Concatenate and minify dependencies for enqueued JavaScript files

I’m loading a JavaScript file using wp_enqueue_script into my theme. However, along with it, I’m loading several jQuery files as well, as dependencies for the enqueued script (which has already been concatenated and minified by Grunt). Here is my code:

add_action('wp_enqueue_scripts', function() {
    wp_enqueue_script( 'customscripts', get_template_directory_uri() . '/assets/js/main.min.js', array('jquery', 'jquery-form', 'json2', 'jquery-ui-autocomplete'), NULL, true );
});

For the dependencies array, how would I go about concatenating and minifying those jQuery dependencies? I’m trying to get my site to load as fast as possible, and the less JS files it has to load the better. Also if it were possible to make them load asynchronously (using the async property for <script> tags) that’d be ace.

I’d rather do it without using a plugin but I will use a plugin if necessary.

Thanks for any help 🙂

W3 Total Cache offers JS/CSS minification. I’m not familiar with the process they use, but if you are wanting to avoid using a plugin, you could take a look at their source code how they handle it.