react-resizable-panels/src/utils/dom/getResizeHandleElementIndex.ts

React components for resizable panel groups/layouts

import { getResizeHandleElementsForGroup } from "./getResizeHandleElementsForGroup";

export function getResizeHandleElementIndex(
  groupId: string,
  id: string,
  scope: ParentNode | HTMLElement = document
): number | null {
  const handles = getResizeHandleElementsForGroup(groupId, scope);
  const index = handles.findIndex(
    (handle) => handle.getAttribute("data-panel-resize-handle-id") === id
  );
  return index ?? null;
}