page-express-mimicry.js

'send': function (data) {
        var virtualDOMTree = document.createElement('html');
        virtualDOMTree.innerHTML = data;
        ['head', 'body'].forEach(function (tagName) {
            var virtualRoot = virtualDOMTree.querySelector(tagName),
                realRoot = document.querySelector(tagName);
            if (!realRoot) {
                document.documentElement.appendChild(realRoot = document.createElement(tagName));
            }
            var diff = LCSdiff(realRoot.childNodes, virtualRoot.childNodes);

            diff.remove.forEach(function (record) {
                record.remove();
            });
            diff.addGrouped.forEach(function (record) {
                var html = record.elements.map(function (el) {
                    return el.outerHTML
                }).join('');
                if (record.prev) {
                    record.prev.insertAdjacentHTML('afterend', html);
                } else {
                    realRoot.insertAdjacentHTML('afterbegin', html);
                }
            })
        });
    }