date-fns/locale/_lib/buildMatchPatternFn.js

Modern JavaScript date utility library

export function buildMatchPatternFn(args) {
  return (string, options = {}) => {
    const matchResult = string.match(args.matchPattern);
    if (!matchResult) return null;
    const matchedString = matchResult[0];

    const parseResult = string.match(args.parsePattern);
    if (!parseResult) return null;
    let value = args.valueCallback
      ? args.valueCallback(parseResult[0])
      : parseResult[0];

    // [TODO] I challenge you to fix the type
    value = options.valueCallback ? options.valueCallback(value) : value;

    const rest = string.slice(matchedString.length);

    return { value, rest };
  };
}