mermaid/src/logger.js

import moment from 'moment-mini';
//
export const LEVELS = {
  debug: 1,
  info: 2,
  warn: 3,
  error: 4,
  fatal: 5
};

export const logger = {
  debug: () => {},
  info: () => {},
  warn: () => {},
  error: () => {},
  fatal: () => {}
};

export const setLogLevel = function(level = 'fatal') {
  if (isNaN(level)) {
    level = level.toLowerCase();
    if (LEVELS[level] !== undefined) {
      level = LEVELS[level];
    }
  }
  logger.trace = () => {};
  logger.debug = () => {};
  logger.info = () => {};
  logger.warn = () => {};
  logger.error = () => {};
  logger.fatal = () => {};
  if (level <= LEVELS.fatal) {
    logger.fatal = console.error
      ? console.error.bind(console, format('FATAL'), 'color: orange')
      : console.log.bind(console, '\x1b[35m', format('FATAL'));
  }
  if (level <= LEVELS.error) {
    logger.error = console.error
      ? console.error.bind(console, format('ERROR'), 'color: orange')
      : console.log.bind(console, '\x1b[31m', format('ERROR'));
  }
  if (level <= LEVELS.warn) {
    logger.warn = console.warn
      ? console.warn.bind(console, format('WARN'), 'color: orange')
      : console.log.bind(console, `\x1b[33m`, format('WARN'));
  }
  if (level <= LEVELS.info) {
    logger.info = console.info
      ? // ? console.info.bind(console, '\x1b[34m', format('INFO'), 'color: blue')
        console.info.bind(console, format('INFO'), 'color: lightblue')
      : console.log.bind(console, '\x1b[34m', format('INFO'));
  }
  if (level <= LEVELS.debug) {
    logger.debug = console.debug
      ? console.debug.bind(console, format('DEBUG'), 'color: lightgreen')
      : console.log.bind(console, '\x1b[32m', format('DEBUG'));
  }
};

const format = level => {
  const time = moment().format('ss.SSS');
  return `%c${time} : ${level} : `;
};