mu parser

mu_parser.js

const pipe = (...fns) => x => fns.reduce((y, f) => f(y), x);

const wordsCounter = text => text.split(' ').length;

const removeMultipleSpaces = text => text.replace(/\s\s+/gim, '');

const removeStartEndNonAlphabetic = text =>
  text.replace(/^[^A-Za-zА-Яа-я0-9]|[^A-Za-zА-Яа-я0-9]$/gim, '');

const removeStartEndSpace = text => text.replace(/^\s|\s$/gim, '');

const toLowerCase = text => text.toLowerCase();

const removeRating = text => text.replace(/^(\s+)?\d{0,2}(\.|\)| - |-)/gim, '');

const cleanUpWord = pipe(
  removeMultipleSpaces,
  removeStartEndNonAlphabetic,
  removeStartEndSpace,
  toLowerCase,
);

const parse = () => {
  let result = {};

  const posts = Array.from(document.querySelectorAll('.post__message '));
  posts.forEach(post =>
    post.childNodes.forEach(words => {
      if (words.nodeType !== 3 || !words.textContent) {
        return;
      }
      const textHasBandAndSong = words.textContent.includes('-');
      if (!textHasBandAndSong) {
        return;
      }
      const bandAndSong = removeRating(words.textContent);
      let [band, song] = bandAndSong.split(' - ');
      if (!song) {
        [band, song] = bandAndSong.split('-');
        if (!song) {
          return;
        }
      }
      if (wordsCounter(band) > 12 || wordsCounter(song) > 12) {
        return;
      }

      band = cleanUpWord(band);
      song = cleanUpWord(song);

      result = {
        ...result,
        [band]: {
          ...(result[band] || {}),
          [song]: ((result[band] || [])[song] || 0) + 1,
          _totalSongs: ((result[band] || {})._totalSongs || 0) + 1,
        },
      };
    }),
  );
  return result;
};

const parsedData = parse();

const sortedArtists = Object.keys(parsedData)
  .sort((a, b) => parsedData[b]._totalSongs - parsedData[a]._totalSongs)
  .map(band => `${band} - ${parsedData[band]._totalSongs}`);

console.log('FULL DATA - ', parsedData);
console.log('SORTED ARTISTS - ', sortedArtists);