Regular expression to match Chord symbol / name

ChordRegex.js

function chordRegex() {
  const note = '[A-G][b#]?';
  const altered = `(?:5|dim(5|7)?|aug5?|\\+5?|-5?)`;
  const minor = '(?:mi?n?)';
  const major = '(?:maj?|Ma?j?)';
  const majorableExt = `(?:6|7|9|11|13)`;
  const ext = `(?:4|6|7|9|11|13|6\\/9)`;
  const _mod = '(?:[b-](5|6|9|13)|[#+](4|5|9|11))';
  const mod = `(?:\\(${_mod}\\)|${_mod})`
  const sus = '(?:sus(2|4|24|2sus4)?)';
  const add = '(?:add[b#]?(?:2|4|6|7|9|11|13))';
  const bass = `(?:\\/${note})`;

  const lookahead = '(?=$| )';
  const source = `${note}${
    `(?:${altered}|${
      `(?:${minor}?(?:${ext}|${major}?${majorableExt})?)`
      + `${mod}*${sus}?${mod}*${add}?`
    })`
    }${bass}?${lookahead}`;

  console.log(JSON.stringify(source));
  return source;
}

// result:
const source = "[A-G][b#]?(?:(?:5|dim(5|7)?|aug5?|\\+5?|-5?)|(?:(?:mi?n?)?(?:(?:4|6|7|9|11|13|6\\/9)|(?:maj?|Ma?j?)?(?:6|7|9|11|13))?)(?:\\((?:[b-](5|6|9|13)|[#+](4|5|9|11))\\)|(?:[b-](5|6|9|13)|[#+](4|5|9|11)))*(?:sus(2|4|24|2sus4)?)?(?:\\((?:[b-](5|6|9|13)|[#+](4|5|9|11))\\)|(?:[b-](5|6|9|13)|[#+](4|5|9|11)))*(?:add[b#]?(?:2|4|6|7|9|11|13))?)(?:\\/[A-G][b#]?)?(?=$| )";

const regex = chord: new RegExp(chordRegex());