How to document an object property/method, when this property/method gets added to the object later, after the object has been initialized?

Example:

Let's say that I declare the following object. Documentation of ID and name work fine:

let AppUser = {
   /** The user's id */
   ID: 0,
   /** The user's name */
   name: "guest",
};

Later, I decide to add a property (let's say in another js file):

/** The role of the AppUser */
App.role = "admin";

In that case, App.role 's documentation does not work. At least, VSCode does not open the tooltip to inform me about its description.

What I do now, is declare an empty property inside the object: role:null, and also writing its documentation. This workaround works OK.