErrorLogs = level === LogLevel.ERROR && (this.isHttp || process.env.DEBUG === 'true');
// Check environment variables FIRST, before level check
// In stdio mode, suppress ALL console output to avoid corrupting JSON-RPC (except errors when debugging)
// Also suppress in test mode unless debug is explicitly enabled
if (this.isStdio || this.isDisabled || (this.isTest && process.env.DEBUG !== 'true')) {
// Allow error logs through if debugging is enabled
if (!allowErrorLogs) {
return;
}
}
if (level <= this.config.level || allowErrorLogs) {
const formattedMessage = this.formatMessage(levelName, message);
// In HTTP mode during request handling, suppress console output (except errors)
// The ConsoleManager will handle this, but we add a safety check
if (this.isHttp && process.env.MCP_REQUEST_ACTIVE === 'true' && !allowErrorLogs) {
// Silently drop the log during active MCP requests (except errors)
return;
}
switch (level) {
case LogLevel.ERROR:
console.error(formattedMessage, ...args);
break;
case LogLevel.WARN:
console.warn(formattedMessage, ...args);
break;
default:
console.log(formattedMessage, ...args);
}
}
}
error(message: string, ...args: any[]): void {
this.log(LogLevel.ERROR, 'ERROR', message, ...args);
}
warn(message: string, ...args: any[]): void {
this.log(LogLevel.WARN, 'WARN', message, ...args);
}
info(message: string, ...args: any[]): void {
this.log(LogLevel.INFO, 'INFO', message, ...args);
}
debug(message: string, ...args: any[]): void {
this.log(LogLevel.DEBUG, 'DEBUG', message, ...args);
}
setLevel(level: LogLevel): void {
this.config.level = level;
}
static parseLogLevel(level: string): LogLevel {
switch (level.toLowerCase()) {
case 'error':
return LogLevel.ERROR;
case 'warn':
return LogLevel.WARN;
case 'debug':
return LogLevel.DEBUG;
case 'info':
default:
return LogLevel.INFO;
}
}
}
// Create a default logger instance
export const logger = Logger.getInstance({
level: Logger.parseLogLevel(process.env.LOG_LEVEL || 'info'),
});