takeWhile implementation for JavaScript Iterables

takeWhile.js

function* takeWhile(iterable /* Sequence, Array, etc. */, predicate = () => true) {
  // TODO: Test that iterable is, well, iterable and not something else
  for (const item of iterable) {
    if (predicate(item)) {
      yield item;
    } else {
      break;
    }
  }
}

console.log(Array.from(takeWhile([1, 2, 3, 4, 5, 6, 7], x => x < 3)));

Add index param so that a predicate can use it to determine whether to take. For example, I only want the first 20.

function* takeWhile(iterable /* Sequence, Array, etc. */, predicate = () => true) {
  // TODO: Test that iterable is, well, iterable and not something else
  let index = 0;
  for (const item of iterable) {
    if (predicate(item, index++, iterable)) {
      yield item;
    } else {
      break;
    }
  }
}