Disallow initializing CalDateTime from DateTimeKind.Local and some cleanup

Ical.Net.Tests/CalDateTimeTests.cs

@@ -6,6 +6,7 @@
 using Ical.Net.CalendarComponents;
 using Ical.Net.DataTypes;
 using NUnit.Framework;
+using NUnit.Framework.Constraints;
 using System;
 using System.Collections;
 using System.Collections.Generic;
@@ -343,4 +344,21 @@ public void AddAndSubtract_ShouldBeReversible(CalDateTime t, Duration d)
             Assert.That(t.Add(d).SubtractExact(t), Is.EqualTo(d.ToTimeSpan()));
         });
     }
+
+    private static TestCaseData[] CalDateTime_FromDateTime_HandlesKindCorrectlyTestCases =>
+        [
+            new TestCaseData(DateTimeKind.Unspecified, Is.EqualTo(new CalDateTime(2024, 12, 30, 10, 44, 50, null))),
+            new TestCaseData(DateTimeKind.Utc, Is.EqualTo(new CalDateTime(2024, 12, 30, 10, 44, 50, "UTC"))),
+            new TestCaseData(DateTimeKind.Local, Throws.ArgumentException),
+        ];
+
+    [Test, TestCaseSource(nameof(CalDateTime_FromDateTime_HandlesKindCorrectlyTestCases))]
+
+
+    public void CalDateTime_FromDateTime_HandlesKindCorrectly(DateTimeKind kind, IResolveConstraint constraint)
+    {
+        var dt = new DateTime(2024, 12, 30, 10, 44, 50, kind);
+
+        Assert.That(() => new CalDateTime(dt), constraint);
+    }
 }

Ical.Net.Tests/CopyComponentTests.cs

@@ -53,7 +53,7 @@ public static IEnumerable CopyCalendarTest_TestCases()
         yield return new TestCaseData(IcsFiles.XProperty2).SetName("XProperty2");
     }
 
-    private static readonly DateTime _now = DateTime.Now;
+    private static readonly DateTime _now = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified);
     private static readonly DateTime _later = _now.AddHours(1);
 
     private static CalendarEvent GetSimpleEvent() => new CalendarEvent
@@ -154,7 +154,7 @@ public void CopyTodoTest()
         {
             Summary = "Test Todo",
             Description = "This is a test todo",
-            Due = new CalDateTime(DateTime.Now.AddDays(10)),
+            Due = new CalDateTime(DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified).AddDays(10)),
             Priority = 1,
             Contacts = new[] { "John", "Paul" },
             Status = "NeedsAction"
@@ -180,7 +180,7 @@ public void CopyJournalTest()
         {
             Summary = "Test Journal",
             Description = "This is a test journal",
-            DtStart = new CalDateTime(DateTime.Now),
+            DtStart = new CalDateTime(DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified)),
             Categories = new List<string> { "Category1", "Category2" },
             Priority = 1,
             Status = "Draft"

Ical.Net.Tests/EqualityAndHashingTests.cs

@@ -19,7 +19,7 @@ namespace Ical.Net.Tests;
 public class EqualityAndHashingTests
 {
     private const string TzId = "America/Los_Angeles";
-    private static readonly DateTime _nowTime = DateTime.Parse("2016-07-16T16:47:02.9310521-04:00");
+    private static readonly DateTime _nowTime = DateTime.SpecifyKind(DateTime.Parse("2016-07-16T16:47:02.9310521-04:00"), DateTimeKind.Unspecified);
     private static readonly DateTime _later = _nowTime.AddHours(1);
 
     [Test, TestCaseSource(nameof(CalDateTime_TestCases))]

Ical.Net.Tests/RecurrenceTests.cs

@@ -1189,8 +1189,8 @@ public void YearlyByDay1()
     [Test, Category("Recurrence")]
     public void WeekNoOrderingShouldNotMatter()
     {
-        var start = new DateTime(2019, 1, 1);
-        var end = new DateTime(2019, 12, 31);
+        var start = new CalDateTime(2019, 1, 1);
+        var end = new CalDateTime(2019, 12, 31);
         var rpe1 = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=YEARLY;WKST=MO;BYDAY=MO;BYWEEKNO=1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53"));
         var rpe2 = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=YEARLY;WKST=MO;BYDAY=MO;BYWEEKNO=53,51,49,47,45,43,41,39,37,35,33,31,29,27,25,23,21,19,17,15,13,11,9,7,5,3,1"));
 
@@ -2585,11 +2585,11 @@ public void DurationOfRecurrencesOverDst(string dtStart, string dtEnd, string d1
     [Test, Category("Recurrence")]
     public void BugByWeekNoNotWorking()
     {
-        var start = new DateTime(2019, 1, 1);
-        var end = new DateTime(2019, 12, 31);
+        var start = new CalDateTime(2019, 1, 1);
+        var end = new CalDateTime(2019, 12, 31);
         var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=WEEKLY;BYDAY=MO;BYWEEKNO=2"));
 
-        var recurringPeriods = rpe.Evaluate(new CalDateTime(start, false), start, end, false).ToList();
+        var recurringPeriods = rpe.Evaluate(start, start, end, false).ToList();
 
         Assert.That(recurringPeriods, Has.Count.EqualTo(1));
         Assert.That(recurringPeriods.First().StartTime, Is.EqualTo(new CalDateTime(2019, 1, 7)));
@@ -2601,11 +2601,11 @@ public void BugByWeekNoNotWorking()
     [Test, Category("Recurrence")]
     public void BugByMonthWhileFreqIsWeekly()
     {
-        var start = new DateTime(2020, 1, 1);
-        var end = new DateTime(2020, 12, 31);
+        var start = new CalDateTime(2020, 1, 1);
+        var end = new CalDateTime(2020, 12, 31);
         var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=WEEKLY;BYDAY=MO;BYMONTH=1"));
 
-        var recurringPeriods = rpe.Evaluate(new CalDateTime(start, false), start, end, false).OrderBy(x => x).ToList();
+        var recurringPeriods = rpe.Evaluate(start, start, end, false).OrderBy(x => x).ToList();
 
         Assert.That(recurringPeriods, Has.Count.EqualTo(4));
         Assert.Multiple(() =>
@@ -2644,11 +2644,11 @@ public void ReccurencePattern_MaxDate_StopsOnCount()
     [Test, Category("Recurrence")]
     public void BugByMonthWhileFreqIsMonthly()
     {
-        var start = new DateTime(2020, 1, 1);
-        var end = new DateTime(2020, 12, 31);
+        var start = new CalDateTime(2020, 1, 1);
+        var end = new CalDateTime(2020, 12, 31);
         var rpe = new RecurrencePatternEvaluator(new RecurrencePattern("FREQ=MONTHLY;BYDAY=MO;BYMONTH=1"));
 
-        var recurringPeriods = rpe.Evaluate(new CalDateTime(start, false), start, end, false).OrderBy(x => x).ToList();
+        var recurringPeriods = rpe.Evaluate(start, start, end, false).OrderBy(x => x).ToList();
 
         Assert.That(recurringPeriods, Has.Count.EqualTo(4));
         Assert.Multiple(() =>
@@ -2669,11 +2669,11 @@ public void Bug3119920()
     {
         using (var sr = new StringReader("FREQ=WEEKLY;UNTIL=20251126T120000;INTERVAL=1;BYDAY=MO"))
         {
-            var start = DateTime.Parse("2010-11-27 9:00:00");
+            var start = new CalDateTime(2010, 11, 27, 9, 0, 0);
             var serializer = new RecurrencePatternSerializer();
             var rp = (RecurrencePattern)serializer.Deserialize(sr);
             var rpe = new RecurrencePatternEvaluator(rp);
-            var recurringPeriods = rpe.Evaluate(new CalDateTime(start), start, rp.Until, false).ToList();
+            var recurringPeriods = rpe.Evaluate(new CalDateTime(start), start, rp.Until?.AsCalDateTime(), false).ToList();
 
             var period = recurringPeriods.ElementAt(recurringPeriods.Count - 1);
 
@@ -2740,15 +2740,15 @@ public void Issue432()
         };
         var vEvent = new CalendarEvent
         {
-            Start = new CalDateTime(DateTime.Parse("2019-01-04T08:00Z")),
+            Start = new CalDateTime(DateTime.Parse("2019-01-04T08:00Z").ToUniversalTime()),
         };
 
         vEvent.RecurrenceRules.Add(rrule);
 
         //Testing on both the first day and the next, results used to be different
         for (var i = 0; i <= 1; i++)
         {
-            var checkTime = DateTime.Parse("2019-01-04T08:00Z");
+            var checkTime = DateTime.Parse("2019-01-04T08:00Z").ToUniversalTime();
             checkTime = checkTime.AddDays(i);
             //Valid asking for the exact moment
             var occurrences = vEvent.GetOccurrences(checkTime, checkTime).ToList();
@@ -2897,8 +2897,8 @@ public void RecurrencePattern1()
 
         var occurrences = evaluator.Evaluate(
             startDate,
-            SimpleDateTimeToMatch(fromDate, startDate),
-            SimpleDateTimeToMatch(toDate, startDate),
+            fromDate,
+            toDate,
             false)
             .OrderBy(o => o.StartTime)
             .ToList();
@@ -2930,8 +2930,8 @@ public void RecurrencePattern2()
 
         var occurrences = evaluator.Evaluate(
             startDate,
-            SimpleDateTimeToMatch(fromDate, startDate),
-            SimpleDateTimeToMatch(toDate, startDate),
+            fromDate,
+            toDate,
             false);
         Assert.That(occurrences.Count, Is.Not.EqualTo(0));
     }
@@ -3038,8 +3038,8 @@ public void Test4()
         // Add the exception dates
         var periods = evaluator.Evaluate(
             evtStart,
-            DateUtil.GetSimpleDateTimeData(evtStart),
-            SimpleDateTimeToMatch(evtEnd, evtStart),
+            evtStart,
+            evtEnd,
             false)
             .OrderBy(p => p.StartTime)
             .ToList();
@@ -3295,7 +3295,7 @@ public void AddExDateToEventAfterGetOccurrencesShouldRecomputeResult()
         Assert.That(occurrences, Has.Count.EqualTo(3));
     }
 
-    private static readonly DateTime _now = DateTime.Now;
+    private static readonly DateTime _now = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified);
     private static readonly DateTime _later = _now.AddHours(1);
     private static CalendarEvent GetEventWithRecurrenceRules()
     {
@@ -3830,23 +3830,6 @@ public void ShouldCreateARecurringYearlyEvent()
         Assert.That(occurrences.Count, Is.EqualTo(27));
     }
 
-    private static DateTime SimpleDateTimeToMatch(IDateTime dt, IDateTime toMatch)
-    {
-        if (toMatch.IsUtc && dt.IsUtc)
-        {
-            return dt.Value;
-        }
-        if (toMatch.IsUtc)
-        {
-            return dt.Value.ToUniversalTime();
-        }
-        if (dt.IsUtc)
-        {
-            return dt.Value.ToLocalTime();
-        }
-        return dt.Value;
-    }
-
     [Test]
     public void GetOccurrenceShouldExcludeDtEndFloating()
     {
@@ -3897,4 +3880,38 @@ public void TestGetOccurrenceIndefinite()
 
         Assert.That(instances.Count(), Is.EqualTo(100));
     }
+
+    [Test, Category("Recurrence")]
+    [TestCase(null)]
+    [TestCase("UTC")]
+    [TestCase("Europe/Vienna")]
+    [TestCase("America/New_York")]
+    public void TestDtStartTimezone(string tzId)
+    {
+        var icalText = """
+            BEGIN:VCALENDAR
+            BEGIN:VEVENT
+            UID:ignore
+            DTSTAMP:20180613T154237Z
+            DTSTART;TZID=Europe/Vienna:20180612T180000
+            DTEND;TZID=Europe/Vienna:20180612T181000
+            RRULE:FREQ=HOURLY
+            END:VEVENT
+            END:VCALENDAR
+            """;
+
+        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), evt.DtStart.AddMinutes(61).ToTimeZone(tzId), false);
+        var occurrencesStartTimes = occurrences.Select(x => x.StartTime).Take(2).ToList();
+
+        var expectedStartTimes = new[]
+        {
+            new CalDateTime(2018, 06, 12, 18, 0, 0, "Europe/Vienna"),
+            new CalDateTime(2018, 06, 12, 19, 0, 0, "Europe/Vienna"),
+        };
+
+        Assert.That(expectedStartTimes.SequenceEqual(occurrencesStartTimes), Is.True);
+    }
 }

Ical.Net.Tests/SerializationTests.cs

@@ -22,7 +22,7 @@ namespace Ical.Net.Tests;
 [TestFixture]
 public class SerializationTests
 {
-    private static readonly DateTime _nowTime = DateTime.Now;
+    private static readonly DateTime _nowTime = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified);
     private static readonly DateTime _later = _nowTime.AddHours(1);
     private static CalendarSerializer GetNewSerializer() => new CalendarSerializer();
     private static string SerializeToString(Calendar c) => GetNewSerializer().SerializeToString(c);

Ical.Net.Tests/SymmetricSerializationTests.cs

@@ -22,7 +22,7 @@ public class SymmetricSerializationTests
 {
     private const string _ldapUri = "ldap://example.com:6666/o=eDABC Industries,c=3DUS??(cn=3DBMary Accepted)";
 
-    private static readonly DateTime _nowTime = DateTime.Now;
+    private static readonly DateTime _nowTime = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified);
     private static readonly DateTime _later = _nowTime.AddHours(1);
     private static CalendarSerializer GetNewSerializer() => new CalendarSerializer();
     private static string SerializeToString(Calendar c) => GetNewSerializer().SerializeToString(c);

Ical.Net/DataTypes/CalDateTime.cs

@@ -78,15 +78,25 @@ public CalDateTime(IDateTime value)
     /// It will represent an RFC 5545, Section 3.3.4, DATE value, if <see paramref="hasTime"/> is <see langword="false"/>.
     /// <para/>
     /// The <see cref="TzId"/> will be set to "UTC" if the <paramref name="value"/>
-    /// has <see cref="DateTimeKind.Utc"/> and <paramref name="hasTime"/> is <see langword="true"/>.
-    /// Otherwise <see cref="TzId"/> will be <see langword="null"/>.
+    /// has kind <see cref="DateTimeKind.Utc"/> and <paramref name="hasTime"/> is <see langword="true"/>.
+    /// It will be set to <see langword="null"/> if the kind is kind <see cref="DateTimeKind.Unspecified"/>
+    /// and will throw otherwise.
     /// </summary>
     /// <param name="value">The <see cref="DateTime"/> value. Its <see cref="DateTimeKind"/> will be ignored.</param>
     /// <param name="hasTime">
     /// The instance will represent an RFC 5545, Section 3.3.5, DATE-TIME value, if <see paramref="hasTime"/> is <see langword="true"/>.
     /// It will represent an RFC 5545, Section 3.3.4, DATE value, if <see paramref="hasTime"/> is <see langword="false"/>.
     /// </param>
-    public CalDateTime(DateTime value, bool hasTime = true) : this(value, value.Kind == DateTimeKind.Utc ? UtcTzId : null, hasTime)
+    /// <exception cref="System.ArgumentException">If the specified value's kind is <see cref="DateTimeKind.Local"/></exception>
+    public CalDateTime(DateTime value, bool hasTime = true) : this(
+        value,
+        value.Kind switch
+        {
+            DateTimeKind.Utc => UtcTzId,
+            DateTimeKind.Unspecified => null,
+            _ => throw new ArgumentException($"An instance of {nameof(CalDateTime)} can only be initializd from a {nameof(DateTime)} of kind {nameof(DateTimeKind.Utc)} or {nameof(DateTimeKind.Unspecified)}.")
+        },
+        hasTime)
     { }
 
     /// <summary>

Ical.Net/Evaluation/Evaluator.cs

@@ -3,6 +3,7 @@
 // Licensed under the MIT license.
 //
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Globalization;
@@ -13,25 +14,11 @@ namespace Ical.Net.Evaluation;
 
 public abstract class Evaluator : IEvaluator
 {
-    private ICalendarObject _mAssociatedObject;
-
     protected Evaluator()
-    {
-        Initialize();
-    }
-
-    private void Initialize()
     {
         Calendar = CultureInfo.CurrentCulture.Calendar;
     }
 
-    protected IDateTime ConvertToIDateTime(DateTime dt, IDateTime referenceDate)
-    {
-        IDateTime newDt = new CalDateTime(dt, referenceDate.TzId);
-        newDt.AssociateWith(referenceDate);
-        return newDt;
-    }
-
     protected void IncrementDate(ref DateTime dt, RecurrencePattern pattern, int interval)
     {
         if (interval == 0)
@@ -69,11 +56,5 @@ protected void IncrementDate(ref DateTime dt, RecurrencePattern pattern, int int
 
     public System.Globalization.Calendar Calendar { get; private set; }
 
-    public virtual ICalendarObject AssociatedObject
-    {
-        get => _mAssociatedObject;
-        protected set => _mAssociatedObject = value;
-    }
-
-    public abstract IEnumerable<Period> Evaluate(IDateTime referenceDate, DateTime? periodStart, DateTime? periodEnd, bool includeReferenceDateInResults);
+    public abstract IEnumerable<Period> Evaluate(IDateTime referenceDate, IDateTime? periodStart, IDateTime? periodEnd, bool includeReferenceDateInResults);
 }

Ical.Net/Evaluation/EventEvaluator.cs

@@ -42,7 +42,7 @@ public EventEvaluator(CalendarEvent evt) : base(evt) { }
     /// <param name="periodEnd">The end date of the range to evaluate.</param>
     /// <param name="includeReferenceDateInResults"></param>
     /// <returns></returns>
-    public override IEnumerable<Period> Evaluate(IDateTime referenceTime, DateTime? periodStart, DateTime? periodEnd, bool includeReferenceDateInResults)
+    public override IEnumerable<Period> Evaluate(IDateTime referenceTime, IDateTime? periodStart, IDateTime? periodEnd, bool includeReferenceDateInResults)
     {
         // Evaluate recurrences normally
         var periods = base.Evaluate(referenceTime, periodStart, periodEnd, includeReferenceDateInResults)

Ical.Net/Evaluation/IEvaluator.cs

@@ -3,6 +3,7 @@
 // Licensed under the MIT license.
 //
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using Ical.Net.DataTypes;
@@ -16,11 +17,6 @@ public interface IEvaluator
     /// </summary>
     System.Globalization.Calendar Calendar { get; }
 
-    /// <summary>
-    /// Gets the object associated with this evaluator.
-    /// </summary>
-    ICalendarObject AssociatedObject { get; }
-
     /// <summary>
     /// Evaluates this item to determine the dates and times for which it occurs/recurs.
     /// This method only evaluates items which occur/recur between <paramref name="periodStart"/>
@@ -46,5 +42,5 @@ public interface IEvaluator
     ///     A sequence of <see cref="Ical.Net.DataTypes.Period"/> objects for
     ///     each date/time when this item occurs/recurs.
     /// </returns>
-    IEnumerable<Period> Evaluate(IDateTime referenceDate, DateTime? periodStart, DateTime? periodEnd, bool includeReferenceDateInResults);
+    IEnumerable<Period> Evaluate(IDateTime referenceDate, IDateTime? periodStart, IDateTime? periodEnd, bool includeReferenceDateInResults);
 }