@material-ui/popper.js/src/utils/findIndex.js

A fork of popper.js to avoid the deprecation warnings: https://github.com/mui-org/material-ui/issues/19358.

import find from './find';

/**
 * Return the index of the matching object
 * @method
 * @memberof Popper.Utils
 * @argument {Array} arr
 * @argument prop
 * @argument value
 * @returns index or -1
 */
export default function findIndex(arr, prop, value) {
  // use native findIndex if supported
  if (Array.prototype.findIndex) {
    return arr.findIndex(cur => cur[prop] === value);
  }

  // use `find` + `indexOf` if `findIndex` isn't supported
  const match = find(arr, obj => obj[prop] === value);
  return arr.indexOf(match);
}