react-day-picker
Version:
Customizable Date Picker for React
90 lines (84 loc) • 3.02 kB
text/typescript
import { defaultDateLib, type DateLib } from "../classes/DateLib.js";
import type { DateRange } from "../types/index.js";
/**
* Adds a date to an existing range, considering constraints like minimum and
* maximum range size.
*
* @param date - The date to add to the range.
* @param initialRange - The initial range to which the date will be added.
* @param min - The minimum number of days in the range.
* @param max - The maximum number of days in the range.
* @param required - Whether the range must always include at least one date.
* @param dateLib - The date utility library instance.
* @returns The updated date range, or `undefined` if the range is cleared.
* @group Utilities
*/
export function addToRange(
date: Date,
initialRange: DateRange | undefined,
min = 0,
max = 0,
required = false,
dateLib: DateLib = defaultDateLib
): DateRange | undefined {
const { from, to } = initialRange || {};
const { isSameDay, isAfter, isBefore } = dateLib;
let range: DateRange | undefined;
if (!from && !to) {
// the range is empty, add the date
range = { from: date, to: min > 0 ? undefined : date };
} else if (from && !to) {
// adding date to an incomplete range
if (isSameDay(from, date)) {
// adding a date equal to the start of the range
if (required) {
range = { from, to: undefined };
} else {
range = undefined;
}
} else if (isBefore(date, from)) {
// adding a date before the start of the range
range = { from: date, to: from };
} else {
// adding a date after the start of the range
range = { from, to: date };
}
} else if (from && to) {
// adding date to a complete range
if (isSameDay(from, date) && isSameDay(to, date)) {
// adding a date that is equal to both start and end of the range
if (required) {
range = { from, to };
} else {
range = undefined;
}
} else if (isSameDay(from, date)) {
// adding a date equal to the the start of the range
range = { from, to: min > 0 ? undefined : date };
} else if (isSameDay(to, date)) {
// adding a dare equal to the end of the range
range = { from: date, to: min > 0 ? undefined : date };
} else if (isBefore(date, from)) {
// adding a date before the start of the range
range = { from: date, to: to };
} else if (isAfter(date, from)) {
// adding a date after the start of the range
range = { from, to: date };
} else if (isAfter(date, to)) {
// adding a date after the end of the range
range = { from, to: date };
} else {
throw new Error("Invalid range");
}
}
// check for min / max
if (range?.from && range?.to) {
const diff = dateLib.differenceInCalendarDays(range.to, range.from);
if (max > 0 && diff > max) {
range = { from: date, to: undefined };
} else if (min > 1 && diff < min) {
range = { from: date, to: undefined };
}
}
return range;
}