Added support for Nigeria working culture (en-NG)

src/DateTimeExtensions/WorkingDays/CultureStrategies/EN_NGHolidayStrategy.cs

@@ -0,0 +1,103 @@
+#region License
+
+// 
+// Copyright (c) 2011-2012, João Matos Silva <kappy@acydburne.com.pt>
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// 
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using DateTimeExtensions.Common;
+
+namespace DateTimeExtensions.WorkingDays.CultureStrategies
+{
+    [Locale("en-NG")] 
+    public class EN_NGHolidayStrategy : HolidayStrategyBase, IHolidayStrategy
+    {
+        public EN_NGHolidayStrategy()
+        {
+            InnerHolidays.Add(GlobalHolidays.NewYear);
+
+            InnerHolidays.Add(ChristianHolidays.GoodFriday);
+            InnerHolidays.Add(ChristianHolidays.EasterMonday);
+            InnerHolidays.Add(ChristianHolidays.Christmas);
+
+            InnerHolidays.Add(IndependenceDay);
+            InnerHolidays.Add(DemocracyDay);
+
+            InnerHolidays.Add(GlobalHolidays.InternationalWorkersDay);
+            InnerHolidays.Add(GlobalHolidays.BoxingDay);
+        }
+
+        protected override IDictionary<DateTime, Holiday> BuildObservancesMap(int year)
+        {
+            IDictionary<DateTime, Holiday> holidayMap = new Dictionary<DateTime, Holiday>();
+            foreach (var innerHoliday in InnerHolidays)
+            {
+                var date = innerHoliday.GetInstance(year);
+                if (date.HasValue)
+                {
+                    if (holidayMap.ContainsKey(date.Value))
+                    {
+                        // Check to see if holiday falling on the Sunday then moves to the monday, and there is another holiday scheduled for the monday
+                        // Update the Holiday Name of the Monday
+                        holidayMap[date.Value] = innerHoliday;
+                    }
+
+                    else
+                    {
+                        holidayMap.Add(date.Value, innerHoliday);
+                    }
+
+                    //if the holiday is a sunday, the holiday is observed on next monday
+                    if (date.Value.DayOfWeek == DayOfWeek.Sunday)
+                    {
+                        holidayMap.AddIfInexistent(date.Value.AddDays(1), innerHoliday);
+                    }
+                }
+            }
+            return holidayMap;
+        }
+
+        // 12 June - Democracy Day
+        private static Holiday democracyDay;
+        public static Holiday DemocracyDay
+        {
+            get
+            {
+                if (democracyDay == null)
+                {
+                    democracyDay = new FixedHoliday("Democracy Day", 6, 12);
+                }
+                return democracyDay;
+            }
+        }
+
+        // 1st October - Independence Day
+        private static Holiday independenceDay;
+        public static Holiday IndependenceDay
+        {
+            get
+            {
+                if (independenceDay == null)
+                {
+                    independenceDay = new FixedHoliday("IndependenceDay Day", 10, 1);
+                }
+                return independenceDay;
+            }
+        }
+    }
+}

src/DateTimeExtensions/WorkingDaysExtensions.cs

@@ -175,10 +175,11 @@ public static IDictionary<DateTime, Holiday> AllYearHolidays(this DateTime day,
             IWorkingDayCultureInfo workingDayCultureInfo)
         {
             var holidays = new SortedDictionary<DateTime, Holiday>();
-            foreach (Holiday holiday in workingDayCultureInfo.GetHolidaysOfYear(day.Year))
+            var holidaysOfTheYear = workingDayCultureInfo.GetHolidaysOfYear(day.Year).ToList();
+            foreach (Holiday holiday in holidaysOfTheYear)
             {
                 var date = holiday.GetInstance(day.Year);
-                if (date.HasValue)
+                if (date.HasValue && !holidays.ContainsKey(date.Value))
                 {
                     holidays.Add(date.Value, holiday);
                 }

tests/DateTimeExtensions.Tests/FrCaHolidaysTests.cs

@@ -10,7 +10,7 @@ namespace DateTimeExtensions.Tests
     public class FrCaHolidaysTests
     {
         [Test]
-        public void can_get_stratery()
+        public void can_get_strategy()
         {
             var dateTimeCulture = new WorkingDayCultureInfo("fr-CA");
             var strategy = dateTimeCulture.LocateHolidayStrategy(dateTimeCulture.Name, null);

tests/DateTimeExtensions.Tests/enNGHolidaysTests.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Linq;
+using DateTimeExtensions.WorkingDays;
+using DateTimeExtensions.WorkingDays.CultureStrategies;
+using NUnit.Framework;
+
+namespace DateTimeExtensions.Tests
+{
+    [TestFixture]
+    public class EN_NGHolidayStrategyTests
+    {
+        private readonly WorkingDayCultureInfo workingDayCultureInfo = new("en-NG");
+
+        [Test]
+        public void StrategyResolution_Returns_EN_NGHolidayStrategy()
+        {
+            var strategy = workingDayCultureInfo.LocateHolidayStrategy(workingDayCultureInfo.Name, null);
+            Assert.That(strategy, Is.TypeOf<EN_NGHolidayStrategy>());
+        }
+
+        [Test]
+        public void Holidays_Collection_Count_Is_8()
+        {
+            var holidays = workingDayCultureInfo.Holidays;
+            Assert.That(holidays.Count(), Is.EqualTo(8));
+        }
+
+        [Test]
+        public void Christmas_On_Sunday_2022_And_BoxingDay_Collision_Behaviour()
+        {
+            // 2022: Christmas (25 Dec) is Sunday, Boxing Day (26 Dec) is Monday.
+            // Verify both dates are present as holidays and final mapping for Dec 26 is Boxing Day.
+            var year = 2022;
+            var christmas = new DateTime(year, 12, 25);
+            var boxingDay = new DateTime(year, 12, 26);
+
+            var holidaysMap = new DateTime(year, 1, 1).AllYearHolidays(workingDayCultureInfo);
+
+            Assert.Multiple(() =>
+            {
+                Assert.That(christmas.DayOfWeek, Is.EqualTo(DayOfWeek.Sunday));
+                Assert.That(holidaysMap.ContainsKey(christmas), Is.True, "Christmas (original date) should be present.");
+                Assert.That(holidaysMap.ContainsKey(boxingDay), Is.True, "Boxing Day / observed slot should be present.");
+
+                // According to current strategy implementation Boxing Day should be the entry for Dec 26.
+                Assert.That(holidaysMap[christmas].Name, Is.EqualTo("Christmas"));
+                Assert.That(holidaysMap[boxingDay].Name, Is.EqualTo("Boxing Day"));
+
+                // Both dates should be treated as non-working (holidays / weekend)
+                Assert.That(christmas.IsWorkingDay(workingDayCultureInfo), Is.False);
+                Assert.That(boxingDay.IsWorkingDay(workingDayCultureInfo), Is.False);
+            });
+        }
+
+        [Test]
+        public void Christmas_Sunday_2033_Is_Observed_On_Monday_2033()
+        {
+            // Verify a case where Christmas is on Sunday and the following Monday is considered a holiday.
+            var christmasSunday = new DateTime(2033, 12, 25);
+            var observed = christmasSunday.AddDays(1);
+
+            Assert.Multiple(() =>
+            {
+                Assert.That(christmasSunday.DayOfWeek, Is.EqualTo(DayOfWeek.Sunday));
+                Assert.That(observed.IsHoliday(workingDayCultureInfo), Is.True, "Following Monday should be observed as a holiday.");
+            });
+        }
+
+        [Test]
+        public void Assert_DemocracyDayHoliday_On_Sunday_Observed_On_Monday()
+        {
+            // 12-06-2022 Democracy day on a Sunday
+            var mondayAfterDemocracyDay = new DateTime(2022, 06, 13);
+            Assert.Multiple(() =>
+            {
+                Assert.That(mondayAfterDemocracyDay.DayOfWeek, Is.EqualTo(DayOfWeek.Monday));
+                Assert.That(mondayAfterDemocracyDay.IsWorkingDay(workingDayCultureInfo), Is.False);
+            });
+        }
+
+        [Test]
+        public void Assert_IndependenceDayHolidays_On_Sunday_Observed_On_Monday()
+        {
+            // 12-06-2022 Independence day on a Sunday
+            var mondayAfterIndependenceDay = new DateTime(2028, 10, 02);
+            Assert.Multiple(() =>
+            {
+                Assert.That(mondayAfterIndependenceDay.DayOfWeek, Is.EqualTo(DayOfWeek.Monday));
+                Assert.That(mondayAfterIndependenceDay.IsWorkingDay(workingDayCultureInfo), Is.False);
+            });
+        }
+    }
+}