Merge pull request #275 from CommunityToolkit/dev/improve-command-generator-with-inheritance

Fix ICommand generator with inherited CanExecute members

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/Extensions/INamedTypeSymbolExtensions.cs

@@ -67,7 +67,7 @@ public static IEnumerable<ISymbol> GetAllMembers(this INamedTypeSymbol symbol)
     /// <returns>A sequence of all member symbols for <paramref name="symbol"/>.</returns>
     public static IEnumerable<ISymbol> GetAllMembers(this INamedTypeSymbol symbol, string name)
     {
-        for (INamedTypeSymbol? currentSymbol = symbol; currentSymbol is not null; currentSymbol = currentSymbol.BaseType)
+        for (INamedTypeSymbol? currentSymbol = symbol; currentSymbol is { SpecialType: not SpecialType.System_Object }; currentSymbol = currentSymbol.BaseType)
         {
             foreach (ISymbol memberSymbol in currentSymbol.GetMembers(name))
             {

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

@@ -630,7 +630,7 @@ private static bool TryGetCanExecuteExpressionType(
                 goto Failure;
             }
 
-            ImmutableArray<ISymbol> canExecuteSymbols = methodSymbol.ContainingType!.GetMembers(memberName);
+            ImmutableArray<ISymbol> canExecuteSymbols = methodSymbol.ContainingType!.GetAllMembers(memberName).ToImmutableArray();
 
             if (canExecuteSymbols.IsEmpty)
             {

tests/CommunityToolkit.Mvvm.ExternalAssembly/ModelWithObservablePropertyAndMethod.cs

@@ -0,0 +1,21 @@
+// 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 CommunityToolkit.Mvvm.ComponentModel;
+
+namespace CommunityToolkit.Mvvm.ExternalAssembly;
+
+/// <summary>
+/// Test viewmodel for https://github.com/CommunityToolkit/dotnet/issues/222.
+/// </summary>
+public abstract partial class ModelWithObservablePropertyAndMethod : ObservableObject
+{
+    [ObservableProperty]
+    private bool canSave;
+
+    /// <summary>
+    /// Base method to then generate a command.
+    /// </summary>
+    public abstract void Save();
+}

tests/CommunityToolkit.Mvvm.UnitTests/Test_ObservablePropertyAttribute.cs

@@ -747,6 +747,24 @@ public void Test_ObservableProperty_ModelWithObservablePropertyInRootNamespace()
         CollectionAssert.AreEqual(propertyNames, new[] { nameof(model.Number) });
     }
 
+    // See https://github.com/CommunityToolkit/dotnet/issues/272
+    [TestMethod]
+    public void Test_ObservableProperty_WithCommandReferencingGeneratedPropertyFromOtherAssembly()
+    {
+        ModelWithOverriddenCommandMethodFromExternalBaseModel model = new();
+
+        Assert.IsFalse(model.HasSaved);
+        Assert.IsFalse(model.SaveCommand.CanExecute(null));
+
+        model.CanSave = true;
+
+        Assert.IsTrue(model.SaveCommand.CanExecute(null));
+
+        model.SaveCommand.Execute(null);
+
+        Assert.IsTrue(model.HasSaved);
+    }
+
     public abstract partial class BaseViewModel : ObservableObject
     {
         public string? Content { get; set; }
@@ -1175,4 +1193,15 @@ public partial class ModelWithAdditionalDataAnnotationAttributes : ObservableVal
         [ScaffoldColumn(true)]
         private string? name;
     }
+
+    public partial class ModelWithOverriddenCommandMethodFromExternalBaseModel : ModelWithObservablePropertyAndMethod
+    {
+        public bool HasSaved { get; private set; }
+
+        [ICommand(CanExecute = nameof(CanSave))]
+        public override void Save()
+        {
+            HasSaved = true;
+        }
+    }
 }