fix stack overflow in WriteAllBytesAsync

Author: SimonCropp

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;NETSDK1138;NU1901;NU1902;NU1903;CA1822;CA1847;CA1861;NU1510;NU1608;NU1109</NoWarn>
-    <Version>9.3.0</Version>
+    <Version>9.3.1</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>Polyfill</PackageTags>
     <DisableImplicitNamespaceImports>true</DisableImplicitNamespaceImports>

src/Polyfill/FilePolyfill.cs

@@ -89,8 +89,11 @@ public static void AppendAllBytes(string path, ReadOnlySpan<byte> bytes)
         /// Asynchronously creates a new file, writes the specified byte array to the file, and then closes the file. If the target file already exists, it is truncated and overwritten.
         /// </summary>
         //Link: https://learn.microsoft.com/en-us/dotnet/api/system.io.file.appendallbytesasync?view=net-10.0#system-io-file-appendallbytesasync(system-string-system-readonlymemory((system-byte))-system-threading-cancellationtoken)
-        public static Task WriteAllBytesAsync(string path, ReadOnlyMemory<byte> bytes, CancellationToken cancellationToken = default) =>
-            WriteAllBytesAsync(path, bytes.ToArray(), cancellationToken);
+        public static async Task WriteAllBytesAsync(string path, ReadOnlyMemory<byte> bytes, CancellationToken cancellationToken = default)
+        {
+            using var stream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None, bufferSize: 4096, useAsync: true);
+            await stream.WriteAsync(bytes.ToArray(), 0, bytes.Length, cancellationToken);
+        }
 
         /// <summary>
         /// Creates a new file, writes the specified string to the file, and then closes the file.

src/Tests/FilePolyfillTests.cs

@@ -148,6 +148,17 @@ public async Task WriteAllBytesAsync()
         var result = await File.ReadAllBytesAsync(TestFilePath);
         Assert.AreEqual(data, result);
     }
+
+    [Test]
+    public async Task WriteAllBytesAsyncMemory()
+    {
+        ReadOnlyMemory<byte> data = "Hello, Write Bytes!"u8.ToArray();
+        await File.WriteAllBytesAsync(TestFilePath, data);
+
+        var result = await File.ReadAllTextAsync(TestFilePath);
+        Assert.AreEqual("Hello, Write Bytes!", result);
+    }
+
 #endif
 
     [Test]