Update version

Closes #127

.github/workflows/main.yml

@@ -4,7 +4,9 @@ on: [push, pull_request]
 
 jobs:
   main:
-    uses: Tyrrrz/.github/.github/workflows/NuGet.yml@master
+    uses: Tyrrrz/.github/.github/workflows/nuget.yml@master
+    with:
+      dotnet-version: 6.0.x
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
       NUGET_TOKEN: ${{ secrets.NUGET_TOKEN }}

Changelog.md

@@ -1,3 +1,18 @@
+### v2.2.6 (14-Jun-2022)
+
+- Added an overload of `CliApplicationBuilder.UseTypeActivator(...)` that accepts an instance of `IServiceProvider`. This slightly simplifies integration with many DI containers.
+- Fixed minor grammar mistakes in user-facing error messages.
+
+### v2.2.5 (10-May-2022)
+
+- Updated default value resolution for the application executable name. It will now resolve to `myapp.exe` instead of `dotnet myapp.dll` when the application is launched through the EXE apphost on Windows. On other platforms, or when running the application through the .NET CLI, the behavior will be the same as before.
+
+### v2.2.4 (22-Apr-2022)
+
+- Added more contextual information to analyzer diagnostics.
+- Fixed an issue where the analyzer incorrectly reported an error on converters that didn't directly match the target type but were compatible through known built-in conversions.
+- Fixed an issue where MSBuild produced a lot of analyzer-related warnings in certain circumstances.
+
 ### v2.2.3 (17-Apr-2022)
 
 - Changed method signature of `IConsole.ReadKey()` to return `ConsoleKeyInfo` instead of `void`. The return type was originally defined as `void` by mistake. This change is source-backwards-compatible but may break on binary level if you were previously calling this method indirectly (i.e. through a library).

CliFx.Analyzers.Tests/CliFx.Analyzers.Tests.csproj

@@ -10,12 +10,12 @@
 
   <ItemGroup>
     <PackageReference Include="Basic.Reference.Assemblies" Version="1.2.4" />
-    <PackageReference Include="GitHubActionsTestLogger" Version="1.3.0" PrivateAssets="all" />
-    <PackageReference Include="FluentAssertions" Version="6.5.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.1.0" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.0.0" PrivateAssets="all" />
+    <PackageReference Include="FluentAssertions" Version="6.7.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.2.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" PrivateAssets="all" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" PrivateAssets="all" />
     <PackageReference Include="coverlet.collector" Version="3.1.2" PrivateAssets="all" />
   </ItemGroup>
 

CliFx.Analyzers.Tests/OptionMustHaveValidConverterAnalyzerSpecs.cs

@@ -9,7 +9,7 @@ public class OptionMustHaveValidConverterAnalyzerSpecs
     private static DiagnosticAnalyzer Analyzer { get; } = new OptionMustHaveValidConverterAnalyzer();
 
     [Fact]
-    public void Analyzer_reports_an_error_if_the_specified_option_converter_does_not_derive_from_BindingConverter()
+    public void Analyzer_reports_an_error_if_an_option_has_a_converter_that_does_not_derive_from_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -33,7 +33,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_reports_an_error_if_the_specified_option_converter_does_not_derive_from_a_compatible_BindingConverter()
+    public void Analyzer_reports_an_error_if_an_option_has_a_converter_that_does_not_derive_from_a_compatible_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -57,7 +57,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_does_not_report_an_error_if_the_specified_option_converter_derives_from_a_compatible_BindingConverter()
+    public void Analyzer_does_not_report_an_error_if_an_option_has_a_converter_that_derives_from_a_compatible_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -80,6 +80,54 @@ public class MyCommand : ICommand
         Analyzer.Should().NotProduceDiagnostics(code);
     }
 
+    [Fact]
+    public void Analyzer_does_not_report_an_error_if_a_nullable_option_has_a_converter_that_derives_from_a_compatible_BindingConverter()
+    {
+        // Arrange
+        // language=cs
+        const string code = @"
+public class MyConverter : BindingConverter<int>
+{
+    public override int Convert(string rawValue) => 42;
+}
+
+[Command]
+public class MyCommand : ICommand
+{
+    [CommandOption(""foo"", Converter = typeof(MyConverter))]
+    public int? Foo { get; set; }
+
+    public ValueTask ExecuteAsync(IConsole console) => default;
+}";
+
+        // Act & assert
+        Analyzer.Should().NotProduceDiagnostics(code);
+    }
+
+    [Fact]
+    public void Analyzer_does_not_report_an_error_if_a_non_scalar_option_has_a_converter_that_derives_from_a_compatible_BindingConverter()
+    {
+        // Arrange
+        // language=cs
+        const string code = @"
+public class MyConverter : BindingConverter<string>
+{
+    public override string Convert(string rawValue) => rawValue;
+}
+
+[Command]
+public class MyCommand : ICommand
+{
+    [CommandOption(""foo"", Converter = typeof(MyConverter))]
+    public IReadOnlyList<string> Foo { get; set; }
+
+    public ValueTask ExecuteAsync(IConsole console) => default;
+}";
+
+        // Act & assert
+        Analyzer.Should().NotProduceDiagnostics(code);
+    }
+
     [Fact]
     public void Analyzer_does_not_report_an_error_if_an_option_does_not_have_a_converter()
     {

CliFx.Analyzers.Tests/OptionMustHaveValidValidatorsAnalyzerSpecs.cs

@@ -9,7 +9,7 @@ public class OptionMustHaveValidValidatorsAnalyzerSpecs
     private static DiagnosticAnalyzer Analyzer { get; } = new OptionMustHaveValidValidatorsAnalyzer();
 
     [Fact]
-    public void Analyzer_reports_an_error_if_one_of_the_specified_option_validators_does_not_derive_from_BindingValidator()
+    public void Analyzer_reports_an_error_if_an_option_has_a_validator_that_does_not_derive_from_BindingValidator()
     {
         // Arrange
         // language=cs
@@ -33,7 +33,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_reports_an_error_if_one_of_the_specified_option_validators_does_not_derive_from_a_compatible_BindingValidator()
+    public void Analyzer_reports_an_error_if_an_option_has_a_validator_that_does_not_derive_from_a_compatible_BindingValidator()
     {
         // Arrange
         // language=cs
@@ -57,7 +57,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_does_not_report_an_error_if_each_specified_option_validator_derives_from_a_compatible_BindingValidator()
+    public void Analyzer_does_not_report_an_error_if_an_option_has_validators_that_all_derive_from_compatible_BindingValidators()
     {
         // Arrange
         // language=cs

CliFx.Analyzers.Tests/ParameterMustHaveValidConverterAnalyzerSpecs.cs

@@ -9,7 +9,7 @@ public class ParameterMustHaveValidConverterAnalyzerSpecs
     private static DiagnosticAnalyzer Analyzer { get; } = new ParameterMustHaveValidConverterAnalyzer();
 
     [Fact]
-    public void Analyzer_reports_an_error_if_the_specified_parameter_converter_does_not_derive_from_BindingConverter()
+    public void Analyzer_reports_an_error_if_a_parameter_has_a_converter_that_does_not_derive_from_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -33,7 +33,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_reports_an_error_if_the_specified_parameter_converter_does_not_derive_from_a_compatible_BindingConverter()
+    public void Analyzer_reports_an_error_if_a_parameter_has_a_converter_that_does_not_derive_from_a_compatible_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -58,7 +58,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_does_not_report_an_error_if_the_specified_parameter_converter_derives_from_a_compatible_BindingConverter()
+    public void Analyzer_does_not_report_an_error_if_a_parameter_has_a_converter_that_derives_from_a_compatible_BindingConverter()
     {
         // Arrange
         // language=cs
@@ -81,6 +81,54 @@ public class MyCommand : ICommand
         Analyzer.Should().NotProduceDiagnostics(code);
     }
 
+    [Fact]
+    public void Analyzer_does_not_report_an_error_if_a_nullable_parameter_has_a_converter_that_derives_from_a_compatible_BindingConverter()
+    {
+        // Arrange
+        // language=cs
+        const string code = @"
+public class MyConverter : BindingConverter<int>
+{
+    public override int Convert(string rawValue) => 42;
+}
+
+[Command]
+public class MyCommand : ICommand
+{
+    [CommandOption(""foo"", Converter = typeof(MyConverter))]
+    public int? Foo { get; set; }
+
+    public ValueTask ExecuteAsync(IConsole console) => default;
+}";
+
+        // Act & assert
+        Analyzer.Should().NotProduceDiagnostics(code);
+    }
+
+    [Fact]
+    public void Analyzer_does_not_report_an_error_if_a_non_scalar_parameter_has_a_converter_that_derives_from_a_compatible_BindingConverter()
+    {
+        // Arrange
+        // language=cs
+        const string code = @"
+public class MyConverter : BindingConverter<string>
+{
+    public override string Convert(string rawValue) => rawValue;
+}
+
+[Command]
+public class MyCommand : ICommand
+{
+    [CommandParameter(0, Converter = typeof(MyConverter))]
+    public IReadOnlyList<string> Foo { get; set; }
+
+    public ValueTask ExecuteAsync(IConsole console) => default;
+}";
+
+        // Act & assert
+        Analyzer.Should().NotProduceDiagnostics(code);
+    }
+
     [Fact]
     public void Analyzer_does_not_report_an_error_if_a_parameter_does_not_have_a_converter()
     {

CliFx.Analyzers.Tests/ParameterMustHaveValidValidatorsAnalyzerSpecs.cs

@@ -9,7 +9,7 @@ public class ParameterMustHaveValidValidatorsAnalyzerSpecs
     private static DiagnosticAnalyzer Analyzer { get; } = new ParameterMustHaveValidValidatorsAnalyzer();
 
     [Fact]
-    public void Analyzer_reports_an_error_if_one_of_the_specified_parameter_validators_does_not_derive_from_BindingValidator()
+    public void Analyzer_reports_an_error_a_parameter_has_a_validator_that_does_not_derive_from_BindingValidator()
     {
         // Arrange
         // language=cs
@@ -33,7 +33,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_reports_an_error_if_one_of_the_specified_parameter_validators_does_not_derive_from_a_compatible_BindingValidator()
+    public void Analyzer_reports_an_error_if_a_parameter_has_a_validator_that_does_not_derive_from_a_compatible_BindingValidator()
     {
         // Arrange
         // language=cs
@@ -57,7 +57,7 @@ public class MyCommand : ICommand
     }
 
     [Fact]
-    public void Analyzer_does_not_report_an_error_if_each_specified_parameter_validator_derives_from_a_compatible_BindingValidator()
+    public void Analyzer_does_not_report_an_error_if_a_parameter_has_validators_that_all_derive_from_compatible_BindingValidators()
     {
         // Arrange
         // language=cs

CliFx.Analyzers/CliFx.Analyzers.csproj

@@ -8,7 +8,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.1.0" PrivateAssets="all" />
+    <!-- Keep this dependency as low as possible since we can't bundle it -->
+    <!-- https://github.com/Tyrrrz/CliFx/issues/127 -->
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.8.0" PrivateAssets="all" />
   </ItemGroup>
 
 </Project>

CliFx.Analyzers/ObjectModel/CommandOptionSymbol.cs

@@ -5,8 +5,10 @@ using Microsoft.CodeAnalysis;
 
 namespace CliFx.Analyzers.ObjectModel;
 
-internal partial class CommandOptionSymbol
+internal partial class CommandOptionSymbol : ICommandMemberSymbol
 {
+    public IPropertySymbol Property { get; }
+
     public string? Name { get; }
 
     public char? ShortName { get; }
@@ -16,11 +18,13 @@ internal partial class CommandOptionSymbol
     public IReadOnlyList<ITypeSymbol> ValidatorTypes { get; }
 
     public CommandOptionSymbol(
+        IPropertySymbol property,
         string? name,
         char? shortName,
         ITypeSymbol? converterType,
         IReadOnlyList<ITypeSymbol> validatorTypes)
     {
+        Property = property;
         Name = name;
         ShortName = shortName;
         ConverterType = converterType;
@@ -30,22 +34,25 @@ internal partial class CommandOptionSymbol
 
 internal partial class CommandOptionSymbol
 {
-    private static AttributeData? TryGetOptionAttribute(IPropertySymbol property) =>
-        property
+    private static AttributeData? TryGetOptionAttribute(IPropertySymbol property) => property
         .GetAttributes()
-            .FirstOrDefault(a => a.AttributeClass.DisplayNameMatches(SymbolNames.CliFxCommandOptionAttribute));
+        .FirstOrDefault(a => a.AttributeClass?.DisplayNameMatches(SymbolNames.CliFxCommandOptionAttribute) == true);
 
-    private static CommandOptionSymbol FromAttribute(AttributeData attribute)
+    public static CommandOptionSymbol? TryResolve(IPropertySymbol property)
     {
+        var attribute = TryGetOptionAttribute(property);
+        if (attribute is null)
+            return null;
+
         var name = attribute
             .ConstructorArguments
-            .Where(a => a.Type.DisplayNameMatches("string") || a.Type.DisplayNameMatches("System.String"))
+            .Where(a => a.Type?.SpecialType == SpecialType.System_String)
             .Select(a => a.Value)
             .FirstOrDefault() as string;
 
         var shortName = attribute
             .ConstructorArguments
-            .Where(a => a.Type.DisplayNameMatches("char") || a.Type.DisplayNameMatches("System.Char"))
+            .Where(a => a.Type?.SpecialType == SpecialType.System_Char)
             .Select(a => a.Value)
             .FirstOrDefault() as char?;
 
@@ -64,16 +71,7 @@ internal partial class CommandOptionSymbol
             .Cast<ITypeSymbol>()
             .ToArray();
 
-        return new CommandOptionSymbol(name, shortName, converter, validators);
-    }
-
-    public static CommandOptionSymbol? TryResolve(IPropertySymbol property)
-    {
-        var attribute = TryGetOptionAttribute(property);
-
-        return attribute is not null
-            ? FromAttribute(attribute)
-            : null;
+        return new CommandOptionSymbol(property, name, shortName, converter, validators);
     }
 
     public static bool IsOptionProperty(IPropertySymbol property) =>

CliFx.Analyzers/ObjectModel/CommandParameterSymbol.cs

@@ -5,8 +5,10 @@ using Microsoft.CodeAnalysis;
 
 namespace CliFx.Analyzers.ObjectModel;
 
-internal partial class CommandParameterSymbol
+internal partial class CommandParameterSymbol : ICommandMemberSymbol
 {
+    public IPropertySymbol Property { get; }
+
     public int Order { get; }
 
     public string? Name { get; }
@@ -18,12 +20,14 @@ internal partial class CommandParameterSymbol
     public IReadOnlyList<ITypeSymbol> ValidatorTypes { get; }
 
     public CommandParameterSymbol(
+        IPropertySymbol property,
         int order,
         string? name,
         bool? isRequired,
         ITypeSymbol? converterType,
         IReadOnlyList<ITypeSymbol> validatorTypes)
     {
+        Property = property;
         Order = order;
         Name = name;
         IsRequired = isRequired;
@@ -34,13 +38,16 @@ internal partial class CommandParameterSymbol
 
 internal partial class CommandParameterSymbol
 {
-    private static AttributeData? TryGetParameterAttribute(IPropertySymbol property) =>
-        property
+    private static AttributeData? TryGetParameterAttribute(IPropertySymbol property) => property
         .GetAttributes()
-            .FirstOrDefault(a => a.AttributeClass.DisplayNameMatches(SymbolNames.CliFxCommandParameterAttribute));
+        .FirstOrDefault(a => a.AttributeClass?.DisplayNameMatches(SymbolNames.CliFxCommandParameterAttribute) == true);
 
-    private static CommandParameterSymbol FromAttribute(AttributeData attribute)
+    public static CommandParameterSymbol? TryResolve(IPropertySymbol property)
     {
+        var attribute = TryGetParameterAttribute(property);
+        if (attribute is null)
+            return null;
+
         var order = (int)attribute
             .ConstructorArguments
             .Select(a => a.Value)
@@ -73,16 +80,7 @@ internal partial class CommandParameterSymbol
             .Cast<ITypeSymbol>()
             .ToArray();
 
-        return new CommandParameterSymbol(order, name, isRequired, converter, validators);
-    }
-
-    public static CommandParameterSymbol? TryResolve(IPropertySymbol property)
-    {
-        var attribute = TryGetParameterAttribute(property);
-
-        return attribute is not null
-            ? FromAttribute(attribute)
-            : null;
+        return new CommandParameterSymbol(property, order, name, isRequired, converter, validators);
     }
 
     public static bool IsParameterProperty(IPropertySymbol property) =>

CliFx.Analyzers/ObjectModel/ICommandMemberSymbol.cs

@@ -0,0 +1,21 @@
+using System.Collections.Generic;
+using CliFx.Analyzers.Utils.Extensions;
+using Microsoft.CodeAnalysis;
+
+namespace CliFx.Analyzers.ObjectModel;
+
+internal interface ICommandMemberSymbol
+{
+    IPropertySymbol Property { get; }
+
+    ITypeSymbol? ConverterType { get; }
+
+    IReadOnlyList<ITypeSymbol> ValidatorTypes { get; }
+}
+
+internal static class CommandMemberSymbolExtensions
+{
+    public static bool IsScalar(this ICommandMemberSymbol member) =>
+        member.Property.Type.SpecialType == SpecialType.System_String ||
+        member.Property.Type.TryGetEnumerableUnderlyingType() is null;
+}

CliFx.Analyzers/OptionMustHaveUniqueNameAnalyzer.cs

@@ -15,7 +15,8 @@ public class OptionMustHaveUniqueNameAnalyzer : AnalyzerBase
         : base(
             "Options must have unique names",
             "This option's name must be unique within the command (comparison IS NOT case sensitive). " +
-            "Specified name: '{0}'.")
+            "Specified name: `{0}`. " +
+            "Property bound to another option with the same name: `{1}`.")
     {
     }
 
@@ -55,7 +56,8 @@ public class OptionMustHaveUniqueNameAnalyzer : AnalyzerBase
                 context.ReportDiagnostic(
                     CreateDiagnostic(
                         propertyDeclaration.Identifier.GetLocation(),
-                        option.Name
+                        option.Name,
+                        otherProperty.Name
                     )
                 );
             }

CliFx.Analyzers/OptionMustHaveUniqueShortNameAnalyzer.cs

@@ -14,7 +14,8 @@ public class OptionMustHaveUniqueShortNameAnalyzer : AnalyzerBase
         : base(
             "Options must have unique short names",
             "This option's short name must be unique within the command (comparison IS case sensitive). " +
-            "Specified short name: '{0}'.")
+            "Specified short name: `{0}` " +
+            "Property bound to another option with the same short name: `{1}`.")
     {
     }
 
@@ -54,7 +55,8 @@ public class OptionMustHaveUniqueShortNameAnalyzer : AnalyzerBase
                 context.ReportDiagnostic(
                     CreateDiagnostic(
                         propertyDeclaration.Identifier.GetLocation(),
-                        option.ShortName
+                        option.ShortName,
+                        otherProperty.Name
                     )
                 );
             }

CliFx.Analyzers/OptionMustHaveValidConverterAnalyzer.cs

@@ -37,7 +37,16 @@ public class OptionMustHaveValidConverterAnalyzer : AnalyzerBase
             .FirstOrDefault();
 
         // Value returned by the converter must be assignable to the property type
-        if (converterValueType is null || !property.Type.IsAssignableFrom(converterValueType))
+        var isCompatible =
+            converterValueType is not null && (option.IsScalar()
+                // Scalar
+                ? context.Compilation.IsAssignable(converterValueType, property.Type)
+                // Non-scalar (assume we can handle all IEnumerable types for simplicity)
+                : property.Type.TryGetEnumerableUnderlyingType() is { } enumerableUnderlyingType &&
+                  context.Compilation.IsAssignable(converterValueType, enumerableUnderlyingType)
+            );
+
+        if (!isCompatible)
         {
             context.ReportDiagnostic(
                 CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())

CliFx.Analyzers/OptionMustHaveValidNameAnalyzer.cs

@@ -13,7 +13,7 @@ public class OptionMustHaveValidNameAnalyzer : AnalyzerBase
         : base(
             "Options must have valid names",
             "This option's name must be at least 2 characters long and must start with a letter. " +
-            "Specified name: '{0}'.")
+            "Specified name: `{0}`.")
     {
     }
 

CliFx.Analyzers/OptionMustHaveValidShortNameAnalyzer.cs

@@ -13,7 +13,7 @@ public class OptionMustHaveValidShortNameAnalyzer : AnalyzerBase
         : base(
             "Option short names must be letter characters",
             "This option's short name must be a single letter character. " +
-            "Specified short name: '{0}'.")
+            "Specified short name: `{0}`.")
     {
     }
 

CliFx.Analyzers/OptionMustHaveValidValidatorsAnalyzer.cs

@@ -35,7 +35,11 @@ public class OptionMustHaveValidValidatorsAnalyzer : AnalyzerBase
                 .FirstOrDefault();
 
             // Value passed to the validator must be assignable from the property type
-            if (validatorValueType is null || !validatorValueType.IsAssignableFrom(property.Type))
+            var isCompatible =
+                validatorValueType is not null &&
+                context.Compilation.IsAssignable(property.Type, validatorValueType);
+
+            if (!isCompatible)
             {
                 context.ReportDiagnostic(
                     CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())

CliFx.Analyzers/ParameterMustBeLastIfNonRequiredAnalyzer.cs

@@ -13,7 +13,8 @@ public class ParameterMustBeLastIfNonRequiredAnalyzer : AnalyzerBase
     public ParameterMustBeLastIfNonRequiredAnalyzer()
         : base(
             "Parameters marked as non-required must be the last in order",
-            "This parameter is non-required so it must be the last in order (its order must be highest within the command).")
+            "This parameter is non-required so it must be the last in order (its order must be highest within the command). " +
+            "Property bound to another non-required parameter: `{0}`.")
     {
     }
 
@@ -48,7 +49,10 @@ public class ParameterMustBeLastIfNonRequiredAnalyzer : AnalyzerBase
             if (otherParameter.Order > parameter.Order)
             {
                 context.ReportDiagnostic(
-                    CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())
+                    CreateDiagnostic(
+                        propertyDeclaration.Identifier.GetLocation(),
+                        otherProperty.Name
+                    )
                 );
             }
         }

CliFx.Analyzers/ParameterMustBeLastIfNonScalarAnalyzer.cs

@@ -13,17 +13,11 @@ public class ParameterMustBeLastIfNonScalarAnalyzer : AnalyzerBase
     public ParameterMustBeLastIfNonScalarAnalyzer()
         : base(
             "Parameters of non-scalar types must be the last in order",
-            "This parameter has a non-scalar type so it must be the last in order (its order must be highest within the command).")
+            "This parameter has a non-scalar type so it must be the last in order (its order must be highest within the command). " +
+            "Property bound to another non-scalar parameter: `{0}`.")
     {
     }
 
-    private static bool IsScalar(ITypeSymbol type) =>
-        type.DisplayNameMatches("string") ||
-        type.DisplayNameMatches("System.String") ||
-        !type.AllInterfaces
-            .Select(i => i.ConstructedFrom)
-            .Any(t => t.DisplayNameMatches("System.Collections.Generic.IEnumerable<T>"));
-
     private void Analyze(
         SyntaxNodeAnalysisContext context,
         PropertyDeclarationSyntax propertyDeclaration,
@@ -32,13 +26,13 @@ public class ParameterMustBeLastIfNonScalarAnalyzer : AnalyzerBase
         if (property.ContainingType is null)
             return;
 
-        if (IsScalar(property.Type))
-            return;
-
         var parameter = CommandParameterSymbol.TryResolve(property);
         if (parameter is null)
             return;
 
+        if (parameter.IsScalar())
+            return;
+
         var otherProperties = property
             .ContainingType
             .GetMembers()
@@ -55,7 +49,10 @@ public class ParameterMustBeLastIfNonScalarAnalyzer : AnalyzerBase
             if (otherParameter.Order > parameter.Order)
             {
                 context.ReportDiagnostic(
-                    CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())
+                    CreateDiagnostic(
+                        propertyDeclaration.Identifier.GetLocation(),
+                        otherProperty.Name
+                    )
                 );
             }
         }

CliFx.Analyzers/ParameterMustBeSingleIfNonRequiredAnalyzer.cs

@@ -13,7 +13,8 @@ public class ParameterMustBeSingleIfNonRequiredAnalyzer : AnalyzerBase
     public ParameterMustBeSingleIfNonRequiredAnalyzer()
         : base(
             "Parameters marked as non-required are limited to one per command",
-            "This parameter is non-required so it must be the only such parameter in the command.")
+            "This parameter is non-required so it must be the only such parameter in the command. " +
+            "Property bound to another non-required parameter: `{0}`.")
     {
     }
 
@@ -48,7 +49,10 @@ public class ParameterMustBeSingleIfNonRequiredAnalyzer : AnalyzerBase
             if (otherParameter.IsRequired == false)
             {
                 context.ReportDiagnostic(
-                    CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())
+                    CreateDiagnostic(
+                        propertyDeclaration.Identifier.GetLocation(),
+                        otherProperty.Name
+                    )
                 );
             }
         }

CliFx.Analyzers/ParameterMustBeSingleIfNonScalarAnalyzer.cs

@@ -13,17 +13,11 @@ public class ParameterMustBeSingleIfNonScalarAnalyzer : AnalyzerBase
     public ParameterMustBeSingleIfNonScalarAnalyzer()
         : base(
             "Parameters of non-scalar types are limited to one per command",
-            "This parameter has a non-scalar type so it must be the only such parameter in the command.")
+            "This parameter has a non-scalar type so it must be the only such parameter in the command. " +
+            "Property bound to another non-scalar parameter: `{0}`.")
     {
     }
 
-    private static bool IsScalar(ITypeSymbol type) =>
-        type.DisplayNameMatches("string") ||
-        type.DisplayNameMatches("System.String") ||
-        !type.AllInterfaces
-            .Select(i => i.ConstructedFrom)
-            .Any(t => t.DisplayNameMatches("System.Collections.Generic.IEnumerable<T>"));
-
     private void Analyze(
         SyntaxNodeAnalysisContext context,
         PropertyDeclarationSyntax propertyDeclaration,
@@ -32,10 +26,11 @@ public class ParameterMustBeSingleIfNonScalarAnalyzer : AnalyzerBase
         if (property.ContainingType is null)
             return;
 
-        if (!CommandParameterSymbol.IsParameterProperty(property))
+        var parameter = CommandParameterSymbol.TryResolve(property);
+        if (parameter is null)
             return;
 
-        if (IsScalar(property.Type))
+        if (parameter.IsScalar())
             return;
 
         var otherProperties = property
@@ -47,13 +42,17 @@ public class ParameterMustBeSingleIfNonScalarAnalyzer : AnalyzerBase
 
         foreach (var otherProperty in otherProperties)
         {
-            if (!CommandParameterSymbol.IsParameterProperty(otherProperty))
+            var otherParameter = CommandParameterSymbol.TryResolve(otherProperty);
+            if (otherParameter is null)
                 continue;
 
-            if (!IsScalar(otherProperty.Type))
+            if (!otherParameter.IsScalar())
             {
                 context.ReportDiagnostic(
-                    CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())
+                    CreateDiagnostic(
+                        propertyDeclaration.Identifier.GetLocation(),
+                        otherProperty.Name
+                    )
                 );
             }
         }

CliFx.Analyzers/ParameterMustHaveUniqueNameAnalyzer.cs

@@ -15,7 +15,8 @@ public class ParameterMustHaveUniqueNameAnalyzer : AnalyzerBase
         : base(
             "Parameters must have unique names",
             "This parameter's name must be unique within the command (comparison IS NOT case sensitive). " +
-            "Specified name: '{0}'.")
+            "Specified name: `{0}`. " +
+            "Property bound to another parameter with the same name: `{1}`.")
     {
     }
 
@@ -55,7 +56,8 @@ public class ParameterMustHaveUniqueNameAnalyzer : AnalyzerBase
                 context.ReportDiagnostic(
                     CreateDiagnostic(
                         propertyDeclaration.Identifier.GetLocation(),
-                        parameter.Name
+                        parameter.Name,
+                        otherProperty.Name
                     )
                 );
             }

CliFx.Analyzers/ParameterMustHaveUniqueOrderAnalyzer.cs

@@ -14,7 +14,8 @@ public class ParameterMustHaveUniqueOrderAnalyzer : AnalyzerBase
         : base(
             "Parameters must have unique order",
             "This parameter's order must be unique within the command. " +
-            "Specified order: {0}.")
+            "Specified order: {0}. " +
+            "Property bound to another parameter with the same order: `{1}`.")
     {
     }
 
@@ -48,7 +49,8 @@ public class ParameterMustHaveUniqueOrderAnalyzer : AnalyzerBase
                 context.ReportDiagnostic(
                     CreateDiagnostic(
                         propertyDeclaration.Identifier.GetLocation(),
-                        parameter.Order
+                        parameter.Order,
+                        otherProperty.Name
                     )
                 );
             }

CliFx.Analyzers/ParameterMustHaveValidConverterAnalyzer.cs

@@ -37,7 +37,16 @@ public class ParameterMustHaveValidConverterAnalyzer : AnalyzerBase
             .FirstOrDefault();
 
         // Value returned by the converter must be assignable to the property type
-        if (converterValueType is null || !property.Type.IsAssignableFrom(converterValueType))
+        var isCompatible =
+            converterValueType is not null && (parameter.IsScalar()
+                // Scalar
+                ? context.Compilation.IsAssignable(converterValueType, property.Type)
+                // Non-scalar (assume we can handle all IEnumerable types for simplicity)
+                : property.Type.TryGetEnumerableUnderlyingType() is { } enumerableUnderlyingType &&
+                  context.Compilation.IsAssignable(converterValueType, enumerableUnderlyingType)
+            );
+
+        if (!isCompatible)
         {
             context.ReportDiagnostic(
                 CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())

CliFx.Analyzers/ParameterMustHaveValidValidatorsAnalyzer.cs

@@ -35,7 +35,11 @@ public class ParameterMustHaveValidValidatorsAnalyzer : AnalyzerBase
                 .FirstOrDefault();
 
             // Value passed to the validator must be assignable from the property type
-            if (validatorValueType is null || !validatorValueType.IsAssignableFrom(property.Type))
+            var isCompatible =
+                validatorValueType is not null &&
+                context.Compilation.IsAssignable(property.Type, validatorValueType);
+
+            if (!isCompatible)
             {
                 context.ReportDiagnostic(
                     CreateDiagnostic(propertyDeclaration.Identifier.GetLocation())

CliFx.Analyzers/Utils/Extensions/RoslynExtensions.cs

@@ -29,10 +29,13 @@ internal static class RoslynExtensions
         }
     }
 
-    public static bool IsAssignableFrom(this ITypeSymbol target, ITypeSymbol source) =>
-        SymbolEqualityComparer.Default.Equals(target, source) ||
-        source.GetBaseTypes().Contains(target, SymbolEqualityComparer.Default) ||
-        source.AllInterfaces.Contains(target, SymbolEqualityComparer.Default);
+    public static ITypeSymbol? TryGetEnumerableUnderlyingType(this ITypeSymbol type) => type
+        .AllInterfaces
+        .FirstOrDefault(i => i.ConstructedFrom.SpecialType == SpecialType.System_Collections_Generic_IEnumerable_T)?
+        .TypeArguments[0];
+
+    public static bool IsAssignable(this Compilation compilation, ITypeSymbol source, ITypeSymbol destination) =>
+        compilation.ClassifyConversion(source, destination).Exists;
 
     public static void HandleClassDeclaration(
         this AnalysisContext analysisContext,

CliFx.Benchmarks/CliFx.Benchmarks.csproj

@@ -9,7 +9,7 @@
     <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
     <PackageReference Include="clipr" Version="1.6.1" />
     <PackageReference Include="Cocona" Version="2.0.3" />
-    <PackageReference Include="CommandLineParser" Version="2.8.0" />
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="McMaster.Extensions.CommandLineUtils" Version="4.0.1" />
     <PackageReference Include="PowerArgs" Version="3.6.0" />
     <PackageReference Include="System.CommandLine" Version="2.0.0-beta1.20574.7" />

CliFx.Demo/CliFx.Demo.csproj

@@ -12,7 +12,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\CliFx\CliFx.csproj" />
-    <ProjectReference Include="..\CliFx.Analyzers\CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="Analyzer" />
+    <ProjectReference Include="..\CliFx.Analyzers\CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="analyzer" />
   </ItemGroup>
 
 </Project>

CliFx.Tests.Dummy/CliFx.Tests.Dummy.csproj

@@ -7,7 +7,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\CliFx\CliFx.csproj" />
-    <ProjectReference Include="..\CliFx.Analyzers\CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="Analyzer" />
+    <ProjectReference Include="..\CliFx.Analyzers\CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="analyzer" />
   </ItemGroup>
 
 </Project>

CliFx.Tests.Dummy/Program.cs

@@ -1,4 +1,5 @@
-using System.Reflection;
+using System;
+using System.Reflection;
 using System.Threading.Tasks;
 
 namespace CliFx.Tests.Dummy;
@@ -14,9 +15,17 @@ public static partial class Program
 
 public static partial class Program
 {
-    public static async Task Main() =>
+    public static async Task Main()
+    {
+        // Make sure color codes are not produced because we rely on the output in tests
+        Environment.SetEnvironmentVariable(
+            "DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION",
+            "false"
+        );
+
         await new CliApplicationBuilder()
             .AddCommandsFromThisAssembly()
             .Build()
             .RunAsync();
+    }
 }

CliFx.Tests/CliFx.Tests.csproj

@@ -10,13 +10,14 @@
 
   <ItemGroup>
     <PackageReference Include="Basic.Reference.Assemblies" Version="1.2.4" />
-    <PackageReference Include="CliWrap" Version="3.4.1" />
-    <PackageReference Include="FluentAssertions" Version="6.5.1" />
-    <PackageReference Include="GitHubActionsTestLogger" Version="1.3.0" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.1.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="CliWrap" Version="3.4.4" />
+    <PackageReference Include="FluentAssertions" Version="6.7.0" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.0.0" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.2.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" PrivateAssets="all" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" PrivateAssets="all" />
     <PackageReference Include="coverlet.collector" Version="3.1.2" PrivateAssets="all" />
   </ItemGroup>
 

CliFx.Tests/ConsoleSpecs.cs

@@ -31,7 +31,8 @@ public class ConsoleSpecs : SpecsBase
         var command = "Hello world" | Cli.Wrap("dotnet")
             .WithArguments(a => a
                 .Add(Dummy.Program.Location)
-                .Add("console-test"));
+                .Add("console-test")
+            );
 
         // Act
         var result = await command.ExecuteBufferedAsync();

CliFx.Tests/DirectivesSpecs.cs

@@ -28,7 +28,8 @@ public class DirectivesSpecs : SpecsBase
         var command = Cli.Wrap("dotnet")
             .WithArguments(a => a
                 .Add(Dummy.Program.Location)
-                .Add("[debug]")) | stdOutBuffer;
+                .Add("[debug]")
+            ) | stdOutBuffer;
 
         // Act
         try
@@ -57,7 +58,7 @@ public class DirectivesSpecs : SpecsBase
         }
         catch (OperationCanceledException)
         {
-            // It's expected to fail
+            // This is expected
         }
 
         var stdOut = stdOutBuffer.ToString();

CliFx.Tests/EnvironmentSpecs.cs

@@ -246,9 +246,11 @@ public class Command : ICommand
         var command = Cli.Wrap("dotnet")
             .WithArguments(a => a
                 .Add(Dummy.Program.Location)
-                .Add("env-test"))
+                .Add("env-test")
+            )
             .WithEnvironmentVariables(e => e
-                .Set("ENV_TARGET", "Mars"));
+                .Set("ENV_TARGET", "Mars")
+            );
 
         // Act
         var result = await command.ExecuteBufferedAsync();

CliFx.Tests/TypeActivationSpecs.cs

@@ -4,6 +4,7 @@ using System.Threading.Tasks;
 using CliFx.Infrastructure;
 using CliFx.Tests.Utils;
 using FluentAssertions;
+using Microsoft.Extensions.DependencyInjection;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -87,7 +88,7 @@ public class Command : ICommand
     }
 
     [Fact]
-    public async Task Delegate_type_activator_can_initialize_a_type_using_a_custom_function()
+    public async Task Custom_type_activator_can_initialize_a_type_using_a_given_function()
     {
         // Arrange
         var commandType = DynamicCommandBuilder.Compile(
@@ -110,7 +111,7 @@ public class Command : ICommand
         var application = new CliApplicationBuilder()
             .AddCommand(commandType)
             .UseConsole(FakeConsole)
-            .UseTypeActivator(type => Activator.CreateInstance(type, "hello world")!)
+            .UseTypeActivator(type => Activator.CreateInstance(type, "Hello world")!)
             .Build();
 
         // Act
@@ -123,11 +124,55 @@ public class Command : ICommand
 
         // Assert
         exitCode.Should().Be(0);
-        stdOut.Trim().Should().Be("hello world");
+        stdOut.Trim().Should().Be("Hello world");
     }
 
     [Fact]
-    public async Task Delegate_type_activator_fails_if_the_underlying_function_returns_null()
+    public async Task Custom_type_activator_can_initialize_a_type_using_a_service_provider()
+    {
+        // Arrange
+        var commandType = DynamicCommandBuilder.Compile(
+            // language=cs
+            @"
+[Command]
+public class Command : ICommand
+{
+    private readonly string _foo;
+
+    public Command(string foo) => _foo = foo;
+
+    public ValueTask ExecuteAsync(IConsole console)
+    {
+        console.Output.WriteLine(_foo);
+        return default;
+    }
+}");
+
+        var serviceProvider = new ServiceCollection()
+            .AddSingleton(commandType, Activator.CreateInstance(commandType, "Hello world")!)
+            .BuildServiceProvider();
+
+        var application = new CliApplicationBuilder()
+            .AddCommand(commandType)
+            .UseConsole(FakeConsole)
+            .UseTypeActivator(serviceProvider)
+            .Build();
+
+        // Act
+        var exitCode = await application.RunAsync(
+            Array.Empty<string>(),
+            new Dictionary<string, string>()
+        );
+
+        var stdOut = FakeConsole.ReadOutputString();
+
+        // Assert
+        exitCode.Should().Be(0);
+        stdOut.Trim().Should().Be("Hello world");
+    }
+
+    [Fact]
+    public async Task Custom_type_activator_fails_if_the_underlying_function_returns_null()
     {
         // Arrange
         var commandType = DynamicCommandBuilder.Compile(

CliFx/CliApplicationBuilder.cs

@@ -6,6 +6,7 @@ using System.Reflection;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 using CliFx.Schema;
+using CliFx.Utils;
 using CliFx.Utils.Extensions;
 
 namespace CliFx;
@@ -21,7 +22,7 @@ public partial class CliApplicationBuilder
     private bool _isPreviewModeAllowed = true;
     private string? _title;
     private string? _executableName;
-    private string? _versionText;
+    private string? _version;
     private string? _description;
     private IConsole? _console;
     private ITypeActivator? _typeActivator;
@@ -144,7 +145,7 @@ public partial class CliApplicationBuilder
     /// </remarks>
     public CliApplicationBuilder SetVersion(string version)
     {
-        _versionText = version;
+        _version = version;
         return this;
     }
 
@@ -181,6 +182,12 @@ public partial class CliApplicationBuilder
     public CliApplicationBuilder UseTypeActivator(Func<Type, object> typeActivator) =>
         UseTypeActivator(new DelegateTypeActivator(typeActivator));
 
+    /// <summary>
+    /// Configures the application to use the specified service provider for activating types.
+    /// </summary>
+    public CliApplicationBuilder UseTypeActivator(IServiceProvider serviceProvider) =>
+        UseTypeActivator(serviceProvider.GetService);
+
     /// <summary>
     /// Creates a configured instance of <see cref="CliApplication"/>.
     /// </summary>
@@ -189,7 +196,7 @@ public partial class CliApplicationBuilder
         var metadata = new ApplicationMetadata(
             _title ?? GetDefaultTitle(),
             _executableName ?? GetDefaultExecutableName(),
-            _versionText ?? GetDefaultVersionText(),
+            _version ?? GetDefaultVersionText(),
             _description
         );
 
@@ -210,14 +217,9 @@ public partial class CliApplicationBuilder
 
 public partial class CliApplicationBuilder
 {
-    private static readonly Lazy<Assembly?> EntryAssemblyLazy = new(Assembly.GetEntryAssembly);
-
-    // Entry assembly can be null, for example in tests
-    private static Assembly? EntryAssembly => EntryAssemblyLazy.Value;
-
     private static string GetDefaultTitle()
     {
-        var entryAssemblyName = EntryAssembly?.GetName().Name;
+        var entryAssemblyName = EnvironmentEx.EntryAssembly?.GetName().Name;
         if (string.IsNullOrWhiteSpace(entryAssemblyName))
             return "App";
 
@@ -226,26 +228,39 @@ public partial class CliApplicationBuilder
 
     private static string GetDefaultExecutableName()
     {
-        var entryAssemblyLocation = EntryAssembly?.Location;
+        var entryAssemblyLocation = EnvironmentEx.EntryAssembly?.Location;
         if (string.IsNullOrWhiteSpace(entryAssemblyLocation))
             return "app";
 
-        // The assembly can be an .exe or a .dll, depending on how it was packaged
+        // If the application was launched via matching EXE apphost, use that as the executable name
+        var isLaunchedViaAppHost = string.Equals(
+            EnvironmentEx.ProcessPath,
+            Path.ChangeExtension(entryAssemblyLocation, ".exe"),
+            StringComparison.OrdinalIgnoreCase
+        );
+
+        if (isLaunchedViaAppHost)
+            return Path.GetFileNameWithoutExtension(entryAssemblyLocation);
+
+        // Otherwise, use the entry assembly as the executable name.
+        // Prefix it with `dotnet` if it's a DLL file.
         var isDll = string.Equals(
             Path.GetExtension(entryAssemblyLocation),
             ".dll",
             StringComparison.OrdinalIgnoreCase
         );
 
-        var name = isDll
+        return isDll
             ? "dotnet " + Path.GetFileName(entryAssemblyLocation)
             : Path.GetFileNameWithoutExtension(entryAssemblyLocation);
-
-        return name;
     }
 
-    private static string GetDefaultVersionText() =>
-        EntryAssembly is not null
-            ? "v" + EntryAssembly.GetName().Version.ToSemanticString()
-            : "v1.0";
+    private static string GetDefaultVersionText()
+    {
+        var entryAssemblyVersion = EnvironmentEx.EntryAssembly?.GetName().Version;
+        if (entryAssemblyVersion is null)
+            return "v1.0";
+
+        return "v" + entryAssemblyVersion.ToSemanticString();
+    }
 }

CliFx/CliFx.csproj

@@ -33,10 +33,8 @@
 
   <!-- Pack the analyzer assembly inside the package -->
   <ItemGroup>
-    <ProjectReference Include="../CliFx.Analyzers/CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="Analyzer" />
+    <ProjectReference Include="../CliFx.Analyzers/CliFx.Analyzers.csproj" ReferenceOutputAssembly="false" OutputItemType="analyzer" />
     <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/CliFx.Analyzers.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
-    <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/Microsoft.CodeAnalysis.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
-    <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/Microsoft.CodeAnalysis.CSharp.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
     <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/System.Buffers.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
     <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/System.Collections.Immutable.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
     <None Include="../CliFx.Analyzers/bin/$(Configuration)/netstandard2.0/System.Memory.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />

CliFx/CommandBinder.cs

@@ -169,7 +169,7 @@ internal class CommandBinder
                 : ex.Message;
 
             throw CliFxException.UserError(
-                $"{memberSchema.GetKind()} {memberSchema.GetFormattedIdentifier()} cannot be set from provided argument(s):" +
+                $"{memberSchema.GetKind()} {memberSchema.GetFormattedIdentifier()} cannot be set from the provided argument(s):" +
                 Environment.NewLine +
                 rawValues.Select(v => '<' + v + '>').JoinToString(" ") +
                 Environment.NewLine +

CliFx/Infrastructure/ConsoleReader.cs

@@ -99,10 +99,8 @@ public partial class ConsoleReader : StreamReader
 
 public partial class ConsoleReader
 {
-    internal static ConsoleReader Create(IConsole console, Stream? stream) => new(
+    internal static ConsoleReader Create(IConsole console, Stream stream) => new(
         console,
-        stream is not null
-            ? Stream.Synchronized(stream)
-            : Stream.Null
+        Stream.Synchronized(stream)
     );
 }

CliFx/Infrastructure/ConsoleWriter.cs

@@ -272,10 +272,8 @@ public partial class ConsoleWriter : StreamWriter
 
 public partial class ConsoleWriter
 {
-    internal static ConsoleWriter Create(IConsole console, Stream? stream) => new(
+    internal static ConsoleWriter Create(IConsole console, Stream stream) => new(
         console,
-        stream is not null
-            ? Stream.Synchronized(stream)
-            : Stream.Null
+        Stream.Synchronized(stream)
     ) {AutoFlush = true};
 }

CliFx/Infrastructure/FakeConsole.cs

@@ -59,9 +59,28 @@ public class FakeConsole : IConsole, IDisposable
     /// </summary>
     public FakeConsole(Stream? input = null, Stream? output = null, Stream? error = null)
     {
-        Input = ConsoleReader.Create(this, input);
-        Output = ConsoleWriter.Create(this, output);
-        Error = ConsoleWriter.Create(this, error);
+        Input = ConsoleReader.Create(this, input ?? Stream.Null);
+        Output = ConsoleWriter.Create(this, output ?? Stream.Null);
+        Error = ConsoleWriter.Create(this, error ?? Stream.Null);
+    }
+
+    /// <inheritdoc />
+    public ConsoleKeyInfo ReadKey(bool intercept = false) =>
+        _keys.TryDequeue(out var key)
+            ? key
+            : throw new InvalidOperationException(
+                "Cannot read key because there are no key presses enqueued. " +
+                $"Use the `{nameof(EnqueueKey)}(...)` method to simulate a key press."
+            );
+
+    /// <summary>
+    /// Enqueues a simulated key press, which can then be read by calling <see cref="ReadKey"/>.
+    /// </summary>
+    public void EnqueueKey(ConsoleKeyInfo key) => _keys.Enqueue(key);
+    
+    /// <inheritdoc />
+    public void Clear()
+    {
     }
 
     /// <inheritdoc />
@@ -87,25 +106,6 @@ public class FakeConsole : IConsole, IDisposable
         }
     }
 
-    /// <inheritdoc />
-    public void Clear()
-    {
-    }
-
-    /// <inheritdoc />
-    public ConsoleKeyInfo ReadKey(bool intercept = false) =>
-        _keys.TryDequeue(out var key)
-            ? key
-            : throw new InvalidOperationException(
-                "Cannot read key because there are no key presses enqueued. " +
-                $"Use the `{nameof(EnqueueKey)}(...)` method to simulate a key press."
-            );
-
-    /// <summary>
-    /// Enqueues a simulated key press, which can then be read by calling <see cref="ReadKey"/>.
-    /// </summary>
-    public void EnqueueKey(ConsoleKeyInfo key) => _keys.Enqueue(key);
-
     /// <inheritdoc />
     public virtual void Dispose() => _cancellationTokenSource.Dispose();
 }

CliFx/Infrastructure/IConsole.cs

@@ -64,10 +64,20 @@ public interface IConsole
     /// </summary>
     int CursorTop { get; set; }
 
+    /// <summary>
+    /// Obtains the next character or function key pressed by the user.
+    /// </summary>
+    ConsoleKeyInfo ReadKey(bool intercept = false);
+    
+    /// <summary>
+    /// Clears the console buffer and corresponding console window of display information.
+    /// </summary>
+    void Clear();
+    
     /// <summary>
     /// Registers a handler for the interrupt signal (Ctrl+C) on the console and returns
     /// a token representing the cancellation request.
-    /// Subsequent calls to this method have no side-effects and return the same token.
+    /// Subsequent calls to this method have no side effects and return the same token.
     /// </summary>
     /// <remarks>
     /// <para>
@@ -82,16 +92,6 @@ public interface IConsole
     /// </para>
     /// </remarks>
     CancellationToken RegisterCancellationHandler();
-
-    /// <summary>
-    /// Clears the console buffer and corresponding console window of display information.
-    /// </summary>
-    void Clear();
-
-    /// <summary>
-    /// Obtains the next character or function key pressed by the user.
-    /// </summary>
-    ConsoleKeyInfo ReadKey(bool intercept = false);
 }
 
 /// <summary>

CliFx/Infrastructure/SystemConsole.cs

@@ -42,6 +42,20 @@ public class SystemConsole : IConsole, IDisposable
         set => Console.BackgroundColor = value;
     }
     
+    /// <inheritdoc />
+    public int CursorLeft
+    {
+        get => Console.CursorLeft;
+        set => Console.CursorLeft = value;
+    }
+
+    /// <inheritdoc />
+    public int CursorTop
+    {
+        get => Console.CursorTop;
+        set => Console.CursorTop = value;
+    }
+
     /// <summary>
     /// Initializes an instance of <see cref="SystemConsole"/>.
     /// </summary>
@@ -56,18 +70,10 @@ public class SystemConsole : IConsole, IDisposable
     public void ResetColor() => Console.ResetColor();
 
     /// <inheritdoc />
-    public int CursorLeft
-    {
-        get => Console.CursorLeft;
-        set => Console.CursorLeft = value;
-    }
+    public ConsoleKeyInfo ReadKey(bool intercept = false) => Console.ReadKey(intercept);
     
     /// <inheritdoc />
-    public int CursorTop
-    {
-        get => Console.CursorTop;
-        set => Console.CursorTop = value;
-    }
+    public void Clear() => Console.Clear();
     
     /// <inheritdoc />
     public CancellationToken RegisterCancellationHandler()
@@ -90,12 +96,6 @@ public class SystemConsole : IConsole, IDisposable
         return (_cancellationTokenSource = cts).Token;
     }
     
-    /// <inheritdoc />
-    public void Clear() => Console.Clear();
-
-    /// <inheritdoc />
-    public ConsoleKeyInfo ReadKey(bool intercept = false) => Console.ReadKey(intercept);
-
     /// <inheritdoc />
     public void Dispose()
     {

CliFx/Utils/EnvironmentEx.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Diagnostics;
+using System.Reflection;
+
+namespace CliFx.Utils;
+
+internal static class EnvironmentEx
+{
+    private static readonly Lazy<string?> ProcessPathLazy = new(() =>
+    {
+        using var process = Process.GetCurrentProcess();
+        return process.MainModule?.FileName;
+    });
+
+    public static string? ProcessPath => ProcessPathLazy.Value;
+
+    private static readonly Lazy<Assembly?> EntryAssemblyLazy = new(Assembly.GetEntryAssembly);
+
+    public static Assembly? EntryAssembly => EntryAssemblyLazy.Value;
+}

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <Version>2.2.3</Version>
+    <Version>2.2.6</Version>
     <Company>Tyrrrz</Company>
     <Copyright>Copyright (C) Oleksii Holub</Copyright>
     <LangVersion>latest</LangVersion>

NuGet.config

@@ -2,6 +2,9 @@
 <configuration>
   <packageSources>
     <clear />
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
   </packageSources>
+  <config>
+    <add key="defaultPushSource" value="https://api.nuget.org/v3/index.json" />
+  </config>
 </configuration>

Readme.md

@@ -14,7 +14,7 @@
 **CliFx** is a simple to use, yet powerful framework for building command line applications.
 Its primary goal is to completely take over the user input layer, allowing you to forget about infrastructural concerns and instead focus on writing your application.
 
-## Terms of use
+## Terms of use<sup>[[?]](https://github.com/Tyrrrz/.github/blob/master/docs/why-so-political.md)</sup>
 
 By using this project or its source code, for any purpose and in any shape or form, you grant your **implicit agreement** to all the following statements:
 
@@ -34,7 +34,7 @@ To learn more about the war and how you can help, [click here](https://tyrrrz.me
 - Complete application framework, not just an argument parser
 - Minimum boilerplate and easy to get started
 - Class-first configuration via attributes
-- Comprehensive autogenerated help text
+- Comprehensive auto-generated help text
 - Support for deeply nested command hierarchies
 - Graceful cancellation via interrupt signals
 - Support for reading and writing binary data
@@ -45,13 +45,11 @@ To learn more about the war and how you can help, [click here](https://tyrrrz.me
 
 ## Screenshots
 
-![help screen](.screenshots/help.png)
+![help screen](.assets/help-screen.png)
 
 ## Usage
 
-### Quick start
-
-![quick start animated](https://i.imgur.com/uouNh2u.gif)
+### Application and commands
 
 To turn your program into a command line interface, modify your `Main` method so that it delegates execution to `CliApplication`.
 You can use `CliApplicationBuilder` to fluently create and configure an instance of `CliApplication`:
@@ -67,10 +65,15 @@ public static class Program
 }
 ```
 
-> ⚠️ Ensure that your `Main()` method returns the integer exit code provided by `CliApplication.RunAsync()`, as shown in the above example.
-Exit code is used to communicate execution result to the parent process, so it's important that your program returns it.
+> **Warning**:
+> Ensure that your `Main()` method returns the integer exit code provided by `CliApplication.RunAsync()`, as shown in the above example.
+> Exit code is used to communicate execution result to the parent process, so it's important that your program propagates it.
 
-The code above calls `AddCommandsFromThisAssembly()` to scan and resolve command types defined within the current assembly.
+> **Note**:
+> When calling `CliApplication.RunAsync()`, **CliFx** resolves command line arguments and environment variables from `Environment.GetCommandLineArgs()` and `Environment.GetEnvironmentVariables()` respectively.
+> You can also provide them explicitly if you choose.
+
+The code above uses `AddCommandsFromThisAssembly()` to detect command types defined within the current assembly.
 Commands are entry points, through which the user can interact with your application.
 
 To define a command, create a new class by implementing the `ICommand` interface and annotate it with the `[Command]` attribute:
@@ -92,12 +95,12 @@ public class HelloWorldCommand : ICommand
 In order to implement `ICommand`, the class needs to define an `ExecuteAsync(...)` method.
 This is the method that gets called by the framework when the user decides to execute this command.
 
-As a parameter, this method takes an instance of `IConsole`, which is an abstraction around the system console.
+As the only parameter, this method takes an instance of `IConsole`, which is an abstraction around the system console.
 Use this abstraction in place of `System.Console` whenever you need to write output, read input, or otherwise interact with the console.
 
 With the basic setup above, the user can now run the application and get a greeting in return:
 
-```sh
+```powershell
 > dotnet myapp.dll
 
 Hello world!
@@ -106,7 +109,7 @@ Hello world!
 Out of the box, the application also comes with built-in `--help` and `--version` options.
 They can be used to show help text or application version respectively:
 
-```sh
+```powershell
 > dotnet myapp.dll --help
 
 MyApp v1.0
@@ -119,7 +122,7 @@ OPTIONS
   --version         Shows version information.
 ```
 
-```sh
+```powershell
 > dotnet myapp.dll --version
 
 v1.0
@@ -128,12 +131,12 @@ v1.0
 ### Parameters and options
 
 Commands can be configured to take input from command line arguments.
-To do that, you need to add properties to the command class and annotate them with special attributes.
+To do that, you need to add properties to the command class and bind them using special attributes.
 
 In **CliFx**, there are two types of argument bindings: **parameters** and **options**.
-Parameters are positional arguments identified by the order they appear in, while options represent sets of arguments identified by their name.
+Parameters are bound from arguments based on the order they appear in, while options are bound by their name.
 
-As an example, here's a command that calculates the logarithm of a value, using a parameter binding to specify the input and an option binding to configure the logarithm base:
+As an example, here's a command that calculates logarithm of a value — it uses a parameter binding to specify the input value and an option binding for the logarithm base:
 
 ```csharp
 [Command]
@@ -158,9 +161,13 @@ public class LogCommand : ICommand
 }
 ```
 
+> **Note**:
+> **CliFx** has built-in analyzers that detect common errors in command definitions.
+> Your code will not compile if the command contains duplicate options, overlapping parameters, or otherwise invalid configuration.
+
 In order to execute this command, at a minimum, the user needs to provide the input value:
 
-```sh
+```powershell
 > dotnet myapp.dll 10000
 
 4
@@ -168,7 +175,7 @@ In order to execute this command, at a minimum, the user needs to provide the in
 
 They can also pass the `base` option to override the default logarithm base of 10:
 
-```sh
+```powershell
 > dotnet myapp.dll 729 -b 3
 
 6
@@ -176,7 +183,7 @@ They can also pass the `base` option to override the default logarithm base of 1
 
 In case the user forgets to specify the `value` parameter, the application will exit with an error:
 
-```sh
+```powershell
 > dotnet myapp.dll -b 10
 
 Missing required parameter(s):
@@ -185,7 +192,7 @@ Missing required parameter(s):
 
 Available parameters and options are also listed in the command's help text, which can be accessed by passing the `--help` option:
 
-```sh
+```powershell
 > dotnet myapp.dll --help
 
 MyApp v1.0
@@ -204,14 +211,14 @@ OPTIONS
 
 Overall, parameters and options are both used to consume input from the command line, but they differ in a few important ways:
 
-|                    | Parameters                                                                                            | Options                                                                                         |
-|--------------------|-------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------|
-| **Identification** | Positional (by relative order).                                                                       | Named (by name or short name).                                                                  |
+|                    | Parameter                                                                      | Option                                                                                               |
+|--------------------|--------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------|
+| **Identification** | Positional (by relative order).                                                | Nominal (by name or short name).                                                                     |
 | **Requiredness**   | Required by default. Only the last parameter can be configured to be optional. | Optional by default. Any option can be configured to be required without limitations.                |
-| **Arity**          | Depends on the property type. Only the last parameter can be bound to a non-scalar type (i.e. array). | Depends on the property type. Any option can be bound to a non-scalar type without limitations. |
-| **Fallback**       | —                                                                                                     | Can be configured to use an environment variable as fallback, in case the option isn't set.     |
+| **Arity**          | Only the last parameter can be bound to a non-scalar property (i.e. an array). | Any option can be bound to a non-scalar property without limitations.                                |
+| **Fallback**       | —                                                                              | Can be configured to use an environment variable as fallback if the value isn't explicitly provided. |
 
-As a general guideline, it's recommended to use parameters for required inputs that the command can't function without.
+As a general guideline, use parameters for required inputs that the command can't function without.
 Use options for all other non-required inputs or when specifying the name explicitly makes the usage clearer.
 
 ### Argument syntax
@@ -227,26 +234,26 @@ Here are some examples of how it works:
 - `myapp -xqf bar` sets options `'x'` and `'q'` without value, and option `'f'` to value `"bar"`
 - `myapp -i file1.txt file2.txt` sets option `'i'` to a sequence of values `"file1.txt"` and `"file2.txt"`
 - `myapp -i file1.txt -i file2.txt` sets option `'i'` to a sequence of values `"file1.txt"` and `"file2.txt"`
-- `myapp cmd abc -o` routes to command `cmd` (assuming it's an existing command) with parameter `abc` and sets option `'o'` without value
+- `myapp cmd abc -o` routes to command `cmd` (assuming it's a command) with parameter `abc` and sets option `'o'` without value
 
 Additionally, argument parsing in **CliFx** aims to be as deterministic as possible, ideally yielding the same result regardless of the application configuration.
-In fact, the only context-sensitive part in the parser is the command name resolution, which needs to know the list of available commands in order to discern between arguments that correspond to command name and arguments which map as parameters.
+In fact, the only context-sensitive part in the parser is the command name resolution, which needs to know the list of available commands in order to discern them from parameters.
 
 The parser's context-free nature has several implications on how it consumes arguments.
-For example, passing `myapp -i file1.txt file2.txt` will always be parsed as an option with multiple values, regardless of the arity of the underlying property it's bound to.
+For example, `myapp -i file1.txt file2.txt` will always be parsed as an option with multiple values, regardless of the arity of the underlying property it's bound to.
 Similarly, unseparated arguments in the form of `myapp -ofile` will be treated as five distinct options `'o'`, `'f'`, `'i'`, `'l'`, `'e'`, instead of `'o'` being set to value `"file"`.
 
-Because of these rules, order of arguments is semantically important and must always follow this pattern:
+These rules also make the order of arguments important — command line string is expected to follow this pattern:
 
-```txt
-[directives] [command name] [parameters] [options]
+```powershell
+> myapp [...directives] [command] [...parameters] [...options]
 ```
 
 ### Value conversion
 
-Parameters and options can have the following underlying types:
+Parameters and options can be bound to properties with the following underlying types:
 
-- Standard types
+- Basic types
   - Primitive types (`int`, `bool`, `double`, `ulong`, `char`, etc.)
   - Date and time types (`DateTime`, `DateTimeOffset`, `TimeSpan`)
   - Enum types (converted from either name or numeric value)
@@ -284,7 +291,7 @@ public class FileSizeCalculatorCommand : ICommand
 }
 ```
 
-```sh
+```powershell
 > dotnet myapp.dll file1.bin file2.exe
 
 Total file size: 186368 bytes
@@ -310,7 +317,7 @@ public class FileSizeCalculatorCommand : ICommand
 }
 ```
 
-```sh
+```powershell
 > dotnet myapp.dll --files file1.bin file2.exe
 
 Total file size: 186368 bytes
@@ -366,10 +373,42 @@ public class SurfaceCalculatorCommand : ICommand
 }
 ```
 
+### Environment variables
+
+An option can be configured to use a specific environment variable as fallback.
+If the user does not provide value for such option through command line arguments, the current value of the environment variable will be used instead.
+
+```csharp
+[Command]
+public class AuthCommand : ICommand
+{
+    [CommandOption("token", IsRequired = true, EnvironmentVariable = "AUTH_TOKEN")]
+    public string AuthToken { get; init; }
+
+    public ValueTask ExecuteAsync(IConsole console)
+    {
+        console.Output.WriteLine(AuthToken);
+
+        return default;
+    }
+}
+```
+
+```powershell
+> $env:AUTH_TOKEN="test"
+
+> dotnet myapp.dll
+
+test
+```
+
+Environment variables can be configured for options of non-scalar types (arrays, lists, etc.) as well.
+In such case, the values of the environment variable will be split by `Path.PathSeparator` (`;` on Windows, `:` on Linux).
+
 ### Multiple commands
 
 In order to facilitate a variety of different workflows, command line applications may provide the user with more than just a single command.
-Complex applications may also nest commands within each other, employing a multi-level hierarchical structure.
+Complex applications may also nest commands underneath each other, employing a multi-level hierarchical structure.
 
 With **CliFx**, this is achieved by simply giving each command a unique name through the `[Command]` attribute.
 Commands that have common name segments are considered to be hierarchically related, which affects how they're listed in the help text.
@@ -404,12 +443,12 @@ public class SubCommand : ICommand
 }
 ```
 
-Once configured, the user can execute a specific command by including its name in the passed arguments.
+Once configured, the user can execute a specific command by pre-pending its name to the passed arguments.
 For example, running `dotnet myapp.dll cmd1 arg1 -p 42` will execute `FirstCommand` in the above example.
 
 Requesting help will show direct subcommands of the current command:
 
-```sh
+```powershell
 > dotnet myapp.dll --help
 
 MyApp v1.0
@@ -431,7 +470,7 @@ You can run `dotnet myapp.dll [command] --help` to show help on a specific comma
 
 The user can also refine their help request by querying it on a specific command:
 
-```sh
+```powershell
 > dotnet myapp.dll cmd1 --help
 
 USAGE
@@ -447,8 +486,9 @@ COMMANDS
 You can run `dotnet myapp.dll cmd1 [command] --help` to show help on a specific command.
 ```
 
-> 💡 Defining a default (unnamed) command is not required.
-If it's absent, running the application without specifying a command will just show the root level help text.
+> **Note**:
+> Defining a default (unnamed) command is not required.
+> If it's absent, running the application without specifying a command will just show the root level help text.
 
 ### Reporting errors
 
@@ -481,7 +521,7 @@ public class DivideCommand : ICommand
 }
 ```
 
-```sh
+```powershell
 > dotnet myapp.dll --dividend 10 --divisor 0
 
 Division by zero is not supported.
@@ -492,8 +532,9 @@ Division by zero is not supported.
 133
 ```
 
-> ⚠️ Even though exit codes are represented by 32-bit integers in .NET, using values outside of 8-bit unsigned range will cause an overflow on Unix systems.
-To avoid unexpected results, use numbers between 1 and 255 for exit codes that indicate failure.
+> **Warning**:
+> Even though exit codes are represented by 32-bit integers in .NET, using values outside 8-bit unsigned range will cause an overflow on Unix systems.
+> To avoid unexpected results, use numbers between 1 and 255 for exit codes that indicate failure.
 
 ### Graceful cancellation
 
@@ -525,15 +566,16 @@ public class CancellableCommand : ICommand
 }
 ```
 
-> ⚠️ Forceful termination of a command can only be delayed once.
-If the user issues a second interrupt signal, the process will be killed immediately without waiting for graceful cancellation.
+> **Warning**:
+> Forceful termination of a command can only be delayed once.
+> If the user issues a second interrupt signal, the process will be killed immediately without waiting for graceful cancellation.
 
 ### Type activation
 
 Because **CliFx** takes responsibility for the application's entire lifecycle, it needs to be capable of instantiating various user-defined types at runtime.
 To facilitate that, it uses an interface called `ITypeActivator` that determines how to create a new instance of a given type.
 
-The default implementation of `ITypeActivator` only supports types that have public parameterless constructors, which is sufficient for majority of scenarios.
+The default implementation of `ITypeActivator` only supports types that have public parameterless constructors, which is sufficient for the majority of scenarios.
 However, in some cases you may also want to define a custom initializer, for example when integrating with an external dependency container.
 
 The following example shows how to configure your application to use [`Microsoft.Extensions.DependencyInjection`](https://nuget.org/packages/Microsoft.Extensions.DependencyInjection) as the type activator in **CliFx**:
@@ -555,7 +597,7 @@ public static class Program
 
         return await new CliApplicationBuilder()
             .AddCommandsFromThisAssembly()
-            .UseTypeActivator(serviceProvider.GetService)
+            .UseTypeActivator(serviceProvider)
             .Build()
             .RunAsync();
     }
@@ -652,7 +694,7 @@ To do that, you need to pass the corresponding directive before any other argume
 In order to run the application in debug mode, use the `[debug]` directive.
 This will cause the program to launch in a suspended state, waiting for debugger to be attached to the process:
 
-```sh
+```powershell
 > dotnet myapp.dll [debug] cmd -o
 
 Attach debugger to PID 3148 to continue.
@@ -661,7 +703,7 @@ Attach debugger to PID 3148 to continue.
 To run the application in preview mode, use the `[preview]` directive.
 This will short-circuit the execution and instead print the consumed command line arguments as they were parsed, along with resolved environment variables:
 
-```sh
+```powershell
 > dotnet myapp.dll [preview] cmd arg1 arg2 -o foo --option bar1 bar2
 
 Command line:
@@ -682,38 +724,7 @@ var app = new CliApplicationBuilder()
     .Build();
 ```
 
-### Environment variables
-
-An option can be configured to use a specific environment variable as fallback.
-If the user does not provide value for such option through command line arguments, the current value of the environment variable will be used instead.
-
-```csharp
-[Command]
-public class AuthCommand : ICommand
-{
-    [CommandOption("token", IsRequired = true, EnvironmentVariable = "AUTH_TOKEN")]
-    public string AuthToken { get; init; }
-
-    public ValueTask ExecuteAsync(IConsole console)
-    {
-        console.Output.WriteLine(AuthToken);
-
-        return default;
-    }
-}
-```
-
-```sh
-> $env:AUTH_TOKEN="test"
-
-> dotnet myapp.dll
-
-test
-```
-
-Environment variables can be configured for options of non-scalar types (arrays, lists, etc.) as well.
-In such case, the values of the environment variable will be split by `Path.PathSeparator` (`;` on Windows, `:` on Linux).
-
 ## Etymology
 
-**CliFx** is made out of "Cli" for "Command Line Interface" and "Fx" for "Framework". It's pronounced as "cliff ex".
+**CliFx** is made out of "Cli" for "Command Line Interface" and "Fx" for "Framework".
+It's pronounced as "cliff ex".