JSDoc – Wow, I just learned something cool

As I start to delve deeper into the world of Office.JS and JavaScript, I am having some fits with how things are done and how things are implemented. Besides getting used to a whole new load of terms, finding out that there are more frameworks than there are developers (ok, maybe that is a small exaggeration), or that JavaScript is not “really” object-oriented (and that’s “ok”) is just nearly too much to handle.

Then there is one of my biggest complains with JavaScript is it use of types. You can get in a lot of trouble here and you can even break JavaScript from its root if you really prototype something wrong (see monkey patching). Additionally, scope can be an issue. And then there is Visual Studio 2015 doing it’s best to try to help you with types, but then it fails you. For example, you type “something(dot)” and you expect IntelliSense to come to the rescue – and low and behold, you get what I like to call: “The yellow bangs of hell.“(tm) 

I have been coding with this problem thinking I am all alone in this world screaming every time an object, string, or number fails at IntelliSense. Then on an internal Microsoft email thread where the virtues of TypeScript and JavaScript were being contemplated, a whole world was opened before my eyes. Enter JSDoc. Turns out there is an entire specification around this. And even better – Visual Studio 2015 support it. And it is pretty easy to use. Plus type definition is just the tip of the iceberg, there is a LOT more for me to lesrn. But for now, here is an example of how to define a few common types I frequently use:

[code language=”javascript”]
/** @type {XMLDocument} */
var xmlDoc = $.parseXML(ewsResult.value);
/** @type {string} */
var theString;
/** @type {number} */
var myNumber;
[/code]

I have started to use this very recently in my proof of concepts I work on with my customers and I think I just increased my productivity by 50% (or more). Holy cow.