validate-note/es/index.js

🎼 Validates a note (scientific pitch notation) and throws errors if needed

import convertFlatToSharp from './lib/convertFlatToSharp';

var isSignature = function isSignature(value) {
  return value === 'b' || value === '#';
};
var isOctave = function isOctave(value) {
  return !Number.isNaN(value);
};

export default (function (note) {
  var _ref = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

  var _ref$maxOctave = _ref.maxOctave;
  var maxOctave = _ref$maxOctave === undefined ? 8 : _ref$maxOctave;
  var _ref$flatToSharp = _ref.flatToSharp;
  var flatToSharp = _ref$flatToSharp === undefined ? false : _ref$flatToSharp;
  var _ref$octave = _ref.octave;
  var rOct = _ref$octave === undefined ? false : _ref$octave;


  var oct = rOct ? '1' : '0,1';

  var regex = new RegExp('^(?!([EB]#)|([CF]b))([A-G]{1})([#|b]{0,1})([0-' + maxOctave + ']{' + oct + '})$', 'ig');

  if (!regex.test(note)) throw new Error('\'' + note + '\' is not a valid note');

  var letter = note.charAt(0);
  var signature = '';
  var octave = void 0;

  for (var i = 1; i < note.length; i++) {
    var part = note[i];
    if (isSignature(part)) signature = part;
    if (isOctave(part)) octave = parseInt(part);
  }

  if (signature === 'b' && flatToSharp) {
    var _convertFlatToSharp = convertFlatToSharp(letter, signature);

    signature = _convertFlatToSharp.signature;
    letter = _convertFlatToSharp.letter;
  }

  var obj = {
    letter: letter,
    signature: signature,
    octave: octave
  };

  Object.keys(obj).forEach(function (key) {
    return !obj[key] && delete obj[key];
  });

  return obj;
});