From 3465c633cdc4db075b42a9f49a980fa3a4a9df3b Mon Sep 17 00:00:00 2001
From: Tom Longhurst <30480171+thomhurst@users.noreply.github.com>
Date: Tue, 21 Jul 2026 19:26:45 +0100
Subject: [PATCH] build!: require .NET 8 or later

Drop net6.0 and netstandard2.0 compatibility shims and packages now that v4 targets supported .NET releases.

BREAKING CHANGE: v4 no longer supports net6.0 or netstandard2.0. Consumers must target net8.0 or later.

Refs #334
---
 .../DisposalExample.cs                        |  2 --
 .../ProcessInParallelExample.cs               |  2 --
 EnumerableAsyncProcessor.Example/Program.cs   |  2 --
 .../AsyncEnumerableParallelExtensionsTests.cs |  2 --
 .../AsyncEnumerableProcessorTests.cs          |  3 --
 .../EnumerableAsyncProcessor.UnitTests.csproj |  2 +-
 .../EnumerableAsyncProcessor.csproj           | 11 +-----
 .../Abstract/AbstractAsyncProcessorBase.cs    |  4 ---
 .../ResultAbstractAsyncProcessorBase.cs       |  4 ---
 .../TaskCompletionSource.cs                   | 34 -------------------
 .../Validation/ValidationHelper.cs            | 23 +------------
 README.md                                     |  4 +++
 12 files changed, 7 insertions(+), 86 deletions(-)
 delete mode 100644 EnumerableAsyncProcessor/TaskCompletionSource.cs

diff --git a/EnumerableAsyncProcessor.Example/DisposalExample.cs b/EnumerableAsyncProcessor.Example/DisposalExample.cs
index 1484137..dd38a8e 100644
--- a/EnumerableAsyncProcessor.Example/DisposalExample.cs
+++ b/EnumerableAsyncProcessor.Example/DisposalExample.cs
@@ -1,4 +1,3 @@
-#if NET6_0_OR_GREATER
 using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
@@ -169,4 +168,3 @@ private static async IAsyncEnumerable<int> GenerateAsyncEnumerable(
         }
     }
 }
-#endif
diff --git a/EnumerableAsyncProcessor.Example/ProcessInParallelExample.cs b/EnumerableAsyncProcessor.Example/ProcessInParallelExample.cs
index 50f663f..f47457e 100644
--- a/EnumerableAsyncProcessor.Example/ProcessInParallelExample.cs
+++ b/EnumerableAsyncProcessor.Example/ProcessInParallelExample.cs
@@ -1,4 +1,3 @@
-#if NET6_0_OR_GREATER
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -111,4 +110,3 @@ private static async IAsyncEnumerable<int> GenerateAsyncEnumerable(
         }
     }
 }
-#endif
\ No newline at end of file
diff --git a/EnumerableAsyncProcessor.Example/Program.cs b/EnumerableAsyncProcessor.Example/Program.cs
index ca659c9..0b04205 100644
--- a/EnumerableAsyncProcessor.Example/Program.cs
+++ b/EnumerableAsyncProcessor.Example/Program.cs
@@ -66,7 +66,6 @@ Task<HttpResponseMessage> PingAsync()
     }
 }
 
-#if NET6_0_OR_GREATER
 // Run IAsyncEnumerable examples
 Console.WriteLine("\n\n=== Running IAsyncEnumerable Examples ===\n");
 await AsyncEnumerableExample.RunExamples();
@@ -78,4 +77,3 @@ Task<HttpResponseMessage> PingAsync()
 // Run disposal pattern examples
 Console.WriteLine("\n\n=== Running Disposal Pattern Examples ===\n");
 await DisposalExample.RunExamples();
-#endif
\ No newline at end of file
diff --git a/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableParallelExtensionsTests.cs b/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableParallelExtensionsTests.cs
index 5222179..cfa0577 100644
--- a/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableParallelExtensionsTests.cs
+++ b/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableParallelExtensionsTests.cs
@@ -1,4 +1,3 @@
-#if NET6_0_OR_GREATER
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -219,4 +218,3 @@ public async Task ProcessInParallel_PreservesExceptionFromTransformation()
         await Assert.That(exception.Message).IsEqualTo("Test exception");
     }
 }
-#endif
\ No newline at end of file
diff --git a/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableProcessorTests.cs b/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableProcessorTests.cs
index ccde121..30db4f6 100644
--- a/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableProcessorTests.cs
+++ b/EnumerableAsyncProcessor.UnitTests/AsyncEnumerableProcessorTests.cs
@@ -1,4 +1,3 @@
-#if NET6_0_OR_GREATER
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -142,7 +141,6 @@ public async Task SelectAsync_ProcessInParallel_WithHighConcurrency_HandlesCorre
         await Assert.That(results.OrderBy(x => x)).IsEquivalentTo(Enumerable.Range(1, 50).Select(x => x * 3));
     }
 
-
     [Test]
     public async Task ForEachAsync_WithCancellation_StopsProcessing()
     {
@@ -368,4 +366,3 @@ public static async Task<List<T>> ToListAsync<T>(this IAsyncEnumerable<T> source
         return list;
     }
 }
-#endif
\ No newline at end of file
diff --git a/EnumerableAsyncProcessor.UnitTests/EnumerableAsyncProcessor.UnitTests.csproj b/EnumerableAsyncProcessor.UnitTests/EnumerableAsyncProcessor.UnitTests.csproj
index 4af377b..6141aa7 100644
--- a/EnumerableAsyncProcessor.UnitTests/EnumerableAsyncProcessor.UnitTests.csproj
+++ b/EnumerableAsyncProcessor.UnitTests/EnumerableAsyncProcessor.UnitTests.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <!-- net8.0 also exercises the pre-net9 completion-order streaming path in ToIAsyncEnumerable -->
-        <TargetFrameworks>net9.0;net8.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
         <Nullable>enable</Nullable>
         <IsPackable>false</IsPackable>
         <!-- Do not warn about non-strong named dependencies, as we target .NET (not .NET Framework).
diff --git a/EnumerableAsyncProcessor/EnumerableAsyncProcessor.csproj b/EnumerableAsyncProcessor/EnumerableAsyncProcessor.csproj
index 8417bd8..e917f3e 100644
--- a/EnumerableAsyncProcessor/EnumerableAsyncProcessor.csproj
+++ b/EnumerableAsyncProcessor/EnumerableAsyncProcessor.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>net6.0;net8.0;net9.0;netstandard2.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <LangVersion>latest</LangVersion>
@@ -21,10 +21,6 @@
         <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
     </PropertyGroup>
 
-    <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
-        <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="6.0.0" />
-    </ItemGroup>
-
     <ItemGroup>
         <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
             <_Parameter1>$(MSBuildProjectName).UnitTests, PublicKey=$(PublicKey)</_Parameter1>
@@ -34,11 +30,6 @@
         
         <PackageReference Include="Microsoft.SourceLink.GitHub" Version="10.0.301" PrivateAssets="All"/>
 
-        <PackageReference Include="Polyfill" Version="11.0.1">
-          <PrivateAssets>all</PrivateAssets>
-          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-        </PackageReference>
-        
     </ItemGroup>
 
     <PropertyGroup>
diff --git a/EnumerableAsyncProcessor/RunnableProcessors/Abstract/AbstractAsyncProcessorBase.cs b/EnumerableAsyncProcessor/RunnableProcessors/Abstract/AbstractAsyncProcessorBase.cs
index 5150896..87f6d53 100644
--- a/EnumerableAsyncProcessor/RunnableProcessors/Abstract/AbstractAsyncProcessorBase.cs
+++ b/EnumerableAsyncProcessor/RunnableProcessors/Abstract/AbstractAsyncProcessorBase.cs
@@ -71,11 +71,7 @@ public async ValueTask DisposeAsync()
 
     protected virtual ValueTask DisposeAsyncCore()
     {
-#if NET6_0_OR_GREATER
         return ValueTask.CompletedTask;
-#else
-        return new ValueTask(Task.CompletedTask);
-#endif
     }
 
     public void Dispose()
diff --git a/EnumerableAsyncProcessor/RunnableProcessors/ResultProcessors/Abstract/ResultAbstractAsyncProcessorBase.cs b/EnumerableAsyncProcessor/RunnableProcessors/ResultProcessors/Abstract/ResultAbstractAsyncProcessorBase.cs
index a073fe5..0f21396 100644
--- a/EnumerableAsyncProcessor/RunnableProcessors/ResultProcessors/Abstract/ResultAbstractAsyncProcessorBase.cs
+++ b/EnumerableAsyncProcessor/RunnableProcessors/ResultProcessors/Abstract/ResultAbstractAsyncProcessorBase.cs
@@ -77,11 +77,7 @@ public async ValueTask DisposeAsync()
 
     protected virtual ValueTask DisposeAsyncCore()
     {
-#if NET6_0_OR_GREATER
         return ValueTask.CompletedTask;
-#else
-        return new ValueTask(Task.CompletedTask);
-#endif
     }
 
     public void Dispose()
diff --git a/EnumerableAsyncProcessor/TaskCompletionSource.cs b/EnumerableAsyncProcessor/TaskCompletionSource.cs
deleted file mode 100644
index c32f1f7..0000000
--- a/EnumerableAsyncProcessor/TaskCompletionSource.cs
+++ /dev/null
@@ -1,34 +0,0 @@
-#if NETSTANDARD2_0
-
-namespace EnumerableAsyncProcessor
-{
-    /// <inheritdoc cref="TaskCompletionSource{TResult}"/>
-    public class TaskCompletionSource : TaskCompletionSource<object?>
-    {
-        /// <inheritdoc cref="TaskCompletionSource{TResult}()"/>
-        public TaskCompletionSource()
-        {
-        }
-
-        /// <inheritdoc cref="TaskCompletionSource{TResult}(TaskCreationOptions)"/>
-        public TaskCompletionSource(TaskCreationOptions creationOptions) : base(creationOptions)
-        {
-        }
-
-        /// <inheritdoc cref="TaskCompletionSource{TResult}.TrySetResult"/>
-        public bool TrySetResult()
-        {
-            return TrySetResult(null);
-        }
-
-        /// <inheritdoc cref="TaskCompletionSource{TResult}.SetResult"/>
-        public void SetResult()
-        {
-            base.SetResult(null);
-        }
-
-        /// <inheritdoc cref="TaskCompletionSource{TResult}.Task"/>
-        public new Task Task => base.Task;
-    }
-}
-#endif
diff --git a/EnumerableAsyncProcessor/Validation/ValidationHelper.cs b/EnumerableAsyncProcessor/Validation/ValidationHelper.cs
index fbcfef6..35495da 100644
--- a/EnumerableAsyncProcessor/Validation/ValidationHelper.cs
+++ b/EnumerableAsyncProcessor/Validation/ValidationHelper.cs
@@ -9,7 +9,7 @@ namespace EnumerableAsyncProcessor.Validation;
 internal static class ValidationHelper
 {
     /// <summary>
-    /// Validates that an object is not null using modern or fallback methods.
+    /// Validates that an object is not null.
     /// </summary>
     /// <typeparam name="T">The type of the object to validate.</typeparam>
     /// <param name="value">The value to validate.</param>
@@ -17,14 +17,7 @@ internal static class ValidationHelper
     /// <exception cref="ArgumentNullException">Thrown when the value is null.</exception>
     public static void ThrowIfNull<T>([NotNull] T? value, [CallerArgumentExpression(nameof(value))] string? paramName = null)
     {
-#if NET6_0_OR_GREATER
         ArgumentNullException.ThrowIfNull(value, paramName);
-#else
-        if (value is null)
-        {
-            throw new ArgumentNullException(paramName);
-        }
-#endif
     }
 
     /// <summary>
@@ -35,14 +28,7 @@ public static void ThrowIfNull<T>([NotNull] T? value, [CallerArgumentExpression(
     /// <exception cref="ArgumentOutOfRangeException">Thrown when the value is negative.</exception>
     public static void ThrowIfNegative(int value, [CallerArgumentExpression(nameof(value))] string? paramName = null)
     {
-#if NET8_0_OR_GREATER
         ArgumentOutOfRangeException.ThrowIfNegative(value, paramName);
-#else
-        if (value < 0)
-        {
-            throw new ArgumentOutOfRangeException(paramName, value, $"'{paramName}' must be a non-negative value.");
-        }
-#endif
     }
 
     /// <summary>
@@ -53,14 +39,7 @@ public static void ThrowIfNegative(int value, [CallerArgumentExpression(nameof(v
     /// <exception cref="ArgumentOutOfRangeException">Thrown when the value is negative or zero.</exception>
     public static void ThrowIfNegativeOrZero(int value, [CallerArgumentExpression(nameof(value))] string? paramName = null)
     {
-#if NET8_0_OR_GREATER
         ArgumentOutOfRangeException.ThrowIfNegativeOrZero(value, paramName);
-#else
-        if (value <= 0)
-        {
-            throw new ArgumentOutOfRangeException(paramName, value, $"'{paramName}' must be a positive value.");
-        }
-#endif
     }
 
     /// <summary>
diff --git a/README.md b/README.md
index 813bb27..9328c04 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,10 @@ Process Multiple Asynchronous Tasks in Various Ways - One at a time / Batched /
 Install via Nuget
 `Install-Package EnumerableAsyncProcessor`
 
+### Supported frameworks
+
+Version 4 requires .NET 8 or later. The package targets and tests `net8.0`, `net9.0`, and `net10.0`.
+
 ## Why I built this
 
 Because I've come across situations where you need to fine tune the rate at which you do things.