More complete UTC offset parsing #102 #236

release-notes.md

@@ -4,6 +4,7 @@ A listing of what each [Nuget package](https://www.nuget.org/packages/Ical.Net)
 
 ### v2
 
+* 2.2.31: .NET's UTC offset parsing semantics don't match the RFC (which allows for `hhmmss` UTC offsets), so I extended the offset serializer to account for these differences. ([#102](https://github.com/rianjs/ical.net/issues/102), [#236](https://github.com/rianjs/ical.net/issues/236))
 * 2.2.30: `Event.Resources` is an `IList` again. Event.Resources wasn't being deserialized, so I have reverted back to an IList to fix this. Sorry everyone. I'm intentionally violating my own semver rules. In the future, I'll call version n+1 "vNext" so I can more freely rev the major version number.
 * 2.2.29: Calling `GetOccurrences()` on a recurrable component should recompute the recurrence set. Specifying `EXDATE` values that don't have a `TimeOfDay` component should "black out" that day from a recurring component's `StartTime`.[#223](https://github.com/rianjs/ical.net/issues/223)
 * 2.2.25: Fix for Collection was modified exception, and better handling of recurrence ids when calling `Calendar.GetOccurrences` ([#188](https://github.com/rianjs/ical.net/issues/188)) ([#148](https://github.com/rianjs/ical.net/issues/148))

v2/Ical.Net.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
  <metadata>
  <id>Ical.Net</id>
- <version>2.2.31</version>
+ <version>2.2.32</version>
  <title>Ical.Net</title>
  <authors>Rian Stockbower, Douglas Day, M. David Peterson</authors>
  <owners>Rian Stockbower</owners>

v2/ical.NET.UnitTests/EventTest.cs

@@ -6,6 +6,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using Ical.Net.General;
 using Ical.Net.Interfaces.DataTypes;
 using Ical.Net.Serialization.iCalendar.Serializers;
 
@@ -396,5 +397,56 @@ public void EventResourcesCanBeZeroedOut()
  //See https://github.com/rianjs/ical.net/issues/208 -- this should be changed later so the collection is really null
  Assert.AreEqual(0, e.Resources?.Count);
  }
+
+ [Test]
+ public void HourMinuteSecondOffsetParsingTest()
+ {
+ const string ical =
+@"BEGIN:VCALENDAR
+PRODID:-//1&1 Mail & Media GmbH/GMX Kalender Server 3.10.0//NONSGML//DE
+VERSION:2.0
+CALSCALE:GREGORIAN
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:Europe/Brussels
+TZURL:http://tzurl.org/zoneinfo/Europe/Brussels
+X-LIC-LOCATION:Europe/Brussels
+BEGIN:DAYLIGHT
+TZOFFSETFROM:-001730
+TZOFFSETTO:-001730
+TZNAME:CEST
+DTSTART:19810329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+001730
+TZOFFSETTO:+001730
+TZNAME:BMT
+DTSTART:18800101T000000
+RDATE:18800101T000000
+END:STANDARD
+END:VTIMEZONE
+END:VCALENDAR";
+ using (var reader = new StringReader(ical))
+ {
+ var timezones = Calendar.LoadFromStream(reader)
+ .First()
+ .TimeZones.First()
+ .Children.Cast<CalendarComponent>();
+
+ var positiveOffset = timezones
+ .Skip(1).Take(1).First()
+ .Properties.First().Value as UtcOffset;
+ var expectedPositive = TimeSpan.FromMinutes(17.5);
+ Assert.AreEqual(expectedPositive, positiveOffset?.Offset);
+
+ var negativeOffset = timezones
+ .First()
+ .Properties.First().Value as UtcOffset;
+
+ var expectedNegative = TimeSpan.FromMinutes(-17.5);
+ Assert.AreEqual(expectedNegative, negativeOffset?.Offset);
+ }
+ }
  }
 }

v2/ical.NET/Serialization/iCalendar/Serializers/DataTypes/UTCOffsetSerializer.cs

@@ -1,5 +1,7 @@
 using System;
+using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Text.RegularExpressions;
 using Ical.Net.DataTypes;
 using Ical.Net.Interfaces.DataTypes;
@@ -39,8 +41,29 @@ public static TimeSpan GetOffset(string rawOffset)
  {
  rawOffset = rawOffset.Substring(0, rawOffset.Length - 2);
  }
- var dummyOffset = DateTimeOffset.Parse("2016-01-01 00:00:00 " + rawOffset);
- return dummyOffset.Offset;
+
+ DateTimeOffset temp;
+ if (DateTimeOffset.TryParse("2016-01-01 00:00:00 " + rawOffset, out temp))
+ {
+ return temp.Offset;
+ }
+
+ TimeSpan ts;
+ var isNegative = rawOffset.StartsWith("-");
+
+ if (isNegative || rawOffset.StartsWith("+"))
+ {
+ rawOffset = rawOffset.Substring(1, rawOffset.Length - 1);
+ }
+
+ if (!TimeSpan.TryParseExact(rawOffset, "hhmmss", CultureInfo.InvariantCulture, out ts))
+ {
+ throw new FormatException($"{rawOffset} is not a valid UTC offset");
+ }
+
+ return isNegative
+ ? -ts
+ : ts;
  }
  }
 }

v3/ical.NET.UnitTests/CalendarEventTest.cs

@@ -393,5 +393,57 @@ public void EventResourcesCanBeZeroedOut()
  //See https://github.com/rianjs/ical.net/issues/208 -- this should be changed later so the collection is really null
  Assert.AreEqual(0, e.Resources?.Count);
  }
+
+ [Test]
+ public void HourMinuteSecondOffsetParsingTest()
+ {
+ const string ical =
+@"BEGIN:VCALENDAR
+PRODID:-//1&1 Mail & Media GmbH/GMX Kalender Server 3.10.0//NONSGML//DE
+VERSION:2.0
+CALSCALE:GREGORIAN
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:Europe/Brussels
+TZURL:http://tzurl.org/zoneinfo/Europe/Brussels
+X-LIC-LOCATION:Europe/Brussels
+BEGIN:DAYLIGHT
+TZOFFSETFROM:-001730
+TZOFFSETTO:-001730
+TZNAME:CEST
+DTSTART:19810329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+001730
+TZOFFSETTO:+001730
+TZNAME:BMT
+DTSTART:18800101T000000
+RDATE:18800101T000000
+END:STANDARD
+END:VTIMEZONE
+END:VCALENDAR";
+
+ using (var reader = new StringReader(ical))
+ {
+ var timezones = Calendar.LoadFromStream(reader)
+ .First()
+ .TimeZones.First()
+ .Children.Cast<CalendarComponent>();
+
+ var positiveOffset = timezones
+ .Skip(1).Take(1).First()
+ .Properties.First().Value as UtcOffset;
+ var expectedPositive = TimeSpan.FromMinutes(17.5);
+ Assert.AreEqual(expectedPositive, positiveOffset?.Offset);
+
+ var negativeOffset = timezones
+ .First()
+ .Properties.First().Value as UtcOffset;
+
+ var expectedNegative = TimeSpan.FromMinutes(-17.5);
+ Assert.AreEqual(expectedNegative, negativeOffset?.Offset);
+ }
+ }
  }
 }

v3/ical.NET/Serialization/iCalendar/Serializers/DataTypes/UTCOffsetSerializer.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using System.IO;
 using System.Text.RegularExpressions;
 using Ical.Net.DataTypes;
@@ -38,8 +39,29 @@ public static TimeSpan GetOffset(string rawOffset)
  {
  rawOffset = rawOffset.Substring(0, rawOffset.Length - 2);
  }
- var dummyOffset = DateTimeOffset.Parse("2016-01-01 00:00:00 " + rawOffset);
- return dummyOffset.Offset;
+
+ DateTimeOffset temp;
+ if (DateTimeOffset.TryParse("2016-01-01 00:00:00 " + rawOffset, out temp))
+ {
+ return temp.Offset;
+ }
+
+ TimeSpan ts;
+ var isNegative = rawOffset.StartsWith("-");
+
+ if (isNegative || rawOffset.StartsWith("+"))
+ {
+ rawOffset = rawOffset.Substring(1, rawOffset.Length - 1);
+ }
+
+ if (!TimeSpan.TryParseExact(rawOffset, "hhmmss", CultureInfo.InvariantCulture, out ts))
+ {
+ throw new FormatException($"{rawOffset} is not a valid UTC offset");
+ }
+
+ return isNegative
+ ? -ts
+ : ts;
  }
  }
 }