MilliSecond Granualrity added to Copy operation on unix (#30996)

* test added

* Test Modified

* Adding Implementation

* tabs removed

* modifyingTest

* Fixing build on HFS

* Space around arithemetic operator

1 files changed, 51 insertions, 0 deletions

diff --git a/src/System.IO.FileSystem/tests/FileInfo/GetSetTimes.cs b/src/System.IO.FileSystem/tests/FileInfo/GetSetTimes.cs
index 60bffcfad2..a09ee642d0 100644
--- a/src/System.IO.FileSystem/tests/FileInfo/GetSetTimes.cs
+++ b/src/System.IO.FileSystem/tests/FileInfo/GetSetTimes.cs
@@ -105,6 +105,57 @@ namespace System.IO.Tests
         }
 
         [Fact]
+        public void CopyToMillisecondPresent()
+        {
+            FileInfo input = new FileInfo(Path.Combine(TestDirectory, GetTestFileName()));
+            input.Create().Dispose();
+
+            string driveFormat = new DriveInfo(input.DirectoryName).DriveFormat;
+            if (!driveFormat.Equals(HFS, StringComparison.InvariantCultureIgnoreCase))
+            {
+                for (int i = 0; i < 5; i++)
+                {
+                    if (input.LastWriteTime.Millisecond != 0)
+                        break;
+
+                    // This case should only happen 1/1000 times, unless the OS/Filesystem does
+                    // not support millisecond granularity.
+
+                    // If it's 1/1000, or low granularity, this may help:
+                    Thread.Sleep(1234);
+                    input = new FileInfo(Path.Combine(TestDirectory, GetTestFileName()));
+                    input.Create().Dispose();
+                }
+
+                FileInfo output = new FileInfo(Path.Combine(TestDirectory, GetTestFileName(), input.Name));
+                Assert.Equal(0, output.LastWriteTime.Millisecond);
+                output.Directory.Create();
+                output = input.CopyTo(output.FullName, true);
+
+                Assert.NotEqual(0, input.LastWriteTime.Millisecond);
+                Assert.NotEqual(0, output.LastWriteTime.Millisecond);
+            }
+        }
+
+        [Fact]
+        [PlatformSpecific(TestPlatforms.OSX)]
+        public void CopyToMillisecondPresent_HFS()
+        {
+            FileInfo input = new FileInfo(Path.Combine(TestDirectory, GetTestFileName()));
+            input.Create().Dispose();
+            FileInfo output = new FileInfo(Path.Combine(TestDirectory, GetTestFileName(), input.Name));
+
+            string driveFormat = new DriveInfo(input.DirectoryName).DriveFormat;
+            if (driveFormat.Equals(HFS, StringComparison.InvariantCultureIgnoreCase))
+            {             
+                output.Directory.Create();
+                output = input.CopyTo(output.FullName, true);
+                Assert.Equal(0, input.LastWriteTime.Millisecond);
+                Assert.Equal(0, output.LastWriteTime.Millisecond);
+            }
+        }
+
+        [Fact]
         public void DeleteAfterEnumerate_TimesStillSet()
         {
             // When enumerating we populate the state as we already have it.