date-fns/esm/locale/_lib/buildMatchFn/index.js

Modern JavaScript date utility library

export default function buildMatchFn(args) {
  return function (dirtyString, dirtyOptions) {
    var string = String(dirtyString);
    var options = dirtyOptions || {};
    var width = options.width;
    var matchPattern = width && args.matchPatterns[width] || args.matchPatterns[args.defaultMatchWidth];
    var matchResult = string.match(matchPattern);

    if (!matchResult) {
      return null;
    }

    var matchedString = matchResult[0];
    var parsePatterns = width && args.parsePatterns[width] || args.parsePatterns[args.defaultParseWidth];
    var value;

    if (Object.prototype.toString.call(parsePatterns) === '[object Array]') {
      value = findIndex(parsePatterns, function (pattern) {
        return pattern.test(matchedString);
      });
    } else {
      value = findKey(parsePatterns, function (pattern) {
        return pattern.test(matchedString);
      });
    }

    value = args.valueCallback ? args.valueCallback(value) : value;
    value = options.valueCallback ? options.valueCallback(value) : value;
    return {
      value: value,
      rest: string.slice(matchedString.length)
    };
  };
}

function findKey(object, predicate) {
  for (var key in object) {
    if (object.hasOwnProperty(key) && predicate(object[key])) {
      return key;
    }
  }
}

function findIndex(array, predicate) {
  for (var key = 0; key < array.length; key++) {
    if (predicate(array[key])) {
      return key;
    }
  }
}