fix: bank holidays fix

Author: f-steel

src/components/Holidays/RequestLeave.tsx

@@ -10,7 +10,7 @@ import { format } from 'date-fns'
 import { CalendarIcon } from 'lucide-react'
 import { useRouter } from 'next/navigation'
 import { Toaster, toast } from 'sonner'
-import { getTotalDaysBetween, isDayOff, getIsMultipleDays } from '@/lib/utils/DaysUtil'
+import { getTotalDaysBetween, getIsMultipleDays } from '@/lib/utils/DaysUtil'
 
 interface RequestLeaveProps {
   remainingDays: number

src/utils/BankHolidays.ts

@@ -1,9 +1,21 @@
 export const bankHolidays = [
-  { date: new Date(2025, 3, 18), name: 'Good Friday' },
-  { date: new Date(2025, 3, 21), name: 'Easter Monday' },
-  { date: new Date(2025, 4, 5), name: 'Early May bank holiday' },
-  { date: new Date(2025, 5, 26), name: 'Spring bank holiday' },
-  { date: new Date(2025, 7, 25), name: 'Summer bank holiday' },
-  { date: new Date(2025, 11, 25), name: 'Christmas Day' },
-  { date: new Date(2025, 11, 26), name: 'Boxing Day' },
+  // 2025 Bank Holidays
+  new Date(2025, 0, 1), // New Year's Day
+  new Date(2025, 3, 18), // Good Friday
+  new Date(2025, 3, 21), // Easter Monday
+  new Date(2025, 4, 5), // Early May bank holiday
+  new Date(2025, 4, 26), // Spring bank holiday
+  new Date(2025, 7, 25), // Summer bank holiday
+  new Date(2025, 11, 25), // Christmas Day
+  new Date(2025, 11, 26), // Boxing Day
+
+  // 2026 Bank Holidays
+  new Date(2026, 0, 1), // New Year's Day
+  new Date(2026, 3, 3), // Good Friday
+  new Date(2026, 3, 6), // Easter Monday
+  new Date(2026, 4, 4), // Early May bank holiday
+  new Date(2026, 4, 25), // Spring bank holiday
+  new Date(2026, 7, 31), // Summer bank holiday
+  new Date(2026, 11, 25), // Christmas Day
+  new Date(2026, 11, 28), // Boxing Day
 ]

src/utils/DaysUtil.ts

@@ -3,7 +3,7 @@ import { bankHolidays } from './BankHolidays'
 export const isDayOff = (date: Date) => {
   const isSunday = date.getDay() === 0
   const isSaturday = date.getDay() === 6
-  const isBankHoliday = bankHolidays.some((h) => h.date.toISOString() === date.toISOString())
+  const isBankHoliday = bankHolidays.some((h) => h.toISOString() === date.toISOString())
 
   return isSunday || isSaturday || isBankHoliday
 }

tests/DaysUtil.test.ts

@@ -12,14 +12,48 @@ describe('DaysUtil', () => {
     })
 
     test('returns true for bank holidays', () => {
-      bankHolidays.forEach(({ date }) => {
+      bankHolidays.forEach((date) => {
         expect(isDayOff(date)).toBe(true)
       })
     })
 
     test("returns false for a regular weekday that's not a bank holiday", () => {
       expect(isDayOff(new Date(2025, 3, 22))).toBe(false) // Tuesday, 22 April 2025 (Not a holiday)
-      expect(isDayOff(new Date(2025, 3, 25))).toBe(false) // Friday, 23 April 2025 (Not a holiday)
+      expect(isDayOff(new Date(2025, 3, 25))).toBe(false) // Friday, 25 April 2025 (Not a holiday)
+    })
+
+    // New comprehensive tests for specific bank holidays
+    test('correctly identifies specific 2025 bank holidays', () => {
+      expect(isDayOff(new Date(2025, 0, 1))).toBe(true) // New Year's Day - Jan 1
+      expect(isDayOff(new Date(2025, 3, 18))).toBe(true) // Good Friday - April 18
+      expect(isDayOff(new Date(2025, 3, 21))).toBe(true) // Easter Monday - April 21
+      expect(isDayOff(new Date(2025, 4, 5))).toBe(true) // Early May bank holiday - May 5
+      expect(isDayOff(new Date(2025, 4, 26))).toBe(true) // Spring bank holiday - May 26
+      expect(isDayOff(new Date(2025, 7, 25))).toBe(true) // Summer bank holiday - Aug 25
+      expect(isDayOff(new Date(2025, 11, 25))).toBe(true) // Christmas Day - Dec 25
+      expect(isDayOff(new Date(2025, 11, 26))).toBe(true) // Boxing Day - Dec 26
+    })
+
+    test('correctly identifies specific 2026 bank holidays', () => {
+      expect(isDayOff(new Date(2026, 0, 1))).toBe(true) // New Year's Day - Jan 1
+      expect(isDayOff(new Date(2026, 3, 3))).toBe(true) // Good Friday - April 3
+      expect(isDayOff(new Date(2026, 3, 6))).toBe(true) // Easter Monday - April 6
+      expect(isDayOff(new Date(2026, 4, 4))).toBe(true) // Early May bank holiday - May 4
+      expect(isDayOff(new Date(2026, 4, 25))).toBe(true) // Spring bank holiday - May 25
+      expect(isDayOff(new Date(2026, 7, 31))).toBe(true) // Summer bank holiday - Aug 31
+      expect(isDayOff(new Date(2026, 11, 25))).toBe(true) // Christmas Day - Dec 25
+      expect(isDayOff(new Date(2026, 11, 28))).toBe(true) // Boxing Day - Dec 28
+    })
+
+    test('correctly rejects dates that are NOT bank holidays', () => {
+      expect(isDayOff(new Date(2025, 0, 2))).toBe(false) // Jan 2 (not a holiday)
+      expect(isDayOff(new Date(2025, 3, 17))).toBe(false) // April 17 (day before Good Friday)
+      expect(isDayOff(new Date(2025, 3, 19))).toBe(true) // April 19 is Saturday (weekend)
+      expect(isDayOff(new Date(2025, 3, 22))).toBe(false) // April 22 (day after Easter Monday)
+      expect(isDayOff(new Date(2025, 4, 4))).toBe(true) // May 4 is Sunday (weekend)
+      expect(isDayOff(new Date(2025, 4, 6))).toBe(false) // May 6 (day after Early May holiday)
+      expect(isDayOff(new Date(2025, 11, 24))).toBe(false) // Dec 24 (Christmas Eve, not a UK bank holiday)
+      expect(isDayOff(new Date(2025, 11, 29))).toBe(false) // Dec 29 (Monday after Boxing Day, not a holiday)
     })
   })
 
@@ -39,6 +73,87 @@ describe('DaysUtil', () => {
       expect(getTotalDaysBetween(new Date(2025, 3, 17), new Date(2025, 3, 24))).toBe(4) // easter weekend
       expect(getTotalDaysBetween(new Date(2025, 2, 3), new Date(2025, 2, 14))).toBe(10)
     })
+
+    // New comprehensive tests for edge cases
+    test('handles periods around New Year correctly', () => {
+      // Dec 30 2024 (Mon) to Jan 3 2025 (Fri) - should exclude Jan 1 (New Year's Day)
+      expect(getTotalDaysBetween(new Date(2024, 11, 30), new Date(2025, 0, 3))).toBe(4)
+
+      // Dec 31 2024 (Tue) to Jan 2 2025 (Thu) - should exclude Jan 1 (New Year's Day)
+      expect(getTotalDaysBetween(new Date(2024, 11, 31), new Date(2025, 0, 2))).toBe(2)
+    })
+
+    test('handles Easter period correctly', () => {
+      // April 17-22 (Thu-Tue) includes Good Friday (18th) and Easter Monday (21st), plus weekend
+      // Working days: 17th (Thu), 22nd (Tue) = 2 days
+      expect(getTotalDaysBetween(new Date(2025, 3, 17), new Date(2025, 3, 22))).toBe(2)
+
+      // April 14-25 (Mon-Fri) - longer period including Easter
+      // Excludes: 18th (Good Friday), 19th-20th (weekend), 21st (Easter Monday)
+      // Working days: 14th, 15th, 16th, 17th, 22nd, 23rd, 24th, 25th = 8 days
+      expect(getTotalDaysBetween(new Date(2025, 3, 14), new Date(2025, 3, 25))).toBe(8)
+    })
+
+    test('handles May bank holidays correctly', () => {
+      // May 1-9 (Thu-Fri) includes Early May holiday (5th) and weekend
+      // Working days: 1st, 2nd, 6th, 7th, 8th, 9th = 6 days
+      expect(getTotalDaysBetween(new Date(2025, 4, 1), new Date(2025, 4, 9))).toBe(6)
+
+      // May 22-30 (Thu-Fri) includes Spring bank holiday (26th) and weekend
+      // Working days: 22nd, 23rd, 27th, 28th, 29th, 30th = 6 days
+      expect(getTotalDaysBetween(new Date(2025, 4, 22), new Date(2025, 4, 30))).toBe(6)
+    })
+
+    test('handles Christmas period correctly', () => {
+      // Dec 22-30 (Mon-Tue) includes Christmas Day (25th), Boxing Day (26th), and weekend
+      // Working days: 22nd, 23rd, 24th, 29th, 30th = 5 days
+      expect(getTotalDaysBetween(new Date(2025, 11, 22), new Date(2025, 11, 30))).toBe(5)
+    })
+
+    test('handles 2026 Easter period correctly', () => {
+      // April 1-8 (Wed-Wed) includes Good Friday (3rd), Easter Monday (6th), and weekend
+      // Working days: 1st (Wed), 2nd (Thu), 7th (Tue), 8th (Wed) = 4 days
+      expect(getTotalDaysBetween(new Date(2026, 3, 1), new Date(2026, 3, 8))).toBe(4)
+    })
+
+    test('handles 2026 Christmas period correctly', () => {
+      // Dec 23-30 (Wed-Wed) includes Christmas Day (25th), Boxing Day (28th), and weekend
+      // Working days: 23rd (Wed), 24th (Thu), 29th (Tue), 30th (Wed) = 4 days
+      expect(getTotalDaysBetween(new Date(2026, 11, 23), new Date(2026, 11, 30))).toBe(4)
+    })
+
+    test('handles full month calculations correctly', () => {
+      // January 2025: 31 days total, minus weekends (8 days) and New Year's Day = 22 working days
+      expect(getTotalDaysBetween(new Date(2025, 0, 1), new Date(2025, 0, 31))).toBe(22)
+
+      // April 2025: 30 days total, minus weekends (8 days), Good Friday, and Easter Monday = 20 working days
+      expect(getTotalDaysBetween(new Date(2025, 3, 1), new Date(2025, 3, 30))).toBe(20)
+    })
+
+    test('handles single day calculations', () => {
+      // Single working day
+      expect(getTotalDaysBetween(new Date(2025, 0, 2), new Date(2025, 0, 2))).toBe(1)
+
+      // Single bank holiday
+      expect(getTotalDaysBetween(new Date(2025, 0, 1), new Date(2025, 0, 1))).toBe(0)
+
+      // Single weekend day
+      expect(getTotalDaysBetween(new Date(2025, 0, 4), new Date(2025, 0, 4))).toBe(0) // Saturday
+    })
+
+    test('handles edge case with bank holidays falling on weekends', () => {
+      // If a bank holiday falls on a weekend, it should still be counted as a day off
+      // Test with various scenarios to ensure no double-counting
+
+      // Check if any 2025 bank holidays fall on weekends
+      const newYearsDay = new Date(2025, 0, 1) // Wednesday
+      const goodFriday = new Date(2025, 3, 18) // Friday
+      const easterMonday = new Date(2025, 3, 21) // Monday
+
+      expect(newYearsDay.getDay()).toBe(3) // Wednesday
+      expect(goodFriday.getDay()).toBe(5) // Friday
+      expect(easterMonday.getDay()).toBe(1) // Monday
+    })
   })
 
   describe('isMultipleDays', () => {
@@ -57,4 +172,31 @@ describe('DaysUtil', () => {
       expect(getIsMultipleDays(undefined, new Date(2025, 0, 3))).toBe(false)
     })
   })
+
+  describe('BankHolidays integrity', () => {
+    test('has correct number of bank holidays for 2025 and 2026', () => {
+      expect(bankHolidays).toHaveLength(16) // 8 for 2025 + 8 for 2026
+    })
+
+    test('all bank holidays are in 2025 or 2026', () => {
+      bankHolidays.forEach((date) => {
+        const year = date.getFullYear()
+        expect(year === 2025 || year === 2026).toBe(true)
+      })
+    })
+
+    test('bank holidays are in chronological order', () => {
+      for (let i = 1; i < bankHolidays.length; i++) {
+        expect(bankHolidays[i].getTime()).toBeGreaterThan(bankHolidays[i - 1].getTime())
+      }
+    })
+
+    test('has correct number of holidays per year', () => {
+      const holidays2025 = bankHolidays.filter((date) => date.getFullYear() === 2025)
+      const holidays2026 = bankHolidays.filter((date) => date.getFullYear() === 2026)
+
+      expect(holidays2025).toHaveLength(8)
+      expect(holidays2026).toHaveLength(8)
+    })
+  })
 })