Function _sanitizeShadowDOM

src/purify.ts:2363–2412

(fragment: DocumentFragment)

   * @param fragment to iterate over recursively
   */
  const _sanitizeShadowDOM = function (fragment: DocumentFragment): void {
    let shadowNode = null;
    const shadowIterator = _createNodeIterator(fragment);

    /* Execute a hook if present */
    _executeHooks(hooks.beforeSanitizeShadowDOM, fragment, null);

    while ((shadowNode = shadowIterator.nextNode())) {
      /* Execute a hook if present */
      _executeHooks(hooks.uponSanitizeShadowNode, shadowNode, null);

      /* Sanitize tags and elements */
      _sanitizeElements(shadowNode, fragment);

      /* Check attributes next */
      _sanitizeAttributes(shadowNode);

      /* Deep shadow DOM detected.
         Realm-safe check (GHSA-hpcv-96wg-7vj8): use nodeType against the
         DOCUMENT_FRAGMENT_NODE constant rather than instanceof, so we
         recurse into <template>.content from foreign realms too. */
      if (_isDocumentFragment(shadowNode.content)) {
        _sanitizeShadowDOM(shadowNode.content);
      }

      /* An element iterated here may itself host an attached
         shadow root. The default NodeIterator does not enter shadow
         trees, so a shadow root nested inside template.content was
         previously reached by no walk at all (the pre-pass at
         _sanitizeAttachedShadowRoots descends via childNodes, which
         doesn't enter template.content; the template-content recursion
         above iterates the content but never inspected shadowRoot).
         Walk it explicitly. The nodeType guard avoids reading
         shadowRoot off text / comment / CDATA / PI nodes that the
         iterator also surfaces. */
      const shadowNodeType = getNodeType
        ? getNodeType(shadowNode)
        : shadowNode.nodeType;
      if (shadowNodeType === NODE_TYPE.element) {
        const innerSr = getShadowRoot(shadowNode);
        if (_isDocumentFragment(innerSr)) {
          _sanitizeAttachedShadowRoots(innerSr);
          _sanitizeShadowDOM(innerSr);
        }
      }
    }

    /* Execute a hook if present */
    _executeHooks(hooks.afterSanitizeShadowDOM, fragment, null);
  };

  /**
   * _sanitizeAttachedShadowRoots