Levenshtein distance implementation in JavaScript

editDistance.js

const editDistance = (a, b) => {
  if (a === '' || b === '') {
    return Math.max(a.length, b.length);
  }

  return (a[0] === b[0] ? 0 : 1) + Math.min(
    editDistance(a.substring(1), b.substring(1)),
    editDistance(a.substring(1), b),
    editDistance(a, b.substring(1))
  );
};