logger.ts•3.47 kB
/**
* Logger utility for Steampipe MCP
*
* Uses stderr for all output to avoid interfering with MCP protocol,
* and supports suppressing logs during tests.
*/
// Define log levels
export enum LogLevel {
DEBUG = 'debug',
INFO = 'info',
WARN = 'warn',
ERROR = 'error',
SILENT = 'silent'
}
interface LoggerOptions {
level?: LogLevel;
isTestEnvironment?: boolean;
}
export class Logger {
private options: Required<LoggerOptions>;
private logs: string[] = []; // Store logs when in test mode
constructor(options: LoggerOptions = {}) {
const envLevel = (process.env.STEAMPIPE_MCP_LOG_LEVEL || 'info').toLowerCase();
this.options = {
level: options.level || (this.isValidLogLevel(envLevel) ? envLevel as LogLevel : LogLevel.INFO),
isTestEnvironment: options.isTestEnvironment || false
};
}
private isValidLogLevel(level: string): level is LogLevel {
return Object.values(LogLevel).includes(level as LogLevel);
}
/**
* Configure the logger
*/
configure(options: Partial<LoggerOptions>): void {
this.options = { ...this.options, ...options };
}
private shouldLog(targetLevel: LogLevel): boolean {
const levels = [LogLevel.DEBUG, LogLevel.INFO, LogLevel.WARN, LogLevel.ERROR, LogLevel.SILENT];
const currentLevelIndex = levels.indexOf(this.options.level);
const targetLevelIndex = levels.indexOf(targetLevel);
return currentLevelIndex <= targetLevelIndex && this.options.level !== LogLevel.SILENT;
}
/**
* Debug level logging
*/
debug(message: string, ...args: any[]): void {
if (this.shouldLog(LogLevel.DEBUG)) {
this.log('DEBUG', message, ...args);
}
}
/**
* Info level logging
*/
info(message: string, ...args: any[]): void {
if (this.shouldLog(LogLevel.INFO)) {
this.log('INFO', message, ...args);
}
}
/**
* Warning level logging
*/
warn(message: string, ...args: any[]): void {
if (this.shouldLog(LogLevel.WARN)) {
this.log('WARN', message, ...args);
}
}
/**
* Error level logging
*/
error(message: string, ...args: any[]): void {
if (this.shouldLog(LogLevel.ERROR)) {
this.log('ERROR', message, ...args);
}
}
/**
* Internal log function
*/
private log(level: string, message: string, ...args: any[]): void {
const timestamp = new Date().toISOString();
let formattedMessage = `[${timestamp}] [${level}] ${message}`;
// Format additional arguments if present
if (args.length > 0) {
const formattedArgs = args.map(arg => {
if (arg instanceof Error) {
return arg.message;
} else if (typeof arg === 'object') {
try {
return JSON.stringify(arg);
} catch (e) {
return String(arg);
}
}
return String(arg);
});
formattedMessage += `: ${formattedArgs.join(' ')}`;
}
// In test environment, store logs instead of printing
if (this.options.isTestEnvironment) {
this.logs.push(formattedMessage);
} else {
// Always use stderr to avoid interfering with MCP protocol
console.error(formattedMessage);
}
}
/**
* Get collected logs (useful for tests)
*/
getCollectedLogs(): string[] {
return [...this.logs];
}
/**
* Clear collected logs
*/
clearLogs(): void {
this.logs = [];
}
}
// Export singleton instance
export const logger = new Logger();