95 lines
3.6 KiB
JavaScript
95 lines
3.6 KiB
JavaScript
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import toDate from '../toDate/index.js';
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var MILLISECONDS_IN_DAY = 24 * 60 * 60 * 1000;
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/**
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* @name getOverlappingDaysInIntervals
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* @category Interval Helpers
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* @summary Get the number of days that overlap in two time intervals
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*
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* @description
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* Get the number of days that overlap in two time intervals
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*
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* ### v2.0.0 breaking changes:
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*
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* - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
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*
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* - The function was renamed from `getOverlappingDaysInRanges` to `getOverlappingDaysInIntervals`.
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* This change was made to mirror the use of the word "interval" in standard ISO 8601:2004 terminology:
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*
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* ```
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* 2.1.3
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* time interval
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* part of the time axis limited by two instants
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* ```
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*
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* Also, this function now accepts an object with `start` and `end` properties
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* instead of two arguments as an interval.
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* This function now throws `RangeError` if the start of the interval is after its end
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* or if any date in the interval is `Invalid Date`.
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*
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* ```javascript
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* // Before v2.0.0
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*
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* getOverlappingDaysInRanges(
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* new Date(2014, 0, 10), new Date(2014, 0, 20),
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* new Date(2014, 0, 17), new Date(2014, 0, 21)
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* )
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*
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* // v2.0.0 onward
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*
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* getOverlappingDaysInIntervals(
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* { start: new Date(2014, 0, 10), end: new Date(2014, 0, 20) },
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* { start: new Date(2014, 0, 17), end: new Date(2014, 0, 21) }
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* )
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* ```
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*
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* @param {Interval} intervalLeft - the first interval to compare. See [Interval]{@link docs/Interval}
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* @param {Interval} intervalRight - the second interval to compare. See [Interval]{@link docs/Interval}
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* @returns {Number} the number of days that overlap in two time intervals
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* @throws {TypeError} 2 arguments required
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* @throws {RangeError} The start of an interval cannot be after its end
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* @throws {RangeError} Date in interval cannot be `Invalid Date`
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*
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* @example
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* // For overlapping time intervals adds 1 for each started overlapping day:
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* getOverlappingDaysInIntervals(
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* { start: new Date(2014, 0, 10), end: new Date(2014, 0, 20) },
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* { start: new Date(2014, 0, 17), end: new Date(2014, 0, 21) }
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* )
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* //=> 3
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*
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* @example
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* // For non-overlapping time intervals returns 0:
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* getOverlappingDaysInIntervals(
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* { start: new Date(2014, 0, 10), end: new Date(2014, 0, 20) },
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* { start: new Date(2014, 0, 21), end: new Date(2014, 0, 22) }
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* )
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* //=> 0
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*/
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export default function getOverlappingDaysInIntervals(dirtyIntervalLeft, dirtyIntervalRight) {
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if (arguments.length < 2) {
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throw new TypeError('2 arguments required, but only ' + arguments.length + ' present');
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}
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var intervalLeft = dirtyIntervalLeft || {};
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var intervalRight = dirtyIntervalRight || {};
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var leftStartTime = toDate(intervalLeft.start).getTime();
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var leftEndTime = toDate(intervalLeft.end).getTime();
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var rightStartTime = toDate(intervalRight.start).getTime();
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var rightEndTime = toDate(intervalRight.end).getTime(); // Throw an exception if start date is after end date or if any date is `Invalid Date`
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if (!(leftStartTime <= leftEndTime && rightStartTime <= rightEndTime)) {
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throw new RangeError('Invalid interval');
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}
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var isOverlapping = leftStartTime < rightEndTime && rightStartTime < leftEndTime;
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if (!isOverlapping) {
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return 0;
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}
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var overlapStartDate = rightStartTime < leftStartTime ? leftStartTime : rightStartTime;
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var overlapEndDate = rightEndTime > leftEndTime ? leftEndTime : rightEndTime;
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var differenceInMs = overlapEndDate - overlapStartDate;
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return Math.ceil(differenceInMs / MILLISECONDS_IN_DAY);
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}
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