fix: set last access time with unspecified date time kind

src/System.IO.Abstractions.TestingHelpers/MockFileInfo.cs

@@ -1,6 +1,5 @@
 using System.Runtime.Versioning;
 using System.Security.AccessControl;
-using System.Text;
 
 namespace System.IO.Abstractions.TestingHelpers
 {
@@ -65,7 +64,7 @@ public override DateTime CreationTime
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.CreationTime = value;
+                mockFileData.CreationTime = AdjustUnspecifiedKind(value, DateTimeKind.Local);
             }
         }
 
@@ -80,7 +79,7 @@ public override DateTime CreationTimeUtc
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.CreationTime = value.ToLocalTime();
+                mockFileData.CreationTime = AdjustUnspecifiedKind(value, DateTimeKind.Utc);
             }
         }
 
@@ -122,7 +121,7 @@ public override DateTime LastAccessTime
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.LastAccessTime = value;
+                mockFileData.LastAccessTime = AdjustUnspecifiedKind(value, DateTimeKind.Local);
             }
         }
 
@@ -137,7 +136,7 @@ public override DateTime LastAccessTimeUtc
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.LastAccessTime = value;
+                mockFileData.LastAccessTime = AdjustUnspecifiedKind(value, DateTimeKind.Utc);
             }
         }
 
@@ -152,7 +151,7 @@ public override DateTime LastWriteTime
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.LastWriteTime = value;
+                mockFileData.LastWriteTime = AdjustUnspecifiedKind(value, DateTimeKind.Local);
             }
         }
 
@@ -167,7 +166,7 @@ public override DateTime LastWriteTimeUtc
             set
             {
                 var mockFileData = GetMockFileDataForWrite();
-                mockFileData.LastWriteTime = value.ToLocalTime();
+                mockFileData.LastWriteTime = AdjustUnspecifiedKind(value, DateTimeKind.Utc);
             }
         }
 
@@ -381,6 +380,16 @@ public override string ToString()
             return originalPath;
         }
 
+        private static DateTime AdjustUnspecifiedKind(DateTime time, DateTimeKind fallbackKind)
+        {
+            if (time.Kind == DateTimeKind.Unspecified)
+            {
+                return DateTime.SpecifyKind(time, fallbackKind);
+            }
+
+            return time;
+        }
+
         private MockFileData GetMockFileDataForRead()
         {
             if (refreshOnNextRead)

tests/System.IO.Abstractions.TestingHelpers.Tests/MockFileInfoTests.cs

@@ -392,6 +392,57 @@ public void MockFileInfo_LastAccessTimeUtc_ShouldSetCreationTimeUtcOfFileInMemor
             Assert.AreEqual(newUtcTime, fileInfo.LastAccessTimeUtc);
         }
 
+        [Test]
+        public void MockFileInfo_CreationTimeUtcWithUnspecifiedDateTimeKind_ShouldSetCreationTimeUtcOfFileInMemoryFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileData = new MockFileData("Demo text content");
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                { MockUnixSupport.Path(@"c:\a.txt"), fileData }
+            });
+            var fileInfo = new MockFileInfo(fileSystem, MockUnixSupport.Path(@"c:\a.txt"))
+            {
+                CreationTimeUtc = date,
+            };
+
+            Assert.AreEqual(date, fileInfo.CreationTimeUtc);
+        }
+
+        [Test]
+        public void MockFileInfo_LastAccessTimeUtcWithUnspecifiedDateTimeKind_ShouldSetLastAccessTimeUtcOfFileInMemoryFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileData = new MockFileData("Demo text content");
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                { MockUnixSupport.Path(@"c:\a.txt"), fileData }
+            });
+            var fileInfo = new MockFileInfo(fileSystem, MockUnixSupport.Path(@"c:\a.txt"))
+            {
+                LastAccessTimeUtc = date
+            };
+
+            Assert.AreEqual(date, fileInfo.LastAccessTimeUtc);
+        }
+
+        [Test]
+        public void MockFileInfo_LastWriteTimeUtcWithUnspecifiedDateTimeKind_ShouldSetLastWriteTimeUtcOfFileInMemoryFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileData = new MockFileData("Demo text content");
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                { MockUnixSupport.Path(@"c:\a.txt"), fileData }
+            });
+            var fileInfo = new MockFileInfo(fileSystem, MockUnixSupport.Path(@"c:\a.txt"))
+            {
+                LastWriteTimeUtc = date,
+            };
+
+            Assert.AreEqual(date, fileInfo.LastWriteTimeUtc);
+        }
+
         [Test]
         public void MockFileInfo_LastWriteTime_ShouldReturnDefaultTimeForNonExistingFile()
         {
@@ -879,5 +930,101 @@ public void MockFileInfo_Delete_ShouldThrowIfFileAccessShareHasNoWriteOrDeleteAc
 
             Assert.Throws(typeof(System.IO.IOException), () => fi.Delete());
         }
+
+        [Test]
+        public void MockFileInfo_LastAccessTimeUtcWithUnspecifiedDateTimeKind_ShouldSetLastAccessTimeUtcOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                LastAccessTimeUtc = date
+            };
+
+            Assert.AreEqual(date, fileInfo.LastAccessTimeUtc);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.LastAccessTimeUtc);
+        }
+
+        [Test]
+        public void MockFileInfo_LastAccessTimeWithUnspecifiedDateTimeKind_ShouldSetLastAccessTimeOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                LastAccessTime = date
+            };
+
+            Assert.AreEqual(date, fileInfo.LastAccessTime);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.LastAccessTime);
+        }
+
+        [Test]
+        public void MockFileInfo_CreationTimeUtcWithUnspecifiedDateTimeKind_ShouldSetCreationTimeUtcOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                CreationTimeUtc = date
+            };
+
+            Assert.AreEqual(date, fileInfo.CreationTimeUtc);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.CreationTimeUtc);
+        }
+
+        [Test]
+        public void MockFileInfo_CreationTimeWithUnspecifiedDateTimeKind_ShouldSetCreationTimeOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                CreationTime = date
+            };
+
+            Assert.AreEqual(date, fileInfo.CreationTime);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.CreationTime);
+        }
+
+        [Test]
+        public void MockFileInfo_LastWriteTimeUtcWithUnspecifiedDateTimeKind_ShouldSetLastWriteTimeUtcOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                LastWriteTimeUtc = date
+            };
+
+            Assert.AreEqual(date, fileInfo.LastWriteTimeUtc);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.LastWriteTimeUtc);
+        }
+
+        [Test]
+        public void MockFileInfo_LastWriteTimeWithUnspecifiedDateTimeKind_ShouldSetLastWriteTimeOfFileInFileSystem()
+        {
+            var date = DateTime.SpecifyKind(DateTime.Now.AddHours(-4), DateTimeKind.Unspecified);
+            var fileSystem = new MockFileSystem();
+            fileSystem.Directory.CreateDirectory(@"c:\test");
+            fileSystem.File.WriteAllText(@"c:\test\a.txt", "Demo text content");
+            var fileInfo = new MockFileInfo(fileSystem, @"c:\test\a.txt")
+            {
+                LastWriteTime = date
+            };
+
+            Assert.AreEqual(date, fileInfo.LastWriteTime);
+            Assert.AreNotEqual(DateTimeKind.Unspecified, fileInfo.LastWriteTime);
+        }
     }
 }