Remove extra projection and comparers from command generator

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/Input/Models/CommandInfo.cs

@@ -42,10 +42,16 @@ internal sealed record CommandInfo(
     bool FlowExceptionsToTaskScheduler,
     bool IncludeCancelCommand)
 {
+    /// <inheritdoc/>
+    public bool Equals(CommandInfo? obj) => Comparer.Default.Equals(this, obj);
+
+    /// <inheritdoc/>
+    public override int GetHashCode() => Comparer.Default.GetHashCode(this);
+
     /// <summary>
     /// An <see cref="IEqualityComparer{T}"/> implementation for <see cref="CommandInfo"/>.
     /// </summary>
-    public sealed class Comparer : Comparer<CommandInfo, Comparer>
+    private sealed class Comparer : Comparer<CommandInfo, Comparer>
     {
         /// <inheritdoc/>
         protected override void AddToHashCode(ref HashCode hashCode, CommandInfo obj)

CommunityToolkit.Mvvm.SourceGenerators/Input/RelayCommandGenerator.Execute.cs

@@ -27,13 +27,18 @@ partial class RelayCommandGenerator
     internal static class Execute
     {
         /// <summary>
-        /// Processes a given target method.
+        /// Processes a given annotated methods and produces command info, if possible.
         /// </summary>
         /// <param name="methodSymbol">The input <see cref="IMethodSymbol"/> instance to process.</param>
         /// <param name="attributeData">The <see cref="AttributeData"/> instance the method was annotated with.</param>
+        /// <param name="commandInfo">The resulting <see cref="CommandInfo"/> instance, if successfully generated.</param>
         /// <param name="diagnostics">The resulting diagnostics from the processing operation.</param>
-        /// <returns>The resulting <see cref="CommandInfo"/> instance for <paramref name="methodSymbol"/>, if available.</returns>
-        public static CommandInfo? GetInfo(IMethodSymbol methodSymbol, AttributeData attributeData, out ImmutableArray<DiagnosticInfo> diagnostics)
+        /// <returns>Whether a <see cref="CommandInfo"/> instance could be generated successfully.</returns>
+        public static bool TryGetInfo(
+            IMethodSymbol methodSymbol,
+            AttributeData attributeData,
+            [NotNullWhen(true)] out CommandInfo? commandInfo,
+            out ImmutableArray<DiagnosticInfo> diagnostics)
         {
             ImmutableArray<DiagnosticInfo>.Builder builder = ImmutableArray.CreateBuilder<DiagnosticInfo>();
 
@@ -107,9 +112,7 @@ internal static class Execute
                 goto Failure;
             }
 
-            diagnostics = builder.ToImmutable();
-
-            return new(
+            commandInfo = new CommandInfo(
                 methodSymbol.Name,
                 fieldName,
                 propertyName,
@@ -124,10 +127,15 @@ internal static class Execute
                 flowExceptionsToTaskScheduler,
                 generateCancelCommand);
 
+            diagnostics = builder.ToImmutable();
+
+            return true;
+
             Failure:
+            commandInfo = null;
             diagnostics = builder.ToImmutable();
 
-            return null;
+            return false;
         }
 
         /// <summary>

CommunityToolkit.Mvvm.SourceGenerators/Input/RelayCommandGenerator.cs

@@ -38,31 +38,30 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
                     IMethodSymbol methodSymbol = (IMethodSymbol)context.TargetSymbol;
 
-                    // Produce the incremental models
-                    HierarchyInfo hierarchy = HierarchyInfo.From(methodSymbol.ContainingType);
-                    CommandInfo? commandInfo = Execute.GetInfo(methodSymbol, context.Attributes[0], out ImmutableArray<DiagnosticInfo> diagnostics);
+                    // Get the hierarchy info for the target symbol, and try to gather the command info
+                    HierarchyInfo? hierarchy = HierarchyInfo.From(methodSymbol.ContainingType);
+
+                    _ = Execute.TryGetInfo(methodSymbol, context.Attributes[0], out CommandInfo? commandInfo, out ImmutableArray<DiagnosticInfo> diagnostics);
 
                     return (Hierarchy: hierarchy, new Result<CommandInfo?>(commandInfo, diagnostics));
                 })
-            .Where(static item => item.Hierarchy is not null);
+            .Where(static item => item.Hierarchy is not null)!;
 
         // Output the diagnostics
         context.ReportDiagnostics(commandInfoWithErrors.Select(static (item, _) => item.Info.Errors));
 
         // Get the filtered sequence to enable caching
-        IncrementalValuesProvider<(HierarchyInfo Hierarchy, CommandInfo Info)> commandInfo =
+        IncrementalValuesProvider<(HierarchyInfo Hierarchy, Result<CommandInfo> Info)> commandInfo =
             commandInfoWithErrors
-            .Where(static item => item.Info.Value is not null)
-            .Select(static (item, _) => (item.Hierarchy, item.Info.Value!))
-            .WithComparers(HierarchyInfo.Comparer.Default, CommandInfo.Comparer.Default);      
+            .Where(static item => item.Info.Value is not null)!;
 
         // Generate the commands
         context.RegisterSourceOutput(commandInfo, static (context, item) =>
         {
-            ImmutableArray<MemberDeclarationSyntax> memberDeclarations = Execute.GetSyntax(item.Info);
+            ImmutableArray<MemberDeclarationSyntax> memberDeclarations = Execute.GetSyntax(item.Info.Value);
             CompilationUnitSyntax compilationUnit = item.Hierarchy.GetCompilationUnit(memberDeclarations);
 
-            context.AddSource($"{item.Hierarchy.FilenameHint}.{item.Info.MethodName}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.Hierarchy.FilenameHint}.{item.Info.Value.MethodName}.g.cs", compilationUnit.GetText(Encoding.UTF8));
         });
     }
 }