Current File : /var/www/html/node_modules/date-fns/esm/differenceInMonths/index.js
import toDate from "../toDate/index.js";
import differenceInCalendarMonths from "../differenceInCalendarMonths/index.js";
import compareAsc from "../compareAsc/index.js";
import requiredArgs from "../_lib/requiredArgs/index.js";
import isLastDayOfMonth from "../isLastDayOfMonth/index.js";
/**
* @name differenceInMonths
* @category Month Helpers
* @summary Get the number of full months between the given dates.
*
* @description
* Get the number of full months between the given dates using trunc as a default rounding method.
*
* ### v2.0.0 breaking changes:
*
* - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
*
* @param {Date|Number} dateLeft - the later date
* @param {Date|Number} dateRight - the earlier date
* @returns {Number} the number of full months
* @throws {TypeError} 2 arguments required
*
* @example
* // How many full months are between 31 January 2014 and 1 September 2014?
* const result = differenceInMonths(new Date(2014, 8, 1), new Date(2014, 0, 31))
* //=> 7
*/
export default function differenceInMonths(dirtyDateLeft, dirtyDateRight) {
requiredArgs(2, arguments);
var dateLeft = toDate(dirtyDateLeft);
var dateRight = toDate(dirtyDateRight);
var sign = compareAsc(dateLeft, dateRight);
var difference = Math.abs(differenceInCalendarMonths(dateLeft, dateRight));
var result; // Check for the difference of less than month
if (difference < 1) {
result = 0;
} else {
if (dateLeft.getMonth() === 1 && dateLeft.getDate() > 27) {
// This will check if the date is end of Feb and assign a higher end of month date
// to compare it with Jan
dateLeft.setDate(30);
}
dateLeft.setMonth(dateLeft.getMonth() - sign * difference); // Math.abs(diff in full months - diff in calendar months) === 1 if last calendar month is not full
// If so, result must be decreased by 1 in absolute value
var isLastMonthNotFull = compareAsc(dateLeft, dateRight) === -sign; // Check for cases of one full calendar month
if (isLastDayOfMonth(toDate(dirtyDateLeft)) && difference === 1 && compareAsc(dirtyDateLeft, dateRight) === 1) {
isLastMonthNotFull = false;
}
result = sign * (difference - Number(isLastMonthNotFull));
} // Prevent negative zero
return result === 0 ? 0 : result;
}
Mini Shell