Polyfill File.GetUnixFileMode, File.SetUnixFileMode, and Directory.CreateDirectory(path, UnixFileMode)

PolyShim.Tests/Net60/FileTests.cs

@@ -0,0 +1,128 @@
+using System;
+using System.IO;
+using System.Runtime.Versioning;
+using FluentAssertions;
+using PolyShim.Tests.Utils.Extensions;
+using Xunit;
+
+namespace PolyShim.Tests.Net60;
+
+public class FileTests
+{
+    [Fact]
+    public void Open_Test()
+    {
+        // Arrange
+        var tempFilePath = Path.GetTempFileName();
+        File.WriteAllBytes(tempFilePath, [0x00, 0x01, 0x02]);
+
+        try
+        {
+            var options = new FileStreamOptions();
+
+            // Act
+            using var stream = File.Open(tempFilePath, options);
+
+            // Assert
+            stream.CanRead.Should().BeTrue();
+            stream.Length.Should().Be(3);
+        }
+        finally
+        {
+            File.TryDelete(tempFilePath);
+        }
+    }
+
+    [Fact]
+    public void Open_Write_Test()
+    {
+        // Arrange
+        var tempFilePath = Path.GetTempFileName();
+
+        try
+        {
+            var options = new FileStreamOptions
+            {
+                Mode = FileMode.Create,
+                Access = FileAccess.Write,
+                Share = FileShare.None,
+            };
+
+            // Act
+            using var stream = File.Open(tempFilePath, options);
+            stream.Write([0x0A, 0x0B, 0x0C], 0, 3);
+
+            // Assert
+            stream.CanWrite.Should().BeTrue();
+            stream.Position.Should().Be(3);
+        }
+        finally
+        {
+            File.TryDelete(tempFilePath);
+        }
+    }
+
+    [Fact]
+    public void Open_ReadWrite_Test()
+    {
+        // Arrange
+        var tempFilePath = Path.GetTempFileName();
+        File.WriteAllBytes(tempFilePath, [0x00, 0x01, 0x02]);
+
+        try
+        {
+            var options = new FileStreamOptions
+            {
+                Mode = FileMode.Open,
+                Access = FileAccess.ReadWrite,
+                Share = FileShare.None,
+            };
+
+            // Act
+            using var stream = File.Open(tempFilePath, options);
+
+            // Assert
+            stream.CanRead.Should().BeTrue();
+            stream.CanWrite.Should().BeTrue();
+        }
+        finally
+        {
+            File.TryDelete(tempFilePath);
+        }
+    }
+
+    [SkippableFact]
+    [UnsupportedOSPlatform("windows")]
+    public void Open_UnixFileMode_Test()
+    {
+        Skip.If(OperatingSystem.IsWindows());
+
+        // Arrange
+        var tempFilePath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+
+        try
+        {
+            var expectedMode = UnixFileMode.UserRead | UnixFileMode.UserWrite;
+
+            var options = new FileStreamOptions
+            {
+                Mode = FileMode.Create,
+                Access = FileAccess.Write,
+                Share = FileShare.None,
+                UnixCreateMode = expectedMode,
+            };
+
+            // Act
+            using (var stream = File.Open(tempFilePath, options))
+                stream.Write([0x0A, 0x0B], 0, 2);
+
+            // Assert
+            var actualMode = File.GetUnixFileMode(tempFilePath);
+            actualMode.Should().Be(expectedMode);
+        }
+        finally
+        {
+            File.TryDelete(tempFilePath);
+        }
+    }
+}

PolyShim.Tests/Net70/DirectoryTests.cs

@@ -0,0 +1,39 @@
+using System;
+using System.IO;
+using System.Runtime.Versioning;
+using FluentAssertions;
+using Xunit;
+
+namespace PolyShim.Tests.Net70;
+
+public class DirectoryTests
+{
+    [SkippableFact]
+    [UnsupportedOSPlatform("windows")]
+    public void CreateDirectory_UnixFileMode_Test()
+    {
+        Skip.If(OperatingSystem.IsWindows());
+
+        // Arrange
+        var tempDirPath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+
+        try
+        {
+            var expectedMode =
+                UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.UserExecute;
+
+            // Act
+            var info = Directory.CreateDirectory(tempDirPath, expectedMode);
+
+            // Assert
+            info.Should().NotBeNull();
+            info.Exists.Should().BeTrue();
+            File.GetUnixFileMode(tempDirPath).Should().Be(expectedMode);
+        }
+        finally
+        {
+            if (Directory.Exists(tempDirPath))
+                Directory.Delete(tempDirPath);
+        }
+    }
+}

PolyShim.Tests/Net70/FileTests.cs

@@ -1,5 +1,7 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.Versioning;
 using System.Threading.Tasks;
 using FluentAssertions;
 using PolyShim.Tests.Utils.Extensions;
@@ -32,4 +34,30 @@ public async Task ReadLinesAsync_Test()
             File.TryDelete(tempFilePath);
         }
     }
+
+    [SkippableFact]
+    [UnsupportedOSPlatform("windows")]
+    public void SetUnixFileMode_Test()
+    {
+        Skip.If(OperatingSystem.IsWindows());
+
+        // Arrange
+        var tempFilePath = Path.GetTempFileName();
+
+        try
+        {
+            var expectedMode = UnixFileMode.UserRead | UnixFileMode.UserWrite;
+
+            // Act
+            File.SetUnixFileMode(tempFilePath, expectedMode);
+
+            // Assert
+            var actualMode = File.GetUnixFileMode(tempFilePath);
+            actualMode.Should().Be(expectedMode);
+        }
+        finally
+        {
+            File.TryDelete(tempFilePath);
+        }
+    }
 }

PolyShim/Net60/File.cs

@@ -0,0 +1,62 @@
+#if (NETCOREAPP && !NET6_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+#pragma warning disable CS0436
+
+// No file I/O on .NET Standard prior to 1.3
+#if !NETSTANDARD || NETSTANDARD1_3_OR_GREATER
+
+using System;
+using System.IO;
+using System.Diagnostics.CodeAnalysis;
+
+#if !POLYSHIM_INCLUDE_COVERAGE
+[ExcludeFromCodeCoverage]
+#endif
+internal static class MemberPolyfills_Net60_File
+{
+    extension(File)
+    {
+        // https://learn.microsoft.com/dotnet/api/system.io.file.open#system-io-file-open(system-string-system-io-filestreamoptions)
+        public static FileStream Open(string path, FileStreamOptions options)
+        {
+            var existed = File.Exists(path);
+
+            var stream = new FileStream(
+                path,
+                options.Mode,
+                options.Access,
+                options.Share,
+                options.BufferSize,
+                options.Options
+            );
+
+            try
+            {
+#if !NETFRAMEWORK || NET40_OR_GREATER
+                if (
+                    !existed
+                    && !OperatingSystem.IsWindows()
+                    && options.UnixCreateMode is { } unixCreateMode
+                    && options.Mode
+                        is FileMode.CreateNew
+                            or FileMode.Create
+                            or FileMode.OpenOrCreate
+                            or FileMode.Append
+                )
+                {
+                    File.SetUnixFileMode(path, unixCreateMode & File.GetUnixFileMode(path));
+                }
+#endif
+            }
+            catch
+            {
+                stream.Dispose();
+                throw;
+            }
+
+            return stream;
+        }
+    }
+}
+#endif
+#endif

PolyShim/Net60/FileStreamOptions.cs

@@ -0,0 +1,41 @@
+#if (NETCOREAPP && !NET6_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+#pragma warning disable CS0436
+
+// No file I/O on .NET Standard prior to 1.3
+#if !NETSTANDARD || NETSTANDARD1_3_OR_GREATER
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.IO;
+
+// https://learn.microsoft.com/dotnet/api/system.io.filestreamoptions
+#if !POLYSHIM_INCLUDE_COVERAGE
+[ExcludeFromCodeCoverage]
+#endif
+internal class FileStreamOptions
+{
+    public FileMode Mode { get; set; } = FileMode.Open;
+
+    public FileAccess Access { get; set; } = FileAccess.Read;
+
+    public FileShare Share { get; set; } = FileShare.Read;
+
+    public int BufferSize
+    {
+        get;
+        set => field = value >= 0 ? value : throw new ArgumentOutOfRangeException(nameof(value));
+    } = 4096;
+
+    public FileOptions Options { get; set; } = FileOptions.None;
+
+    public long PreallocationSize
+    {
+        get;
+        set => field = value >= 0 ? value : throw new ArgumentOutOfRangeException(nameof(value));
+    }
+}
+
+#endif
+#endif

PolyShim/Net70/Directory.cs

@@ -0,0 +1,54 @@
+#if (NETCOREAPP && !NET7_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+#pragma warning disable CS0436
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using System.Diagnostics.CodeAnalysis;
+
+// No file I/O on .NET Standard prior to 1.3
+#if !NETSTANDARD || NETSTANDARD1_3_OR_GREATER
+
+file static class NativeMethods
+{
+    [DllImport("libc", EntryPoint = "chmod", SetLastError = true)]
+    public static extern int Chmod(string path, uint mode);
+}
+
+#if !POLYSHIM_INCLUDE_COVERAGE
+[ExcludeFromCodeCoverage]
+#endif
+internal static class MemberPolyfills_Net70_Directory
+{
+    extension(Directory)
+    {
+        // https://learn.microsoft.com/dotnet/api/system.io.directory.createdirectory#system-io-directory-createdirectory(system-string-system-io-unixfilemode)
+        [UnsupportedOSPlatform("windows")]
+        public static DirectoryInfo CreateDirectory(string path, UnixFileMode unixCreateMode)
+        {
+            if (OperatingSystem.IsWindows())
+                throw new PlatformNotSupportedException();
+
+            var existed = Directory.Exists(path);
+            var info = Directory.CreateDirectory(path);
+
+            if (!existed)
+            {
+                var effectiveMode = unixCreateMode & File.GetUnixFileMode(info.FullName);
+                if (NativeMethods.Chmod(info.FullName, (uint)effectiveMode) != 0)
+                {
+                    throw new IOException(
+                        $"Could not set Unix file mode for '{path}' (errno={Marshal.GetLastWin32Error()})."
+                    );
+                }
+            }
+
+            return info;
+        }
+    }
+}
+
+#endif
+#endif