Function getParentRElement

packages/core/src/render3/node_manipulation.ts:490–515

(
  tView: TView,
  tNode: TNode | null,
  lView: LView,
)

 * @param lView: Current `LView`.
 */
export function getParentRElement(
  tView: TView,
  tNode: TNode | null,
  lView: LView,
): RElement | null {
  // `tNode` can genuinely be null here, not just as a defensive type-widening measure. An
  // `@if`/`@switch` branch's content is its own embedded view with its own `TView`, built the
  // first time that branch is rendered. If an error interrupts that first creation pass (for
  // example, a hydration mismatch on one of the branch's later nodes, after an earlier node's
  // `TNode` was already created), `TView.firstCreatePass` still gets flipped to `false` before
  // the error propagates (see `renderView()`'s `catch` block in `instructions/render.ts`),
  // permanently marking the view's `TNode` data as "already created" even though it isn't.
  // Unlike a component's `TView`, nothing rebuilds an embedded view's `TView` afterward, so the
  // next time that same branch is selected, its instructions read directly from the still-null
  // slot in `tView.data` instead of creating a fresh `TNode` — which is what surfaces here.
  // Guard against it so production throws a coded RuntimeError instead of a raw TypeError when
  // dereferencing `tNode.parent` below.
  if (tNode === null) {
    throw new RuntimeError(
      RuntimeErrorCode.PARENT_NODE_NOT_FOUND,
      ngDevMode &&
        'getParentRElement() was called with a null TNode, so no parent element could be resolved. This usually means a TNode was never created for this node, or was already destroyed.',
    );
  }
  return getClosestRElement(tView, tNode.parent, lView);
}

/**
 * Get closest `RElement` or `null` if it can't be found.