feature: Add XML doc comment support for generated properties (#377)

* Add XML doc comment support for generated properties

This update enhances the source generator to extract and include XML documentation comments for generated properties, improving IntelliSense and documentation. It also updates the PropertyInfo model to store XML comments, adjusts code generation to use these comments, and adds a summary for an internal test property. Minor code cleanup and a new .slnx solution file are included.

* Delete ReactiveUI.SourceGenerators.sln

* Preserve XML documentation in generated commands

Added support to extract and include XML documentation comments from method symbols into the generated command properties. This helps retain developer documentation in the generated code for better maintainability and IntelliSense support.

Author: ChrisPulman

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactivePropertiesCalledValue#TestNs.TestVM.Properties.g.verified.cs

@@ -10,7 +10,7 @@ namespace TestNs
         public partial class TestVM
     {
 
-        /// <inheritdoc cref="this.value"/>
+        /// <inheritdoc cref="value"/>
         [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
         public string Value
         { 

src/ReactiveUI.SourceGenerators.Execute/TestViewModel.cs

@@ -358,6 +358,9 @@ public TestViewModel()
     [ObservableAsProperty(InitialValue = "10")]
     public partial int ObservableAsPropertyFromProperty { get; }
 
+    /// <summary>
+    /// Gets or sets the value for internal use within the partial class or assembly.
+    /// </summary>
     [Reactive]
     internal partial int InternalPartialPropertyTest { get; set; }
 

src/ReactiveUI.SourceGenerators.Roslyn/Core/Extensions/FieldSyntaxExtensions.cs

@@ -4,7 +4,9 @@
 // See the LICENSE file in the project root for full license information.
 
 using System.Globalization;
+using System.Linq;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 using ReactiveUI.SourceGenerators.Helpers;
 
 namespace ReactiveUI.SourceGenerators.Extensions;

src/ReactiveUI.SourceGenerators.Roslyn/Reactive/Models/PropertyInfo.cs

@@ -23,4 +23,5 @@ internal sealed record PropertyInfo(
     string UseRequired,
     bool IsProperty,
     string PropertyAccessModifier,
-    EquatableArray<string> AlsoNotify);
+    EquatableArray<string> AlsoNotify,
+    string? XmlComment);

src/ReactiveUI.SourceGenerators.Roslyn/Reactive/ReactiveGenerator.Execute.cs

@@ -155,6 +155,19 @@ public sealed partial class ReactiveGenerator
 
         token.ThrowIfCancellationRequested();
 
+        var xmlTrivia = propertySymbol.GetDocumentationCommentXml(cancellationToken: token);
+
+        // Remove Member attributes from xmlTrivia on the first and last lines
+        if (xmlTrivia?.Length > 0)
+        {
+            var s = xmlTrivia.Split('\n').ToList();
+            s.RemoveAt(0);
+            s.Remove(s.Last());
+            s.Remove(s.Last());
+            xmlTrivia = string.Concat(s.Select(c => "        /// " + c.TrimStart() + "\n"));
+            xmlTrivia = xmlTrivia.TrimEnd();
+        }
+
         return new(
             new(
             targetInfo,
@@ -169,19 +182,20 @@ public sealed partial class ReactiveGenerator
             useRequired,
             true,
             propertyAccessModifier!,
-            alsoNotify),
+            alsoNotify,
+            xmlTrivia),
             builder.ToImmutable());
     }
 #endif
 
-        /// <summary>
-        /// Gets the observable method information.
-        /// </summary>
-        /// <param name="context">The context.</param>
-        /// <param name="token">The token.</param>
-        /// <returns>
-        /// The value.
-        /// </returns>
+    /// <summary>
+    /// Gets the observable method information.
+    /// </summary>
+    /// <param name="context">The context.</param>
+    /// <param name="token">The token.</param>
+    /// <returns>
+    /// The value.
+    /// </returns>
     private static Result<PropertyInfo?>? GetVariableInfo(in GeneratorAttributeSyntaxContext context, CancellationToken token)
     {
         using var builder = ImmutableArrayBuilder<DiagnosticInfo>.Rent();
@@ -300,7 +314,8 @@ public sealed partial class ReactiveGenerator
             useRequired,
             false,
             "public",
-            alsoNotify),
+            alsoNotify,
+            string.Empty),
             builder.ToImmutable());
     }
 
@@ -393,12 +408,18 @@ private static string GetPropertySyntax(PropertyInfo propertyInfo)
 """;
         }
 
+        var docSource = string.Empty;
         if (propertyInfo.IsProperty)
         {
+            docSource = !string.IsNullOrWhiteSpace(propertyInfo.XmlComment)
+                ? propertyInfo.XmlComment
+                : $$"""        /// <inheritdoc cref="{{propertyInfo.PropertyName}}"/>""";
+
             propertyAttributes = string.Join("\n        ", AttributeDefinitions.ExcludeFromCodeCoverage);
         }
         else
         {
+            docSource = $$"""        /// <inheritdoc cref="{{getFieldName}}"/>""";
             propertyAttributes = string.Join("\n        ", AttributeDefinitions.ExcludeFromCodeCoverage.Concat(propertyInfo.ForwardedAttributes));
         }
 
@@ -416,7 +437,7 @@ private static string GetPropertySyntax(PropertyInfo propertyInfo)
             return
 $$"""
         {{fieldSyntax}}
-        /// <inheritdoc cref="{{setFieldName}}"/>
+{{docSource}}
         [global::System.CodeDom.Compiler.GeneratedCode("{{GeneratorName}}", "{{GeneratorVersion}}")]
         {{propertyAttributes}}
         {{accessModifier}}{{propertyInfo.Inheritance}} {{propertyInfo.UseRequired}}{{partialModifier}}{{propertyInfo.TypeNameWithNullabilityAnnotations}} {{propertyInfo.PropertyName}}
@@ -434,7 +455,7 @@ private static string GetPropertySyntax(PropertyInfo propertyInfo)
         return
 $$"""
         {{fieldSyntax}}
-        /// <inheritdoc cref="{{setFieldName}}"/>
+{{docSource}}
         [global::System.CodeDom.Compiler.GeneratedCode("{{GeneratorName}}", "{{GeneratorVersion}}")]
         {{propertyAttributes}}
         {{accessModifier}}{{propertyInfo.Inheritance}} {{propertyInfo.UseRequired}}{{partialModifier}}{{propertyInfo.TypeNameWithNullabilityAnnotations}} {{propertyInfo.PropertyName}}

src/ReactiveUI.SourceGenerators.Roslyn/ReactiveCommand/Models/CommandInfo.cs

@@ -19,7 +19,8 @@ internal record CommandInfo(
     CanExecuteTypeInfo? CanExecuteTypeInfo,
     string? OutputScheduler,
     EquatableArray<string> ForwardedPropertyAttributes,
-    string AccessModifier)
+    string AccessModifier,
+    string? XmlComment)
 {
     private const string UnitTypeName = "global::System.Reactive.Unit";
 

src/ReactiveUI.SourceGenerators.Roslyn/ReactiveCommand/ReactiveCommandGenerator.Execute.cs

@@ -123,6 +123,19 @@ public partial class ReactiveCommandGenerator
 
         token.ThrowIfCancellationRequested();
 
+        var xmlTrivia = methodSymbol.GetDocumentationCommentXml(cancellationToken: token);
+
+        // Remove Member attributes from xmlTrivia on the first and last lines
+        if (xmlTrivia?.Length > 0)
+        {
+            var s = xmlTrivia.Split('\n').ToList();
+            s.RemoveAt(0);
+            s.Remove(s.Last());
+            s.Remove(s.Last());
+            xmlTrivia = string.Concat(s.Select(c => "        /// " + c.TrimStart() + "\n"));
+            xmlTrivia = xmlTrivia.TrimEnd();
+        }
+
         return new(
             targetInfo,
             symbol.Name,
@@ -135,7 +148,8 @@ public partial class ReactiveCommandGenerator
             canExecuteTypeInfo,
             outputScheduler,
             forwardedPropertyAttributes,
-            accessModifier);
+            accessModifier,
+            xmlTrivia);
     }
 
     private static string GenerateSource(string containingTypeName, string containingNamespace, string containingClassVisibility, string containingType, CommandInfo[] commands)
@@ -217,6 +231,7 @@ private static string GetCommandSyntax(CommandInfo commandExtensionInfo)
 $$"""
         private {{RxCmd}}<{{inputType}}, {{outputType}}>? {{fieldName}};
 
+{{commandExtensionInfo.XmlComment}}
         [global::System.CodeDom.Compiler.GeneratedCode("{{GeneratorName}}", "{{GeneratorVersion}}")]
         {{forwardedPropertyAttributesString}}
         {{commandExtensionInfo.AccessModifier}} {{RxCmd}}<{{inputType}}, {{outputType}}> {{commandName}} { get => {{initializer}} }