Add net6/net8 multitargeting with polyfills

src/Ramstack.FileProviders.Extensions/FileInfoExtensions.cs

@@ -153,38 +153,11 @@ public static ValueTask<string> ReadAllTextAsync(this IFileInfo file, Cancellati
     /// </returns>
     public static async ValueTask<string> ReadAllTextAsync(this IFileInfo file, Encoding? encoding, CancellationToken cancellationToken = default)
     {
-        const int BufferSize = 4096;
-
-        var stream = file.OpenRead();
-        var reader = new StreamReader(stream, encoding ??= Encoding.UTF8);
-        var buffer = (char[]?)null;
-
-        try
-        {
-            cancellationToken.ThrowIfCancellationRequested();
-
-            buffer = ArrayPool<char>.Shared.Rent(encoding.GetMaxCharCount(BufferSize));
-            var sb = new StringBuilder();
-
-            while (true)
-            {
-                var count = await reader
-                    .ReadAsync(new Memory<char>(buffer), cancellationToken)
-                    .ConfigureAwait(false);
-
-                if (count == 0)
-                    return sb.ToString();
-
-                sb.Append(buffer.AsSpan(0, count));
-            }
-        }
-        finally
-        {
-            reader.Dispose();
+        // ReSharper disable once UseAwaitUsing
+        using var stream = file.OpenRead();
+        using var reader = new StreamReader(stream, encoding!);
 
-            if (buffer is not null)
-                ArrayPool<char>.Shared.Return(buffer);
-        }
+        return await reader.ReadToEndAsync(cancellationToken).ConfigureAwait(false);
     }
 
     /// <summary>
@@ -211,15 +184,13 @@ public static ValueTask<string[]> ReadAllLinesAsync(this IFileInfo file, Cancell
     /// </returns>
     public static async ValueTask<string[]> ReadAllLinesAsync(this IFileInfo file, Encoding? encoding, CancellationToken cancellationToken = default)
     {
-        var stream = file.OpenRead();
+        // ReSharper disable once UseAwaitUsing
+        using var stream = file.OpenRead();
         using var reader = new StreamReader(stream, encoding!);
 
         var list = new List<string>();
-        while (await reader.ReadLineAsync().ConfigureAwait(false) is { } line)
-        {
-            cancellationToken.ThrowIfCancellationRequested();
+        while (await reader.ReadLineAsync(cancellationToken).ConfigureAwait(false) is { } line)
             list.Add(line);
-        }
 
         return list.ToArray();
     }

src/Ramstack.FileProviders.Extensions/Internal/StreamReaderExtensions.cs

@@ -0,0 +1,62 @@
+#if NET6_0
+using System.Buffers;
+using System.Text;
+
+// ReSharper disable once CheckNamespace
+namespace System.IO;
+/// <summary>
+/// Provides extension methods for the <see cref="StreamReader"/> to offer API compatibility with newer .NET versions.
+/// </summary>
+internal static class StreamReaderExtensions
+{
+    /// <summary>
+    /// Reads a line of characters asynchronously from the current stream and returns the data as a string.
+    /// </summary>
+    /// <param name="reader">The <see cref="StreamReader"/> to read from.</param>
+    /// <param name="cancellationToken">An optional cancellation token to cancel the operation.</param>
+    /// <returns>
+    /// A <see cref="ValueTask{TResult}"/> that represents the asynchronous read operation.
+    /// The value of the task contains the next line from the stream, or is <see langword="null"/>
+    /// if the end of the stream is reached.
+    /// </returns>
+    public static ValueTask<string?> ReadLineAsync(this StreamReader reader, CancellationToken cancellationToken = default)
+    {
+        if (cancellationToken.IsCancellationRequested)
+            return ValueTask.FromCanceled<string?>(cancellationToken);
+
+        return new ValueTask<string?>(reader.ReadLineAsync());
+    }
+
+    /// <summary>
+    /// Reads all characters from the current position to the end of the stream asynchronously and returns them as one string.
+    /// </summary>
+    /// <param name="reader">The <see cref="StreamReader"/> to read from.</param>
+    /// <param name="cancellationToken">An optional cancellation token to cancel the operation.</param>
+    /// <returns>
+    /// A <see cref="Task{TResult}"/> that represents the asynchronous read operation.
+    /// The value of the task contains a string with the characters from the current position to the end of the stream.
+    /// </returns>
+    public static async Task<string> ReadToEndAsync(this StreamReader reader, CancellationToken cancellationToken = default)
+    {
+        const int BufferSize = 4096;
+
+        var chars = ArrayPool<char>.Shared.Rent(BufferSize);
+        var sb = new StringBuilder();
+
+        while (true)
+        {
+            var count = await reader
+                .ReadAsync(new Memory<char>(chars), cancellationToken)
+                .ConfigureAwait(false);
+
+            if (count == 0)
+                break;
+
+            sb.Append(chars.AsSpan(0, count));
+        }
+
+        ArrayPool<char>.Shared.Return(chars);
+        return sb.ToString();
+    }
+}
+#endif

src/Ramstack.FileProviders.Extensions/Ramstack.FileProviders.Extensions.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
     <Description>A lightweight .NET library of useful and convenient extensions for IFileProvider.</Description>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
@@ -36,8 +36,15 @@
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
     <PackageReference Include="Microsoft.Extensions.FileProviders.Abstractions" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+    <PackageReference Include="Microsoft.Extensions.FileProviders.Abstractions" VersionOverride="8.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
@@ -63,7 +70,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Update="README.md">
+    <None Include="README.md">
       <Link>Properties\README.md</Link>
       <Pack>True</Pack>
       <PackagePath>\</PackagePath>

tests/Ramstack.FileProviders.Extensions.Tests/Ramstack.FileProviders.Extensions.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>