Add diagnostic if Handle method is not private (#52)

Author: viceroypenguin

src/Immediate.Handlers.Analyzers/AnalyzerReleases.Shipped.md

@@ -13,3 +13,4 @@ IHR0007 | ImmediateHandler | Error    | BehaviorsAnalyzer
 IHR0008 | ImmediateHandler | Error    | BehaviorsAnalyzer
 IHR0009 | ImmediateHandler | Error | HandlerClassAnalyzer
 IHR0010 | ImmediateHandler | Error | HandlerClassAnalyzer
+IHR0011 | ImmediateHandler | Error | HandlerClassAnalyzer

src/Immediate.Handlers.Analyzers/DiagnosticIds.cs

@@ -14,4 +14,5 @@ internal static class DiagnosticIds
 	public const string IHR0008BehaviorsMustUseUnboundGenerics = "IHR0008";
 	public const string IHR0009HandlerMethodMustBeStatic = "IHR0009";
 	public const string IHR0010HandlerMethodMustBeUnique = "IHR0010";
+	public const string IHR0011HandlerMethodMustBePrivate = "IHR0011";
 }

src/Immediate.Handlers.Analyzers/HandlerClassAnalyzer.cs

@@ -62,6 +62,17 @@ public sealed class HandlerClassAnalyzer : DiagnosticAnalyzer
 			description: "Static handler method must be static."
 		);
 
+	private static readonly DiagnosticDescriptor HandlerMethodMustBePrivate =
+		new(
+			id: DiagnosticIds.IHR0011HandlerMethodMustBePrivate,
+			title: "Handler method must be private",
+			messageFormat: "Method '{0}' must not conflict with another static handler method",
+			category: "ImmediateHandler",
+			defaultSeverity: DiagnosticSeverity.Error,
+			isEnabledByDefault: true,
+			description: "Static handler method must be static."
+		);
+
 	public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } =
 		ImmutableArray.Create(
 			[
@@ -70,6 +81,7 @@ public sealed class HandlerClassAnalyzer : DiagnosticAnalyzer
 				HandlerMustNotBeNestedInAnotherClass,
 				HandlerMethodMustBeStatic,
 				HandlerMethodMustBeUnique,
+				HandlerMethodMustBePrivate,
 			]);
 
 	public override void Initialize(AnalysisContext context)
@@ -164,7 +176,19 @@ private static void AnalyzeSymbol(SymbolAnalysisContext context)
 						Diagnostic.Create(
 							HandlerMethodMustReturnTask,
 							methodSymbol.Locations[0],
-							methodSymbol.Name)
+							methodSymbol.Name
+						)
+					);
+				}
+
+				if (methodSymbol.DeclaredAccessibility is not Accessibility.Private)
+				{
+					context.ReportDiagnostic(
+						Diagnostic.Create(
+							HandlerMethodMustBePrivate,
+							methodSymbol.Locations[0],
+							methodSymbol.Name
+						)
 					);
 				}
 

tests/Immediate.Handlers.Tests/AnalyzerTests/AnalyzerTestHelpers.cs

@@ -9,9 +9,7 @@ public static class AnalyzerTestHelpers
 {
 	public static CSharpAnalyzerTest<TAnalyzer, DefaultVerifier> CreateAnalyzerTest<TAnalyzer>(
 		string inputSource,
-		DriverReferenceAssemblies assemblies,
-		IEnumerable<DiagnosticResult> expectedDiagnostics
-	)
+		DriverReferenceAssemblies assemblies)
 		where TAnalyzer : DiagnosticAnalyzer, new()
 	{
 		var csTest = new CSharpAnalyzerTest<TAnalyzer, DefaultVerifier>
@@ -31,9 +29,6 @@ IEnumerable<DiagnosticResult> expectedDiagnostics
 		csTest.TestState.AdditionalReferences
 			.AddRange(assemblies.GetAdditionalReferences());
 
-		csTest.TestState.ExpectedDiagnostics
-			.AddRange(expectedDiagnostics);
-
 		return csTest;
 	}
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/BehaviorAnalyzerTests/Tests.BehaviorTypeDoesNotHaveTwoGenericParameters.cs

@@ -72,7 +72,6 @@ private static ValueTask<IEnumerable<User>> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/BehaviorAnalyzerTests/Tests.BehaviorTypeDoesNotInheritFromGenericBehavior.cs

@@ -71,7 +71,6 @@ private static ValueTask<IEnumerable<User>> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/BehaviorAnalyzerTests/Tests.BehaviorTypeDoesNotUseUnboundedReference.cs

@@ -68,7 +68,6 @@ private static ValueTask<IEnumerable<User>> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/BehaviorAnalyzerTests/Tests.BehaviorTypeIsUsedMoreThanOnce.cs

@@ -70,7 +70,6 @@ private static ValueTask<IEnumerable<User>> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/BehaviorAnalyzerTests/Tests.BehaviorTypeIsValid.cs

@@ -79,7 +79,6 @@ private static ValueTask<IEnumerable<User>> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -25,7 +25,6 @@ public static class {|IHR0001:GetUsersQuery|}
 				public record Query;
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -45,7 +45,6 @@ public ValueTask<IEnumerable<User>> GetUsers()
 
 			public interface ILogger<T>;
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -39,7 +39,6 @@ private ValueTask<int> Handle(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -37,7 +37,6 @@ private async ValueTask Handle(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -0,0 +1,37 @@
+using Immediate.Handlers.Analyzers;
+using Immediate.Handlers.Tests.Helpers;
+
+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 partial class Tests
+{
+	[Fact]
+	public async Task HandleMethodIsNotPrivate_AlertDiagnostic() =>
+		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;
+
+			[Handler]
+			public class GetUsersQuery
+			{
+				public record Query;
+			
+				public static ValueTask<int> {|IHR0011:HandleAsync|}(
+					Query _,
+					CancellationToken token)
+				{
+					return ValueTask.FromResult(0);
+				}
+			}
+			""",
+			DriverReferenceAssemblies.Normal
+		).RunAsync();
+}

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

@@ -53,7 +53,6 @@ public ValueTask<IEnumerable<User>> GetUsers()
 
 			public interface ILogger<T>;
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -39,7 +39,6 @@ public record Query;
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

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

@@ -33,7 +33,6 @@ private static ValueTask<int> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/RenderModeAnalyzerTests/Tests.RenderModeCast.cs

@@ -35,7 +35,6 @@ private static ValueTask<int> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/RenderModeAnalyzerTests/Tests.RenderModeIsNone.cs

@@ -35,7 +35,6 @@ private static ValueTask<int> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }

tests/Immediate.Handlers.Tests/AnalyzerTests/RenderModeAnalyzerTests/Tests.RenderModeIsNormal.cs

@@ -35,7 +35,6 @@ private static ValueTask<int> HandleAsync(
 				}
 			}
 			""",
-			DriverReferenceAssemblies.Normal,
-			[]
+			DriverReferenceAssemblies.Normal
 		).RunAsync();
 }