JavaScript's arguments object is useful. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/arguments

0-arguments-wrapper-example.js

// Example of creating wrapper function using `arguments`

function add(a, b) {
    return a + b;
}

// Example call:
// > verboseAdd(1, 2);
//   Calculating 1 + 2
// < 3
function verboseAdd(/* arguments */) {
    // Convert arguments to real Array.
    // arguments is similar to Array but lacks some properties
    var args = Array.prototype.slice.call(arguments);
    console.log('Calculating', args.join(' + '));

    // Call add function with arguments which were given to verboseAdd function
    return add.apply(this, arguments);
}

1-ajax-wrapper.js

// Real life example of how to create wrapper for jQuery's ajax function

// Works exactly like jQuery's Ajax function except it logs some details of the request
function ajax(/* arguments */) {
    // Do stuff before actual ajax call
    console.log('About to call ajax');

    var ajaxPromise = $.ajax.apply(this, arguments);

    // Do stuff after actual ajax call
    ajaxPromise.done(function() {
        console.log('Ajax call finished successfully');
    }).fail(function() {
        console.log('Ajax call failed');
    });

    return ajaxPromise;
}