[tillWhen] Weird Part: How to break the LOOP in JavaScript

tillWhen.js

const _ = {};
// fn: (any[], function, () => boolean) ->  any[]
_.tillWhen = (data, fn, predicate) => {
  if (!data || !Array.isArray(data)) return data;
  let index = 0;
  let arr = [];
  do {
    arr.push(fn(data[index]));
  } while (index < data.length && !predicate(data[index++]));
  return arr;
};
module.exports = _