Is this the proper way to wrap a third-party library as an Angular.js service?

Question

I'm trying to wrap Snap.svg as a service of my application. The code below works, but is this the right way to go about it?

var svgService = angular.module("svgService", []);

svgService.factory("svgService", [
  function () {
    if (Snap) {
      return Snap;
    }
  }
]);

Answer 1

Your if check would throw an ReferenceError: Snap is not defined error anyway if the Snap doesn't exist.

You could replace the condition statement like this to be safe:

if (typeof Snap !== 'undefined') {

or if the Snap is in window, just reference it directly:

if (window.Snap) {

and even better, at least when it come to unit testing, using a built-in $window service as it allow you to mock it out.

svgService.factory("svgService", function ($window) {
  // the if check is unnecessary since an undefined
  // is returned anyway when the Snap doesn't exist.
  return $window.Snap; 
});

Hope this helps.