Question

I am working on JavaScript architecture with requireJS module.
Module definition is pretty simple:

define([
    "dependency1.js",
    "dependency2.js"
], function (dep1, dep2) {

    dep1.dropdown = new Module("dropdown", function (sandbox) {
      // Private functions
      function getWhatever() {
        // do something
      }

      function getAnother() {
        // do another thing
      }

      // Public methods
      return {
         doSomething: function () {
            // do one more thing
            getAnother();
         }
      };
    });
});

Than I have a class called ‘Module’, inside which I am trying to apply try catch block to module methods like this:

var Module = function (id, creator) {
  var instance,
      sandbox = buildSandbox(),
      name,
      method;

  instance = creator(sandbox);

  for (name in instance) {
    // Looping though all methods inside module instance
    method = instance[name];

    if (typeof method === "function") {
        // Making every function execute within try catch block
        instance[name] = (function (name, method) {
           return function () {
             try { return method.apply(this, arguments); }
             catch (ex) { console.log("ERROR", name + "(): " + ex.message); }
           };
        })(name, method);
    }
  }
}

The problem is that as module instance holds only public methods, I cannot apply try catch blocks to private methods.

I am thinking if I make all instance methods public it’s not going to be secure anymore.

Is there’s a way to apply try catch block to private methods as well without reworking each module itself?

Answer 1

Unless you want to add code inside of the module to automatically add a try-catch, then no, there isn’t a way to do it.

You basically have two options:

1. Make all of the methods that you want to surround in a try–catch public and then use the code that you have.
2. Don’t worry about it. If your public methods end up calling your private ones, then you’re getting decent coverage of errors anyway.

I wouldn’t let “security” affect your decision. You’re writing JavaScript, people can always view source and see what’s going on, it will never be truly secure.