logger.js

const DEBUG = true;

const logger = (fn, label) => {
  if (!DEBUG)
    return fn
  return function() {
    console.debug('='.repeat(3), !!fn.name ? fn.name + ': ' + label : label)
    console.debug(arguments)
    console.debug(fn.toString())
    fn.apply(this, arguments)
  }
}

const myFunction = logger((arg1, arg2, arg3) => {
  console.log("called with", arg1, arg2, arg3)
}, "the function")

myFunction(1, 2, 3)

const myOtherFunction = logger(function myOtherFunction(arg1, arg2, arg3) {
  console.log("called with", arg1, arg2, arg3)
}, "the other function")

myOtherFunction(1, 2, 3)

function log(args, level="log") {
  try {
    console[level](args)
  } catch (e) {
    console.error(e)
  }
}

log("log log")
log("abc", level="error")
log("abc", level="er")