59 lines
2.2 KiB
JavaScript
59 lines
2.2 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = differenceInISOWeekYears;
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var _index = _interopRequireDefault(require("../toDate/index.js"));
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var _index2 = _interopRequireDefault(require("../differenceInCalendarISOWeekYears/index.js"));
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var _index3 = _interopRequireDefault(require("../compareAsc/index.js"));
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var _index4 = _interopRequireDefault(require("../subISOWeekYears/index.js"));
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var _index5 = _interopRequireDefault(require("../_lib/requiredArgs/index.js"));
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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/**
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* @name differenceInISOWeekYears
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* @category ISO Week-Numbering Year Helpers
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* @summary Get the number of full ISO week-numbering years between the given dates.
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*
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* @description
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* Get the number of full ISO week-numbering years between the given dates.
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*
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* ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
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*
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* @param {Date|Number} dateLeft - the later date
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* @param {Date|Number} dateRight - the earlier date
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* @returns {Number} the number of full ISO week-numbering years
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* @throws {TypeError} 2 arguments required
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*
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* @example
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* // How many full ISO week-numbering years are between 1 January 2010 and 1 January 2012?
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* const result = differenceInISOWeekYears(
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* new Date(2012, 0, 1),
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* new Date(2010, 0, 1)
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* )
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* //=> 1
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*/
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function differenceInISOWeekYears(dirtyDateLeft, dirtyDateRight) {
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(0, _index5.default)(2, arguments);
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var dateLeft = (0, _index.default)(dirtyDateLeft);
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var dateRight = (0, _index.default)(dirtyDateRight);
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var sign = (0, _index3.default)(dateLeft, dateRight);
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var difference = Math.abs((0, _index2.default)(dateLeft, dateRight));
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dateLeft = (0, _index4.default)(dateLeft, sign * difference); // Math.abs(diff in full ISO years - diff in calendar ISO years) === 1
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// if last calendar ISO year is not full
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// If so, result must be decreased by 1 in absolute value
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var isLastISOWeekYearNotFull = Number((0, _index3.default)(dateLeft, dateRight) === -sign);
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var result = sign * (difference - isLastISOWeekYearNotFull); // Prevent negative zero
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return result === 0 ? 0 : result;
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}
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module.exports = exports.default; |