Add polyfill for File.Move(..., overwrite)

PolyShim.Tests/NetCore30/FileTests.cs

@@ -0,0 +1,71 @@
+using System.IO;
+using FluentAssertions;
+using Xunit;
+
+namespace PolyShim.Tests.NetCore30;
+
+public class FileTests
+{
+    [Fact]
+    public void Move_Overwrite_TargetDoesNotExist_Test()
+    {
+        // Arrange
+        var sourceFileName = Path.GetTempFileName();
+        var destFileName = Path.GetTempFileName();
+
+        try
+        {
+            // Path.GetTempFileName() pre-creates the file, so delete it to simulate non-existence
+            File.Delete(destFileName);
+
+            // Act
+            File.Move(sourceFileName, destFileName, true);
+
+            // Assert
+            File.Exists(sourceFileName).Should().BeFalse();
+            File.Exists(destFileName).Should().BeTrue();
+        }
+        finally
+        {
+            try
+            {
+                File.Delete(sourceFileName);
+                File.Delete(destFileName);
+            }
+            catch
+            {
+                // Ignore
+            }
+        }
+    }
+
+    [Fact]
+    public void Move_Overwrite_TargetExists_Test()
+    {
+        // Arrange
+        var sourceFileName = Path.GetTempFileName();
+        var destFileName = Path.GetTempFileName();
+
+        try
+        {
+            // Act
+            File.Move(sourceFileName, destFileName, true);
+
+            // Assert
+            File.Exists(sourceFileName).Should().BeFalse();
+            File.Exists(destFileName).Should().BeTrue();
+        }
+        finally
+        {
+            try
+            {
+                File.Delete(sourceFileName);
+                File.Delete(destFileName);
+            }
+            catch
+            {
+                // Ignore
+            }
+        }
+    }
+}

PolyShim/NetCore30/File.cs

@@ -0,0 +1,28 @@
+// The following comment is required to instruct analyzers to skip this file
+// <auto-generated/>
+
+#if (NETCOREAPP && !NETCOREAPP3_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+// ReSharper disable RedundantUsingDirective
+// ReSharper disable CheckNamespace
+// ReSharper disable InconsistentNaming
+// ReSharper disable PartialTypeWithSinglePart
+
+using System.IO;
+
+internal static partial class PolyfillExtensions
+{
+// No file I/O on .NET Standard prior to 1.3
+#if !NETSTANDARD || NETSTANDARD1_3_OR_GREATER
+    extension(File)
+    {
+        // https://learn.microsoft.com/dotnet/api/system.io.file.move#system-io-file-move(system-string-system-string-system-boolean)
+        public static void Move(string sourceFileName, string destFileName, bool overwrite)
+        {
+            File.Copy(sourceFileName, destFileName, overwrite);
+            File.Delete(sourceFileName);
+        }
+    }
+#endif
+}
+#endif