JSDoc: Return object structure

问题:

How can I tell JSDoc about the structure of an object that is returned. I have found the @return {{field1: type, field2: type, ...}} description syntax and tried it:

/**
 * Returns a coordinate from a given mouse or touch event
 * @param  {TouchEvent|MouseEvent|jQuery.Event} e    
 *         A valid mouse or touch event or a jQuery event wrapping such an
 *         event. 
 * @param  {string} [type="page"]
 *         A string representing the type of location that should be
 *         returned. Can be either "page", "client" or "screen".
 * @return {{x: Number, y: Number}} 
 *         The location of the event
 */
var getEventLocation = function(e, type) {
    ...

    return {x: xLocation, y: yLocation};
}

While this parses successfully, the resulting documentation simply states:

Returns: 
    The location of an event
    Type: Object

I am developing an API and need people to know about the object that they will get returned. Is this possible in JSDoc? I am using JSDoc3.3.0-beta1.

回答1:

Define separately:

/**
 * @typedef {Object} Point
 * @property {number} x - The X Coordinate
 * @property {number} y - The Y Coordinate
 */

And use:

/**
 * Returns a coordinate from a given mouse or touch event
 * @param  {TouchEvent|MouseEvent|jQuery.Event} e    
 *         A valid mouse or touch event or a jQuery event wrapping such an
 *         event. 
 * @param  {string} [type="page"]
 *         A string representing the type of location that should be
 *         returned. Can be either "page", "client" or "screen".
 * @return {Point} 
 *         The location of the event
 */
var getEventLocation = function(e, type) {
    ...

    return {x: xLocation, y: yLocation};
}

回答2:

An alternative to the suggestions already posted, you can use this format:

/**
 * Get the connection state.
 *
 * @returns {Object} connection The connection state.
 * @returns {boolean} connection.isConnected Whether the authenticated user is currently connected.
 * @returns {boolean} connection.isPending Whether the authenticated user's connection is currently pending.
 * @returns {Object} connection.error The error object if an error occurred.
 * @returns {string} connection.error.message The error message.
 * @returns {string} connection.error.stack The stack trace of the error.
 */
getConnection () {
  return {
    isConnected: true,
    isPending: false,
    error
  }
}

which will give the following documentation output:

    Get the connection state.

    getConnection(): Object

    Returns
    Object: connection The connection state.
    boolean: connection.isConnected Whether the authenticated user is currently connected.
    boolean: connection.isPending Whether the authenticated users connection is currently pending.
    Object: connection.error The error object if an error occurred.
    string: connection.error.message The error message.
    string: connection.error.stack The stack trace of the error.

回答3:

A clean solution is to write a class and return that.

/** 
 *  @class Point
 *  @type {Object}
 *  @property {number} x The X-coordinate.
 *  @property {number} y The Y-coordinate.
 */
function Point(x, y) {
  return {
        x: x,
        y: y
    };
}

/**
 * @returns {Point} The location of the event.
 */
var getEventLocation = function(e, type) {
    ...
    return new Point(x, y);
};