Woocommerce “Add to cart” ajax

On the product category page, when someone clicks “Add to cart”, woocommerce adds “View cart” below this button through Ajax. I found that the script which handle this is /assets/js/frontend/add-to-cart.js

Now, I want to add also “Procceed to checkout”, so someone can go to checkout immediately.

This is the output of the script:

jQuery( function( $ ) {

// wc_add_to_cart_params is required to continue, ensure the object exists
if ( typeof wc_add_to_cart_params === 'undefined' )
    return false;

// Ajax add to cart
$( document ).on( 'click', '.add_to_cart_button', function(e) {

// AJAX add to cart request
var $thisbutton = $( this );

if ( $thisbutton.is( '.product_type_simple' ) ) {

    if ( ! $thisbutton.attr( 'data-product_id' ) )
        return true;

    $thisbutton.removeClass( 'added' );
    $thisbutton.addClass( 'loading' );

    var data = {
        action: 'woocommerce_add_to_cart',
    };

    $.each( $thisbutton.data(), function( key, value ) {
        data[key] = value;
    });

    // Trigger event
    $( 'body' ).trigger( 'adding_to_cart', [ $thisbutton, data ] );

    // Ajax action
    $.post( wc_add_to_cart_params.ajax_url, data, function( response ) {

        if ( ! response )
            return;

        var this_page = window.location.toString();

        this_page = this_page.replace( 'add-to-cart', 'added-to-cart' );

        if ( response.error && response.product_url ) {
            window.location = response.product_url;
            return;
        }

        // Redirect to cart option
        if ( wc_add_to_cart_params.cart_redirect_after_add === 'yes' ) {

            window.location = wc_add_to_cart_params.cart_url;
            return;

        } else {

            $thisbutton.removeClass( 'loading' );

            fragments = response.fragments;
            cart_hash = response.cart_hash;

            // Block fragments class
            if ( fragments ) {
                $.each( fragments, function( key, value ) {
                    $( key ).addClass( 'updating' );
                });
            }

            // Block widgets and fragments
            $( '.shop_table.cart, .updating, .cart_totals' ).fadeTo( '400', '0.6' ).block({
                message: null,
                overlayCSS: {
                    opacity: 0.6
                }
            });

            // Changes button classes
            $thisbutton.addClass( 'added' );

            // View cart text
            if ( ! wc_add_to_cart_params.is_cart && $thisbutton.parent().find( '.added_to_cart' ).size() === 0 ) {
                $thisbutton.after( ' <a href="' + wc_add_to_cart_params.cart_url + '" class="added_to_cart wc-forward" title="' +
                    wc_add_to_cart_params.i18n_view_cart + '">' + wc_add_to_cart_params.i18n_view_cart + '</a>' );
            }

            // Replace fragments
            if ( fragments ) {
                $.each( fragments, function( key, value ) {
                    $( key ).replaceWith( value );
                });
            }

            // Unblock
            $( '.widget_shopping_cart, .updating' ).stop( true ).css( 'opacity', '1' ).unblock();

            // Cart page elements
            $( '.shop_table.cart' ).load( this_page + ' .shop_table.cart:eq(0) > *', function() {

                $( '.shop_table.cart' ).stop( true ).css( 'opacity', '1' ).unblock();

                $( 'body' ).trigger( 'cart_page_refreshed' );
            });

            $( '.cart_totals' ).load( this_page + ' .cart_totals:eq(0) > *', function() {
                $( '.cart_totals' ).stop( true ).css( 'opacity', '1' ).unblock();
            });

            // Trigger event so themes can refresh other areas
            $( 'body' ).trigger( 'added_to_cart', [ fragments, cart_hash, $thisbutton ] );
        }
    });

    return false;

}

return true;
});

Is there anybody who has done something similar?