/* monkey-patch console.log to prefix with file/line-number */
function lineLogger(logFn) {
  let cwd = process.cwd(),
    cwdRe = new RegExp("^[^/]*" + cwd.replace("/", "\\/") + "\/([^:]*:[0-9]*).*$");

  function getErrorObject() {
    try {
      throw Error();
    } catch (err) {
      return err;
    }
  }

  let err = getErrorObject(),
    caller_line = err.stack.split("\n")[4],
    args = [caller_line.replace(cwdRe, "$1 -")];

  /* arguments.unshift() doesn't exist... */
  for (var i = 1; i < arguments.length; i++) {
    args.push(arguments[i]);
  }

  logFn.apply(this, args);
}

console.log = lineLogger.bind(console, console.log);
console.warn = lineLogger.bind(console, console.warn);
console.error = lineLogger.bind(console, console.error);