Required options type to be annotated with [OptionsType] attribute

README.md

@@ -55,6 +55,7 @@ partial class Program
     }
 }
 
+[OptionsType]
 class Options
 {
     [Option('v'), HelpInfo("Enables verbose logging")]

src/ArgumentParsing.Generators/AnalyzerReleases.Unshipped.md

@@ -1 +1,5 @@
-
+### New Rules
+
+Rule ID | Category | Severity | Notes
+--------|----------|----------|-------
+ARGP0034 | ArgumentParsing | Error |

src/ArgumentParsing.Generators/ArgumentParserGenerator.Extract.cs

@@ -55,7 +55,11 @@ private static (ArgumentParserInfo? ArgumentParserInfo, OptionsHelpInfo? Options
             return default;
         }
 
-        if (optionsType is not INamedTypeSymbol { SpecialType: SpecialType.None, TypeKind: TypeKind.Class or TypeKind.Struct } namedOptionsType || !namedOptionsType.Constructors.Any(c => c.Parameters.Length == 0))
+        var optionsTypeAttributeType = compilation.GetTypeByMetadataName("ArgumentParsing.OptionsTypeAttribute")!;
+
+        if (optionsType is not INamedTypeSymbol { SpecialType: SpecialType.None, TypeKind: TypeKind.Class or TypeKind.Struct } namedOptionsType ||
+            !namedOptionsType.Constructors.Any(c => c.Parameters.Length == 0) ||
+            !namedOptionsType.GetAttributes().Any(a => a.AttributeClass?.Equals(optionsTypeAttributeType, SymbolEqualityComparer.Default) == true))
         {
             return default;
         }

src/ArgumentParsing.Generators/Diagnostics/Analyzers/ArgumentParserAnalyzer.ParserSignatureAnalysis.cs

@@ -68,6 +68,7 @@ private static void AnalyzeParserSignature(SymbolAnalysisContext context, KnownT
         if (returnType.TypeKind != TypeKind.Error)
         {
             var returnTypeSyntax = ((MethodDeclarationSyntax)method.DeclaringSyntaxReferences.First().GetSyntax(context.CancellationToken)).ReturnType;
+            var genericArgumentErrorSyntax = returnTypeSyntax is GenericNameSyntax { TypeArgumentList.Arguments: [var genericArgument] } ? genericArgument : returnTypeSyntax;
 
             if (returnType is not INamedTypeSymbol { TypeArguments: [var optionsType] } namedReturnType ||
                 !namedReturnType.ConstructedFrom.Equals(knownTypes.ParseResultOfTType, SymbolEqualityComparer.Default))
@@ -80,13 +81,17 @@ private static void AnalyzeParserSignature(SymbolAnalysisContext context, KnownT
             {
                 if (optionsType.TypeKind != TypeKind.Error)
                 {
-                    var errorNode = returnTypeSyntax is GenericNameSyntax { TypeArgumentList.Arguments: [var genericArgument] } ? genericArgument : returnTypeSyntax;
-
                     context.ReportDiagnostic(
                         Diagnostic.Create(
-                            DiagnosticDescriptors.InvalidOptionsType, errorNode.GetLocation()));
+                            DiagnosticDescriptors.InvalidOptionsType, genericArgumentErrorSyntax.GetLocation()));
                 }
             }
+            else if (!namedOptionsType.GetAttributes().Any(a => a.AttributeClass?.Equals(knownTypes.OptionsTypeAttributeType, SymbolEqualityComparer.Default) == true))
+            {
+                context.ReportDiagnostic(
+                    Diagnostic.Create(
+                        DiagnosticDescriptors.OptionsTypeMustBeAnnotatedWithAttribute, genericArgumentErrorSyntax.GetLocation()));
+            }
             else
             {
                 if (namedOptionsType.DeclaredAccessibility < Accessibility.Internal)

src/ArgumentParsing.Generators/Diagnostics/Analyzers/ArgumentParserAnalyzer.cs

@@ -41,7 +41,8 @@ public sealed partial class ArgumentParserAnalyzer : DiagnosticAnalyzer
             DiagnosticDescriptors.InvalidRemainingParametersPropertyType,
             // ARGP0031
             DiagnosticDescriptors.TooLowAccessibilityOfOptionsType,
-            DiagnosticDescriptors.NoOptionNames);
+            DiagnosticDescriptors.NoOptionNames,
+            DiagnosticDescriptors.OptionsTypeMustBeAnnotatedWithAttribute);
 
     public override void Initialize(AnalysisContext context)
     {
@@ -55,6 +56,7 @@ public override void Initialize(AnalysisContext context)
             {
                 GeneratedArgumentParserAttributeType = comp.GetTypeByMetadataName("ArgumentParsing.GeneratedArgumentParserAttribute")!,
                 ParseResultOfTType = comp.GetTypeByMetadataName("ArgumentParsing.Results.ParseResult`1")!,
+                OptionsTypeAttributeType = comp.GetTypeByMetadataName("ArgumentParsing.OptionsTypeAttribute")!,
                 OptionAttributeType = comp.GetTypeByMetadataName("ArgumentParsing.OptionAttribute")!,
                 ParameterAttributeType = comp.GetTypeByMetadataName("ArgumentParsing.ParameterAttribute")!,
                 RemainingParametersAttributeType = comp.GetTypeByMetadataName("ArgumentParsing.RemainingParametersAttribute")!,
@@ -75,6 +77,8 @@ private readonly struct KnownTypes
 
         public required INamedTypeSymbol ParseResultOfTType { get; init; }
 
+        public required INamedTypeSymbol OptionsTypeAttributeType { get; init; }
+
         public required INamedTypeSymbol OptionAttributeType { get; init; }
 
         public required INamedTypeSymbol ParameterAttributeType { get; init; }

src/ArgumentParsing.Generators/Diagnostics/DiagnosticDescriptors.cs

@@ -244,4 +244,12 @@ public static class DiagnosticDescriptors
         category: ArgumentParsingCategoryName,
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor OptionsTypeMustBeAnnotatedWithAttribute = new(
+        id: "ARGP0034",
+        title: "Option type must be annotated with [OptionsType] attribute",
+        messageFormat: "Option type must be annotated with [OptionsType] attribute",
+        category: ArgumentParsingCategoryName,
+        defaultSeverity: DiagnosticSeverity.Error,
+        isEnabledByDefault: true);
 }

src/ArgumentParsing/OptionsTypeAttribute.cs

@@ -0,0 +1,9 @@
+namespace ArgumentParsing;
+
+/// <summary>
+/// Indicates an options type, i.e. type, parsed arguments are mapped to
+/// </summary>
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]
+public sealed class OptionsTypeAttribute : Attribute
+{
+}

tests/ArgumentParsing.Tests.Functional/MixedFlagOptionsAndParametersTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedFlagOptionsAndParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('f', "flag")]

tests/ArgumentParsing.Tests.Functional/MixedFlagsOptionsTests.cs

@@ -5,6 +5,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedFlagsOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('f')]

tests/ArgumentParsing.Tests.Functional/MixedNullableOptionsTests.cs

@@ -5,6 +5,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedNullableOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('b')]

tests/ArgumentParsing.Tests.Functional/MixedNullableParametersTests.cs

@@ -5,6 +5,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedNullableParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/MixedSequenceOptionsTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedSequenceOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('s')]

tests/ArgumentParsing.Tests.Functional/MixedStringOptionsAndParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class MixedStringOptionsAndParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('o')]

tests/ArgumentParsing.Tests.Functional/SampleSumAppTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SampleSumAppTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('v')]

tests/ArgumentParsing.Tests.Functional/SimpleCharOptionsTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleCharOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('c')]

tests/ArgumentParsing.Tests.Functional/SimpleCharParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleCharParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleCharRemainingParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleCharRemainingParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleEnumOptionsTests.cs

@@ -11,6 +11,7 @@ private enum MyEnum
         EnumValue1, EnumValue2
     }
 
+    [OptionsType]
     private sealed class Options
     {
         [Option('e')]

tests/ArgumentParsing.Tests.Functional/SimpleEnumParametersTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleEnumParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleEnumRemainingParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleEnumRemainingParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleFlagOptionsTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleFlagOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('a')]

tests/ArgumentParsing.Tests.Functional/SimpleFlagParametersTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleFlagParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleFlagRemainingParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleFlagRemainingParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleHelpCommandTest.cs

@@ -10,6 +10,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleHelpCommandTest
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('o'), HelpInfo("Option help description")]

tests/ArgumentParsing.Tests.Functional/SimpleIntegerRemainingParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleIntegerRemainingParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleNullableFlagOptionsTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleNullableFlagOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('a', "flag-a")]

tests/ArgumentParsing.Tests.Functional/SimpleNumericOptionsTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleNumericOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('i')]

tests/ArgumentParsing.Tests.Functional/SimpleNumericParametersTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleNumericParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleRequiredOptionsTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleRequiredOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('r')]

tests/ArgumentParsing.Tests.Functional/SimpleRequiredParametersTests.cs

@@ -8,6 +8,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleRequiredParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleStringOptionsTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleStringOptionsTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Option('a')]

tests/ArgumentParsing.Tests.Functional/SimpleStringParametersTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleStringParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleStringRemainingParametersTests.cs

@@ -6,6 +6,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleStringRemainingParametersTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
         [Parameter(0)]

tests/ArgumentParsing.Tests.Functional/SimpleVersionCommandTests.cs

@@ -7,6 +7,7 @@ namespace ArgumentParsing.Tests.Functional;
 public sealed partial class SimpleVersionCommandTests
 {
     #region OptionsAndParser
+    [OptionsType]
     private sealed class Options
     {
     }