fix: Directory.Move fails on Windows if destination has different case from source (#1256)

On Windows, `MockFileSystem.Directory.Move` no longer throws a `System.IO.IOException` when source and destination path only differ in casing.

Author: oni-shiro

src/TestableIO.System.IO.Abstractions.TestingHelpers/MockDirectory.cs

@@ -503,7 +503,7 @@ public override void Move(string sourceDirName, string destDirName)
         var fullSourcePath = mockFileDataAccessor.Path.GetFullPath(sourceDirName).TrimSlashes();
         var fullDestPath = mockFileDataAccessor.Path.GetFullPath(destDirName).TrimSlashes();
 
-        if (mockFileDataAccessor.StringOperations.Equals(fullSourcePath, fullDestPath))
+        if (string.Equals(fullSourcePath, fullDestPath, StringComparison.Ordinal))
         {
             throw new IOException("Source and destination path must be different.");
         }
@@ -537,9 +537,13 @@ public override void Move(string sourceDirName, string destDirName)
 
         if (mockFileDataAccessor.Directory.Exists(fullDestPath) || mockFileDataAccessor.File.Exists(fullDestPath))
         {
-            throw CommonExceptions.CannotCreateBecauseSameNameAlreadyExists(fullDestPath);
+            // In Windows, file/dir names are case sensetive, C:\\temp\\src and C:\\temp\\SRC and treated different
+            if (XFS.IsUnixPlatform() ||
+                !string.Equals(fullSourcePath, fullDestPath, StringComparison.OrdinalIgnoreCase))
+            {
+                throw CommonExceptions.CannotCreateBecauseSameNameAlreadyExists(fullDestPath);
+            }
         }
-
         mockFileDataAccessor.MoveDirectory(fullSourcePath, fullDestPath);
     }
 
@@ -653,15 +657,15 @@ public override IEnumerable<string> EnumerateDirectories(string path, string sea
             .Where(p => !mockFileDataAccessor.StringOperations.Equals(p, path))
             .Select(p => FixPrefix(p, originalPath));
     }
-        
+
     private string FixPrefix(string path, string originalPath)
     {
         var normalizedOriginalPath = mockFileDataAccessor.Path.GetFullPath(originalPath);
         var pathWithoutOriginalPath = path.Substring(normalizedOriginalPath.Length)
             .TrimStart(mockFileDataAccessor.Path.DirectorySeparatorChar);
         return mockFileDataAccessor.Path.Combine(originalPath, pathWithoutOriginalPath);
     }
-        
+
 #if FEATURE_ENUMERATION_OPTIONS
         /// <inheritdoc />
         public override IEnumerable<string> EnumerateDirectories(string path, string searchPattern, EnumerationOptions enumerationOptions)

tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockDirectoryTests.cs

@@ -2204,4 +2204,19 @@ public async Task MockDirectory_Exists_ShouldReturnTrue_IfArgIsFrontSlashAndRoot
 
         await That(fileSystem.Directory.Exists("/")).IsEqualTo(true);
     }
+
+    [Test]
+    public static void MockDirectory_Move_ShouldNotThrowException_InWindows_When_SourceAndDestinationDifferOnlyInCasing()
+    {
+        // Arrange
+        MockFileSystem mockFs = new MockFileSystem();
+        string tempDir = mockFs.Path.GetTempPath();
+        string src = mockFs.Path.Combine(tempDir, "src");
+        string dest = mockFs.Path.Combine(tempDir, "SRC");
+        IDirectoryInfo srcDir = mockFs.DirectoryInfo.New(src);
+        srcDir.Create();
+        
+        // Act & Assert
+        Assert.DoesNotThrow(() => mockFs.Directory.Move(src, dest));
+    }
 }