Add RelayCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor

Author: Sergio0694

src/CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.projitems

@@ -45,6 +45,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\Analyzers\FieldWithOrphanedDependentObservablePropertyAttributesAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\Analyzers\FieldReferenceForObservablePropertyFieldAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\Analyzers\UnsupportedCSharpLanguageVersionAnalyzer.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\Suppressors\RelayCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\Suppressors\ObservablePropertyAttributeWithPropertyTargetDiagnosticSuppressor.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\DiagnosticDescriptors.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Diagnostics\SuppressionDescriptors.cs" />

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/SuppressionDescriptors.cs

@@ -12,10 +12,18 @@ namespace CommunityToolkit.Mvvm.SourceGenerators.Diagnostics;
 internal static class SuppressionDescriptors
 {
     /// <summary>
-    /// Gets a <see cref="SuppressionDescriptor"/> for a field using [ObservableProperty] with on attribute list targeting a property.
+    /// Gets a <see cref="SuppressionDescriptor"/> for a field using [ObservableProperty] with an attribute list targeting a property.
     /// </summary>
     public static readonly SuppressionDescriptor PropertyAttributeListForObservablePropertyField = new(
         id: "MVVMTKSPR0001",
         suppressedDiagnosticId: "CS0657",
         justification: "Fields using [ObservableProperty] can use [property:] attribute lists to forward attributes to the generated properties");
+
+    /// <summary>
+    /// Gets a <see cref="SuppressionDescriptor"/> for a method using [RelayCommand] with an attribute list targeting a field or property.
+    /// </summary>
+    public static readonly SuppressionDescriptor FieldOrPropertyAttributeListForRelayCommandMethod = new(
+        id: "MVVMTKSPR0002",
+        suppressedDiagnosticId: "CS0657",
+        justification: "Methods using [RelayCommand] can use [field:] and [property:] attribute lists to forward attributes to the generated fields and properties");
 }

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Suppressors/ObservablePropertyAttributeWithPropertyTargetDiagnosticSuppressor.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Immutable;
-using System.Linq;
+using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -19,7 +19,7 @@ namespace CommunityToolkit.Mvvm.SourceGenerators;
 /// <para>
 /// That is, this diagnostic suppressor will suppress the following diagnostic:
 /// <code>
-/// public class MyViewModel : ObservableObject
+/// public partial class MyViewModel : ObservableObject
 /// {
 ///     [ObservableProperty]
 ///     [property: JsonPropertyName("Name")]
@@ -53,7 +53,7 @@ public override void ReportSuppressions(SuppressionAnalysisContext context)
                 // Check if the field is using [ObservableProperty], in which case we should suppress the warning
                 if (declaredSymbol is IFieldSymbol fieldSymbol &&
                     semanticModel.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservablePropertyAttribute") is INamedTypeSymbol observablePropertySymbol &&
-                    fieldSymbol.GetAttributes().Select(attribute => attribute.AttributeClass).Contains(observablePropertySymbol, SymbolEqualityComparer.Default))
+                    fieldSymbol.HasAttributeWithType(observablePropertySymbol))
                 {
                     context.ReportSuppression(Suppression.Create(PropertyAttributeListForObservablePropertyField, diagnostic));
                 }

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Suppressors/RelayCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor.cs

@@ -0,0 +1,65 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Immutable;
+using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using static CommunityToolkit.Mvvm.SourceGenerators.Diagnostics.SuppressionDescriptors;
+
+namespace CommunityToolkit.Mvvm.SourceGenerators;
+
+/// <summary>
+/// <para>
+/// A diagnostic suppressor to suppress CS0657 warnings for methods with [RelayCommand] using a [field:] or [property:] attribute list.
+/// </para>
+/// <para>
+/// That is, this diagnostic suppressor will suppress the following diagnostic:
+/// <code>
+/// public partial class MyViewModel : ObservableObject
+/// {
+///     [RelayCommand]
+///     [field: JsonIgnore]
+///     [property: SomeOtherAttribute]
+///     private void DoSomething()
+///     {
+///     }
+/// }
+/// </code>
+/// </para>
+/// </summary>
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class RelayCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor : DiagnosticSuppressor
+{
+    /// <inheritdoc/>
+    public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => ImmutableArray.Create(FieldOrPropertyAttributeListForRelayCommandMethod);
+
+    /// <inheritdoc/>
+    public override void ReportSuppressions(SuppressionAnalysisContext context)
+    {
+        foreach (Diagnostic diagnostic in context.ReportedDiagnostics)
+        {
+            SyntaxNode? syntaxNode = diagnostic.Location.SourceTree?.GetRoot(context.CancellationToken).FindNode(diagnostic.Location.SourceSpan);
+
+            // Check that the target is effectively [field:] or [property:] over a method declaration, which is the case we're looking for
+            if (syntaxNode is AttributeTargetSpecifierSyntax { Parent.Parent: MethodDeclarationSyntax methodDeclaration, Identifier: SyntaxToken(SyntaxKind.FieldKeyword or SyntaxKind.PropertyKeyword) })
+            {
+                SemanticModel semanticModel = context.GetSemanticModel(syntaxNode.SyntaxTree);
+
+                // Get the method symbol from the first variable declaration
+                ISymbol? declaredSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration, context.CancellationToken);
+
+                // Check if the method is using [RelayCommand], in which case we should suppress the warning
+                if (declaredSymbol is IMethodSymbol methodSymbol &&
+                    semanticModel.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.Input.RelayCommandAttribute") is INamedTypeSymbol relayCommandSymbol &&
+                    methodSymbol.HasAttributeWithType(relayCommandSymbol))
+                {
+                    context.ReportSuppression(Suppression.Create(FieldOrPropertyAttributeListForRelayCommandMethod, diagnostic));
+                }
+            }
+        }
+    }
+}