Document destructured function parameter in JSDoc

Question

Previously I've always documented my object parameters as follows:

/**
 * Description of the function
 *
 * @param {Object} config - The configuration
 * @param {String} config.foo
 * @param {Boolean} [config.bar] - Optional value
 * @return {String}
 */
function doSomething (config = {}) {
  const { foo, bar } = config;
  console.log(foo, bar);
  // do something
}

But I am unsure what the best approach is with desctructured function parameter. Do I just ignore the object, define it somehow or what is the best way of documenting it?

/**
 * Description of the function
 *
 * @param {String} foo
 * @param {Boolean} [bar] - Optional value
 * @return {String}
 */
function doSomething ({ foo, bar } = {}) {
  console.log(foo, bar);
  // do something
}

I feel like my approach above doesn't make it obvious that the function expects an object and not two different parameter.

Another way I could think of would be using @typedef, but that might end up being a huge mess (especially in a larger file with many methods)?

/**
 * @typedef {Object} doSomethingConfiguration
 * @property {String} foo
 * @property {Boolean} [bar] - Optional value
 */

/**
 * Description of the function
 *
 * @param {doSomethingConfiguration}
 * @return {String}
 */
function doSomething ({ foo, bar } = {}) {
  console.log(foo, bar);
  // do something
}

Answer 1

This is how it's intended, as described in the documentation.

/**
 * My cool function.
 *
 * @param {Object} obj - An object.
 * @param {string} obj.prop1 - Property 1.
 * @param {string} obj.prop2 - Property 2.
 */
var fn = function ({prop1, prop2}) {
  // Do something with prop1 and prop2
}

So, your first example is pretty much correct.

Another example with some deeper nesting:

/**
 * Nesting example.
 *
 * @param {object} param
 * @param {number} param.a - First value
 * @param {object} param.b - Wrapper
 * @param {number} param.b.c - Second value
 * @return {number} sum a and b
 */
letters = ({a, b: {c}}) => a + c;

Answer 2

See JSDoc's "Documenting a parameter's properties":

/**
 * Assign the project to an employee.
 * @param {Object} employee - The employee who is responsible for the project.
 * @param {string} employee.name - The name of the employee.
 * @param {string} employee.department - The employee's department.
 */
Project.prototype.assign = function(employee) {
    // ...
};

(Google Closure compiler type checking, that was based on but diverted from JSDoc, also allows @param {{x:number,y:number}} point A "point-shaped" object.)

Answer 3

I personally use this one:

/**
* @param {{
  a: number
  b: number
}} param0
* @returns {number} The sum
*/
const func = ({ a, b }) => a + b;

Just create the object right there.

I also take advantage of TypeScript, and would declare obtional b as b? or b: number | undefined as JSDoc also allows unions