"Forgiving" parsing module for the parse5

parseForgiving.js

// Setup:
// > npm install parse5
// > npm install void-elements
// Usage:
// var parseFragmentForgiving = require('this-module-path');
// var fragment = parseFragmentForgiving(html, [TreeAdapter]);

var parse5 = require('parse5');
var voidElements = require('void-elements');

var HTML_NAMESPACE = 'http://www.w3.org/1999/xhtml';


module.exports = function parseFragmentForgiving(html, treeAdapter) {
    treeAdapter = treeAdapter || parse5.TreeAdapters.default;

    var openElements = [];
    var currentElement = null;
    var fragment = treeAdapter.createDocumentFragment();

    function pushOpenElement(element) {
        openElements.push(element);
        currentElement = element;
    }

    function popOpenElement(tagName) {
        for (var i = openElements.length - 1; i > 0; i--) {
            if (treeAdapter.getTagName(openElements[i]) === tagName) {
                openElements = openElements.slice(0, i);
                currentElement = openElements[openElements.length - 1];
                break;
            }
        }
    }

    pushOpenElement(fragment);

    var parser = new parse5.SimpleApiParser({
        doctype: function (name, publicId, systemId) {
            treeAdapter.setDocumentType(fragment, name, publicId, systemId);
        },

        startTag: function (tagName, attrs, selfClosing) {
            var element = treeAdapter.createElement(tagName, HTML_NAMESPACE, attrs);
            treeAdapter.appendChild(currentElement, element);

            if (!selfClosing && !voidElements[tagName])
                pushOpenElement(element);
        },

        endTag: popOpenElement,

        text: function (text) {
            treeAdapter.insertText(currentElement, text);
        },

        comment: function (text) {
            var comment = treeAdapter.createCommentNode(text);
            treeAdapter.appendChild(currentElement, comment);
        }
    });

    parser.parse(html);

    return fragment;
};