From df714eaa6c194b5f2b8a46713541939d6321b0ce Mon Sep 17 00:00:00 2001
From: Sergio Pedri <sergio0694@live.com>
Date: Tue, 10 Dec 2024 18:50:40 -0800
Subject: [PATCH] Add support for 'get;' accessors too

---
 ...vablePropertyOnSemiAutoPropertyAnalyzer.cs | 30 +++++++++++
 ...ablePropertyOnSemiAutoPropertyCodeFixer.cs | 53 +++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs b/src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs
index 37778a15..ecb6502a 100644
--- a/src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs
+++ b/src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs
@@ -10,6 +10,7 @@
 using System.Linq;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Operations;
@@ -201,6 +202,35 @@ public override void Initialize(AnalysisContext context)
                     }
                 });
 
+                // We also need to track getters which have no body, and we need syntax for that
+                context.RegisterSyntaxNodeAction(context =>
+                {
+                    // Let's just make sure we do have a property symbol
+                    if (context.ContainingSymbol is not IPropertySymbol { GetMethod: not null } propertySymbol)
+                    {
+                        return;
+                    }
+
+                    // Lookup the property to get its flags
+                    if (!propertyMap.TryGetValue(propertySymbol, out bool[]? validFlags))
+                    {
+                        return;
+                    }
+
+                    // We expect two accessors, skip if otherwise (the setter will be validated by the other callback)
+                    if (context.Node is not PropertyDeclarationSyntax { AccessorList.Accessors: [{ } firstAccessor, { } secondAccessor] })
+                    {
+                        return;
+                    }
+
+                    // Check that either of them is a semicolon token 'get;' accessor (it can be in either position)
+                    if (firstAccessor.IsKind(SyntaxKind.GetAccessorDeclaration) && firstAccessor.SemicolonToken.IsKind(SyntaxKind.SemicolonToken) ||
+                        secondAccessor.IsKind(SyntaxKind.GetAccessorDeclaration) && secondAccessor.SemicolonToken.IsKind(SyntaxKind.SemicolonToken))
+                    {
+                        validFlags[0] = true;
+                    }
+                }, SyntaxKind.PropertyDeclaration);
+
                 // Finally, we can consume this information when we finish processing the symbol
                 context.RegisterSymbolEndAction(context =>
                 {
diff --git a/tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_UseObservablePropertyOnSemiAutoPropertyCodeFixer.cs b/tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_UseObservablePropertyOnSemiAutoPropertyCodeFixer.cs
index 7fd8ba72..a41af842 100644
--- a/tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_UseObservablePropertyOnSemiAutoPropertyCodeFixer.cs
+++ b/tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_UseObservablePropertyOnSemiAutoPropertyCodeFixer.cs
@@ -74,6 +74,59 @@ public partial class SampleViewModel : ObservableObject
         await test.RunAsync();
     }
 
+    [TestMethod]
+    public async Task SimpleProperty_WithSemicolonTokenGetAccessor()
+    {
+        string original = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public class SampleViewModel : ObservableObject
+            {
+                public string Name
+                {
+                    get;
+                    set => SetProperty(ref field, value);
+                }
+            }
+            """;
+
+        string @fixed = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public partial class SampleViewModel : ObservableObject
+            {
+                [ObservableProperty]
+                public partial string Name { get; set; }
+            }
+            """;
+
+        CSharpCodeFixTest test = new(LanguageVersion.Preview)
+        {
+            TestCode = original,
+            FixedCode = @fixed,
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net80,
+        };
+
+        test.TestState.AdditionalReferences.Add(typeof(ObservableObject).Assembly);
+        test.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(7,19): info MVVMTK0056: The semi-auto property MyApp.SampleViewModel.Name can be converted to a partial property using [ObservableProperty], which is recommended (doing so makes the code less verbose and results in more optimized code)
+            CSharpCodeFixVerifier.Diagnostic().WithSpan(7, 19, 7, 23).WithArguments("MyApp.SampleViewModel", "Name"),
+        });
+
+        test.FixedState.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(8,27): error CS9248: Partial property 'SampleViewModel.Name' must have an implementation part.
+            DiagnosticResult.CompilerError("CS9248").WithSpan(8, 27, 8, 31).WithArguments("MyApp.SampleViewModel.Name"),
+        });
+
+        await test.RunAsync();
+    }
+
     [TestMethod]
     public async Task SimpleProperty_WithLeadingTrivia()
     {