bilal-fazlani · drewburlingame · Jan 8, 2025 · Jan 8, 2025
diff --git a/CommandDotNet.DataAnnotations/DataAnnotationsMiddleware.cs b/CommandDotNet.DataAnnotations/DataAnnotationsMiddleware.cs
@@ -62,7 +62,7 @@ private static Task<int> DataAnnotationsValidation(CommandContext ctx, Execution
                     console.Error.WriteLine();
                 }
 
-                return ExitCodes.ValidationError;
+                return ExitCodes.ValidationErrorAsync;
             }
 
             return next(ctx);

diff --git a/CommandDotNet.DocExamples/Diagnostics/Exceptions.cs b/CommandDotNet.DocExamples/Diagnostics/Exceptions.cs
@@ -34,7 +34,7 @@ private static int ErrorHandler(CommandContext? ctx, Exception exception)
                     // if the exception occurred before a command could be parsed
                     ctx?.PrintHelp();
 
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 }
 
                 public void Throw(string message)
@@ -64,7 +64,7 @@ static int Main(string[] args)
                         .UseErrorHandler((ctx, ex) =>
                         {
                             (ctx?.Console.Error ?? Console.Error).WriteLine(ex.Message);
-                            return ExitCodes.Error.Result;
+                            return ExitCodes.ErrorAsync.Result;
                         })
                         .Run(args);
                 }
@@ -97,7 +97,7 @@ static int Main(string[] args)
                     catch (Exception ex)
                     {
                         Console.Error.WriteLine(ex.Message);
-                        return ExitCodes.Error.Result;
+                        return ExitCodes.ErrorAsync.Result;
                     }
                 }
                 // end-snippet
@@ -146,7 +146,7 @@ private static int ErrorHandler(CommandContext? ctx, Exception exception)
                     // if the exception occurred before a command could be parsed
                     ctx?.PrintHelp();
 
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 }
 
                 public void Throw(string message)

diff --git a/CommandDotNet.Example/Commands/Prompts.cs b/CommandDotNet.Example/Commands/Prompts.cs
@@ -27,14 +27,14 @@ public Task<int> Intercept(InterceptorExecutionDelegate next,
                 if (username == null)
                 {
                     console.Out.WriteLine("username not provided");
-                    return ExitCodes.Error;
+                    return ExitCodes.ErrorAsync;
                 }
 
                 var pwd = password?.GetPassword();
                 if (string.IsNullOrWhiteSpace(pwd))
                 {
                     console.Out.WriteLine("password not provided");
-                    return ExitCodes.Error;
+                    return ExitCodes.ErrorAsync;
                 }
 
                 console.Out.WriteLine($"authenticated as user:{username} with password:{password}  (actual password:{pwd})");

diff --git a/CommandDotNet.FluentValidation/FluentValidationMiddleware.cs b/CommandDotNet.FluentValidation/FluentValidationMiddleware.cs
@@ -99,13 +99,13 @@ private static Task<int> FluentValidationForModels(CommandContext ctx, Execution
                         console.Error.WriteLine();
                     }
 
-                    return ExitCodes.ValidationError;
+                    return ExitCodes.ValidationErrorAsync;
                 }
             }
             catch (InvalidValidatorException e)
             {
                 ctx.Console.Error.WriteLine(e.ToString());
-                return ExitCodes.Error;
+                return ExitCodes.ErrorAsync;
             }
 
             return next(ctx);

diff --git a/CommandDotNet.NewerReleasesAlerts/AlertOnNewerReleaseMiddleware.cs b/CommandDotNet.NewerReleasesAlerts/AlertOnNewerReleaseMiddleware.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Net.Http;
 using System.Threading.Tasks;
 using CommandDotNet.Builders;
@@ -99,10 +100,8 @@ private static Task<int> AlertOnNewVersion(CommandContext context, ExecutionDele
             return next(context);
         }
 
-        private static bool TryGetCurrentVersion(out SemVersion semVersion)
-        {
-            return SemVersion.TryParse(AppInfo.Instance.Version, out semVersion);
-        }
+        private static bool TryGetCurrentVersion([NotNullWhen(true)] out SemVersion? semVersion) => 
+            SemVersion.TryParse(AppInfo.Instance.Version, out semVersion);
 
         private static bool TryGetLatestReleaseVersion(CommandContext context, NewerReleaseConfig config, out SemVersion? semVersion)
         {

diff --git a/CommandDotNet.TestTools/AppRunnerTestExtensions.cs b/CommandDotNet.TestTools/AppRunnerTestExtensions.cs
@@ -25,7 +25,7 @@ public static AppRunner CaptureState(this AppRunner runner, Action<CommandContex
             {
                 capture(context);
                 return exitAfterCapture 
-                    ? ExitCodes.Success
+                    ? ExitCodes.SuccessAsync
                     : next(context);
             }, middlewareStage, orderWithinStage));
         }

diff --git a/CommandDotNet.TestTools/AssertFailedException.cs b/CommandDotNet.TestTools/AssertFailedException.cs
@@ -4,16 +4,5 @@
 namespace CommandDotNet.TestTools
 {
     [Serializable]
-    public class AssertFailedException : Exception
-    {
-        public AssertFailedException(string message)
-            : base(message)
-        {
-        }
-
-        protected AssertFailedException(SerializationInfo info, StreamingContext context)
-            : base(info, context)
-        {
-        }
-    }
+    public class AssertFailedException(string message) : Exception(message);
 }
diff --git a/CommandDotNet.TestTools/InvocationInfo.cs b/CommandDotNet.TestTools/InvocationInfo.cs
@@ -6,14 +6,11 @@
 
 namespace CommandDotNet.TestTools
 {
-    public class InvocationInfo<T> : InvocationInfo where T: class
+    public class InvocationInfo<T>(CommandContext commandContext, InvocationStep invocationStep)
+        : InvocationInfo(commandContext, invocationStep)
+        where T : class
     {
         public new T? Instance => (T?)base.Instance;
-
-        public InvocationInfo(CommandContext commandContext, InvocationStep invocationStep)
-            : base(commandContext, invocationStep)
-        {
-        }
     }
 
     public class InvocationInfo

diff --git a/CommandDotNet.TestTools/TestDependencyResolver.cs b/CommandDotNet.TestTools/TestDependencyResolver.cs
@@ -33,12 +33,12 @@ public void Add(object service)
             _services.Add(service.GetType(), service);
         }
 
-        public void Add<T>(T? service) where T: class
+        public void Add<T>(T? service) where T: class?
         {
             _services.Add(typeof(T), service);
         }
 
-        public void AddOrUpdate<T>(T? service) where T : class
+        public void AddOrUpdate<T>(T? service) where T : class?
         {
             _services[typeof(T)] = service;
         }

diff --git a/CommandDotNet.TestTools/TrackingInvocation.cs b/CommandDotNet.TestTools/TrackingInvocation.cs
@@ -5,26 +5,21 @@
 
 namespace CommandDotNet.TestTools
 {
-    internal class TrackingInvocation : IInvocation
+    internal class TrackingInvocation(IInvocation backingInvocation) : IInvocation
     {
-        private readonly IInvocation _backingInvocation;
+        private readonly IInvocation _backingInvocation = backingInvocation ?? throw new ArgumentNullException(nameof(backingInvocation));
 
         public bool WasInvoked { get; private set; }
         public bool Errored => InvocationError != null;
         public Exception? InvocationError { get; private set; }
 
         public IReadOnlyCollection<IArgument> Arguments => _backingInvocation.Arguments;
         public IReadOnlyCollection<ParameterInfo> Parameters => _backingInvocation.Parameters;
-        public object[] ParameterValues => _backingInvocation.ParameterValues;
+        public object?[] ParameterValues => _backingInvocation.ParameterValues;
         public MethodInfo MethodInfo => _backingInvocation.MethodInfo;
         public bool IsInterceptor => _backingInvocation.IsInterceptor;
         public IReadOnlyCollection<IArgumentModel> FlattenedArgumentModels => _backingInvocation.FlattenedArgumentModels;
 
-        public TrackingInvocation(IInvocation backingInvocation)
-        {
-            _backingInvocation = backingInvocation ?? throw new ArgumentNullException(nameof(backingInvocation));
-        }
-
         public object? Invoke(CommandContext commandContext, object instance, ExecutionDelegate next)
         {
             WasInvoked = true;

diff --git a/CommandDotNet.Tests/AppRunnerScenarioExtensions.cs b/CommandDotNet.Tests/AppRunnerScenarioExtensions.cs
@@ -9,7 +9,7 @@ namespace CommandDotNet.Tests
     public static class AppRunnerScenarioExtensions
     {
         public static AppRunner StopAfter(this AppRunner runner, MiddlewareStep step)
-            => runner.Configure(cfg => cfg.UseMiddleware((_, _) => ExitCodes.Success, step+1));
+            => runner.Configure(cfg => cfg.UseMiddleware((_, _) => ExitCodes.SuccessAsync, step+1));
 
         public static AppRunner StopAfter(this AppRunner runner, MiddlewareStages stage)
             => runner.StopAfter(new MiddlewareStep(stage));

diff --git a/CommandDotNet.Tests/CommandDotNet.CommandLogger/CommandLoggerTests.cs b/CommandDotNet.Tests/CommandDotNet.CommandLogger/CommandLoggerTests.cs
@@ -410,7 +410,7 @@ public void CommandLogger_Log_CanBeCalled_BeforeParseResults()
                 .Configure(c => c.UseMiddleware((context, next) =>
                 {
                     Diag.CommandLogger.Log(context, context.Console.Out.WriteLine);
-                    return ExitCodes.Success;
+                    return ExitCodes.SuccessAsync;
                 }, MiddlewareStages.PostTokenizePreParseInput))
                 .Verify(new Scenario
                 {

diff --git a/CommandDotNet.Tests/FeatureTests/Arguments/Options_Name_Tests.cs b/CommandDotNet.Tests/FeatureTests/Arguments/Options_Name_Tests.cs
@@ -56,7 +56,7 @@ public void ShortNameShouldBe(string propertyName, char? shortName)
         [InlineData(LongNameNull, null)]
         [InlineData(LongNameEmpty, null)]
         [Theory]
-        public void LongNameShouldBe(string propertyName, string longName)
+        public void LongNameShouldBe(string propertyName, string? longName)
         {
             var option = _options[propertyName];
             option.LongName.Should().Be(longName);

diff --git a/CommandDotNet.Tests/FeatureTests/AsyncTests.cs b/CommandDotNet.Tests/FeatureTests/AsyncTests.cs
@@ -35,7 +35,7 @@ private class App
             [Command("get2", Description = "Invokes an async method and exits with return code 2")]
             public async Task<int> Get2Async()
             {
-                return await ExitCodes.ValidationError;
+                return await ExitCodes.ValidationErrorAsync;
             }
 
             [Command("get00", Description = "Invokes an async method and exits with return code 0")]

diff --git a/CommandDotNet.Tests/FeatureTests/ClassCommands/InterceptorExecutionTests.cs b/CommandDotNet.Tests/FeatureTests/ClassCommands/InterceptorExecutionTests.cs
@@ -202,7 +202,7 @@ public Task<int> Intercept(InterceptorExecutionDelegate next,
             {
                 if (interceptOptions.skipCmd)
                 {
-                    return ExitCodes.Success;
+                    return ExitCodes.SuccessAsync;
                 }
 
                 var returnCode = next();

diff --git a/CommandDotNet.Tests/FeatureTests/ClassCommands/InterceptorExecutionWithDefaultMethodTests.cs b/CommandDotNet.Tests/FeatureTests/ClassCommands/InterceptorExecutionWithDefaultMethodTests.cs
@@ -229,7 +229,7 @@ public Task<int> Intercept(InterceptorExecutionDelegate next,
             {
                 if (interceptOptions.skipCmd)
                 {
-                    return ExitCodes.Success;
+                    return ExitCodes.SuccessAsync;
                 }
 
                 var returnCode = next();

diff --git a/CommandDotNet.Tests/FeatureTests/ClassCommands/SubCommandTests.cs b/CommandDotNet.Tests/FeatureTests/ClassCommands/SubCommandTests.cs
@@ -52,7 +52,7 @@ public void Help_NoArgs_Includes_1stLevelCommands_And_2ndLevelApp(Type type)
                     When = { Args = null },
                     Then =
                     {
-                        ExitCode = ExitCodes.Error.Result,
+                        ExitCode = ExitCodes.Error,
                         Output = @"Required command was not provided
 
 Usage: testhost.dll [command]

diff --git a/CommandDotNet.Tests/FeatureTests/CommandInvocatorTest.cs b/CommandDotNet.Tests/FeatureTests/CommandInvocatorTest.cs
@@ -24,8 +24,8 @@ Task<int> BeforeInvocation(CommandContext context, ExecutionDelegate next)
             {
                 var values = context.InvocationPipeline.TargetCommand!.Invocation.ParameterValues;
                 values.Length.Should().Be(2);
-                var invokedCar = (Car) values[0];
-                var invokedOwner = (string)values[1];
+                var invokedCar = (Car) values[0]!;
+                var invokedOwner = (string)values[1]!;
 
                 invokedCar.Number.Should().Be(1);
                 invokedCar.Number = 2;

diff --git a/CommandDotNet.Tests/FeatureTests/ExceptionHandlingTests.cs b/CommandDotNet.Tests/FeatureTests/ExceptionHandlingTests.cs
@@ -51,7 +51,7 @@ public void CanHandleErrors(string? commandName, string? exceptionMessage = null
                 {
                     context = ctx;
                     exception = ex;
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 })
                 .Run(args);
             exitCode.Should().Be(1);
@@ -69,7 +69,7 @@ public void CanHandleErrorsFromConstructor()
                 {
                     context = ctx;
                     exception = ex;
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 })
                 .Run("Process");
 
@@ -86,7 +86,7 @@ public void ErrorHandlerIsNotTriggeredForValueParsingException()
                 .UseErrorHandler((ctx, ex) =>
                 {
                     exception = ex;
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 })
                 .Run("Process -o");
 
@@ -102,7 +102,7 @@ public void ErrorHandlerIsNotTriggeredForInvalidConfigurationException()
                 .UseErrorHandler((ctx, ex) =>
                 {
                     exception = ex;
-                    return ExitCodes.Error.Result;
+                    return ExitCodes.ErrorAsync.Result;
                 })
                 .Run("Do");
 

diff --git a/CommandDotNet.Tests/FeatureTests/ParseDirective/ParseDirectiveVerifier.cs b/CommandDotNet.Tests/FeatureTests/ParseDirective/ParseDirectiveVerifier.cs
@@ -67,7 +67,7 @@ void ContainsIf(bool yes, string value)
             if (exitBeforeBind)
             {
                 appRunner.Configure(c => 
-                    c.UseMiddleware((ctx, next) => ExitCodes.Success, 
+                    c.UseMiddleware((ctx, next) => ExitCodes.SuccessAsync, 
                         MiddlewareStages.PostParseInputPreBindValues));
             }
 
@@ -94,7 +94,7 @@ void ContainsIf(bool yes, string value)
 
             var result = appRunner
                 .UseParseDirective()
-                .UseErrorHandler((ctx, ex) => ExitCodes.Error.Result)
+                .UseErrorHandler((ctx, ex) => ExitCodes.ErrorAsync.Result)
                 .Verify(new Scenario
                 {
                     When = {Args = $"{parse} {args}"},

diff --git a/CommandDotNet.Tests/UnitTests/Extensions/ArgumentExtensionTests.cs b/CommandDotNet.Tests/UnitTests/Extensions/ArgumentExtensionTests.cs
@@ -22,8 +22,8 @@ public void SwitchAct_ForNullArg_Should_ThrowNullRef()
         {
             Assert.Throws<ArgumentNullException>(() =>
                 ((IArgument) null!).SwitchAct(
-                    o => Assert.True(false, "operandAction should not be called for operand"),
-                    o => Assert.True(false, "optionAction should not be called for operand"))
+                    o => Assert.Fail("operandAction should not be called for operand"),
+                    o => Assert.Fail("optionAction should not be called for operand"))
             );
         }
 
@@ -34,7 +34,7 @@ public void SwitchAct_ForOperand_Should_ExecuteOnlyOperandAction()
 
             AnOperand.SwitchAct(
                 o => actionCalled = true,
-                o => Assert.True(false, "optionAction should not be called for operand"));
+                o => Assert.Fail("optionAction should not be called for operand"));
 
             actionCalled.Should().BeTrue();
         }
@@ -45,7 +45,7 @@ public void SwitchAct_ForOption_Should_ExecuteOnlyOptionAction()
             bool actionCalled = false;
 
             AnOption.SwitchAct(
-                o => Assert.True(false, "operandAction should not be called for option"),
+                o => Assert.Fail("operandAction should not be called for option"),
                 o => actionCalled = true);
 
             actionCalled.Should().BeTrue();

diff --git a/CommandDotNet/AppConfigBuilder.cs b/CommandDotNet/AppConfigBuilder.cs
@@ -29,7 +29,7 @@ public class AppConfigBuilder
 
         private readonly SingleRegistrationGuard<Type> _parameterResolverSingleRegistrationGuard = 
             new("parameter resolver", type => type.FullName);
-        private readonly Dictionary<Type, Func<CommandContext, object>> _parameterResolversByType = new()
+        private readonly Dictionary<Type, Func<CommandContext, object?>> _parameterResolversByType = new()
         {
             [typeof(CommandContext)] = ctx => ctx,
             [typeof(IConsole)] = ctx => ctx.Console,
@@ -93,9 +93,9 @@ public AppConfigBuilder(AppSettings appSettings)
         /// Types must be resolvable from the <see cref="CommandContext"/><br/>
         /// Default types: <see cref="CommandContext"/>, <see cref="IConsole"/>, <see cref="CancellationToken"/>
         /// </summary>
-        public AppConfigBuilder UseParameterResolver<T>(Func<CommandContext,T> resolver) where T: class
+        public AppConfigBuilder UseParameterResolver<T>(Func<CommandContext,T> resolver) where T: class?
         {
-            if (resolver == null) throw new ArgumentNullException(nameof(resolver));
+            ArgumentNullException.ThrowIfNull(resolver);
 
             _parameterResolverSingleRegistrationGuard.Register(typeof(T));
             _parameterResolversByType.Add(typeof(T), resolver);

diff --git a/CommandDotNet/AppRunner.cs b/CommandDotNet/AppRunner.cs
@@ -172,12 +172,12 @@ private int HandleException(Exception ex, CommandContext? commandContext)
             if (ex.IsFor<ValueParsingException>(out var vpe))
             {
                 console.Error.WriteLine(vpe!.Print(excludeTypeName: true));
-                return ExitCodes.Error.Result;
+                return ExitCodes.ErrorAsync.Result;
             }
             if (ex.IsFor<InvalidConfigurationException>(out var ice))
             {
                 console.Error.WriteLine(ice!.Print());
-                return ExitCodes.Error.Result;
+                return ExitCodes.ErrorAsync.Result;
             }
             if (_handleErrorDelegate != null)
             {
@@ -192,7 +192,7 @@ private int HandleException(Exception ex, CommandContext? commandContext)
 
             // code not reached but required to compile
             // compiler does not realize previous line throws an exception
-            return ExitCodes.Error.Result;
+            return ExitCodes.ErrorAsync.Result;
         }
 
         public override string ToString()