Firstly floor from to seconds to handle rare DST cases

HangfireIO · May 26, 2021 · a831ac9 · a831ac9
1 parent e002b8a
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diff --git a/src/Cronos/CronExpression.cs b/src/Cronos/CronExpression.cs
@@ -211,6 +211,8 @@ public static unsafe CronExpression Parse(string expression, CronFormat format)
                 return new DateTime(found, DateTimeKind.Utc);
             }
 
+            fromUtc = DateTimeHelper.FloorToSeconds(fromUtc);
+
             var zonedStart = TimeZoneInfo.ConvertTime(fromUtc, zone);
             var zonedStartOffset = new DateTimeOffset(zonedStart, zonedStart - fromUtc);
             var occurrence = GetOccurrenceByZonedTimes(zonedStartOffset, zone, inclusive);
@@ -254,6 +256,8 @@ public static unsafe CronExpression Parse(string expression, CronFormat format)
                 return new DateTimeOffset(found, TimeSpan.Zero);
             }
 
+            from = DateTimeHelper.FloorToSeconds(from);
+
             var zonedStart = TimeZoneInfo.ConvertTime(from, zone);
             return GetOccurrenceByZonedTimes(zonedStart, zone, inclusive);
         }

diff --git a/src/Cronos/DateTimeHelper.cs b/src/Cronos/DateTimeHelper.cs
@@ -0,0 +1,24 @@
+using System;
+
+namespace Cronos
+{
+    internal static class DateTimeHelper
+    {
+        private static readonly TimeSpan OneSecond = TimeSpan.FromSeconds(1);
+
+        public static DateTimeOffset FloorToSeconds(DateTimeOffset dateTimeOffset)
+        {
+            return dateTimeOffset.AddTicks(-GetExtraTicks(dateTimeOffset.Ticks));
+        }
+
+        public static DateTime FloorToSeconds(DateTime dateTime)
+        {
+            return dateTime.AddTicks(-GetExtraTicks(dateTime.Ticks));
+        }
+
+        private static long GetExtraTicks(long ticks)
+        {
+            return ticks % OneSecond.Ticks;
+        }
+}
+}
diff --git a/tests/Cronos.Tests/CronExpressionFacts.cs b/tests/Cronos.Tests/CronExpressionFacts.cs
@@ -1134,6 +1134,28 @@ public void GetNextOccurrence_HandleDST_WhenTheClockJumpsForward_And_TimeZoneIsE
 
         [Theory]
 
+        [InlineData("30 0 L  * *", "2017-03-30 23:59:59.9999999 +02:00", "2017-03-31 01:00:00 +03:00", false)]
+        [InlineData("30 0 L  * *", "2017-03-30 23:59:59.9999000 +02:00", "2017-03-31 01:00:00 +03:00", false)]
+        [InlineData("30 0 L  * *", "2017-03-30 23:59:59.9990000 +02:00", "2017-03-31 01:00:00 +03:00", false)]
+        [InlineData("30 0 L  * *", "2017-03-30 23:59:59.9900000 +02:00", "2017-03-31 01:00:00 +03:00", false)]
+        [InlineData("30 0 L  * *", "2017-03-30 23:59:59.9000000 +02:00", "2017-03-31 01:00:00 +03:00", false)]
+
+        [InlineData("30 0 L  * *", "2017-03-31 01:00:00.0000001 +02:00", "2017-04-30 00:30:00 +03:00", true)]
+        public void GetNextOccurrence_HandleDST_WhenTheClockJumpsForward_And_FromIsAroundDST(string cronExpression, string fromString, string expectedString, bool inclusive)
+        {
+            var expression = CronExpression.Parse(cronExpression);
+
+            var fromInstant = GetInstant(fromString);
+            var expectedInstant = GetInstant(expectedString);
+
+            var executed = expression.GetNextOccurrence(fromInstant, JordanTimeZone, inclusive);
+
+            Assert.Equal(expectedInstant, executed);
+            Assert.Equal(expectedInstant.Offset, executed?.Offset);
+        }
+
+        [Theory]
+
         // 2017-10-01 is date when the clock jumps forward from 1:59 am +10:30 standard time (ST) to 2:30 am +11:00 DST on Lord Howe.
         // ________1:59 ST///invalid///2:30 DST________
 
@@ -2788,6 +2810,7 @@ private static DateTimeOffset GetInstant(string dateTimeOffsetString)
                 {
                     "yyyy-MM-dd HH:mm:ss zzz",
                     "yyyy-MM-dd HH:mm zzz",
+                    "yyyy-MM-dd HH:mm:ss.fffffff zzz"
                 },
                 CultureInfo.InvariantCulture,
                 DateTimeStyles.None);

diff --git a/tests/Cronos.Tests/DateTimeHelperFacts.cs b/tests/Cronos.Tests/DateTimeHelperFacts.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Globalization;
+using Xunit;
+
+namespace Cronos.Tests
+{
+    public class DateTimeHelperFacts
+    {
+        [Theory]
+
+        [InlineData("2017-03-30 23:59:59.0000000 +02:00", "2017-03-30 23:59:59.0000000 +02:00")]
+
+        [InlineData("2017-03-30 23:59:59.9000000 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9900000 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9990000 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9999000 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9999900 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9999990 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+        [InlineData("2017-03-30 23:59:59.9999999 +03:00", "2017-03-30 23:59:59.0000000 +03:00")]
+
+        [InlineData("2017-03-30 23:59:59.0000001 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.0000010 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.0000100 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.0001000 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.0010000 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.0100000 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        [InlineData("2017-03-30 23:59:59.1000000 +01:00", "2017-03-30 23:59:59.0000000 +01:00")]
+        public void FloorToSeconds_WorksCorrectlyWithDateTimeOffset(string dateTime, string expected)
+        {
+            var dateTimeOffset = GetDateTimeOffsetInstant(dateTime);
+            var expectedDateTimeOffset = GetDateTimeOffsetInstant(expected);
+
+            var flooredDateTimeOffset = DateTimeHelper.FloorToSeconds(dateTimeOffset);
+
+            Assert.Equal(expectedDateTimeOffset, flooredDateTimeOffset);
+            Assert.Equal(expectedDateTimeOffset.Offset, flooredDateTimeOffset.Offset);
+        }
+
+        [Theory]
+
+        [InlineData("2021-04-19 01:45:45.0000000", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+
+        [InlineData("2021-04-19 01:45:45.9000000", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9900000", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9990000", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9999000", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9999900", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9999990", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+        [InlineData("2021-04-19 01:45:45.9999999", "2021-04-19 01:45:45.0000000", DateTimeKind.Utc)]
+
+        [InlineData("2021-04-19 01:45:45.0000001", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.0000010", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.0000100", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.0001000", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.0010000", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.0100000", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        [InlineData("2021-04-19 01:45:45.1000000", "2021-04-19 01:45:45.0000000", DateTimeKind.Unspecified)]
+        public void FloorToSeconds_WorksCorrectlyWithDateTimeUtc(string dateTime, string expected, DateTimeKind kind)
+        {
+            var dateTimeInstant = GetDateTimeUtcInstant(dateTime, kind);
+            var expectedDateTimeInstant = GetDateTimeUtcInstant(expected, kind);
+
+            var flooredDateTime = DateTimeHelper.FloorToSeconds(dateTimeInstant);
+
+            Assert.Equal(expectedDateTimeInstant, flooredDateTime);
+            Assert.Equal(expectedDateTimeInstant.Kind, flooredDateTime.Kind);
+        }
+
+        private static DateTimeOffset GetDateTimeOffsetInstant(string dateTimeOffsetString)
+        {
+            dateTimeOffsetString = dateTimeOffsetString.Trim();
+
+            var dateTime = DateTimeOffset.ParseExact(
+                dateTimeOffsetString,
+                new[]
+                {
+                    "yyyy-MM-dd HH:mm:ss.fffffff zzz",
+                },
+                CultureInfo.InvariantCulture,
+                DateTimeStyles.None);
+
+            return dateTime;
+        }
+
+        private static DateTime GetDateTimeUtcInstant(string dateTimeString, DateTimeKind kind)
+        {
+            dateTimeString = dateTimeString.Trim();
+
+            var dateTime = DateTime.ParseExact(
+                dateTimeString,
+                new[]
+                {
+                    "yyyy-MM-dd HH:mm:ss.fffffff",
+                },
+                CultureInfo.InvariantCulture,
+                DateTimeStyles.None);
+
+            dateTime = DateTime.SpecifyKind(dateTime, kind);
+
+            return dateTime;
+        }
+    }
+}