Merge pull request #518 from rianjs/ByWeekNo

BYWEEKNO & BYMONTH fix & ISO 8601 week number fix

net-core/Ical.Net.CoreUnitTests/RecurrenceTests.cs

@@ -2571,6 +2571,60 @@ public void Bug3007244()
  eventIndex: 0
  );
  }
+
+ /// <summary>
+ /// Tests bug BYWEEKNO not working
+ /// </summary>
+ [Test, Category("Recurrence")]
+ public void BugByWeekNoNotWorking()
+ {
+ var start = new DateTime(2019, 1, 1);
+ var end = new DateTime(2019, 12, 31);
+ var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=WEEKLY;BYDAY=MO;BYWEEKNO=2"));
+
+ var recurringPeriods = rpe.Evaluate(new CalDateTime(start), start, end, false);
+
+ Assert.AreEqual(1, recurringPeriods.Count);
+ Assert.AreEqual(new CalDateTime(2019, 1, 7), recurringPeriods.First().StartTime);
+ }
+
+ /// <summary>
+ /// Tests bug BYMONTH while FREQ=WEEKLY not working
+ /// </summary>
+ [Test, Category("Recurrence")]
+ public void BugByMonthWhileFreqIsWeekly()
+ {
+ var start = new DateTime(2020, 1, 1);
+ var end = new DateTime(2020, 12, 31);
+ var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=WEEKLY;BYDAY=MO;BYMONTH=1"));
+
+ var recurringPeriods = rpe.Evaluate(new CalDateTime(start), start, end, false).OrderBy(x => x).ToList();
+
+ Assert.AreEqual(4, recurringPeriods.Count);
+ Assert.AreEqual(new CalDateTime(2020, 1, 6), recurringPeriods[0].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 13), recurringPeriods[1].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 20), recurringPeriods[2].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 27), recurringPeriods[3].StartTime);
+ }
+
+ /// <summary>
+ /// Tests bug BYMONTH while FREQ=MONTHLY not working
+ /// </summary>
+ [Test, Category("Recurrence")]
+ public void BugByMonthWhileFreqIsMonthly()
+ {
+ var start = new DateTime(2020, 1, 1);
+ var end = new DateTime(2020, 12, 31);
+ var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=MONTHLY;BYDAY=MO;BYMONTH=1"));
+
+ var recurringPeriods = rpe.Evaluate(new CalDateTime(start), start, end, false).OrderBy(x => x).ToList();
+
+ Assert.AreEqual(4, recurringPeriods.Count);
+ Assert.AreEqual(new CalDateTime(2020, 1, 6), recurringPeriods[0].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 13), recurringPeriods[1].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 20), recurringPeriods[2].StartTime);
+ Assert.AreEqual(new CalDateTime(2020, 1, 27), recurringPeriods[3].StartTime);
+ }
 
  /// <summary>
  /// Tests bug #3119920 - missing weekly occurences

net-core/Ical.Net/CalendarExtensions.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Globalization;
+
+namespace Ical.Net
+{
+ public static class CalendarExtensions
+ {
+ /// <summary>
+ /// https://blogs.msdn.microsoft.com/shawnste/2006/01/24/iso-8601-week-of-year-format-in-microsoft-net/
+ /// </summary>
+ public static int GetIso8601WeekOfYear(this System.Globalization.Calendar calendar, DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek)
+ {
+ // Seriously cheat. If its Monday, Tuesday or Wednesday, then it'll
+ // be the same week# as whatever Thursday, Friday or Saturday are,
+ // and we always get those right
+ var day = calendar.GetDayOfWeek(time);
+ if (day >= DayOfWeek.Monday && day <= DayOfWeek.Wednesday)
+ {
+ time = time.AddDays(3);
+ }
+
+ // Return the week of our adjusted day
+ return calendar.GetWeekOfYear(time, rule, firstDayOfWeek);
+ }
+ }
+}

net-core/Ical.Net/Evaluation/RecurrencePatternEvaluator.cs

@@ -410,15 +410,15 @@ private List<DateTime> GetWeekNoVariants(List<DateTime> dates, RecurrencePattern
  {
  var date = t;
  // Determine our current week number
- var currWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ var currWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
  while (currWeekNo > weekNo)
  {
  // If currWeekNo > weekNo, then we're likely at the start of a year
  // where currWeekNo could be 52 or 53. If we simply step ahead 7 days
  // we should be back to week 1, where we can easily make the calculation
  // to move to weekNo.
  date = date.AddDays(7);
- currWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ currWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
  }
 
  // Move ahead to the correct week of the year
@@ -630,25 +630,30 @@ private List<DateTime> GetAbsWeekDays(DateTime date, WeekDay weekDay, Recurrence
  }
  else if (pattern.Frequency == FrequencyType.Weekly || pattern.ByWeekNo.Count > 0)
  {
- var weekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ var weekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
 
  // construct a list of possible week days..
  while (date.DayOfWeek != dayOfWeek)
  {
  date = date.AddDays(1);
  }
 
- var nextWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
- var currentWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ var nextWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ var currentWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
 
  //When we manage weekly recurring pattern and we have boundary case:
  //Weekdays: Dec 31, Jan 1, Feb 1, Mar 1, Apr 1, May 1, June 1, Dec 31 - It's the 53th week of the year, but all another are 1st week number.
  //So we need an EXRULE for this situation, but only for weekly events
  while (currentWeekNo == weekNo || (nextWeekNo < weekNo && currentWeekNo == nextWeekNo && pattern.Frequency == FrequencyType.Weekly))
  {
- days.Add(date);
+ if ((pattern.ByWeekNo.Count == 0 || pattern.ByWeekNo.Contains(currentWeekNo))
+ && (pattern.ByMonth.Count == 0 || pattern.ByMonth.Contains(date.Month)))
+ {
+ days.Add(date);
+ }
+
  date = date.AddDays(7);
- currentWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+ currentWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek,pattern.FirstDayOfWeek);
  }
  }
  else if (pattern.Frequency == FrequencyType.Monthly || pattern.ByMonth.Count > 0)
@@ -664,7 +669,13 @@ private List<DateTime> GetAbsWeekDays(DateTime date, WeekDay weekDay, Recurrence
 
  while (date.Month == month)
  {
- days.Add(date);
+ var currentWeekNo = Calendar.GetIso8601WeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek);
+
+ if ((pattern.ByWeekNo.Count == 0 || pattern.ByWeekNo.Contains(currentWeekNo))
+ && (pattern.ByMonth.Count == 0 || pattern.ByMonth.Contains(date.Month)))
+ {
+ days.Add(date);
+ }
  date = date.AddDays(7);
  }
  }