createFuzzyMatcher.js

const escapeRegExp = (str) => str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");

const ch2pattern = (ch) => {
  const offset = 44032;
  if (/[가-힣]/.test(ch)) {
    const chCode = ch.charCodeAt(0) - offset;
    if (chCode % 28 > 0) {
      return ch;
    }
    const begin = Math.floor(chCode / 28) * 28 + offset;
    const end = begin + 27;
    return `[\\u${begin.toString(16)}-\\u${end.toString(16)}]`;
  }
  if (/[ㄱ-ㅎ]/.test(ch)) {
    const con2syl = {
      ㄱ: "가".charCodeAt(0),
      ㄲ: "까".charCodeAt(0),
      ㄴ: "나".charCodeAt(0),
      ㄷ: "다".charCodeAt(0),
      ㄸ: "따".charCodeAt(0),
      ㄹ: "라".charCodeAt(0),
      ㅁ: "마".charCodeAt(0),
      ㅂ: "바".charCodeAt(0),
      ㅃ: "빠".charCodeAt(0),
      ㅅ: "사".charCodeAt(0),
    };
    const begin =
      con2syl[ch] || (ch.charCodeAt(0) - 12613) * 588 + con2syl["ㅅ"];
    const end = begin + 587;
    return `[${ch}\\u${begin.toString(16)}-\\u${end.toString(16)}]`;
  }
  return escapeRegExp(ch);
};

export const createFuzzyMatcher = (input) => {
  const pattern = input.split("").map(ch2pattern).join(".*?");
  return new RegExp(pattern);
};