react-beautiful-dnd-next/src/view/check-is-valid-inner-ref.js

Beautiful and accessible drag and drop for lists with React

// @flow
import invariant from 'tiny-invariant';
import isHtmlElement from './is-type-of-element/is-html-element';

export default function checkIsValidInnerRef(el: ?HTMLElement) {
  invariant(
    el && isHtmlElement(el),
    `
    provided.innerRef has not been provided with a HTMLElement.

    You can find a guide on using the innerRef callback functions at:
    https://github.com/atlassian/react-beautiful-dnd/blob/master/docs/guides/using-inner-ref.md
  `,
  );
}