dropLastWhile.js

import {_isArray} from './_internals/_isArray'

export function dropLastWhile(predicate, iterable) {
  if (arguments.length === 1) {
    return _iterable => dropLastWhile(predicate, _iterable)
  }
  if (iterable.length === 0) return iterable
  const isArray = _isArray(iterable)

  if (typeof predicate !== 'function') {
    throw new Error(`'predicate' is from wrong type ${typeof predicate}`)
  }
  if (!isArray && typeof iterable !== 'string') {
    throw new Error(`'iterable' is from wrong type ${typeof iterable}`)
  }

  let found = false
  const toReturn = []
  let counter = iterable.length

  while (counter > 0) {
    counter--
    if (!found && predicate(iterable[counter]) === false) {
      found = true
      toReturn.push(iterable[counter])
    } else if (found) {
      toReturn.push(iterable[counter])
    }
  }

  return isArray ? toReturn.reverse() : toReturn.reverse().join('')
}