Function findFiberRoot

packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js:4222–4233

(node: Instance)

export const supportsTestSelectors = true;

export function findFiberRoot(node: Instance): null | FiberRoot {
  const stack = [node];
  let index = 0;
  while (index < stack.length) {
    const current = stack[index++];
    if (isContainerMarkedAsRoot(current)) {
      return ((getInstanceFromNodeDOMTree(current): any): FiberRoot);
    }
    stack.push(...current.children);
  }
  return null;
}

export function getBoundingRect(node: Instance): BoundingRect {
  const rect = node.getBoundingClientRect();