Fix Bug in IHR0020 for CRTP

src/Common/ITypeSymbolExtensions.cs

@@ -126,11 +126,18 @@ public bool Satisfies(ConstraintInfo? constraints, Compilation compilation)
 
 			foreach (var constraint in constraints.TypeConstraints)
 			{
-				if (compilation.ClassifyConversion(typeSymbol, constraint)
-					is not ({ IsIdentity: true } or { IsImplicit: true, IsReference: true }))
+				if (compilation.ClassifyConversion(typeSymbol, constraint) is { IsIdentity: true } or { IsImplicit: true, IsReference: true })
+					continue;
+
+				if (constraint is INamedTypeSymbol { TypeArguments: [ITypeParameterSymbol] } nts)
 				{
-					return false;
+					var constructed = nts.OriginalDefinition.Construct(typeSymbol);
+
+					if (compilation.ClassifyConversion(typeSymbol, constructed) is { IsIdentity: true } or { IsImplicit: true, IsReference: true })
+						continue;
 				}
+
+				return false;
 			}
 
 			return true;

tests/Immediate.Handlers.Tests/AnalyzerTests/HandlerClassAnalyzerTests/Tests.HandlerUsesBehaviorTypeIsMultiplyInherited.cs

@@ -38,7 +38,7 @@ public override async ValueTask<IEnumerable<User>> HandleAsync(GetUsersQuery.Que
 
 					return response;
 				}
-						}
+			}
 
 			public class UsersService(ILogger<UsersService> logger)
 			{
@@ -102,7 +102,7 @@ public override async ValueTask<IEnumerable<User>> HandleAsync(int request, Canc
 
 					return response;
 				}
-						}
+			}
 
 			public class UsersService(ILogger<UsersService> logger)
 			{

tests/Immediate.Handlers.Tests/AnalyzerTests/HandlerClassAnalyzerTests/Tests.HandlerUsesCrtpBehavior.cs

@@ -0,0 +1,63 @@
+using Immediate.Handlers.Analyzers;
+
+namespace Immediate.Handlers.Tests.AnalyzerTests.HandlerClassAnalyzerTests;
+
+[System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1724:Type names should not match namespaces", Justification = "Not being consumed by other code")]
+public sealed partial class Tests
+{
+	[Fact]
+	public async Task CrtpBehaviorTypeIsValid_DoesNotAlert() =>
+		await AnalyzerTestHelpers.CreateAnalyzerTest<HandlerClassAnalyzer>(
+			"""
+			using System;
+			using System.Collections.Generic;
+			using System.IO;
+			using System.Linq;
+			using System.Net.Http;
+			using System.Threading;
+			using System.Threading.Tasks;
+			using Immediate.Handlers.Shared;
+			using Normal;
+
+			namespace Normal;
+
+			public class User { }
+			public interface IValidationTarget<T>;
+
+			public sealed class ValidationBehavior<TRequest, TResponse> : Behavior<TRequest, TResponse>
+				where TRequest : IValidationTarget<TRequest>
+			{
+				public override async ValueTask<TResponse> HandleAsync(TRequest request, CancellationToken cancellationToken)
+				{
+					return await Next(request, cancellationToken).ConfigureAwait(false);
+				}
+			}
+
+			public class UsersService
+			{
+				public ValueTask<IEnumerable<User>> GetUsers()
+				{
+					return ValueTask.FromResult(Enumerable.Empty<User>());
+				}
+			}
+
+			[Handler]
+			[Behaviors(
+				typeof(ValidationBehavior<,>)
+			)]
+			public sealed partial class GetUsersQuery(UsersService usersService)
+			{
+				public record Query : IValidationTarget<Query>;
+
+				private ValueTask<IEnumerable<User>> HandleAsync(
+					Query _,
+					CancellationToken token)
+				{
+					token.ThrowIfCancellationRequested();
+					return usersService.GetUsers();
+				}
+			}
+			""",
+			DriverReferenceAssemblies.Normal
+		).RunAsync(TestContext.Current.CancellationToken);
+}