feat: Add evaluation layer to CalDateTime

Ical.Net.Benchmarks/ApplicationWorkflows.cs

@@ -9,6 +9,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net.Benchmarks;
 

Ical.Net.Benchmarks/CalDateTimePerfTests.cs

@@ -6,6 +6,7 @@
 using BenchmarkDotNet.Attributes;
 using Ical.Net.DataTypes;
 using System;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net.Benchmarks;
 

Ical.Net.Benchmarks/OccurencePerfTests.cs

@@ -9,6 +9,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net.Benchmarks;
 

Ical.Net.Tests/CalDateTimeTests.cs

@@ -12,6 +12,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net.Tests;
 
@@ -55,10 +56,10 @@ public void ToTimeZoneFloating()
     [Test, TestCaseSource(nameof(ToTimeZoneTestCases))]
     public void ToTimeZoneTests(CalendarEvent calendarEvent, string targetTimeZone)
     {
-        var startAsUtc = calendarEvent.Start.AsUtc;
+        var startAsUtc = calendarEvent.Start!.AsUtc();
 
         var convertedStart = calendarEvent.Start.ToTimeZone(targetTimeZone);
-        var convertedAsUtc = convertedStart.AsUtc;
+        var convertedAsUtc = convertedStart.AsUtc();
 
         Assert.That(convertedAsUtc, Is.EqualTo(startAsUtc));
     }
@@ -96,11 +97,11 @@ public void SameDateTimeWithDifferentTzIdShouldReturnSameUtc()
         var someTime = DateTimeOffset.Parse("2018-05-21T11:35:00-04:00", CultureInfo.InvariantCulture);
 
         var someDt = new CalDateTime(someTime.DateTime, "America/New_York");
-        var firstUtc = someDt.AsUtc;
+        var firstUtc = someDt.AsUtc();
         Assert.That(firstUtc, Is.EqualTo(someTime.UtcDateTime));
 
         someDt = new CalDateTime(someTime.DateTime, "Europe/Berlin");
-        var berlinUtc = someDt.AsUtc;
+        var berlinUtc = someDt.AsUtc();
         Assert.That(berlinUtc, Is.Not.EqualTo(firstUtc));
     }
 
@@ -190,15 +191,15 @@ public static IEnumerable DateTimeArithmeticTestCases()
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.AddHours(1)))
             .Returns(dateTime.AddHours(1))
-            .SetName($"{nameof(CalDateTime.AddHours)} 1 hour");
+            .SetName($"{nameof(CalDateTimeExtensions.AddHours)} 1 hour");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.Add(Duration.FromSeconds(30))))
             .Returns(dateTime.Add(TimeSpan.FromSeconds(30)))
-            .SetName($"{nameof(CalDateTime.Add)} 30 seconds");
+            .SetName($"{nameof(CalDateTimeExtensions.Add)} 30 seconds");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.AddMinutes(70)))
             .Returns(dateTime.AddMinutes(70))
-            .SetName($"{nameof(CalDateTime.AddMinutes)} 70 minutes");
+            .SetName($"{nameof(CalDateTimeExtensions.AddMinutes)} 70 minutes");
     }
 
     [Test, TestCaseSource(nameof(EqualityTestCases))]
@@ -259,27 +260,27 @@ public static IEnumerable DateOnlyValidArithmeticTestCases()
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.Add(-Duration.FromDays(1))))
             .Returns((dateTime.AddDays(-1), false))
-            .SetName($"{nameof(CalDateTime.Add)} -1 day TimeSpan");
+            .SetName($"{nameof(CalDateTimeExtensions.Add)} -1 day TimeSpan");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.AddYears(1)))
             .Returns((dateTime.AddYears(1), false))
-            .SetName($"{nameof(CalDateTime.AddYears)} 1 year");
+            .SetName($"{nameof(CalDateTimeExtensions.AddYears)} 1 year");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.AddMonths(2)))
             .Returns((dateTime.AddMonths(2), false))
-            .SetName($"{nameof(CalDateTime.AddMonths)} 2 months");
+            .SetName($"{nameof(CalDateTimeExtensions.AddMonths)} 2 months");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.AddDays(7)))
             .Returns((dateTime.AddDays(7), false))
-            .SetName($"{nameof(CalDateTime.AddDays)} 7 days");
+            .SetName($"{nameof(CalDateTimeExtensions.AddDays)} 7 days");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.Add(Duration.FromDays(1))))
             .Returns((dateTime.Add(TimeSpan.FromDays(1)), false))
-            .SetName($"{nameof(CalDateTime.Add)} 1 day TimeSpan");
+            .SetName($"{nameof(CalDateTimeExtensions.Add)} 1 day TimeSpan");
 
         yield return new TestCaseData(new Func<CalDateTime, CalDateTime>(dt => dt.Add(Duration.Zero)))
             .Returns((dateTime.Add(TimeSpan.Zero), false))
-            .SetName($"{nameof(CalDateTime.Add)} TimeSpan.Zero");
+            .SetName($"{nameof(CalDateTimeExtensions.Add)} TimeSpan.Zero");
     }
 
     [Test]

Ical.Net.Tests/PeriodListWrapperTests.cs

@@ -7,6 +7,7 @@
 using System.Linq;
 using Ical.Net.CalendarComponents;
 using Ical.Net.DataTypes;
+using Ical.Net.Evaluation;
 using Ical.Net.Serialization;
 using NUnit.Framework;
 

Ical.Net.Tests/RecurrenceTests.cs

@@ -3986,7 +3986,7 @@ public void TestDtStartTimezone(string? tzId)
         var cal = Calendar.Load(icalText)!;
         var evt = cal.Events.First();
         var ev = new EventEvaluator(evt);
-        var occurrences = ev.Evaluate(evt.DtStart!, evt.DtStart!.ToTimeZone(tzId), null).TakeWhileBefore(evt.DtStart.AddMinutes(61).ToTimeZone(tzId));
+        var occurrences = ev.Evaluate(evt.DtStart!, evt.DtStart!.ToTimeZone(tzId), null).TakeWhileBefore(evt.DtStart!.AddMinutes(61).ToTimeZone(tzId));
         var occurrencesStartTimes = occurrences.Select(x => x.StartTime).Take(2).ToList();
 
         var expectedStartTimes = new[]
@@ -4111,4 +4111,37 @@ public void Disallowed_Recurrence_RangeChecks_Should_Throw()
             Assert.That(() => serializer.CheckRange("a", (int?) 0, 1, 2, false), Throws.TypeOf<ArgumentOutOfRangeException>());
         });
     }
+
+    [Test]
+    public void AmbiguousLocalTime_WithShortDurationOfRecurrence()
+    {
+        // Short recurrence falls into an ambiguous local time
+        // for the end time of the second occurrence because
+        // of DST transition on 2025-10-25 03:00
+        // See also: https://github.com/ical-org/ical.net/issues/737
+        var ics = """
+                  BEGIN:VCALENDAR
+                  BEGIN:VEVENT
+                  DTSTART;TZID=Europe/Vienna:20201024T023000
+                  DURATION:PT45M
+                  RRULE:FREQ=DAILY;UNTIL=20201025T013000Z
+                  END:VEVENT
+                  END:VCALENDAR
+                  """;
+        var cal = Calendar.Load(ics)!;
+        var occ = cal.GetOccurrences().ToList();
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(occ.Count, Is.EqualTo(2));
+
+            Assert.That(occ[0].Period.StartTime, Is.EqualTo(new CalDateTime(2020, 10, 24, 2, 30, 0, "Europe/Vienna")));
+            Assert.That(occ[0].Period.EndTime, Is.EqualTo(new CalDateTime(2020, 10, 24, 3, 15, 0, "Europe/Vienna")));
+            Assert.That(occ[0].Period.EffectiveDuration, Is.EqualTo(new Duration(0, 0, 0, 45, 0)));
+
+            Assert.That(occ[1].Period.StartTime, Is.EqualTo(new CalDateTime(2020, 10, 25, 2, 30, 0, "Europe/Vienna")));
+            Assert.That(occ[1].Period.EndTime, Is.EqualTo(new CalDateTime(2020, 10, 25, 2, 15, 0, "Europe/Vienna")));
+            Assert.That(occ[1].Period.EffectiveDuration, Is.EqualTo(new Duration(0, 0, 0, 45, 0)));
+        });
+    }
 }

Ical.Net.Tests/RecurrenceWithRDateTests.cs

@@ -9,6 +9,7 @@
 using Ical.Net.CalendarComponents;
 using Ical.Net.Collections;
 using Ical.Net.DataTypes;
+using Ical.Net.Evaluation;
 using Ical.Net.Serialization;
 using Ical.Net.Utility;
 using NUnit.Framework;

Ical.Net.Tests/SerializationTests.cs

@@ -12,6 +12,7 @@
 using System.Text.RegularExpressions;
 using Ical.Net.CalendarComponents;
 using Ical.Net.DataTypes;
+using Ical.Net.Evaluation;
 using Ical.Net.Serialization;
 using Ical.Net.Serialization.DataTypes;
 using Ical.Net.Utility;

Ical.Net/CalendarComponents/VTimeZone.cs

@@ -11,6 +11,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net.CalendarComponents;
 
@@ -323,7 +324,7 @@
                 return;
             }
 
             _nodaZone = DateUtil.GetZone(value);
             var id = _nodaZone.Id;
             if (string.IsNullOrWhiteSpace(id))
             {

Ical.Net/CalendarExtensions.cs

@@ -6,6 +6,7 @@
 using System;
 using System.Globalization;
 using Ical.Net.DataTypes;
+using Ical.Net.Evaluation;
 
 namespace Ical.Net;