date-fns/_lib/getUTCWeekYear/index.js

Modern JavaScript date utility library

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = getUTCWeekYear;

var _index = _interopRequireDefault(require("../toInteger/index.js"));

var _index2 = _interopRequireDefault(require("../../toDate/index.js"));

var _index3 = _interopRequireDefault(require("../startOfUTCWeek/index.js"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

// This function will be a part of public API when UTC function will be implemented.
// See issue: https://github.com/date-fns/date-fns/issues/376
function getUTCWeekYear(dirtyDate, dirtyOptions) {
  if (arguments.length < 1) {
    throw new TypeError('1 argument required, but only ' + arguments.length + ' present');
  }

  var date = (0, _index2.default)(dirtyDate, dirtyOptions);
  var year = date.getUTCFullYear();
  var options = dirtyOptions || {};
  var locale = options.locale;
  var localeFirstWeekContainsDate = locale && locale.options && locale.options.firstWeekContainsDate;
  var defaultFirstWeekContainsDate = localeFirstWeekContainsDate == null ? 1 : (0, _index.default)(localeFirstWeekContainsDate);
  var firstWeekContainsDate = options.firstWeekContainsDate == null ? defaultFirstWeekContainsDate : (0, _index.default)(options.firstWeekContainsDate); // Test if weekStartsOn is between 1 and 7 _and_ is not NaN

  if (!(firstWeekContainsDate >= 1 && firstWeekContainsDate <= 7)) {
    throw new RangeError('firstWeekContainsDate must be between 1 and 7 inclusively');
  }

  var firstWeekOfNextYear = new Date(0);
  firstWeekOfNextYear.setUTCFullYear(year + 1, 0, firstWeekContainsDate);
  firstWeekOfNextYear.setUTCHours(0, 0, 0, 0);
  var startOfNextYear = (0, _index3.default)(firstWeekOfNextYear, dirtyOptions);
  var firstWeekOfThisYear = new Date(0);
  firstWeekOfThisYear.setUTCFullYear(year, 0, firstWeekContainsDate);
  firstWeekOfThisYear.setUTCHours(0, 0, 0, 0);
  var startOfThisYear = (0, _index3.default)(firstWeekOfThisYear, dirtyOptions);

  if (date.getTime() >= startOfNextYear.getTime()) {
    return year + 1;
  } else if (date.getTime() >= startOfThisYear.getTime()) {
    return year;
  } else {
    return year - 1;
  }
}

module.exports = exports.default;