How to JsDoc a "mixed" type?

I found the way to do it:

/**
 * @param {*} foo
 */
function bar(foo) {}

In JSDoc, you can describe values in different ways. For example, using the following tags @type, @param, @return. You can specify optional values using the "?". Here is an example

    /**
     * Returns string or null
     *
     * @param {?string} nullableStringArgument
     *
     * @return {?string}
     */
    function returnNullableString (nullableStringArgument = null) {
        /** @type {?string} */
        const nullableString = [null, 'string'][Math.floor(Math.random() * 2)];

        return nullableString;
    }

Use {}

There is an example from http://usejsdoc.org/tags-type.html:

An object called 'myObj' with properties 'a' (a number), 'b' (a string) and 'c' (any type).

{{a: number, b: string, c}} myObj
// or:
{Object} myObj
{number} myObj.a
{string} myObj.b
{} myObj.c