:breaking-change: bump version to 5.0 and drop support for .NET Standard 2 and < .NET 6

.github/workflows/ci.yml

@@ -42,7 +42,7 @@ jobs:
         with:
           dotnet-version: |
             6.0.x
-            7.0.x
+            8.0.x
       - name: Run build script
         id: build_script
         run: ./build.ps1 -ci

.github/workflows/docs.yml

@@ -21,10 +21,12 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Setup .NET 6
+    - name: Setup .NET
       uses: actions/setup-dotnet@v3
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: |
+          6.0.x
+          8.0.x
     - name: Run docs generation
       run: ./docs/generate.ps1
 

Directory.Build.props

@@ -28,7 +28,6 @@
 
   <PropertyGroup>
     <WarningsNotAsErrors>$(WarningsNotAsErrors);1591</WarningsNotAsErrors>
-    <LangVersion>9.0</LangVersion>
     <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
     <Nullable>enable</Nullable>
     <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)src\StrongName.snk</AssemblyOriginatorKeyFile>
@@ -41,7 +40,7 @@
   </PropertyGroup>
 
    <PropertyGroup>
-    <VersionPrefix>4.1.1</VersionPrefix>
+    <VersionPrefix>5.0.0</VersionPrefix>
     <VersionSuffix>beta</VersionSuffix>
     <IncludePreReleaseLabelInPackageVersion Condition="'$(IS_STABLE_BUILD)' != 'true'">true</IncludePreReleaseLabelInPackageVersion>
     <BuildNumber Condition=" '$(BuildNumber)' == '' ">$(GITHUB_RUN_NUMBER)</BuildNumber>
@@ -53,11 +52,6 @@
     <InformationalVersion Condition="'$(RepositoryCommit)' != ''">$(PackageVersion)+$(RepositoryCommit)</InformationalVersion>
   </PropertyGroup>
 
-  <ItemGroup>
-    <!-- For x-plat development -->
-    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.2" PrivateAssets="All" />
-  </ItemGroup>
-
   <Import Project="$(MSBuildProjectDirectory)/releasenotes.props"
           Condition="Exists('$(MSBuildProjectDirectory)/releasenotes.props')" />
 

docs/generate.ps1

@@ -37,7 +37,7 @@ try {
     if (-not (Test-Path $docfx)) {
         mkdir -p $docfxRoot -ErrorAction Ignore | Out-Null
         $temp = (New-TemporaryFile).FullName + ".zip"
-        Invoke-WebRequest "https://www.nuget.org/api/v2/package/docfx.console/$docfxVersion" -O $temp
+        Invoke-WebRequest "https://www.nuget.org/api/v2/package/docfx.console/$docfxVersion" -OutFile $temp
         Expand-Archive $temp -DestinationPath $docfxRoot
         Remove-Item $temp
         if ($Install) {

docs/samples/attributes/Attributes.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/custom-attribute/CustomAttribute.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/custom-conventions/CustomConvention.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/dependency-injection/custom/CustomServices.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/dependency-injection/generic-host/GenericHostDI.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/dependency-injection/standard/StandardServices.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/generic-host/AttributeApi/AttributeApi.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/generic-host/BuilderApi/BuilderApi.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/helloworld-async-attributes/AsyncAttributes.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/interactive-prompts/Prompt.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/pager/Pager.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/passthru-args/attributes/AttributesPassThru.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/passthru-args/builder-api/BuilderApiPassThru.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/response-file-parsing/attributes/RspAttributes.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/response-file-parsing/builder-api/RspBuilderApi.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/subcommands/builder-api/BuilderApiSubcommands.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/subcommands/inheritance/InheritanceSubcommands.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/subcommands/nested-types/NestedTypeSubcommands.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/validation/attributes/Program.cs

@@ -5,6 +5,9 @@
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using McMaster.Extensions.CommandLineUtils;
+// This is required since .NET 8 introduced a new type System.ComponentModel.DataAnnotations.AllowedValuesAttribute
+// which conflicts with the attribute in this library (added long before .NET 8.)
+using AllowedValues = McMaster.Extensions.CommandLineUtils.AllowedValuesAttribute;
 
 [MaxSizeOptionRequiresAttachmentValidation()]
 class AttributeProgram

docs/samples/validation/attributes/ValidationAttributes.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/samples/validation/builder-api/ValidationBuilderApi.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

src/CommandLineUtils/Abstractions/CommandLineContext.cs

@@ -11,7 +11,7 @@ namespace McMaster.Extensions.CommandLineUtils.Abstractions
     /// </summary>
     public abstract class CommandLineContext
     {
-        private string[] _args = new string[0];
+        private string[] _args = Array.Empty<string>();
         private string _workDir = Directory.GetCurrentDirectory();
         private IConsole _console = PhysicalConsole.Singleton;
 

src/CommandLineUtils/Abstractions/ValueParserProvider.cs

@@ -61,7 +61,11 @@ private static readonly MethodInfo s_getParserGeneric
         public IValueParser GetParser(Type type)
         {
             var method = s_getParserGeneric.MakeGenericMethod(type);
+#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
+#pragma warning disable CS8603 // Possible null reference return.
             return (IValueParser)method.Invoke(this, Array.Empty<object>());
+#pragma warning restore CS8603 // Possible null reference return.
+#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
         }
 
         /// <summary>
@@ -121,8 +125,12 @@ public IValueParser GetParser(Type type)
                 {
                     return null;
                 }
+#pragma warning disable CS8602 // Dereference of a possibly null reference.
                 var method = typeof(ValueTupleValueParser).GetMethod(nameof(ValueTupleValueParser.Create)).MakeGenericMethod(type.GenericTypeArguments[1]);
+#pragma warning restore CS8602 // Dereference of a possibly null reference.
+#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
                 return (IValueParser)method.Invoke(null, new object[] { innerParser });
+#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
             }
 
             return null;

src/CommandLineUtils/Attributes/AllowedValuesAttribute.cs

@@ -40,7 +40,7 @@ public AllowedValuesAttribute(params string[] allowedValues)
         public AllowedValuesAttribute(StringComparison comparer, params string[] allowedValues)
             : base(GetDefaultError(allowedValues))
         {
-            _allowedValues = allowedValues ?? new string[0];
+            _allowedValues = allowedValues ?? Array.Empty<string>();
             Comparer = comparer;
         }
 

src/CommandLineUtils/Attributes/VersionOptionFromMemberAttribute.cs

@@ -60,7 +60,11 @@ internal CommandOption Configure(CommandLineApplication app, Type type, Func<obj
 
                 shortFormGetter = () =>
                 {
+#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
+#pragma warning disable CS8603 // Possible null reference return.
                     return (string)methods[0].Invoke(targetInstanceFactory.Invoke(), Array.Empty<object>());
+#pragma warning restore CS8603 // Possible null reference return.
+#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
                 };
             }
 

src/CommandLineUtils/CommandArgument{T}.cs

@@ -38,7 +38,9 @@ public CommandArgument(IValueParser<T> valueParser)
         /// <summary>
         /// The parsed value.
         /// </summary>
+#pragma warning disable CS8603 // Possible null reference return.
         public T ParsedValue => ParsedValues.FirstOrDefault();
+#pragma warning restore CS8603 // Possible null reference return.
 
         /// <summary>
         /// All parsed values;

src/CommandLineUtils/CommandLineApplication.cs

@@ -877,13 +877,17 @@ void cancelHandler(object o, ConsoleCancelEventArgs e)
 
             try
             {
+#pragma warning disable CS8622 // Nullability of reference types in type of parameter doesn't match the target delegate (possibly because of nullability attributes).
                 _context.Console.CancelKeyPress += cancelHandler;
+#pragma warning restore CS8622 // Nullability of reference types in type of parameter doesn't match the target delegate (possibly because of nullability attributes).
 
                 return await command._handler(handlerCancellationTokenSource.Token);
             }
             finally
             {
+#pragma warning disable CS8622 // Nullability of reference types in type of parameter doesn't match the target delegate (possibly because of nullability attributes).
                 _context.Console.CancelKeyPress -= cancelHandler;
+#pragma warning restore CS8622 // Nullability of reference types in type of parameter doesn't match the target delegate (possibly because of nullability attributes).
             }
         }
 
@@ -1146,7 +1150,9 @@ public virtual void Dispose()
 
         internal IServiceProvider? AdditionalServices { get; set; }
 
+#pragma warning disable CS8603 // Possible null reference return.
         object IServiceProvider.GetService(Type serviceType) => _services.Value.GetService(serviceType);
+#pragma warning restore CS8603 // Possible null reference return.
 
         private sealed class ServiceProvider : IServiceProvider
         {

src/CommandLineUtils/CommandLineApplicationExtensions.cs

@@ -176,9 +176,11 @@ public static CommandOption VersionOptionFromAssemblyAttributes(this CommandLine
             var infoVersion = assembly
                 ?.GetCustomAttribute<AssemblyInformationalVersionAttribute>()
                 ?.InformationalVersion;
+#pragma warning disable CS8602 // Dereference of a possibly null reference.
             return string.IsNullOrWhiteSpace(infoVersion)
                 ? assembly?.GetName().Version.ToString()
                 : infoVersion;
+#pragma warning restore CS8602 // Dereference of a possibly null reference.
         }
     }
 }

src/CommandLineUtils/CommandOption{T}.cs

@@ -39,7 +39,9 @@ public CommandOption(IValueParser<T> valueParser, string template, CommandOption
         /// <summary>
         /// The parsed value.
         /// </summary>
+#pragma warning disable CS8603 // Possible null reference return.
         public T ParsedValue => ParsedValues.FirstOrDefault();
+#pragma warning restore CS8603 // Possible null reference return.
 
         /// <summary>
         /// All parsed values;

src/CommandLineUtils/Conventions/ArgumentAttributeConvention.cs

@@ -151,6 +151,7 @@ private void AddArgument(PropertyInfo prop,
                     if (r.SelectedCommand is IModelAccessor cmd)
                     {
                         var model = cmd.GetModel();
+#pragma warning disable CS8602 // Dereference of a possibly null reference.
                         if (prop.DeclaringType.IsAssignableFrom(model.GetType()))
                         {
                             if (argument.Values.Count == 0)
@@ -175,6 +176,7 @@ private void AddArgument(PropertyInfo prop,
                                         convention.Application.ValueParsers.ParseCulture));
                             }
                         }
+#pragma warning restore CS8602 // Dereference of a possibly null reference.
                     }
                 });
             }

src/CommandLineUtils/Conventions/ConstructorInjectionConvention.cs

@@ -94,9 +94,11 @@ private void ApplyImpl<TModel>(ConventionContext context)
                             goto nextCtor;
                         }
 
+#pragma warning disable CS8604 // Possible null reference argument.
                         return () =>
                             throw new InvalidOperationException(
                                 Strings.NoParameterTypeRegistered(ctorCandidate.DeclaringType, paramType));
+#pragma warning restore CS8604 // Possible null reference argument.
                     }
 
                     args[i] = service;