Fix #32 - don't execute validation check when HelpOption or VersionOption are matched

Author: natemcmaster

build.ps1

@@ -39,8 +39,7 @@ $artifacts = "$PSScriptRoot/artifacts/"
 
 Remove-Item -Recurse $artifacts -ErrorAction Ignore
 
-exec dotnet restore @MSBuildArgs
-exec dotnet build --no-restore --configuration $Configuration @MSBuildArgs
+exec dotnet build --configuration $Configuration @MSBuildArgs
 exec dotnet pack --no-restore --no-build --configuration $Configuration -o $artifacts @MSBuildArgs
 exec dotnet test --no-restore --no-build --configuration $Configuration '-clp:Summary' `
     "$PSScriptRoot/test/CommandLineUtils.Tests/McMaster.Extensions.CommandLineUtils.Tests.csproj" `

releasenotes.props

@@ -1,5 +1,11 @@
 <Project>
   <PropertyGroup>
+    <PackageReleaseNotes Condition="'$(VersionPrefix)' == '2.1.1'">
+2.1.1:
+Bug fixes:
+ - Do not show validation error messages when --help or --version are specified
+ - Fix help text to show correct short option when OptionAttribute.ShortName is overriden
+    </PackageReleaseNotes>
     <PackageReleaseNotes Condition="'$(VersionPrefix)' == '2.1.0'">
 2.1.0:
 New features:

src/CommandLineUtils/CommandLineApplication.Execute.cs

@@ -48,7 +48,7 @@ public static int Execute<TApp>(IConsole console, params string[] args)
             var bindResult = Bind<TApp>(console, args);
             if (bindResult.Command.IsShowingInformation)
             {
-                return 0;
+                return HelpExitCode;
             }
 
             if (bindResult.ValidationResult != ValidationResult.Success)
@@ -101,7 +101,7 @@ public static async Task<int> ExecuteAsync<TApp>(IConsole console, params string
             var bindResult = Bind<TApp>(console, args);
             if (bindResult.Command.IsShowingInformation)
             {
-                return 0;
+                return HelpExitCode;
             }
 
             if (bindResult.ValidationResult != ValidationResult.Success)
@@ -142,7 +142,7 @@ private static int HandleValidationError(IConsole console, BindResult bindResult
                 return (int)result;
             }
 
-            return 1;
+            return ValidationErrorExitCode;
         }
 
         private static BindResult Bind<TApp>(IConsole console, string[] args) where TApp : class, new()

src/CommandLineUtils/CommandLineApplication.Validation.cs

@@ -108,7 +108,7 @@ private int DefaultValidationErrorHandler(ValidationResult result)
             _console.Error.WriteLine(result.ErrorMessage);
             _console.ResetColor();
             ShowHint();
-            return 1;
+            return ValidationErrorExitCode;
         }
 
         private sealed class ServiceProvider : IServiceProvider

src/CommandLineUtils/CommandLineApplication.cs

@@ -20,6 +20,9 @@ namespace McMaster.Extensions.CommandLineUtils
     /// </summary>
     public partial class CommandLineApplication
     {
+        private const int HelpExitCode = 0;
+        private const int ValidationErrorExitCode = 1;
+
         private IConsole _console;
         private IHelpTextGenerator _helpTextGenerator;
 
@@ -379,6 +382,11 @@ public int Execute(params string[] args)
             var processor = new CommandLineProcessor(this, args);
             var command = processor.Process();
 
+            if (command.IsShowingInformation)
+            {
+                return HelpExitCode;
+            }
+
             var result = command.GetValidationResult();
 
             if (result != ValidationResult.Success)

test/CommandLineUtils.Tests/ValidationTests.cs

@@ -3,6 +3,8 @@
 
 using System;
 using System.ComponentModel.DataAnnotations;
+using System.IO;
+using System.Text;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -305,5 +307,48 @@ public void ParentOptionsAreValidated_AttributeBinding()
             var rc = CommandLineApplication.Execute<ValidationParent>("sub");
             Assert.Equal(10, rc);
         }
+
+        [Fact]
+        public void DoesNotValidate_WhenShowingInfo()
+        {
+            var sb = new StringBuilder();
+            var console = new TestConsole(_output)
+            {
+                Out = new StringWriter(sb),
+            };
+            var app = new CommandLineApplication(console);
+            app.HelpOption();
+            var errorMessage = "Version arg is required";
+            app.Argument("version", "Arg").IsRequired(errorMessage: errorMessage);
+            app.OnValidationError((_) => Assert.False(true, "Validation callbacks should not be executed"));
+
+            Assert.Equal(0, app.Execute("--help"));
+            Assert.DoesNotContain(errorMessage, sb.ToString());
+        }
+
+        [HelpOption]
+        private class ProgramWithRequiredArg
+        {
+            [Argument(0), Required(ErrorMessage = "Arg is required")]
+            public string Version { get; }
+
+            private void OnValidationError()
+            {
+                throw new InvalidOperationException("Validation callback should not be executed");
+            }
+        }
+
+        [Fact]
+        public void DoesNotValidate_WhenShowingInfo_AttributeBinding()
+        {
+            var sb = new StringBuilder();
+            var console = new TestConsole(_output)
+            {
+                Out = new StringWriter(sb),
+            };
+
+            Assert.Equal(0, CommandLineApplication.Execute<ProgramWithRequiredArg>(console, "--help"));
+            Assert.DoesNotContain("Arg is required", sb.ToString());
+        }
     }
 }