Add tests for various length DateTime.ToString years (dotnet/corefx#34727)

* Add tests for various length DateTime.ToString years

* Address PR feedback

Commit migrated from https://github.com/dotnet/corefx/commit/b8aeb16796a44110f97f03641f43db075a6b2faf

diff --git a/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.cs b/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.cs
index eb44bc1..c59e3c2 100644 (file)
--- a/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.cs
+++ b/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.cs
@@ -1176,61 +1176,77 @@ namespace System.Tests
             //                     long seed1 = BitConverter.ToInt64(bytes, 0);
             //                     short seed2 = BitConverter.ToInt16(bytes, 0);
             //                     var dto = new DateTimeOffset(seed1, TimeSpan.FromSeconds(seed2));
-            //                     Console.WriteLine($"yield return new object[] {{ new DateTimeOffset({seed1}, TimeSpan.FromSeconds({seed2})), \"{format}\", \"{dto.ToString(format)}\" }};");
+            //                     Console.WriteLine($"yield return new object[] {{ new DateTimeOffset({seed1}, TimeSpan.FromSeconds({seed2})), \"{format}\", null, \"{dto.ToString(format)}\" }};");
             //                     i++;
             //                 }
             //                 catch { }
             //             }
             //         }
             //     }
-
-            yield return new object[] { new DateTimeOffset(2900400428644841236, TimeSpan.FromSeconds(14100)), "R", "Thu, 02 Jan 9192 18:39:24 GMT" };
-            yield return new object[] { new DateTimeOffset(1274262903994885572, TimeSpan.FromSeconds(-23100)), "R", "Fri, 24 Dec 4038 14:11:39 GMT" };
-            yield return new object[] { new DateTimeOffset(1228646631256163984, TimeSpan.FromSeconds(1680)), "R", "Tue, 05 Jun 3894 16:37:25 GMT" };
-            yield return new object[] { new DateTimeOffset(2075652349868341848, TimeSpan.FromSeconds(31320)), "O", "6578-06-25T09:43:06.8341848+08:42" };
-            yield return new object[] { new DateTimeOffset(2552829549675618692, TimeSpan.FromSeconds(8580)), "O", "8090-08-05T19:56:07.5618692+02:23" };
-            yield return new object[] { new DateTimeOffset(2125715934081389968, TimeSpan.FromSeconds(5520)), "o", "6737-02-16T08:50:08.1389968+01:32" };
-            yield return new object[] { new DateTimeOffset(98868902986124576, TimeSpan.FromSeconds(3360)), "O", "0314-04-22T14:24:58.6124576+00:56" };
-            yield return new object[] { new DateTimeOffset(2013251697288306712, TimeSpan.FromSeconds(24600)), "O", "6380-09-28T10:15:28.8306712+06:50" };
-            yield return new object[] { new DateTimeOffset(1037147523427228640, TimeSpan.FromSeconds(23520)), "o", "3287-08-04T05:25:42.7228640+06:32" };
-            yield return new object[] { new DateTimeOffset(2177752403904984188, TimeSpan.FromSeconds(29820)), "r", "Mon, 09 Jan 6902 10:02:50 GMT" };
-            yield return new object[] { new DateTimeOffset(832166470435218996, TimeSpan.FromSeconds(9780)), "r", "Fri, 12 Jan 2638 12:34:23 GMT" };
-            yield return new object[] { new DateTimeOffset(651609783134768240, TimeSpan.FromSeconds(-13200)), "o", "2065-11-13T23:45:13.4768240-03:40" };
-            yield return new object[] { new DateTimeOffset(1436056534611459616, TimeSpan.FromSeconds(-480)), "o", "4551-09-07T11:17:41.1459616-00:08" };
-            yield return new object[] { new DateTimeOffset(1028124353647668124, TimeSpan.FromSeconds(-5220)), "o", "3258-12-30T17:49:24.7668124-01:27" };
-            yield return new object[] { new DateTimeOffset(815446183072290676, TimeSpan.FromSeconds(-10380)), "o", "2585-01-17T10:51:47.2290676-02:53" };
-            yield return new object[] { new DateTimeOffset(2091185090181553120, TimeSpan.FromSeconds(23520)), "r", "Fri, 14 Sep 6627 20:11:38 GMT" };
-            yield return new object[] { new DateTimeOffset(2668855365894778960, TimeSpan.FromSeconds(-20400)), "R", "Mon, 08 Apr 8458 04:56:29 GMT" };
-            yield return new object[] { new DateTimeOffset(1640160533452759488, TimeSpan.FromSeconds(8640)), "O", "5198-06-18T22:49:05.2759488+02:24" };
-            yield return new object[] { new DateTimeOffset(2958665748788957224, TimeSpan.FromSeconds(20520)), "o", "9376-08-21T15:41:18.8957224+05:42" };
-            yield return new object[] { new DateTimeOffset(2902544657562766092, TimeSpan.FromSeconds(-29940)), "R", "Tue, 20 Oct 9198 00:48:16 GMT" };
-            yield return new object[] { new DateTimeOffset(2847595389168931696, TimeSpan.FromSeconds(21360)), "R", "Thu, 02 Sep 9024 17:59:16 GMT" };
-            yield return new object[] { new DateTimeOffset(2010196475667096780, TimeSpan.FromSeconds(9420)), "r", "Sat, 23 Jan 6371 04:22:26 GMT" };
-            yield return new object[] { new DateTimeOffset(613442997756722832, TimeSpan.FromSeconds(32400)), "O", "1944-12-04T11:16:15.6722832+09:00" };
-            yield return new object[] { new DateTimeOffset(921560296274801912, TimeSpan.FromSeconds(13560)), "r", "Wed, 23 Apr 2921 13:21:07 GMT" };
-            yield return new object[] { new DateTimeOffset(1990689515682669052, TimeSpan.FromSeconds(8700)), "o", "6309-03-31T18:59:28.2669052+02:25" };
-            yield return new object[] { new DateTimeOffset(620638066929852080, TimeSpan.FromSeconds(24240)), "O", "1967-09-23T02:18:12.9852080+06:44" };
-            yield return new object[] { new DateTimeOffset(327248350932775524, TimeSpan.FromSeconds(12900)), "O", "1038-01-04T15:58:13.2775524+03:35" };
-            yield return new object[] { new DateTimeOffset(1370257845275318012, TimeSpan.FromSeconds(-10500)), "O", "4343-03-06T13:55:27.5318012-02:55" };
-            yield return new object[] { new DateTimeOffset(1239382730779209800, TimeSpan.FromSeconds(12360)), "O", "3928-06-13T18:04:37.9209800+03:26" };
-            yield return new object[] { new DateTimeOffset(2935667013803687040, TimeSpan.FromSeconds(-17280)), "o", "9303-10-05T17:56:20.3687040-04:48" };
-            yield return new object[] { new DateTimeOffset(2101626275971711700, TimeSpan.FromSeconds(-15660)), "R", "Tue, 16 Oct 6660 00:00:57 GMT" };
-            yield return new object[] { new DateTimeOffset(1417918072364232412, TimeSpan.FromSeconds(28380)), "o", "4494-03-15T21:07:16.4232412+07:53" };
-            yield return new object[] { new DateTimeOffset(962535844977970944, TimeSpan.FromSeconds(3840)), "r", "Thu, 27 Feb 3051 01:44:17 GMT" };
-            yield return new object[] { new DateTimeOffset(2576630638913059544, TimeSpan.FromSeconds(-1320)), "R", "Tue, 07 Jan 8166 09:40:11 GMT" };
-            yield return new object[] { new DateTimeOffset(991481917233718112, TimeSpan.FromSeconds(25440)), "r", "Thu, 19 Nov 3142 05:18:03 GMT" };
-            yield return new object[] { new DateTimeOffset(230115425073485984, TimeSpan.FromSeconds(-10080)), "o", "0730-03-18T07:08:27.3485984-02:48" };
-            yield return new object[] { new DateTimeOffset(1289946780226617584, TimeSpan.FromSeconds(240)), "r", "Sat, 04 Sep 4088 22:56:22 GMT" };
-            yield return new object[] { new DateTimeOffset(3119563990129685280, TimeSpan.FromSeconds(-19680)), "R", "Sun, 04 Jul 9886 16:44:52 GMT" };
-            yield return new object[] { new DateTimeOffset(1167612095351481672, TimeSpan.FromSeconds(-6840)), "r", "Thu, 06 Jan 3701 23:12:55 GMT" };
-            yield return new object[] { new DateTimeOffset(1617181518122280616, TimeSpan.FromSeconds(26280)), "O", "5125-08-24T20:50:12.2280616+07:18" };
+            yield return new object[] { new DateTimeOffset(2900400428644841236, TimeSpan.FromSeconds(14100)), "R", null, "Thu, 02 Jan 9192 18:39:24 GMT" };
+            yield return new object[] { new DateTimeOffset(1274262903994885572, TimeSpan.FromSeconds(-23100)), "R", null, "Fri, 24 Dec 4038 14:11:39 GMT" };
+            yield return new object[] { new DateTimeOffset(1228646631256163984, TimeSpan.FromSeconds(1680)), "R", null, "Tue, 05 Jun 3894 16:37:25 GMT" };
+            yield return new object[] { new DateTimeOffset(2075652349868341848, TimeSpan.FromSeconds(31320)), "O", null, "6578-06-25T09:43:06.8341848+08:42" };
+            yield return new object[] { new DateTimeOffset(2552829549675618692, TimeSpan.FromSeconds(8580)), "O", null, "8090-08-05T19:56:07.5618692+02:23" };
+            yield return new object[] { new DateTimeOffset(2125715934081389968, TimeSpan.FromSeconds(5520)), "o", null, "6737-02-16T08:50:08.1389968+01:32" };
+            yield return new object[] { new DateTimeOffset(98868902986124576, TimeSpan.FromSeconds(3360)), "O", null, "0314-04-22T14:24:58.6124576+00:56" };
+            yield return new object[] { new DateTimeOffset(2013251697288306712, TimeSpan.FromSeconds(24600)), "O", null, "6380-09-28T10:15:28.8306712+06:50" };
+            yield return new object[] { new DateTimeOffset(1037147523427228640, TimeSpan.FromSeconds(23520)), "o", null, "3287-08-04T05:25:42.7228640+06:32" };
+            yield return new object[] { new DateTimeOffset(2177752403904984188, TimeSpan.FromSeconds(29820)), "r", null, "Mon, 09 Jan 6902 10:02:50 GMT" };
+            yield return new object[] { new DateTimeOffset(832166470435218996, TimeSpan.FromSeconds(9780)), "r", null, "Fri, 12 Jan 2638 12:34:23 GMT" };
+            yield return new object[] { new DateTimeOffset(651609783134768240, TimeSpan.FromSeconds(-13200)), "o", null, "2065-11-13T23:45:13.4768240-03:40" };
+            yield return new object[] { new DateTimeOffset(1436056534611459616, TimeSpan.FromSeconds(-480)), "o", null, "4551-09-07T11:17:41.1459616-00:08" };
+            yield return new object[] { new DateTimeOffset(1028124353647668124, TimeSpan.FromSeconds(-5220)), "o", null, "3258-12-30T17:49:24.7668124-01:27" };
+            yield return new object[] { new DateTimeOffset(815446183072290676, TimeSpan.FromSeconds(-10380)), "o", null, "2585-01-17T10:51:47.2290676-02:53" };
+            yield return new object[] { new DateTimeOffset(2091185090181553120, TimeSpan.FromSeconds(23520)), "r", null, "Fri, 14 Sep 6627 20:11:38 GMT" };
+            yield return new object[] { new DateTimeOffset(2668855365894778960, TimeSpan.FromSeconds(-20400)), "R", null, "Mon, 08 Apr 8458 04:56:29 GMT" };
+            yield return new object[] { new DateTimeOffset(1640160533452759488, TimeSpan.FromSeconds(8640)), "O", null, "5198-06-18T22:49:05.2759488+02:24" };
+            yield return new object[] { new DateTimeOffset(2958665748788957224, TimeSpan.FromSeconds(20520)), "o", null, "9376-08-21T15:41:18.8957224+05:42" };
+            yield return new object[] { new DateTimeOffset(2902544657562766092, TimeSpan.FromSeconds(-29940)), "R", null, "Tue, 20 Oct 9198 00:48:16 GMT" };
+            yield return new object[] { new DateTimeOffset(2847595389168931696, TimeSpan.FromSeconds(21360)), "R", null, "Thu, 02 Sep 9024 17:59:16 GMT" };
+            yield return new object[] { new DateTimeOffset(2010196475667096780, TimeSpan.FromSeconds(9420)), "r", null, "Sat, 23 Jan 6371 04:22:26 GMT" };
+            yield return new object[] { new DateTimeOffset(613442997756722832, TimeSpan.FromSeconds(32400)), "O", null, "1944-12-04T11:16:15.6722832+09:00" };
+            yield return new object[] { new DateTimeOffset(921560296274801912, TimeSpan.FromSeconds(13560)), "r", null, "Wed, 23 Apr 2921 13:21:07 GMT" };
+            yield return new object[] { new DateTimeOffset(1990689515682669052, TimeSpan.FromSeconds(8700)), "o", null, "6309-03-31T18:59:28.2669052+02:25" };
+            yield return new object[] { new DateTimeOffset(620638066929852080, TimeSpan.FromSeconds(24240)), "O", null, "1967-09-23T02:18:12.9852080+06:44" };
+            yield return new object[] { new DateTimeOffset(327248350932775524, TimeSpan.FromSeconds(12900)), "O", null, "1038-01-04T15:58:13.2775524+03:35" };
+            yield return new object[] { new DateTimeOffset(1370257845275318012, TimeSpan.FromSeconds(-10500)), "O", null, "4343-03-06T13:55:27.5318012-02:55" };
+            yield return new object[] { new DateTimeOffset(1239382730779209800, TimeSpan.FromSeconds(12360)), "O", null, "3928-06-13T18:04:37.9209800+03:26" };
+            yield return new object[] { new DateTimeOffset(2935667013803687040, TimeSpan.FromSeconds(-17280)), "o", null, "9303-10-05T17:56:20.3687040-04:48" };
+            yield return new object[] { new DateTimeOffset(2101626275971711700, TimeSpan.FromSeconds(-15660)), "R", null, "Tue, 16 Oct 6660 00:00:57 GMT" };
+            yield return new object[] { new DateTimeOffset(1417918072364232412, TimeSpan.FromSeconds(28380)), "o", null, "4494-03-15T21:07:16.4232412+07:53" };
+            yield return new object[] { new DateTimeOffset(962535844977970944, TimeSpan.FromSeconds(3840)), "r", null, "Thu, 27 Feb 3051 01:44:17 GMT" };
+            yield return new object[] { new DateTimeOffset(2576630638913059544, TimeSpan.FromSeconds(-1320)), "R", null, "Tue, 07 Jan 8166 09:40:11 GMT" };
+            yield return new object[] { new DateTimeOffset(991481917233718112, TimeSpan.FromSeconds(25440)), "r", null, "Thu, 19 Nov 3142 05:18:03 GMT" };
+            yield return new object[] { new DateTimeOffset(230115425073485984, TimeSpan.FromSeconds(-10080)), "o", null, "0730-03-18T07:08:27.3485984-02:48" };
+            yield return new object[] { new DateTimeOffset(1289946780226617584, TimeSpan.FromSeconds(240)), "r", null, "Sat, 04 Sep 4088 22:56:22 GMT" };
+            yield return new object[] { new DateTimeOffset(3119563990129685280, TimeSpan.FromSeconds(-19680)), "R", null, "Sun, 04 Jul 9886 16:44:52 GMT" };
+            yield return new object[] { new DateTimeOffset(1167612095351481672, TimeSpan.FromSeconds(-6840)), "r", null, "Thu, 06 Jan 3701 23:12:55 GMT" };
+            yield return new object[] { new DateTimeOffset(1617181518122280616, TimeSpan.FromSeconds(26280)), "O", null, "5125-08-24T20:50:12.2280616+07:18" };
+
+            // Year patterns
+
+            var enUS = new CultureInfo("en-US");
+            var thTH = new CultureInfo("th-TH");
+            yield return new object[] { new DateTimeOffset(new DateTime(1234, 5, 6)), "yy", enUS, "34" };
+            yield return new object[] { DateTimeOffset.MaxValue, "yy", thTH, "42" };
+            for (int i = 3; i < 20; i++)
+            {
+                yield return new object[] { new DateTimeOffset(new DateTime(1234, 5, 6)), new string('y', i), enUS, 1234.ToString("D" + i) };
+                yield return new object[] { DateTimeOffset.MaxValue, new string('y', i), thTH, 10542.ToString("D" + i) };
+            }
         }
 
         [Theory]
         [MemberData(nameof(ToString_MatchesExpected_MemberData))]
-        public static void ToString_MatchesExpected(DateTimeOffset dateTimeOffset, string format, string expected)
+        public static void ToString_MatchesExpected(DateTimeOffset dateTimeOffset, string format, IFormatProvider provider, string expected)
         {
-            Assert.Equal(expected, dateTimeOffset.ToString(format));
+            if (provider == null)
+            {
+                Assert.Equal(expected, dateTimeOffset.ToString(format));
+            }
+
+            Assert.Equal(expected, dateTimeOffset.ToString(format, provider));
         }
 
         public static IEnumerable<object[]> ToString_WithCulture_MatchesExpected_MemberData()

diff --git a/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.netcoreapp.cs b/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.netcoreapp.cs
index 0f6ad1d..c927975 100644 (file)
--- a/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.netcoreapp.cs
+++ b/src/libraries/System.Runtime/tests/System/DateTimeOffsetTests.netcoreapp.cs
@@ -85,13 +85,13 @@ namespace System.Tests
 
         [Theory]
         [MemberData(nameof(ToString_MatchesExpected_MemberData))]
-        public static void TryFormat_MatchesExpected(DateTimeOffset dateTimeOffset, string format, string expected)
+        public static void TryFormat_MatchesExpected(DateTimeOffset dateTimeOffset, string format, IFormatProvider provider, string expected)
         {
             var destination = new char[expected.Length];
 
-            Assert.False(dateTimeOffset.TryFormat(destination.AsSpan(0, destination.Length - 1), out _, format));
+            Assert.False(dateTimeOffset.TryFormat(destination.AsSpan(0, destination.Length - 1), out _, format, provider));
 
-            Assert.True(dateTimeOffset.TryFormat(destination, out int charsWritten, format));
+            Assert.True(dateTimeOffset.TryFormat(destination, out int charsWritten, format, provider));
             Assert.Equal(destination.Length, charsWritten);
             Assert.Equal(expected, new string(destination));
         }

diff --git a/src/libraries/System.Runtime/tests/System/DateTimeTests.cs b/src/libraries/System.Runtime/tests/System/DateTimeTests.cs
index de967be..3b099b7 100644 (file)
--- a/src/libraries/System.Runtime/tests/System/DateTimeTests.cs
+++ b/src/libraries/System.Runtime/tests/System/DateTimeTests.cs
@@ -1978,61 +1978,77 @@ namespace System.Tests
             //                     rand.NextBytes(bytes);
             //                     long seed = BitConverter.ToInt64(bytes, 0);
             //                     var dt = new DateTime(seed, kind);
-            //                     Console.WriteLine($"yield return new object[] {{ new DateTime({seed}, DateTimeKind.{kind}), \"{format}\", \"{dt.ToString(format)}\" }};");
+            //                     Console.WriteLine($"yield return new object[] {{ new DateTime({seed}, DateTimeKind.{kind}), \"{format}\", null, \"{dt.ToString(format)}\" }};");
             //                     i++;
             //                 }
             //                 catch { }
             //             }
             //         }
             //}
-
-            yield return new object[] { new DateTime(2688006240964947440, DateTimeKind.Utc), "O", "8518-12-15T08:01:36.4947440Z" };
-            yield return new object[] { new DateTime(2461197105169450509, DateTimeKind.Utc), "r", "Sun, 23 Mar 7800 18:15:16 GMT" };
-            yield return new object[] { new DateTime(71363981510699949, DateTimeKind.Unspecified), "R", "Fri, 23 Feb 0227 04:49:11 GMT" };
-            yield return new object[] { new DateTime(1678426538898407093, DateTimeKind.Unspecified), "R", "Fri, 22 Sep 5319 07:24:49 GMT" };
-            yield return new object[] { new DateTime(2689041307785948711, DateTimeKind.Utc), "o", "8522-03-27T07:52:58.5948711Z" };
-            yield return new object[] { new DateTime(996610247053299209, DateTimeKind.Unspecified), "r", "Thu, 19 Feb 3159 01:58:25 GMT" };
-            yield return new object[] { new DateTime(3105391438361510074, DateTimeKind.Unspecified), "R", "Fri, 06 Aug 9841 01:17:16 GMT" };
-            yield return new object[] { new DateTime(946433487657072106, DateTimeKind.Utc), "R", "Mon, 17 Feb 3000 03:06:05 GMT" };
-            yield return new object[] { new DateTime(2521748413631767931, DateTimeKind.Unspecified), "R", "Sat, 08 Feb 7992 07:02:43 GMT" };
-            yield return new object[] { new DateTime(49349519375012969, DateTimeKind.Utc), "R", "Fri, 20 May 0157 11:58:57 GMT" };
-            yield return new object[] { new DateTime(796677276139881359, DateTimeKind.Utc), "o", "2525-07-28T04:20:13.9881359Z" };
-            yield return new object[] { new DateTime(3022911536338429542, DateTimeKind.Unspecified), "R", "Mon, 24 Mar 9580 04:53:53 GMT" };
-            yield return new object[] { new DateTime(1144652135553351618, DateTimeKind.Utc), "R", "Tue, 04 Apr 3628 20:39:15 GMT" };
-            yield return new object[] { new DateTime(2570858096011770291, DateTimeKind.Unspecified), "o", "8147-09-23T04:53:21.1770291" };
-            yield return new object[] { new DateTime(15695724649124585, DateTimeKind.Unspecified), "R", "Tue, 27 Sep 0050 08:21:04 GMT" };
-            yield return new object[] { new DateTime(1503933934291527034, DateTimeKind.Unspecified), "O", "4766-10-12T06:37:09.1527034" };
-            yield return new object[] { new DateTime(2688603665097410101, DateTimeKind.Unspecified), "r", "Tue, 05 Nov 8520 19:08:29 GMT" };
-            yield return new object[] { new DateTime(1310336900529542610, DateTimeKind.Unspecified), "r", "Tue, 17 Apr 4153 15:14:12 GMT" };
-            yield return new object[] { new DateTime(2313720085584182693, DateTimeKind.Unspecified), "O", "7332-11-20T18:22:38.4182693" };
-            yield return new object[] { new DateTime(2291958603891779335, DateTimeKind.Unspecified), "o", "7263-12-05T20:46:29.1779335" };
-            yield return new object[] { new DateTime(262036413643976979, DateTimeKind.Unspecified), "o", "0831-05-12T21:16:04.3976979" };
-            yield return new object[] { new DateTime(684781207384421044, DateTimeKind.Utc), "O", "2170-12-26T20:12:18.4421044Z" };
-            yield return new object[] { new DateTime(1444462249169683325, DateTimeKind.Utc), "r", "Mon, 27 Apr 4578 07:21:56 GMT" };
-            yield return new object[] { new DateTime(1155518137384061537, DateTimeKind.Unspecified), "r", "Sun, 10 Sep 3662 06:02:18 GMT" };
-            yield return new object[] { new DateTime(2333390479532380569, DateTimeKind.Unspecified), "O", "7395-03-22T10:12:33.2380569" };
-            yield return new object[] { new DateTime(2217528014591554502, DateTimeKind.Unspecified), "R", "Sat, 26 Jan 7028 08:24:19 GMT" };
-            yield return new object[] { new DateTime(2764551324904480205, DateTimeKind.Utc), "O", "8761-07-08T04:21:30.4480205Z" };
-            yield return new object[] { new DateTime(2880903932678729712, DateTimeKind.Utc), "O", "9130-03-23T13:14:27.8729712Z" };
-            yield return new object[] { new DateTime(507699902578704433, DateTimeKind.Utc), "O", "1609-11-02T15:04:17.8704433Z" };
-            yield return new object[] { new DateTime(2429953022324426129, DateTimeKind.Utc), "O", "7701-03-20T15:03:52.4426129Z" };
-            yield return new object[] { new DateTime(603147512164908366, DateTimeKind.Unspecified), "O", "1912-04-20T09:33:36.4908366" };
-            yield return new object[] { new DateTime(2900400428644841236, DateTimeKind.Utc), "R", "Thu, 02 Jan 9192 22:34:24 GMT" };
-            yield return new object[] { new DateTime(1710845568474490805, DateTimeKind.Utc), "O", "5422-06-16T08:00:47.4490805Z" };
-            yield return new object[] { new DateTime(2988999715803714268, DateTimeKind.Utc), "r", "Sun, 06 Oct 9472 09:53:00 GMT" };
-            yield return new object[] { new DateTime(1068133489112689365, DateTimeKind.Utc), "r", "Wed, 12 Oct 3385 14:41:51 GMT" };
-            yield return new object[] { new DateTime(798784044525059284, DateTimeKind.Unspecified), "R", "Mon, 31 Mar 2532 13:40:52 GMT" };
-            yield return new object[] { new DateTime(2561736813034040593, DateTimeKind.Utc), "O", "8118-10-28T03:55:03.4040593Z" };
-            yield return new object[] { new DateTime(1677975383149674547, DateTimeKind.Utc), "o", "5318-04-18T03:18:34.9674547Z" };
-            yield return new object[] { new DateTime(1101778442151366156, DateTimeKind.Utc), "O", "3492-05-25T12:43:35.1366156Z" };
-            yield return new object[] { new DateTime(221550163152616218, DateTimeKind.Utc), "r", "Sun, 25 Jan 0703 19:11:55 GMT" };
+            yield return new object[] { new DateTime(2688006240964947440, DateTimeKind.Utc), "O", null, "8518-12-15T08:01:36.4947440Z" };
+            yield return new object[] { new DateTime(2461197105169450509, DateTimeKind.Utc), "r", null, "Sun, 23 Mar 7800 18:15:16 GMT" };
+            yield return new object[] { new DateTime(71363981510699949, DateTimeKind.Unspecified), "R", null, "Fri, 23 Feb 0227 04:49:11 GMT" };
+            yield return new object[] { new DateTime(1678426538898407093, DateTimeKind.Unspecified), "R", null, "Fri, 22 Sep 5319 07:24:49 GMT" };
+            yield return new object[] { new DateTime(2689041307785948711, DateTimeKind.Utc), "o", null, "8522-03-27T07:52:58.5948711Z" };
+            yield return new object[] { new DateTime(996610247053299209, DateTimeKind.Unspecified), "r", null, "Thu, 19 Feb 3159 01:58:25 GMT" };
+            yield return new object[] { new DateTime(3105391438361510074, DateTimeKind.Unspecified), "R", null, "Fri, 06 Aug 9841 01:17:16 GMT" };
+            yield return new object[] { new DateTime(946433487657072106, DateTimeKind.Utc), "R", null, "Mon, 17 Feb 3000 03:06:05 GMT" };
+            yield return new object[] { new DateTime(2521748413631767931, DateTimeKind.Unspecified), "R", null, "Sat, 08 Feb 7992 07:02:43 GMT" };
+            yield return new object[] { new DateTime(49349519375012969, DateTimeKind.Utc), "R", null, "Fri, 20 May 0157 11:58:57 GMT" };
+            yield return new object[] { new DateTime(796677276139881359, DateTimeKind.Utc), "o", null, "2525-07-28T04:20:13.9881359Z" };
+            yield return new object[] { new DateTime(3022911536338429542, DateTimeKind.Unspecified), "R", null, "Mon, 24 Mar 9580 04:53:53 GMT" };
+            yield return new object[] { new DateTime(1144652135553351618, DateTimeKind.Utc), "R", null, "Tue, 04 Apr 3628 20:39:15 GMT" };
+            yield return new object[] { new DateTime(2570858096011770291, DateTimeKind.Unspecified), "o", null, "8147-09-23T04:53:21.1770291" };
+            yield return new object[] { new DateTime(15695724649124585, DateTimeKind.Unspecified), "R", null, "Tue, 27 Sep 0050 08:21:04 GMT" };
+            yield return new object[] { new DateTime(1503933934291527034, DateTimeKind.Unspecified), "O", null, "4766-10-12T06:37:09.1527034" };
+            yield return new object[] { new DateTime(2688603665097410101, DateTimeKind.Unspecified), "r", null, "Tue, 05 Nov 8520 19:08:29 GMT" };
+            yield return new object[] { new DateTime(1310336900529542610, DateTimeKind.Unspecified), "r", null, "Tue, 17 Apr 4153 15:14:12 GMT" };
+            yield return new object[] { new DateTime(2313720085584182693, DateTimeKind.Unspecified), "O", null, "7332-11-20T18:22:38.4182693" };
+            yield return new object[] { new DateTime(2291958603891779335, DateTimeKind.Unspecified), "o", null, "7263-12-05T20:46:29.1779335" };
+            yield return new object[] { new DateTime(262036413643976979, DateTimeKind.Unspecified), "o", null, "0831-05-12T21:16:04.3976979" };
+            yield return new object[] { new DateTime(684781207384421044, DateTimeKind.Utc), "O", null, "2170-12-26T20:12:18.4421044Z" };
+            yield return new object[] { new DateTime(1444462249169683325, DateTimeKind.Utc), "r", null, "Mon, 27 Apr 4578 07:21:56 GMT" };
+            yield return new object[] { new DateTime(1155518137384061537, DateTimeKind.Unspecified), "r", null, "Sun, 10 Sep 3662 06:02:18 GMT" };
+            yield return new object[] { new DateTime(2333390479532380569, DateTimeKind.Unspecified), "O", null, "7395-03-22T10:12:33.2380569" };
+            yield return new object[] { new DateTime(2217528014591554502, DateTimeKind.Unspecified), "R", null, "Sat, 26 Jan 7028 08:24:19 GMT" };
+            yield return new object[] { new DateTime(2764551324904480205, DateTimeKind.Utc), "O", null, "8761-07-08T04:21:30.4480205Z" };
+            yield return new object[] { new DateTime(2880903932678729712, DateTimeKind.Utc), "O", null, "9130-03-23T13:14:27.8729712Z" };
+            yield return new object[] { new DateTime(507699902578704433, DateTimeKind.Utc), "O", null, "1609-11-02T15:04:17.8704433Z" };
+            yield return new object[] { new DateTime(2429953022324426129, DateTimeKind.Utc), "O", null, "7701-03-20T15:03:52.4426129Z" };
+            yield return new object[] { new DateTime(603147512164908366, DateTimeKind.Unspecified), "O", null, "1912-04-20T09:33:36.4908366" };
+            yield return new object[] { new DateTime(2900400428644841236, DateTimeKind.Utc), "R", null, "Thu, 02 Jan 9192 22:34:24 GMT" };
+            yield return new object[] { new DateTime(1710845568474490805, DateTimeKind.Utc), "O", null, "5422-06-16T08:00:47.4490805Z" };
+            yield return new object[] { new DateTime(2988999715803714268, DateTimeKind.Utc), "r", null, "Sun, 06 Oct 9472 09:53:00 GMT" };
+            yield return new object[] { new DateTime(1068133489112689365, DateTimeKind.Utc), "r", null, "Wed, 12 Oct 3385 14:41:51 GMT" };
+            yield return new object[] { new DateTime(798784044525059284, DateTimeKind.Unspecified), "R", null, "Mon, 31 Mar 2532 13:40:52 GMT" };
+            yield return new object[] { new DateTime(2561736813034040593, DateTimeKind.Utc), "O", null, "8118-10-28T03:55:03.4040593Z" };
+            yield return new object[] { new DateTime(1677975383149674547, DateTimeKind.Utc), "o", null, "5318-04-18T03:18:34.9674547Z" };
+            yield return new object[] { new DateTime(1101778442151366156, DateTimeKind.Utc), "O", null, "3492-05-25T12:43:35.1366156Z" };
+            yield return new object[] { new DateTime(221550163152616218, DateTimeKind.Utc), "r", null, "Sun, 25 Jan 0703 19:11:55 GMT" };
+
+            // Year patterns
+
+            var enUS = new CultureInfo("en-US");
+            var thTH = new CultureInfo("th-TH");
+            yield return new object[] { new DateTime(1234, 5, 6), "yy", enUS, "34" };
+            yield return new object[] { DateTime.MaxValue, "yy", thTH, "42" };
+            for (int i = 3; i < 20; i++)
+            {
+                yield return new object[] { new DateTime(1234, 5, 6), new string('y', i), enUS, 1234.ToString("D" + i) };
+                yield return new object[] { DateTime.MaxValue, new string('y', i), thTH, 10542.ToString("D" + i) };
+            }
         }
 
         [Theory]
         [MemberData(nameof(ToString_MatchesExpected_MemberData))]
-        public void ToString_Invoke_ReturnsExpected(DateTime dateTime, string format, string expected)
+        public void ToString_Invoke_ReturnsExpected(DateTime dateTime, string format, IFormatProvider provider, string expected)
         {
-            Assert.Equal(expected, dateTime.ToString(format));
+            if (provider == null)
+            {
+                Assert.Equal(expected, dateTime.ToString(format));
+            }
+
+            Assert.Equal(expected, dateTime.ToString(format, provider));
         }
 
         [Fact]

diff --git a/src/libraries/System.Runtime/tests/System/DateTimeTests.netcoreapp.cs b/src/libraries/System.Runtime/tests/System/DateTimeTests.netcoreapp.cs
index 225497d..13eee84 100644 (file)
--- a/src/libraries/System.Runtime/tests/System/DateTimeTests.netcoreapp.cs
+++ b/src/libraries/System.Runtime/tests/System/DateTimeTests.netcoreapp.cs
@@ -37,13 +37,13 @@ namespace System.Tests
 
         [Theory]
         [MemberData(nameof(ToString_MatchesExpected_MemberData))]
-        public static void TryFormat_MatchesExpected(DateTime dateTime, string format, string expected)
+        public static void TryFormat_MatchesExpected(DateTime dateTime, string format, IFormatProvider provider, string expected)
         {
             var destination = new char[expected.Length];
 
-            Assert.False(dateTime.TryFormat(destination.AsSpan(0, destination.Length - 1), out _, format));
+            Assert.False(dateTime.TryFormat(destination.AsSpan(0, destination.Length - 1), out _, format, provider));
 
-            Assert.True(dateTime.TryFormat(destination, out int charsWritten, format));
+            Assert.True(dateTime.TryFormat(destination, out int charsWritten, format, provider));
             Assert.Equal(destination.Length, charsWritten);
             Assert.Equal(expected, new string(destination));
         }