E621 javascript - convert preview/sample images to full res

// This snippet automatically converts any e621.net sample and preview image links into their full resolution when opened.
// Use Chrome plugin "Custom JavaScript for Websites 2"
// Include jQuery 3.2.1 in definition

function searchRedirect() {
    var loc = window.location.pathname;
    var md5 = false;
    if (loc.startsWith('/data/sample/')) {
        md5 = loc.substring(19, 19+32);
    } else if (loc.startsWith('/data/preview/')) {
        md5 = loc.substring(20, 20+32);
    }

    if (md5) {
        $.ajax({url: 'https://e621.net/post/show.json?md5=' + md5,
        dataType: 'jsonp',
        crossDomain: true,
        success: function(data) {
            window.location.replace(data.file_url);
        }});
    }
}

searchRedirect();