A JS Array filter function returning a filtered array witha designated maximum length.

truncatedFilter.js

const truncatedFilter = (arr, length, filter) => {
  length = (arr.length < length) ? arr.length : length;
  let output = new Array(length)
  let count = 0;
  for(let item of arr){
    if(filter(item)){
      output[count] = item;
      count++;
      if(count === length){
        return output;
      }
    }
  }
  return output.slice(0, count);
};