promptfoo/src/logger.ts

import chalk from 'chalk';
import winston from 'winston';

export const LOG_LEVELS = {
  error: 0,
  warn: 1,
  info: 2,
  debug: 3,
};

const customFormatter = winston.format.printf(({ level, message, ...args }) => {
  if (level === 'error') {
    return chalk.red(message);
  } else if (level === 'warn') {
    return chalk.yellow(message);
  } else if (level === 'info') {
    return message;
  } else if (level === 'debug') {
    return chalk.cyan(message);
  }
  throw new Error(`Invalid log level: ${level}`);
});

const logger = winston.createLogger({
  levels: LOG_LEVELS,
  format: winston.format.combine(winston.format.simple(), customFormatter),
  transports: [
    new winston.transports.Console({
      level: process.env.LOG_LEVEL || 'info',
    }),
  ],
});

export function getLogLevel() {
  return logger.transports[0].level;
}

export function setLogLevel(level: keyof typeof LOG_LEVELS) {
  if (LOG_LEVELS.hasOwnProperty(level)) {
    logger.transports[0].level = level;
  } else {
    throw new Error(`Invalid log level: ${level}`);
  }
}

export default logger;