Add Analyzers project to the main package

Avalonia.sln

@@ -233,7 +233,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ReactiveUIDemo", "samples\R
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GpuInterop", "samples\GpuInterop\GpuInterop.csproj", "{C810060E-3809-4B74-A125-F11533AF9C1B}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.Analyzers", "src\tools\PublicAnalyzers\Avalonia.Analyzers.csproj", "{C692FE73-43DB-49CE-87FC-F03ED61F25C9}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.Analyzers", "src\tools\Avalonia.Analyzers\Avalonia.Analyzers.csproj", "{C692FE73-43DB-49CE-87FC-F03ED61F25C9}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{176582E8-46AF-416A-85C1-13A5C6744497}"
 	ProjectSection(SolutionItems) = preProject

build/DevAnalyzers.props

@@ -5,7 +5,7 @@
                       ReferenceOutputAssembly="false"
                       OutputItemType="Analyzer"
                       SetTargetFramework="TargetFramework=netstandard2.0"/>
-    <ProjectReference Include="$(MSBuildThisFileDirectory)..\src\tools\PublicAnalyzers\Avalonia.Analyzers.csproj"
+    <ProjectReference Include="$(MSBuildThisFileDirectory)..\src\tools\Avalonia.Analyzers\Avalonia.Analyzers.csproj"
                       PrivateAssets="all"
                       ReferenceOutputAssembly="false"
                       OutputItemType="Analyzer"

packages/Avalonia/Avalonia.csproj

@@ -15,6 +15,10 @@
                         ReferenceOutputAssembly="false"
                         PrivateAssets="all"
                         OutputItemType="Analyzer" />
+      <ProjectReference Include="..\..\src\tools\Avalonia.Analyzers\Avalonia.Analyzers.csproj"
+                        ReferenceOutputAssembly="false"
+                        PrivateAssets="all"
+                        OutputItemType="Analyzer" />
   </ItemGroup>
 
   <PropertyGroup>

src/tools/PublicAnalyzers/Avalonia.Analyzers.csproj → src/tools/Avalonia.Analyzers/Avalonia.Analyzers.csproj

@@ -11,7 +11,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.4.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.9.0" />
   </ItemGroup>
 
 </Project>

src/tools/PublicAnalyzers/AvaloniaPropertyAnalyzer.cs → src/tools/Avalonia.Analyzers/AvaloniaPropertyAnalyzer.cs

@@ -14,7 +14,6 @@ using Microsoft.CodeAnalysis.Operations;
 namespace Avalonia.Analyzers;
 
 [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
-[SuppressMessage("MicrosoftCodeAnalysisReleaseTracking", "RS2008:Enable analyzer release tracking")]
 public partial class AvaloniaPropertyAnalyzer : DiagnosticAnalyzer
 {
     private const string Category = "AvaloniaProperty";

src/tools/Avalonia.Analyzers/GlobalSuppressions.cs

@@ -0,0 +1,8 @@
+// This file is used by Code Analysis to maintain SuppressMessage
+// attributes that are applied to this project.
+// Project-level suppressions either have no target or are given
+// a specific target and scoped to a namespace, type, member, etc.
+
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage("MicrosoftCodeAnalysisReleaseTracking", "RS2008:Enable analyzer release tracking")]

src/tools/Avalonia.Analyzers/OnPropertyChangedOverrideAnalyzer.cs

@@ -0,0 +1,59 @@
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace Avalonia.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public class OnPropertyChangedOverrideAnalyzer : DiagnosticAnalyzer
+{
+    public const string DiagnosticId = "AVA2001";
+
+    private static readonly DiagnosticDescriptor Rule = new DiagnosticDescriptor(
+        DiagnosticId,
+        "Missing invoke base.OnPropertyChanged",
+        "Method '{0}' do not invoke base.{0}",
+        "Potential issue",
+        DiagnosticSeverity.Warning,
+        isEnabledByDefault: true,
+        description: "The OnPropertyChanged of the base class was not invoked in the override method declaration, which could lead to unwanted behavior.");
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.EnableConcurrentExecution();
+        context.RegisterSyntaxNodeAction(AnalyzeMethod, SyntaxKind.MethodDeclaration);
+    }
+
+    private static void AnalyzeMethod(SyntaxNodeAnalysisContext context)
+    {
+        var method = (MethodDeclarationSyntax)context.Node;
+        if (context.SemanticModel.GetDeclaredSymbol(method, context.CancellationToken) is IMethodSymbol currentMethod
+            && currentMethod.Name == "OnPropertyChanged"
+            && currentMethod.OverriddenMethod is IMethodSymbol originalMethod)
+        {
+            var baseInvocations = method.Body?.DescendantNodes().OfType<BaseExpressionSyntax>();
+            if (baseInvocations?.Any() == true)
+            {
+                foreach (var baseInvocation in baseInvocations)
+                {
+                    if (baseInvocation.Parent is SyntaxNode parent)
+                    {
+                        var targetSymbol = context.SemanticModel.GetSymbolInfo(parent, context.CancellationToken);
+                        if (SymbolEqualityComparer.Default.Equals(targetSymbol.Symbol, originalMethod))
+                        {
+                            return;
+                        }
+                    }
+                }
+            }
+            context.ReportDiagnostic(Diagnostic.Create(Rule, currentMethod.Locations[0], currentMethod.Name));
+        }
+    }
+
+}