Run-time assertions for JSDoc @param and @type tags in Babel

1. Annotate types and functions/methods with JSDoc
2. Closure Compiler syntax is also accepted
3. Use plugin for Babel: https://github.com/azu/babel-plugin-jsdoc-to-assert

Generics in JSDoc

/**
 * @interface
 * @template T
 */
MyEnumerable = function () { };

/**
 * @param {T} item
 */
MyEnumerable.prototype.add = function (item) { };

/**
 * @constructor
 * @template TItemType
 * @extends {MyEnumerable.<TItemType>}
 */
MyList = function () { };

/**
 * @param {TItemType} item the item
 */
MyList.prototype.addItem = function (item) { };

/** @type {MyEnumerable.<string>}*/
var enumerable = new MyList();
enumerable.add("Bob"); // correct
enumerable.add(123); // correct warning: number is not assignable to type string 

/** @type {MyList.<string>}*/
var list = new MyList();
list.add("Bob"); // incorrect warning: number is not assignable to type TITemType 
list.addItem("Bob"); // correct

Now works in WebStorm