text: import * as TAGS from './tags.js';
  import * as ATTRS from './attrs.js';
  import * as EXPRESSIONS from './regexp.js';
  import {
    addToSet,
    clone,
    freeze,
    arrayForEach,
    arrayPop,
    arrayPush,
    stringMatch,
    stringReplace,
    stringToLowerCase,
    stringIndexOf,
    stringTrim,
    regExpTest,
    typeErrorCreate,
    lookupGetter,
  } from './utils.js';
  
  const getGlobal = () => (typeof window === 'undefined' ? null : window);
  
  /**
   * Creates a no-op policy for internal use only.
   * Don't export this function outside this module!
   * @param {?TrustedTypePolicyFactory} trustedTypes The policy factory.
   * @param {Document} document The document object (to determine policy name suffix)
   * @return {?TrustedTypePolicy} The policy created (or null, if Trusted Types
   * are not supported).
   */
  const _createTrustedTypesPolicy = function (trustedTypes, document) {
    if (
      typeof trustedTypes !== 'object' ||
      typeof trustedTypes.createPolicy !== 'function'
    ) {
      return null;
    }
  
    // Allow the callers to control the unique policy name
    // by adding a data-tt-policy-suffix to the script element with the DOMPurify.
    // Policy creation with duplicate names throws in Trusted Types.
    let suffix = null;
    const ATTR_NAME = 'data-tt-policy-suffix';
    if (
      document.currentScript &&
      document.currentScript.hasAttribute(ATTR_NAME)
    ) {
      suffix = document.currentScript.getAttribute(ATTR_NAME);
    }
  
    const policyName = 'dompurify' + (suffix ? '#' + suffix : '');
  
    try {
      return trustedTypes.createPolicy(policyName, {
        createHTML(html) {
          return html;
        },
      });
    } catch (_) {
      // Policy creation failed (most likely another DOMPurify script has
      // already run). Skip creating the policy, as this will only cause errors
      // if TT are enforced.
      console.warn(
        'TrustedTypes policy ' + policyName + ' could not be created.'
      );
      return null;
    }
  };
  
  function createDOMPurify(window = getGlobal()) {
    const DOMPurify = (root) => createDOMPurify(root);
  
    /**
     * Version label, exposed for easier checks
     * if DOMPurify is up to date or not
     */
    DOMPurify.version = VERSION;
  
    /**
     * Array of elements that DOMPurify removed during sanitation.
     * Empty if nothing was removed.
     */
    DOMPurify.removed = [];
  
    if (!window || !window.document || window.document.nodeType !== 9) {
      // Not running in a browser, provide a factory function
      // so that you can pass your own Window
      DOMPurify.isSupported = false;
  
      return DOMPurify;
    }
  
    const originalDocument = window.document;
  
    let { document } = window;
    const {
      DocumentFragment,
      HTMLTemplateElement,
      Node,
      Element,
      NodeFilter,
      NamedNodeMap = window.NamedNodeMap || window.MozNamedAttrMap,
      Text,
      Comment,
      DOMParser,
      trustedTypes,
    } = window;
  
    const ElementPrototype = Element.prototype;
  
    const cloneNode = lookupGetter(ElementPrototype, 'cloneNode');
    const getNextSibling = lookupGetter(ElementPrototype, 'nextSibling');
    const getChildNodes = lookupGetter(ElementPrototype, 'childNodes');
    const getParentNode = lookupGetter(ElementPrototype, 'parentNode');
  
    // As per issue #47, the web-components registry is inherited by a
    // new document created via createHTMLDocument. As per the spec
    // (http://w3c.github.io/webcomponents/spec/custom/#creating-and-passing-registries)
    // a new empty registry is used when creating a template contents owner
    // document, so we use that as our parent document to ensure nothing
    // is inherited.
    if (typeof HTMLTemplateElement === 'function') {
      const template = document.createElement('template');
      if (template.content && template.content.ownerDocument) {
        document = template.content.ownerDocument;
      }
    }
  
    const trustedTypesPolicy = _createTrustedTypesPolicy(
      trustedTypes,
      originalDocument
    );
    const emptyHTML =
      trustedTypesPolicy && RETURN_TRUSTED_TYPE
        ? trustedTypesPolicy.createHTML('')
        : '';
  
    const {
      implementation,
      createNodeIterator,
      createDocumentFragment,
      getElementsByTagName,
    } = document;
    const { importNode } = originalDocument;
  
    let documentMode = {};
    try {
      documentMode = clone(document).documentMode ? document.documentMode : {};
    } catch (_) {}
  
    let hooks = {};
  
    /**
     * Expose whether this browser supports running the full DOMPurify.
     */
    DOMPurify.isSupported =
      typeof getParentNode === 'function' &&
      implementation &&
      typeof implementation.createHTMLDocument !== 'undefined' &&
      documentMode !== 9;
  
    const {
      MUSTACHE_EXPR,
      ERB_EXPR,
      DATA_ATTR,
      ARIA_ATTR,
      IS_SCRIPT_OR_DATA,
      ATTR_WHITESPACE,
    } = EXPRESSIONS;
  
    let { IS_ALLOWED_URI } = EXPRESSIONS;
  
    /**
     * We consider the elements and attributes below to be safe. Ideally
     * don't add any new ones but feel free to remove unwanted ones.
     */
  
    /* allowed element names */
    let ALLOWED_TAGS = null;
    const DEFAULT_ALLOWED_TAGS = addToSet({}, [
      ...TAGS.html,
      ...TAGS.svg,
      ...TAGS.svgFilters,
      ...TAGS.mathMl,
      ...TAGS.text,
    ]);
  
    /* Allowed attribute names */
    let ALLOWED_ATTR = null;
    const DEFAULT_ALLOWED_ATTR = addToSet({}, [
      ...ATTRS.html,
      ...ATTRS.svg,
      ...ATTRS.mathMl,
      ...ATTRS.xml,
    ]);
  
    /* Explicitly forbidden tags (overrides ALLOWED_TAGS/ADD_TAGS) */
    let FORBID_TAGS = null;
  
    /* Explicitly forbidden attributes (overrides ALLOWED_ATTR/ADD_ATTR) */
    let FORBID_ATTR = null;
  
    /* Decide if ARIA attributes are okay */
    let ALLOW_ARIA_ATTR = true;
  
    /* Decide if custom data attributes are okay */
    let ALLOW_DATA_ATTR = true;
  
    /* Decide if unknown protocols are okay */
    let ALLOW_UNKNOWN_PROTOCOLS = false;
  
    /* Output should be safe for common template engines.
     * This means, DOMPurify removes data attributes, mustaches and ERB
     */
    let SAFE_FOR_TEMPLATES = false;
  
    /* Decide if document with <html>... should be returned */
    let WHOLE_DOCUMENT = false;
  
    /* Track whether config is already set on this instance of DOMPurify. */
    let SET_CONFIG = false;
  
    /* Decide if all elements (e.g. style, script) must be children of
     * document.body. By default, browsers might move them to document.head */
    let FORCE_BODY = false;
  
    /* Decide if a DOM `HTMLBodyElement` should be returned, instead of a html
     * string (or a TrustedHTML object if Trusted Types are supported).
     * If `WHOLE_DOCUMENT` is enabled a `HTMLHtmlElement` will be returned instead
     */
    let RETURN_DOM = false;
  
    /* Decide if a DOM `DocumentFragment` should be returned, instead of a html
     * string  (or a TrustedHTML object if Trusted Types are supported) */
    let RETURN_DOM_FRAGMENT = false;
  
    /* If `RETURN_DOM` or `RETURN_DOM_FRAGMENT` is enabled, decide if the returned DOM
     * `Node` is imported into the current `Document`. If this flag is not enabled the
     * `Node` will belong (its ownerDocument) to a fresh `HTMLDocument`, created by
     * DOMPurify.
     *
     * This defaults to `true` starting DOMPurify 2.2.0. Note that setting it to `false`
     * might cause XSS from attacks hidden in closed shadowroots in case the browser
     * supports Declarative Shadow: DOM https://web.dev/declarative-shadow-dom/
     */
    let RETURN_DOM_IMPORT = true;
  
    /* Try to return a Trusted Type object instead of a string, return a string in
     * case Trusted Types are not supported  */
    let RETURN_TRUSTED_TYPE = false;
  
    /* Output should be free from DOM clobbering attacks? */
    let SANITIZE_DOM = true;
  
    /* Keep element content when removing element? */
    let KEEP_CONTENT = true;
  
    /* If a `Node` is passed to sanitize(), then performs sanitization in-place instead
     * of importing it into a new Document and returning a sanitized copy */
    let IN_PLACE = false;
  
    /* Allow usage of profiles like html, svg and mathMl */
    let USE_PROFILES = {};
  
    /* Tags to ignore content of when KEEP_CONTENT is true */
    let FORBID_CONTENTS = null;
    const DEFAULT_FORBID_CONTENTS = addToSet({}, [
      'annotation-xml',
      'audio',
      'colgroup',
      'desc',
      'foreignobject',
      'head',
      'iframe',
      'math',
      'mi',
      'mn',
      'mo',
      'ms',
      'mtext',
      'noembed',
      'noframes',
      'noscript',
      'plaintext',
      'script',
      'style',
      'svg',
      'template',
      'thead',
      'title',
      'video',
      'xmp',
    ]);
  
    /* Tags that are safe for data: URIs */
    let DATA_URI_TAGS = null;
    const DEFAULT_DATA_URI_TAGS = addToSet({}, [
      'audio',
      'video',
      'img',
      'source',
      'image',
      'track',
    ]);
  
    /* Attributes safe for values like "javascript:" */
    let URI_SAFE_ATTRIBUTES = null;
    const DEFAULT_URI_SAFE_ATTRIBUTES = addToSet({}, [
      'alt',
      'class',
      'for',
      'id',
      'label',
      'name',
      'pattern',
      'placeholder',
      'role',
      'summary',
      'title',
      'value',
      'style',
      'xmlns',
    ]);
  
    const MATHML_NAMESPACE = 'http://www.w3.org/1998/Math/MathML';
    const SVG_NAMESPACE = 'http://www.w3.org/2000/svg';
    const HTML_NAMESPACE = 'http://www.w3.org/1999/xhtml';
    /* Document namespace */
    let NAMESPACE = HTML_NAMESPACE;
    let IS_EMPTY_INPUT = false;
  
    /* Keep a reference to config to pass to hooks */
    let CONFIG = null;
  
    /* Ideally, do not touch anything below this line */
    /* ______________________________________________ */
  
    const formElement = document.createElement('form');
  
    /**
     * _parseConfig
     *
     * @param  {Object} cfg optional config literal
     */
    // eslint-disable-next-line complexity
    const _parseConfig = function (cfg) {
      if (CONFIG && CONFIG === cfg) {
        return;
      }
  
      /* Shield configuration object from tampering */
      if (!cfg || typeof cfg !== 'object') {
        cfg = {};
      }
  
      /* Shield configuration object from prototype pollution */
      cfg = clone(cfg);
  
      /* Set configuration parameters */
      ALLOWED_TAGS =
        'ALLOWED_TAGS' in cfg
          ? addToSet({}, cfg.ALLOWED_TAGS)
          : DEFAULT_ALLOWED_TAGS;
      ALLOWED_ATTR =
        'ALLOWED_ATTR' in cfg
          ? addToSet({}, cfg.ALLOWED_ATTR)
          : DEFAULT_ALLOWED_ATTR;
      URI_SAFE_ATTRIBUTES =
        'ADD_URI_SAFE_ATTR' in cfg
          ? addToSet(clone(DEFAULT_URI_SAFE_ATTRIBUTES), cfg.ADD_URI_SAFE_ATTR)
          : DEFAULT_URI_SAFE_ATTRIBUTES;
      DATA_URI_TAGS =
        'ADD_DATA_URI_TAGS' in cfg
          ? addToSet(clone(DEFAULT_DATA_URI_TAGS), cfg.ADD_DATA_URI_TAGS)
          : DEFAULT_DATA_URI_TAGS;
      FORBID_CONTENTS =
        'FORBID_CONTENTS' in cfg
          ? addToSet({}, cfg.FORBID_CONTENTS)
          : DEFAULT_FORBID_CONTENTS;
      FORBID_TAGS = 'FORBID_TAGS' in cfg ? addToSet({}, cfg.FORBID_TAGS) : {};
      FORBID_ATTR = 'FORBID_ATTR' in cfg ? addToSet({}, cfg.FORBID_ATTR) : {};
      USE_PROFILES = 'USE_PROFILES' in cfg ? cfg.USE_PROFILES : false;
      ALLOW_ARIA_ATTR = cfg.ALLOW_ARIA_ATTR !== false; // Default true
      ALLOW_DATA_ATTR = cfg.ALLOW_DATA_ATTR !== false; // Default true
      ALLOW_UNKNOWN_PROTOCOLS = cfg.ALLOW_UNKNOWN_PROTOCOLS || false; // Default false
      SAFE_FOR_TEMPLATES = cfg.SAFE_FOR_TEMPLATES || false; // Default false
      WHOLE_DOCUMENT = cfg.WHOLE_DOCUMENT || false; // Default false
      RETURN_DOM = cfg.RETURN_DOM || false; // Default false
      RETURN_DOM_FRAGMENT = cfg.RETURN_DOM_FRAGMENT || false; // Default false
      RETURN_DOM_IMPORT = cfg.RETURN_DOM_IMPORT !== false; // Default true
      RETURN_TRUSTED_TYPE = cfg.RETURN_TRUSTED_TYPE || false; // Default false
      FORCE_BODY = cfg.FORCE_BODY || false; // Default false
      SANITIZE_DOM = cfg.SANITIZE_DOM !== false; // Default true
      KEEP_CONTENT = cfg.KEEP_CONTENT !== false; // Default true
      IN_PLACE = cfg.IN_PLACE || false; // Default false
      IS_ALLOWED_URI = cfg.ALLOWED_URI_REGEXP || IS_ALLOWED_URI;
      NAMESPACE = cfg.NAMESPACE || HTML_NAMESPACE;
      if (SAFE_FOR_TEMPLATES) {
        ALLOW_DATA_ATTR = false;
      }
  
      if (RETURN_DOM_FRAGMENT) {
        RETURN_DOM = true;
      }
  
      /* Parse profile info */
      if (USE_PROFILES) {
        ALLOWED_TAGS = addToSet({}, [...TAGS.text]);
        ALLOWED_ATTR = [];
        if (USE_PROFILES.html === true) {
          addToSet(ALLOWED_TAGS, TAGS.html);
          addToSet(ALLOWED_ATTR, ATTRS.html);
        }
  
        if (USE_PROFILES.svg === true) {
          addToSet(ALLOWED_TAGS, TAGS.svg);
          addToSet(ALLOWED_ATTR, ATTRS.svg);
          addToSet(ALLOWED_ATTR, ATTRS.xml);
        }
  
        if (USE_PROFILES.svgFilters === true) {
          addToSet(ALLOWED_TAGS, TAGS.svgFilters);
          addToSet(ALLOWED_ATTR, ATTRS.svg);
          addToSet(ALLOWED_ATTR, ATTRS.xml);
        }
  
        if (USE_PROFILES.mathMl === true) {
          addToSet(ALLOWED_TAGS, TAGS.mathMl);
          addToSet(ALLOWED_ATTR, ATTRS.mathMl);
          addToSet(ALLOWED_ATTR, ATTRS.xml);
        }
      }
  
      /* Merge configuration parameters */
      if (cfg.ADD_TAGS) {
        if (ALLOWED_TAGS === DEFAULT_ALLOWED_TAGS) {
          ALLOWED_TAGS = clone(ALLOWED_TAGS);
        }
  
        addToSet(ALLOWED_TAGS, cfg.ADD_TAGS);
      }
  
      if (cfg.ADD_ATTR) {
        if (ALLOWED_ATTR === DEFAULT_ALLOWED_ATTR) {
          ALLOWED_ATTR = clone(ALLOWED_ATTR);
        }
  
        addToSet(ALLOWED_ATTR, cfg.ADD_ATTR);
      }
  
      if (cfg.ADD_URI_SAFE_ATTR) {
        addToSet(URI_SAFE_ATTRIBUTES, cfg.ADD_URI_SAFE_ATTR);
      }
  
      if (cfg.FORBID_CONTENTS) {
        if (FORBID_CONTENTS === DEFAULT_FORBID_CONTENTS) {
          FORBID_CONTENTS = clone(FORBID_CONTENTS);
        }
  
        addToSet(FORBID_CONTENTS, cfg.FORBID_CONTENTS);
      }
  
      /* Add #text in case KEEP_CONTENT is set to true */
      if (KEEP_CONTENT) {
        ALLOWED_TAGS['#text'] = true;
      }
  
      /* Add html, head and body to ALLOWED_TAGS in case WHOLE_DOCUMENT is true */
      if (WHOLE_DOCUMENT) {
        addToSet(ALLOWED_TAGS, ['html', 'head', 'body']);
      }
  
      /* Add tbody to ALLOWED_TAGS in case tables are permitted, see #286, #365 */
      if (ALLOWED_TAGS.table) {
        addToSet(ALLOWED_TAGS, ['tbody']);
        delete FORBID_TAGS.tbody;
      }
  
      // Prevent further manipulation of configuration.
      // Not available in IE8, Safari 5, etc.
      if (freeze) {
        freeze(cfg);
      }
  
      CONFIG = cfg;
    };
  
    const MATHML_TEXT_INTEGRATION_POINTS = addToSet({}, [
      'mi',
      'mo',
      'mn',
      'ms',
      'mtext',
    ]);
  
    const HTML_INTEGRATION_POINTS = addToSet({}, [
      'foreignobject',
      'desc',
      'title',
      'annotation-xml',
    ]);
  
    /* Keep track of all possible SVG and MathML tags
     * so that we can perform the namespace checks
     * correctly. */
    const ALL_SVG_TAGS = addToSet({}, TAGS.svg);
    addToSet(ALL_SVG_TAGS, TAGS.svgFilters);
    addToSet(ALL_SVG_TAGS, TAGS.svgDisallowed);
  
    const ALL_MATHML_TAGS = addToSet({}, TAGS.mathMl);
    addToSet(ALL_MATHML_TAGS, TAGS.mathMlDisallowed);
  
    /**
     *
     *
     * @param  {Element} element a DOM element whose namespace is being checked
     * @returns {boolean} Return false if the element has a
     *  namespace that a spec-compliant parser would never
     *  return. Return true otherwise.
     */
    const _checkValidNamespace = function (element) {
      let parent = getParentNode(element);
  
      // In JSDOM, if we're inside shadow DOM, then parentNode
      // can be null. We just simulate parent in this case.
      if (!parent || !parent.tagName) {
        parent = {
          namespaceURI: HTML_NAMESPACE,
          tagName: 'template',
        };
      }
  
      const tagName = stringToLowerCase(element.tagName);
      const parentTagName = stringToLowerCase(parent.tagName);
  
      if (element.namespaceURI === SVG_NAMESPACE) {
        // The only way to switch from HTML namespace to SVG
        // is via <svg>. If it happens via any other tag, then
        // it should be killed.
        if (parent.namespaceURI === HTML_NAMESPACE) {
          return tagName === 'svg';
        }
  
        // The only way to switch from MathML to SVG is via
        // svg if parent is either <annotation-xml> or MathML
        // text integration points.
        if (parent.namespaceURI === MATHML_NAMESPACE) {
          return (
            tagName === 'svg' &&
            (parentTagName === 'annotation-xml' ||
              MATHML_TEXT_INTEGRATION_POINTS[parentTagName])
          );
        }
  
        // We only allow elements that are defined in SVG
        // spec. All others are disallowed in SVG namespace.
        return Boolean(ALL_SVG_TAGS[tagName]);
      }
  
      if (element.namespaceURI === MATHML_NAMESPACE) {
        // The only way to switch from HTML namespace to MathML
        // is via <math>. If it happens via any other tag, then
        // it should be killed.
        if (parent.namespaceURI === HTML_NAMESPACE) {
          return tagName === 'math';
        }
  
        // The only way to switch from SVG to MathML is via
        // <math> and HTML integration points
        if (parent.namespaceURI === SVG_NAMESPACE) {
          return tagName === 'math' && HTML_INTEGRATION_POINTS[parentTagName];
        }
  
        // We only allow elements that are defined in MathML
        // spec. All others are disallowed in MathML namespace.
        return Boolean(ALL_MATHML_TAGS[tagName]);
      }
  
      if (element.namespaceURI === HTML_NAMESPACE) {
        // The only way to switch from SVG to HTML is via
        // HTML integration points, and from MathML to HTML
        // is via MathML text integration points
        if (
          parent.namespaceURI === SVG_NAMESPACE &&
          !HTML_INTEGRATION_POINTS[parentTagName]
        ) {
          return false;
        }
  
        if (
          parent.namespaceURI === MATHML_NAMESPACE &&
          !MATHML_TEXT_INTEGRATION_POINTS[parentTagName]
        ) {
          return false;
        }
  
        // Certain elements are allowed in both SVG and HTML
        // namespace. We need to specify them explicitly
        // so that they don't get erronously deleted from
        // HTML namespace.
        const commonSvgAndHTMLElements = addToSet({}, [
          'title',
          'style',
          'font',
          'a',
          'script',
        ]);
  
        // We disallow tags that are specific for MathML
        // or SVG and should never appear in HTML namespace
        return (
          !ALL_MATHML_TAGS[tagName] &&
          (commonSvgAndHTMLElements[tagName] || !ALL_SVG_TAGS[tagName])
        );
      }
  
      // The code should never reach this place (this means
      // that the element somehow got namespace that is not
      // HTML, SVG or MathML). Return false just in case.
      return false;
    };
  
    /**
     * _forceRemove
     *
     * @param  {Node} node a DOM node
     */
    const _forceRemove = function (node) {
      arrayPush(DOMPurify.removed, { element: node });
      try {
        // eslint-disable-next-line unicorn/prefer-dom-node-remove
        node.parentNode.removeChild(node);
      } catch (_) {
        try {
          node.outerHTML = emptyHTML;
        } catch (_) {
          node.remove();
        }
      }
    };
  
    /**
     * _removeAttribute
     *
     * @param  {String} name an Attribute name
     * @param  {Node} node a DOM node
     */
    const _removeAttribute = function (name, node) {
      try {
        arrayPush(DOMPurify.removed, {
          attribute: node.getAttributeNode(name),
          from: node,
        });
      } catch (_) {
        arrayPush(DOMPurify.removed, {
          attribute: null,
          from: node,
        });
      }
  
      node.removeAttribute(name);
  
      // We void attribute values for unremovable "is"" attributes
      if (name === 'is' && !ALLOWED_ATTR[name]) {
        if (RETURN_DOM || RETURN_DOM_FRAGMENT) {
          try {
            _forceRemove(node);
          } catch (_) {}
        } else {
          try {
            node.setAttribute(name, '');
          } catch (_) {}
        }
      }
    };
  
    /**
     * _initDocument
     *
     * @param  {String} dirty a string of dirty markup
     * @return {Document} a DOM, filled with the dirty markup
     */
    const _initDocument = function (dirty) {
      /* Create a HTML document */
      let doc;
      let leadingWhitespace;
  
      if (FORCE_BODY) {
        dirty = '<remove></remove>' + dirty;
      } else {
        /* If FORCE_BODY isn't used, leading whitespace needs to be preserved manually */
        const matches = stringMatch(dirty, /^[\r\n\t ]+/);
        leadingWhitespace = matches && matches[0];
      }
  
      const dirtyPayload = trustedTypesPolicy
        ? trustedTypesPolicy.createHTML(dirty)
        : dirty;
      /*
       * Use the DOMParser API by default, fallback later if needs be
       * DOMParser not work for svg when has multiple root element.
       */
      if (NAMESPACE === HTML_NAMESPACE) {
        try {
          doc = new DOMParser().parseFromString(dirtyPayload, 'text/html');
        } catch (_) {}
      }
  
      /* Use createHTMLDocument in case DOMParser is not available */
      if (!doc || !doc.documentElement) {
        doc = implementation.createDocument(NAMESPACE, 'template', null);
        try {
          doc.documentElement.innerHTML = IS_EMPTY_INPUT ? '' : dirtyPayload;
        } catch (_) {
          // Syntax error if dirtyPayload is invalid xml
        }
      }
  
      const body = doc.body || doc.documentElement;
  
      if (dirty && leadingWhitespace) {
        body.insertBefore(
          document.createTextNode(leadingWhitespace),
          body.childNodes[0] || null
        );
      }
  
      /* Work on whole document or just its body */
      if (NAMESPACE === HTML_NAMESPACE) {
        return getElementsByTagName.call(
          doc,
          WHOLE_DOCUMENT ? 'html' : 'body'
        )[0];
      }
  
      return WHOLE_DOCUMENT ? doc.documentElement : body;
    };
  
    /**
     * _createIterator
     *
     * @param  {Document} root document/fragment to create iterator for
     * @return {Iterator} iterator instance
     */
    const _createIterator = function (root) {
      return createNodeIterator.call(
        root.ownerDocument || root,
        root,
        NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_COMMENT | NodeFilter.SHOW_TEXT,
        null,
        false
      );
    };
  
    /**
     * _isClobbered
     *
     * @param  {Node} elm element to check for clobbering attacks
     * @return {Boolean} true if clobbered, false if safe
     */
    const _isClobbered = function (elm) {
      if (elm instanceof Text || elm instanceof Comment) {
        return false;
      }
  
      if (
        typeof elm.nodeName !== 'string' ||
        typeof elm.textContent !== 'string' ||
        typeof elm.removeChild !== 'function' ||
        !(elm.attributes instanceof NamedNodeMap) ||
        typeof elm.removeAttribute !== 'function' ||
        typeof elm.setAttribute !== 'function' ||
        typeof elm.namespaceURI !== 'string' ||
        typeof elm.insertBefore !== 'function'
      ) {
        return true;
      }
  
      return false;
    };
  
    /**
     * _isNode
     *
     * @param  {Node} obj object to check whether it's a DOM node
     * @return {Boolean} true is object is a DOM node
     */
    const _isNode = function (object) {
      return typeof Node === 'object'
        ? object instanceof Node
        : object &&
            typeof object === 'object' &&
            typeof object.nodeType === 'number' &&
            typeof object.nodeName === 'string';
    };
  
    /**
     * _executeHook
     * Execute user configurable hooks
     *
     * @param  {String} entryPoint  Name of the hook's entry point
     * @param  {Node} currentNode node to work on with the hook
     * @param  {Object} data additional hook parameters
     */
    const _executeHook = function (entryPoint, currentNode, data) {
      if (!hooks[entryPoint]) {
        return;
      }
  
      arrayForEach(hooks[entryPoint], (hook) => {
        hook.call(DOMPurify, currentNode, data, CONFIG);
      });
    };
  
    /**
     * _sanitizeElements
     *
     * @protect nodeName
     * @protect textContent
     * @protect removeChild
     *
     * @param   {Node} currentNode to check for permission to exist
     * @return  {Boolean} true if node was killed, false if left alive
     */
    const _sanitizeElements = function (currentNode) {
      let content;
  
      /* Execute a hook if present */
      _executeHook('beforeSanitizeElements', currentNode, null);
  
      /* Check if element is clobbered or can clobber */
      if (_isClobbered(currentNode)) {
        _forceRemove(currentNode);
        return true;
      }
  
      /* Check if tagname contains Unicode */
      if (stringMatch(currentNode.nodeName, /[\u0080-\uFFFF]/)) {
        _forceRemove(currentNode);
        return true;
      }
  
      /* Now let's check the element's type and name */
      const tagName = stringToLowerCase(currentNode.nodeName);
  
      /* Execute a hook if present */
      _executeHook('uponSanitizeElement', currentNode, {
        tagName,
        allowedTags: ALLOWED_TAGS,
      });
  
      /* Detect mXSS attempts abusing namespace confusion */
      if (
        !_isNode(currentNode.firstElementChild) &&
        (!_isNode(currentNode.content) ||
          !_isNode(currentNode.content.firstElementChild)) &&
        regExpTest(/<[/\w]/g, currentNode.innerHTML) &&
        regExpTest(/<[/\w]/g, currentNode.textContent)
      ) {
        _forceRemove(currentNode);
        return true;
      }
  
      /* Mitigate a problem with templates inside select */
      if (
        tagName === 'select' &&
        regExpTest(/<template/i, currentNode.innerHTML)
      ) {
        _forceRemove(currentNode);
        return true;
      }
  
      /* Remove element if anything forbids its presence */
      if (!ALLOWED_TAGS[tagName] || FORBID_TAGS[tagName]) {
        /* Keep content except for bad-listed elements */
        if (KEEP_CONTENT && !FORBID_CONTENTS[tagName]) {
          const parentNode = getParentNode(currentNode) || currentNode.parentNode;
          const childNodes = getChildNodes(currentNode) || currentNode.childNodes;
  
          if (childNodes && parentNode) {
            const childCount = childNodes.length;
  
            for (let i = childCount - 1; i >= 0; --i) {
              parentNode.insertBefore(
                cloneNode(childNodes[i], true),
                getNextSibling(currentNode)
              );
            }
          }
        }
  
        _forceRemove(currentNode);
        return true;
      }
  
      /* Check whether element has a valid namespace */
      if (currentNode instanceof Element && !_checkValidNamespace(currentNode)) {
        _forceRemove(currentNode);
        return true;
      }
  
      if (
        (tagName === 'noscript' || tagName === 'noembed') &&
        regExpTest(/<\/no(script|embed)/i, currentNode.innerHTML)
      ) {
        _forceRemove(currentNode);
        return true;
      }
  
      /* Sanitize element content to be template-safe */
      if (SAFE_FOR_TEMPLATES && currentNode.nodeType === 3) {
        /* Get the element's text content */
        content = currentNode.textContent;
        content = stringReplace(content, MUSTACHE_EXPR, ' ');
        content = stringReplace(content, ERB_EXPR, ' ');
        if (currentNode.textContent !== content) {
          arrayPush(DOMPurify.removed, { element: currentNode.cloneNode() });
          currentNode.textContent = content;
        }
      }
  
      /* Execute a hook if present */
      _executeHook('afterSanitizeElements', currentNode, null);
  
      return false;
    };
  
    /**
     * _isValidAttribute
     *
     * @param  {string} lcTag Lowercase tag name of containing element.
     * @param  {string} lcName Lowercase attribute name.
     * @param  {string} value Attribute value.
     * @return {Boolean} Returns true if `value` is valid, otherwise false.
     */
    // eslint-disable-next-line complexity
    const _isValidAttribute = function (lcTag, lcName, value) {
      /* Make sure attribute cannot clobber */
      if (
        SANITIZE_DOM &&
        (lcName === 'id' || lcName === 'name') &&
        (value in document || value in formElement)
      ) {
        return false;
      }
  
      /* Allow valid data-* attributes: At least one character after "-"
          (https://html.spec.whatwg.org/multipage/dom.html#embedding-custom-non-visible-data-with-the-data-*-attributes)
          XML-compatible (https://html.spec.whatwg.org/multipage/infrastructure.html#xml-compatible and http://www.w3.org/TR/xml/#d0e804)
          We don't need to check the value; it's always URI safe. */
      if (
        ALLOW_DATA_ATTR &&
        !FORBID_ATTR[lcName] &&
        regExpTest(DATA_ATTR, lcName)
      ) {
        // This attribute is safe
      } else if (ALLOW_ARIA_ATTR && regExpTest(ARIA_ATTR, lcName)) {
        // This attribute is safe
        /* Otherwise, check the name is permitted */
      } else if (!ALLOWED_ATTR[lcName] || FORBID_ATTR[lcName]) {
        return false;
  
        /* Check value is safe. First, is attr inert? If so, is safe */
      } else if (URI_SAFE_ATTRIBUTES[lcName]) {
        // This attribute is safe
        /* Check no script, data or unknown possibly unsafe URI
          unless we know URI values are safe for that attribute */
      } else if (
        regExpTest(IS_ALLOWED_URI, stringReplace(value, ATTR_WHITESPACE, ''))
      ) {
        // This attribute is safe
        /* Keep image data URIs alive if src/xlink:href is allowed */
        /* Further prevent gadget XSS for dynamically built script tags */
      } else if (
        (lcName === 'src' || lcName === 'xlink:href' || lcName === 'href') &&
        lcTag !== 'script' &&
        stringIndexOf(value, 'data:') === 0 &&
        DATA_URI_TAGS[lcTag]
      ) {
        // This attribute is safe
        /* Allow unknown protocols: This provides support for links that
          are handled by protocol handlers which may be unknown ahead of
          time, e.g. fb:, spotify: */
      } else if (
        ALLOW_UNKNOWN_PROTOCOLS &&
        !regExpTest(IS_SCRIPT_OR_DATA, stringReplace(value, ATTR_WHITESPACE, ''))
      ) {
        // This attribute is safe
        /* Check for binary attributes */
        // eslint-disable-next-line no-negated-condition
      } else if (!value) {
        // Binary attributes are safe at this point
        /* Anything else, presume unsafe, do not add it back */
      } else {
        return false;
      }
  
      return true;
    };
  
    /**
     * _sanitizeAttributes
     *
     * @protect attributes
     * @protect nodeName
     * @protect removeAttribute
     * @protect setAttribute
     *
     * @param  {Node} currentNode to sanitize
     */
    const _sanitizeAttributes = function (currentNode) {
      let attr;
      let value;
      let lcName;
      let l;
      /* Execute a hook if present */
      _executeHook('beforeSanitizeAttributes', currentNode, null);
  
      const { attributes } = currentNode;
  
      /* Check if we have attributes; if not we might have a text node */
      if (!attributes) {
        return;
      }
  
      const hookEvent = {
        attrName: '',
        attrValue: '',
        keepAttr: true,
        allowedAttributes: ALLOWED_ATTR,
      };
      l = attributes.length;
  
      /* Go backwards over all attributes; safely remove bad ones */
      while (l--) {
        attr = attributes[l];
        const { name, namespaceURI } = attr;
        value = stringTrim(attr.value);
        lcName = stringToLowerCase(name);
  
        /* Execute a hook if present */
        hookEvent.attrName = lcName;
        hookEvent.attrValue = value;
        hookEvent.keepAttr = true;
        hookEvent.forceKeepAttr = undefined; // Allows developers to see this is a property they can set
        _executeHook('uponSanitizeAttribute', currentNode, hookEvent);
        value = hookEvent.attrValue;
        /* Did the hooks approve of the attribute? */
        if (hookEvent.forceKeepAttr) {
          continue;
        }
  
        /* Remove attribute */
        _removeAttribute(name, currentNode);
  
        /* Did the hooks approve of the attribute? */
        if (!hookEvent.keepAttr) {
          continue;
        }
  
        /* Work around a security issue in jQuery 3.0 */
        if (regExpTest(/\/>/i, value)) {
          _removeAttribute(name, currentNode);
          continue;
        }
  
        /* Sanitize attribute content to be template-safe */
        if (SAFE_FOR_TEMPLATES) {
          value = stringReplace(value, MUSTACHE_EXPR, ' ');
          value = stringReplace(value, ERB_EXPR, ' ');
        }
  
        /* Is `value` valid for this attribute? */
        const lcTag = currentNode.nodeName.toLowerCase();
        if (!_isValidAttribute(lcTag, lcName, value)) {
          continue;
        }
  
        /* Handle invalid data-* attribute set by try-catching it */
        try {
          if (namespaceURI) {
            currentNode.setAttributeNS(namespaceURI, name, value);
          } else {
            /* Fallback to setAttribute() for browser-unrecognized namespaces e.g. "x-schema". */
            currentNode.setAttribute(name, value);
          }
  
          arrayPop(DOMPurify.removed);
        } catch (_) {}
      }
  
      /* Execute a hook if present */
      _executeHook('afterSanitizeAttributes', currentNode, null);
    };
  
    /**
     * _sanitizeShadowDOM
     *
     * @param  {DocumentFragment} fragment to iterate over recursively
     */
    const _sanitizeShadowDOM = function (fragment) {
      let shadowNode;
      const shadowIterator = _createIterator(fragment);
  
      /* Execute a hook if present */
      _executeHook('beforeSanitizeShadowDOM', fragment, null);
  
      while ((shadowNode = shadowIterator.nextNode())) {
        /* Execute a hook if present */
        _executeHook('uponSanitizeShadowNode', shadowNode, null);
  
        /* Sanitize tags and elements */
        if (_sanitizeElements(shadowNode)) {
          continue;
        }
  
        /* Deep shadow DOM detected */
        if (shadowNode.content instanceof DocumentFragment) {
          _sanitizeShadowDOM(shadowNode.content);
        }
  
        /* Check attributes, sanitize if necessary */
        _sanitizeAttributes(shadowNode);
      }
  
      /* Execute a hook if present */
      _executeHook('afterSanitizeShadowDOM', fragment, null);
    };
  
    /**
     * Sanitize
     * Public method providing core sanitation functionality
     *
     * @param {String|Node} dirty string or DOM node
     * @param {Object} configuration object
     */
    // eslint-disable-next-line complexity
    DOMPurify.sanitize = function (dirty, cfg) {
      let body;
      let importedNode;
      let currentNode;
      let oldNode;
      let returnNode;
      /* Make sure we have a string to sanitize.
        DO NOT return early, as this will return the wrong type if
        the user has requested a DOM object rather than a string */
      IS_EMPTY_INPUT = !dirty;
      if (IS_EMPTY_INPUT) {
        dirty = '<!-->';
      }
  
      /* Stringify, in case dirty is an object */
      if (typeof dirty !== 'string' && !_isNode(dirty)) {
        // eslint-disable-next-line no-negated-condition
        if (typeof dirty.toString !== 'function') {
          throw typeErrorCreate('toString is not a function');
        } else {
          dirty = dirty.toString();
          if (typeof dirty !== 'string') {
            throw typeErrorCreate('dirty is not a string, aborting');
          }
        }
      }
  
      /* Check we can run. Otherwise fall back or ignore */
      if (!DOMPurify.isSupported) {
        if (
          typeof window.toStaticHTML === 'object' ||
          typeof window.toStaticHTML === 'function'
        ) {
          if (typeof dirty === 'string') {
            return window.toStaticHTML(dirty);
          }
  
          if (_isNode(dirty)) {
            return window.toStaticHTML(dirty.outerHTML);
          }
        }
  
        return dirty;
      }
  
      /* Assign config vars */
      if (!SET_CONFIG) {
        _parseConfig(cfg);
      }
  
      /* Clean up removed elements */
      DOMPurify.removed = [];
  
      /* Check if dirty is correctly typed for IN_PLACE */
      if (typeof dirty === 'string') {
        IN_PLACE = false;
      }
  
      if (IN_PLACE) {
        /* No special handling necessary for in-place sanitization */
      } else if (dirty instanceof Node) {
        /* If dirty is a DOM element, append to an empty document to avoid
           elements being stripped by the parser */
        body = _initDocument('<!---->');
        importedNode = body.ownerDocument.importNode(dirty, true);
        if (importedNode.nodeType === 1 && importedNode.nodeName === 'BODY') {
          /* Node is already a body, use as is */
          body = importedNode;
        } else if (importedNode.nodeName === 'HTML') {
          body = importedNode;
        } else {
          // eslint-disable-next-line unicorn/prefer-dom-node-append
          body.appendChild(importedNode);
        }
      } else {
        /* Exit directly if we have nothing to do */
        if (
          !RETURN_DOM &&
          !SAFE_FOR_TEMPLATES &&
          !WHOLE_DOCUMENT &&
          // eslint-disable-next-line unicorn/prefer-includes
          dirty.indexOf('<') === -1
        ) {
          return trustedTypesPolicy && RETURN_TRUSTED_TYPE
            ? trustedTypesPolicy.createHTML(dirty)
            : dirty;
        }
  
        /* Initialize the document to work on */
        body = _initDocument(dirty);
  
        /* Check we have a DOM node from the data */
        if (!body) {
          return RETURN_DOM ? null : emptyHTML;
        }
      }
  
      /* Remove first element node (ours) if FORCE_BODY is set */
      if (body && FORCE_BODY) {
        _forceRemove(body.firstChild);
      }
  
      /* Get node iterator */
      const nodeIterator = _createIterator(IN_PLACE ? dirty : body);
  
      /* Now start iterating over the created document */
      while ((currentNode = nodeIterator.nextNode())) {
        /* Fix IE's strange behavior with manipulated textNodes #89 */
        if (currentNode.nodeType === 3 && currentNode === oldNode) {
          continue;
        }
  
        /* Sanitize tags and elements */
        if (_sanitizeElements(currentNode)) {
          continue;
        }
  
        /* Shadow DOM detected, sanitize it */
        if (currentNode.content instanceof DocumentFragment) {
          _sanitizeShadowDOM(currentNode.content);
        }
  
        /* Check attributes, sanitize if necessary */
        _sanitizeAttributes(currentNode);
  
        oldNode = currentNode;
      }
  
      oldNode = null;
  
      /* If we sanitized `dirty` in-place, return it. */
      if (IN_PLACE) {
        return dirty;
      }
  
      /* Return sanitized string or DOM */
      if (RETURN_DOM) {
        if (RETURN_DOM_FRAGMENT) {
          returnNode = createDocumentFragment.call(body.ownerDocument);
  
          while (body.firstChild) {
            // eslint-disable-next-line unicorn/prefer-dom-node-append
            returnNode.appendChild(body.firstChild);
          }
        } else {
          returnNode = body;
        }
  
        if (RETURN_DOM_IMPORT) {
          /*
            AdoptNode() is not used because internal state is not reset
            (e.g. the past names map of a HTMLFormElement), this is safe
            in theory but we would rather not risk another attack vector.
            The state that is cloned by importNode() is explicitly defined
            by the specs.
          */
          returnNode = importNode.call(originalDocument, returnNode, true);
        }
  
        return returnNode;
      }
  
      let serializedHTML = WHOLE_DOCUMENT ? body.outerHTML : body.innerHTML;
  
      /* Sanitize final string template-safe */
      if (SAFE_FOR_TEMPLATES) {
        serializedHTML = stringReplace(serializedHTML, MUSTACHE_EXPR, ' ');
        serializedHTML = stringReplace(serializedHTML, ERB_EXPR, ' ');
      }
  
      return trustedTypesPolicy && RETURN_TRUSTED_TYPE
        ? trustedTypesPolicy.createHTML(serializedHTML)
        : serializedHTML;
    };
  
    /**
     * Public method to set the configuration once
     * setConfig
     *
     * @param {Object} cfg configuration object
     */
    DOMPurify.setConfig = function (cfg) {
      _parseConfig(cfg);
      SET_CONFIG = true;
    };
  
    /**
     * Public method to remove the configuration
     * clearConfig
     *
     */
    DOMPurify.clearConfig = function () {
      CONFIG = null;
      SET_CONFIG = false;
    };
  
    /**
     * Public method to check if an attribute value is valid.
     * Uses last set config, if any. Otherwise, uses config defaults.
     * isValidAttribute
     *
     * @param  {string} tag Tag name of containing element.
     * @param  {string} attr Attribute name.
     * @param  {string} value Attribute value.
     * @return {Boolean} Returns true if `value` is valid. Otherwise, returns false.
     */
    DOMPurify.isValidAttribute = function (tag, attr, value) {
      /* Initialize shared config vars if necessary. */
      if (!CONFIG) {
        _parseConfig({});
      }
  
      const lcTag = stringToLowerCase(tag);
      const lcName = stringToLowerCase(attr);
      return _isValidAttribute(lcTag, lcName, value);
    };
  
    /**
     * AddHook
     * Public method to add DOMPurify hooks
     *
     * @param {String} entryPoint entry point for the hook to add
     * @param {Function} hookFunction function to execute
     */
    DOMPurify.addHook = function (entryPoint, hookFunction) {
      if (typeof hookFunction !== 'function') {
        return;
      }
  
      hooks[entryPoint] = hooks[entryPoint] || [];
      arrayPush(hooks[entryPoint], hookFunction);
    };
  
    /**
     * RemoveHook
     * Public method to remove a DOMPurify hook at a given entryPoint
     * (pops it from the stack of hooks if more are present)
     *
     * @param {String} entryPoint entry point for the hook to remove
     */
    DOMPurify.removeHook = function (entryPoint) {
      if (hooks[entryPoint]) {
        arrayPop(hooks[entryPoint]);
      }
    };
  
    /**
     * RemoveHooks
     * Public method to remove all DOMPurify hooks at a given entryPoint
     *
     * @param  {String} entryPoint entry point for the hooks to remove
     */
    DOMPurify.removeHooks = function (entryPoint) {
      if (hooks[entryPoint]) {
        hooks[entryPoint] = [];
      }
    };
  
    /**
     * RemoveAllHooks
     * Public method to remove all DOMPurify hooks
     *
     */
    DOMPurify.removeAllHooks = function () {
      hooks = {};
    };
  
    return DOMPurify;
  }
  
  export default createDOMPurify();
  