makeSimpleLogger

makeSimpleLogger.js

function makeSimpleLogger() {
  const levels = ["verbose", "info", "warn", "debug"];
  const tags = levels.reduce((a, l) => (a[l] = l.toUpperCase(), a), {});

  function log(tag, args) {
    args = Array.prototype.concat.apply([`${tags[tag]}:`], args);

    if (console[tag]) {
      console[tag].apply(console, args);
    } else {
      console.log.apply(console, args);
    }
  }

  return levels.reduce((a, l) => {
    a[l] = function () { log(l, arguments) };
    return a;
  }, {});
}

const logger = makeSimpleLogger();

logger.info("hello");