packages/@uppy/provider-views/src/index.js
function findIndex (array, predicate) {
  for (let i = 0; i < array.length; i++) {
    if (predicate(array[i])) return i
  }
  return -1
}
function findIndex (array, predicate) {
  for (let i = 0; i < array.length; i++) {
    if (predicate(array[i])) return i
  }
  return -1
}
function findIndex ( array , predicate ) { for ( let i = 0 ; i < array . length ; i ++ ) { if ( predicate ( array [ i ] ) ) return i } return - 1 }
Array.prototype.findIndex ponyfill for old browsers.
Array . prototype . findIndex ponyfill for old browsers .