Function locateNextRNode

packages/core/src/hydration/node_lookup_utils.ts:118–178

(
  hydrationInfo: DehydratedView,
  tView: TView,
  lView: LView<unknown>,
  tNode: TNode,
)

 * @returns an RNode that represents a given tNode
 */
export function locateNextRNode<T extends RNode>(
  hydrationInfo: DehydratedView,
  tView: TView,
  lView: LView<unknown>,
  tNode: TNode,
): T | null {
  const noOffsetIndex = getNoOffsetIndex(tNode);
  let native = locateI18nRNodeByIndex(hydrationInfo, noOffsetIndex);

  if (native === undefined) {
    const nodes = hydrationInfo.data[NODES];
    if (nodes?.[noOffsetIndex]) {
      // We know the exact location of the node.
      native = locateRNodeByPath(nodes[noOffsetIndex], lView);
    } else if (tView.firstChild === tNode) {
      // We create a first node in this view, so we use a reference
      // to the first child in this DOM segment.
      native = hydrationInfo.firstChild;
    } else {
      // Locate a node based on a previous sibling or a parent node.
      const previousTNodeParent = tNode.prev === null;
      const previousTNode = (tNode.prev ?? tNode.parent)!;
      ngDevMode &&
        assertDefined(
          previousTNode,
          'Unexpected state: current TNode does not have a connection ' +
            'to the previous node or a parent node.',
        );
      if (isFirstElementInNgContainer(tNode)) {
        const noOffsetParentIndex = getNoOffsetIndex(tNode.parent!);
        native = getSegmentHead(hydrationInfo, noOffsetParentIndex);
      } else {
        let previousRElement = getNativeByTNode(previousTNode, lView);
        if (previousTNodeParent) {
          native = (previousRElement as RElement).firstChild;
        } else {
          // If the previous node is an element, but it also has container info,
          // this means that we are processing a node like `<div #vcrTarget>`, which is
          // represented in the DOM as `<div></div>...<!--container-->`.
          // In this case, there are nodes *after* this element and we need to skip
          // all of them to reach an element that we are looking for.
          const noOffsetPrevSiblingIndex = getNoOffsetIndex(previousTNode);
          const segmentHead = getSegmentHead(hydrationInfo, noOffsetPrevSiblingIndex);
          if (previousTNode.type === TNodeType.Element && segmentHead) {
            const numRootNodesToSkip = calcSerializedContainerSize(
              hydrationInfo,
              noOffsetPrevSiblingIndex,
            );
            // `+1` stands for an anchor comment node after all the views in this container.
            const nodesToSkip = numRootNodesToSkip + 1;
            // First node after this segment.
            native = siblingAfter(nodesToSkip, segmentHead);
          } else {
            native = previousRElement.nextSibling;
          }
        }
      }
    }