Feature Add Attribute Passthrough

README.md

@@ -199,3 +199,58 @@ public partial class MyReactiveClass
     }
 }
 ```
+
+### Usage ReactiveCommand with CanExecute
+```csharp
+using ReactiveUI.SourceGenerators;
+
+public partial class MyReactiveClass
+{
+    private IObservable<bool> _canExecute;
+
+    [Reactive]
+    private string _myProperty1;
+
+    [Reactive]
+    private string _myProperty2;
+
+    public MyReactiveClass()
+    {
+        InitializeCommands();
+        _canExecute = this.WhenAnyValue(x => x.MyProperty1, x => x.MyProperty2, (x, y) => !string.IsNullOrEmpty(x) && !string.IsNullOrEmpty(y));
+    }
+
+    [ReactiveCommand(CanExecute = nameof(_canExecute))]
+    private void Search() { }
+}
+```
+
+### Usage ReactiveCommand with parameterless Attribute pass through
+```csharp
+using ReactiveUI.SourceGenerators;
+
+public partial class MyReactiveClass
+{
+    private IObservable<bool> _canExecute;
+
+    [Reactive]
+    private string _myProperty1;
+
+    [Reactive]
+    private string _myProperty2;
+
+    public MyReactiveClass()
+    {
+        InitializeCommands();
+        _canExecute = this.WhenAnyValue(x => x.MyProperty1, x => x.MyProperty2, (x, y) => !string.IsNullOrEmpty(x) && !string.IsNullOrEmpty(y));
+    }
+
+    [ReactiveCommand(CanExecute = nameof(_canExecute))]
+    [property: JsonIgnore]
+    private void Search() { }
+}
+```
+
+### TODO:
+- Add ReactiveCommand with parameterised Attribute pass through
+- Add ObservableAsProperty to generate from a IObservable creating a property and the property helper wired to the Observable.

src/ReactiveUI.SourceGenerators.Execute/Program.cs

@@ -97,6 +97,7 @@ public TestClass()
     /// Test1s this instance.
     /// </summary>
     [ReactiveCommand(CanExecute = nameof(CanExecuteTest1))]
+    [property: JsonInclude]
     private void Test1() => Console.Out.WriteLine("Test1");
 
     /// <summary>

src/ReactiveUI.SourceGenerators/AnalyzerReleases.Shipped.md

@@ -15,14 +15,10 @@ RXUISG0005 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See
 RXUISG0006 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0006
 RXUISG0007 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0007
 RXUISG0008 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0008
-RXUISG0009 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0009
-RXUISG0010 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0010
-RXUISG0011 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0011
-RXUISG0012 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0012
-RXUISG0013 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0013
-RXUISG0014 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0014
+RXUISG0009 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0009
+RXUISG0010 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0010
+RXUISG0011 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0011
+RXUISG0012 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0012
+RXUISG0013 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0013
+RXUISG0014 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0014
 RXUISG0015 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0015
-RXUISG0016 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0016
-RXUISG0017 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0017
-RXUISG0018 | ReactiveUI.SourceGenerators.ObservableAsPropertyGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0018
-RXUISG0019 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0019

src/ReactiveUI.SourceGenerators/Diagnostics/SuppressionDescriptors.cs

@@ -0,0 +1,24 @@
+// Copyright (c) 2024 .NET Foundation and Contributors. All rights reserved.
+// 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 full license information.
+
+using Microsoft.CodeAnalysis;
+
+namespace ReactiveUI.SourceGenerators.Diagnostics;
+
+internal static class SuppressionDescriptors
+{
+    /// <summary>
+    /// Gets a <see cref="SuppressionDescriptor"/> for a method using [ReactiveCommand] with an attribute list targeting a field or property.
+    /// </summary>
+    public static readonly SuppressionDescriptor FieldOrPropertyAttributeListForReactiveCommandMethod = new(
+        id: "RXUISPR0001",
+        suppressedDiagnosticId: "CS0657",
+        justification: "Methods using [ReactiveCommand] can use [field:] and [property:] attribute lists to forward attributes to the generated fields and properties");
+
+    public static readonly SuppressionDescriptor FieldIsUsedToGenerateAObservableAsPropertyHelper = new(
+        id: "RXUISPR0002",
+        suppressedDiagnosticId: "IDE0052",
+        justification: "Fields using [ObservableAsProperty] are never read");
+}

src/ReactiveUI.SourceGenerators/Diagnostics/Suppressions/ObservableAsPropertyAttributeWithFieldNeverReadDiagnosticSuppressor.cs

@@ -0,0 +1,52 @@
+// Copyright (c) 2024 .NET Foundation and Contributors. All rights reserved.
+// 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 full license information.
+
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using ReactiveUI.SourceGenerators.Extensions;
+using static ReactiveUI.SourceGenerators.Diagnostics.SuppressionDescriptors;
+
+namespace ReactiveUI.SourceGenerators.Diagnostics.Suppressions
+{
+    /// <summary>
+    /// ObservableAsProperty Attribute With Field Never Read Diagnostic Suppressor.
+    /// </summary>
+    /// <seealso cref="Microsoft.CodeAnalysis.Diagnostics.DiagnosticSuppressor" />
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public sealed class ObservableAsPropertyAttributeWithFieldNeverReadDiagnosticSuppressor : DiagnosticSuppressor
+    {
+        /// <inheritdoc/>
+        public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => ImmutableArray.Create(FieldIsUsedToGenerateAObservableAsPropertyHelper);
+
+        /// <inheritdoc/>
+        public override void ReportSuppressions(SuppressionAnalysisContext context)
+        {
+            foreach (var diagnostic in context.ReportedDiagnostics)
+            {
+                var 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) })
+                {
+                    var 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("ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute") is INamedTypeSymbol reactiveCommandSymbol &&
+                        methodSymbol.HasAttributeWithType(reactiveCommandSymbol))
+                    {
+                        context.ReportSuppression(Suppression.Create(FieldIsUsedToGenerateAObservableAsPropertyHelper, diagnostic));
+                    }
+                }
+            }
+        }
+    }
+}

src/ReactiveUI.SourceGenerators/Diagnostics/Suppressions/ReactiveCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor.cs

@@ -0,0 +1,52 @@
+// Copyright (c) 2024 .NET Foundation and Contributors. All rights reserved.
+// 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 full license information.
+
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using ReactiveUI.SourceGenerators.Extensions;
+using static ReactiveUI.SourceGenerators.Diagnostics.SuppressionDescriptors;
+
+namespace ReactiveUI.SourceGenerators.Diagnostics.Suppressions
+{
+    /// <summary>
+    /// ReactiveCommand Attribute With Field Or Property Target Diagnostic Suppressor.
+    /// </summary>
+    /// <seealso cref="DiagnosticSuppressor" />
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public sealed class ReactiveCommandAttributeWithFieldOrPropertyTargetDiagnosticSuppressor : DiagnosticSuppressor
+    {
+        /// <inheritdoc/>
+        public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => ImmutableArray.Create(FieldOrPropertyAttributeListForReactiveCommandMethod);
+
+        /// <inheritdoc/>
+        public override void ReportSuppressions(SuppressionAnalysisContext context)
+        {
+            foreach (var diagnostic in context.ReportedDiagnostics)
+            {
+                var 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) })
+                {
+                    var 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("ReactiveUI.SourceGenerators.ReactiveCommandAttribute") is INamedTypeSymbol reactiveCommandSymbol &&
+                        methodSymbol.HasAttributeWithType(reactiveCommandSymbol))
+                    {
+                        context.ReportSuppression(Suppression.Create(FieldOrPropertyAttributeListForReactiveCommandMethod, diagnostic));
+                    }
+                }
+            }
+        }
+    }
+}

src/ReactiveUI.SourceGenerators/ReactiveCommand/Models/CommandExtensionInfo.cs

@@ -18,7 +18,6 @@ internal record CommandExtensionInfo(
     bool IsObservable,
     string? CanExecuteObservableName,
     CanExecuteTypeInfo? CanExecuteTypeInfo,
-    EquatableArray<AttributeInfo> ForwardedFieldAttributes,
     EquatableArray<AttributeInfo> ForwardedPropertyAttributes)
 {
     private const string UnitTypeName = "global::System.Reactive.Unit";