Function findNearestScrollableAncestor

src/utils/scroll-edge-state.ts:211–226

(
  nodeIndex: number | undefined,
  byIndex: Map<number, SnapshotNode>,
)

}

function findNearestScrollableAncestor(
  nodeIndex: number | undefined,
  byIndex: Map<number, SnapshotNode>,
): SnapshotNode | null {
  if (nodeIndex === undefined) {
    return null;
  }
  let node = byIndex.get(nodeIndex);
  while (node) {
    if (isScrollableNodeLike(node) && isUsableRect(node.rect)) {
      return node;
    }
    node = node.parentIndex === undefined ? undefined : byIndex.get(node.parentIndex);
  }
  return null;
}

function collectSubtreeNodes(nodes: SnapshotNode[], rootIndex: number): SnapshotNode[] {
  const byIndex = new Map(nodes.map((node) => [node.index, node]));