[Fix 🐛] startWeekOn confuses dates in the calendar

Author: onesine

src/components/Datepicker.tsx

@@ -327,7 +327,7 @@ const Datepicker = (props: DatepickerType) => {
             required,
             separator,
             showFooter,
-            startWeekOn,
+            startWeekOn: startWeekOn || START_WEEK,
             toggleClassName,
             toggleIcon,
             updateFirstDate: (newDate: Date) => firstGotoDate(newDate),

src/index.tsx

@@ -1,6 +1,6 @@
 import Datepicker from "./components/Datepicker";
 
-export type {
+/*export type {
     ClassNamesTypeProp,
     Configs,
     ClassNameType,
@@ -11,7 +11,8 @@ export type {
     PopoverDirectionType,
     ColorKeys,
     WeekStringType
-} from "./types";
+} from "./types";*/
 
-// export * from "./types";
+// eslint-disable-next-line react-refresh/only-export-components
+export * from "./types";
 export default Datepicker;

src/libs/date.ts

@@ -577,32 +577,33 @@ export function dayIndexInWeek(date?: Date) {
 export function previousDaysInWeek(date: Date, weekStartDayIndex: WeekDaysIndexType = 0) {
     if (!dateIsValid(date)) return [];
 
-    const dayIndex = dayIndexInWeek(date);
-
     const previousDays: Date[] = [];
 
-    for (let i = weekStartDayIndex; i < dayIndex; i++) {
-        previousDays.push(dayjs(date).day(i).toDate());
+    let i = 1;
+    let previousDay = dateAdd(date, -i, "day");
+    while (dayIndexInWeek(previousDay) !== weekStartDayIndex) {
+        previousDays.push(previousDay);
+        i++;
+        previousDay = dateAdd(date, -i, "day");
     }
 
-    return previousDays;
+    return previousDays.sort((a, b) => {
+        if (dateIsAfter(a, b, "date")) return 1;
+        return -1;
+    });
 }
 
 export function nextDaysInWeek(date: Date, weekStartDayIndex: WeekDaysIndexType = 0) {
     if (!dateIsValid(date)) return [];
 
-    const dayIndex = dayIndexInWeek(date);
-
     const nextDays: Date[] = [];
 
-    let i = dayIndex + 1;
-
-    if (weekStartDayIndex > i) {
-        i = weekStartDayIndex;
-    }
-
-    for (i; i <= 6; i++) {
-        nextDays.push(dayjs(date).day(i).toDate());
+    let i = 1;
+    let nextDay = dateAdd(date, i, "day");
+    while (dayIndexInWeek(nextDay) !== weekStartDayIndex) {
+        nextDays.push(nextDay);
+        i++;
+        nextDay = dateAdd(date, i, "day");
     }
 
     return nextDays;