Should Node.js have a helper method for this pattern? Does it already?

hollaback.js

// Instead of lots of "if err, callback(err), else, callback(null, result)"
exports.doSomething = function(callback) {
  var err, result;
  // a bunch of code
  if (err) {
    callback(err);
  } else {
    callback(null, result);
  }
};

// What if we just could do this?
var util = require('util');
exports.doSomethingElse = function(callback) {
  var err, result;
  // a bunch of code
  util.hollaback(callback, err, result);
};

// Because util.hollaback looked something like:
exports.hollaback = function(callback, err, result) {
  if (err) {
    callback(err);
  } else if (arguments.length === 3) {
    // Make the most common case (one result argument) super fast.
    callback(null, result);
  } else {
    // With the less common case (more arguments) being fast enough.
    callback.apply(null, [null].concat([].slice.call(arguments, 2)));
  }
};

What if we just always do callback(err, result) without the if statement? The callback should/would look for err first anyway and detect there is an error.