Describe property defined with Object.defineProperty

Question

I want to add JSDoc documentation for the property added as Object.defineProperty. I guess that something like this might work:

/** @constructor */                                                         
function MyClass() {                                                        
  /** @property {Number} rnd */                                             
  Object.defineProperty(this, 'rnd', {                                      
    get : function () { return Math.random(); }                             
  });                                                                       
}                                                                           

But the generated JSDoc explanation does not have this property:

$ jsdoc -X test.js
[
    {
        "comment": "/** @constructor */",
        "meta": {
            "range": [ 20, 167 ],
            "filename": "test.js",
            "lineno": 2,
            "path": "/jsdoctest",
            "code": {
                "id": "astnode100000001",
                "name": "MyClass",
                "type": "FunctionDeclaration",
                "paramnames": []
            },
            "vars": { "": null }
        },
        "kind": "class",
        "name": "MyClass",
        "longname": "MyClass",
        "scope": "global"
    },
    {
        "comment": "",
        "meta": {
            "range": [ 116, 159 ],
            "filename": "test.js",
            "lineno": 5,
            "path": "/jsdoctest",
            "code": {
                "id": "astnode100000012",
                "name": "get",
                "type": "FunctionExpression",
                "value": "function"
            }
        },
        "undocumented": true,
        "name": "get",
        "longname": "get",
        "kind": "function",
        "scope": "global"
    },
    {
        "kind": "package",
        "longname": "package:undefined",
        "files": [ "/jsdoctest/test.js" ]
    }
]

What will be the most appropriate approach to document this kind of properties? (Plugin maybe?)

Answer 1

This would do it:

/** @constructor */
function MyClass() {
  /**
   * @property {Number}
   * @name MyClass#rnd
   */
  Object.defineProperty(this, 'rnd', {
    get : function () { return Math.random(); }
  });
}

I've used the @property {type} name syntax but never inside of a class. What I typically do is something like:

/** @property {object} */
this.foo = {};

And then jsdoc uses this.foo to compute the name (foo) and which entity it belongs to. It appears that using @property {type} name in a class does not work.

If you specify the name with @name, then it knows what name to give to it and where it belongs. The # indicates that it is an instance variable (rather than static or inner). See the namepath documentation for details.

Answer 2

If you want to declare the member outside the class you can use:

/**
 * @constructor
 */
function MyClass() {};

/**
 * Get the number of differed values in this map
 *
 * @member {number} count
 * @memberOf module:moduleName.MyClass#
 * @readonly
 */
Object.defineProperty(MyClass.prototype, 'rnd', {
  get : function () { return Math.random(); }
});