Function buildFromNode

packages/rrdom/src/index.ts:217–289

(
  node: Node,
  rrdom: IRRDocument,
  domMirror: NodeMirror,
  parentRRNode?: IRRNode | null,
)

 * @returns the built RRNode
 */
export function buildFromNode(
  node: Node,
  rrdom: IRRDocument,
  domMirror: NodeMirror,
  parentRRNode?: IRRNode | null,
): IRRNode | null {
  let rrNode: IRRNode;

  switch (node.nodeType) {
    case NodeType.DOCUMENT_NODE:
      if (parentRRNode && parentRRNode.nodeName === 'IFRAME')
        rrNode = (parentRRNode as RRIFrameElement).contentDocument;
      else {
        rrNode = rrdom;
        (rrNode as IRRDocument).compatMode = (node as Document).compatMode as
          | 'BackCompat'
          | 'CSS1Compat';
      }
      break;
    case NodeType.DOCUMENT_TYPE_NODE: {
      const documentType = node as DocumentType;
      rrNode = rrdom.createDocumentType(
        documentType.name,
        documentType.publicId,
        documentType.systemId,
      );
      break;
    }
    case NodeType.ELEMENT_NODE: {
      const elementNode = node as HTMLElement;
      const tagName = getValidTagName(elementNode);
      rrNode = rrdom.createElement(tagName);
      const rrElement = rrNode as IRRElement;
      for (const { name, value } of Array.from(elementNode.attributes)) {
        rrElement.attributes[name] = value;
      }
      elementNode.scrollLeft && (rrElement.scrollLeft = elementNode.scrollLeft);
      elementNode.scrollTop && (rrElement.scrollTop = elementNode.scrollTop);
      /**
       * We don't have to record special values of input elements at the beginning.
       * Because if these values are changed later, the mutation will be applied through the batched input events on its RRElement after the diff algorithm is executed.
       */
      break;
    }
    case NodeType.TEXT_NODE:
      rrNode = rrdom.createTextNode((node as Text).textContent || '');
      break;
    case NodeType.CDATA_SECTION_NODE:
      rrNode = rrdom.createCDATASection((node as CDATASection).data);
      break;
    case NodeType.COMMENT_NODE:
      rrNode = rrdom.createComment((node as Comment).textContent || '');
      break;
    // if node is a shadow root
    case NodeType.DOCUMENT_FRAGMENT_NODE:
      rrNode = (parentRRNode as IRRElement).attachShadow({ mode: 'open' });
      break;
    default: