Fix source generators processing nested/generic types

src/CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.projitems

@@ -55,6 +55,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\IncrementalGeneratorInitializationContextExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\IncrementalValuesProviderExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\ISymbolExtensions.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Extensions\SourceProductionContextExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\ITypeSymbolExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\MemberDeclarationSyntaxExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\SyntaxNodeExtensions.cs" />

src/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.cs

@@ -4,7 +4,6 @@
 
 using System.Collections.Immutable;
 using System.Linq;
-using System.Text;
 using CommunityToolkit.Mvvm.SourceGenerators.ComponentModel.Models;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using CommunityToolkit.Mvvm.SourceGenerators.Helpers;
@@ -75,7 +74,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             // Insert all members into the same partial type declaration
             CompilationUnitSyntax compilationUnit = item.Hierarchy.GetCompilationUnit(memberDeclarations);
 
-            context.AddSource($"{item.Hierarchy.FilenameHint}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.Hierarchy.FilenameHint}.g.cs", compilationUnit);
         });
 
         // Gather all property changing names
@@ -92,7 +91,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
             if (compilationUnit is not null)
             {
-                context.AddSource("__KnownINotifyPropertyChangingArgs.g.cs", compilationUnit.GetText(Encoding.UTF8));
+                context.AddSource("__KnownINotifyPropertyChangingArgs.g.cs", compilationUnit);
             }
         });
 
@@ -110,7 +109,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
             if (compilationUnit is not null)
             {
-                context.AddSource("__KnownINotifyPropertyChangedArgs.g.cs", compilationUnit.GetText(Encoding.UTF8));
+                context.AddSource("__KnownINotifyPropertyChangedArgs.g.cs", compilationUnit);
             }
         });
     }

src/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Linq;
-using System.Text;
 using CommunityToolkit.Mvvm.SourceGenerators.ComponentModel.Models;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using Microsoft.CodeAnalysis;
@@ -79,15 +78,15 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         {
             CompilationUnitSyntax compilationUnit = Execute.GetSyntax(item);
 
-            context.AddSource("__ObservableValidatorExtensions.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource("__ObservableValidatorExtensions.g.cs", compilationUnit);
         });
 
         // Generate the class with all validation methods
         context.RegisterImplementationSourceOutput(validationInfo, static (context, item) =>
         {
             CompilationUnitSyntax compilationUnit = Execute.GetSyntax(item);
 
-            context.AddSource($"{item.FilenameHint}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.FilenameHint}.g.cs", compilationUnit);
         });
     }
 }

src/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/TransitiveMembersGenerator.cs

@@ -5,7 +5,6 @@
 using System;
 using System.Collections.Immutable;
 using System.Linq;
-using System.Text;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using CommunityToolkit.Mvvm.SourceGenerators.Models;
 using Microsoft.CodeAnalysis;
@@ -34,12 +33,12 @@ public abstract partial class TransitiveMembersGenerator<TInfo> : IIncrementalGe
     /// <summary>
     /// The sequence of member declarations for sealed types.
     /// </summary>
-    private ImmutableArray<MemberDeclarationSyntax> sealedMemberDeclarations;
+    private readonly ImmutableArray<MemberDeclarationSyntax> sealedMemberDeclarations;
 
     /// <summary>
     /// The resulting sequence of member declarations for non sealed types.
     /// </summary>
-    private ImmutableArray<MemberDeclarationSyntax> nonSealedMemberDeclarations;
+    private readonly ImmutableArray<MemberDeclarationSyntax> nonSealedMemberDeclarations;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="TransitiveMembersGenerator{TInfo}"/> class.
@@ -108,7 +107,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             ImmutableArray<MemberDeclarationSyntax> updatedMemberDeclarations = Execute.AdjustMemberDeclarationNullabilityAnnotations(filteredMemberDeclarations, item.MetadataInfo.IsNullabilitySupported);
             CompilationUnitSyntax compilationUnit = item.Hierarchy.GetCompilationUnit(updatedMemberDeclarations, this.classDeclaration.BaseList);
 
-            context.AddSource($"{item.Hierarchy.FilenameHint}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.Hierarchy.FilenameHint}.g.cs", compilationUnit);
         });
     }
 

src/CommunityToolkit.Mvvm.SourceGenerators/Extensions/SourceProductionContextExtensions.cs

@@ -0,0 +1,33 @@
+// 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 System.Text;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
+
+/// <summary>
+/// Extension methods for the <see cref="SourceProductionContext"/> type.
+/// </summary>
+internal static class SourceProductionContextExtensions
+{
+    /// <summary>
+    /// Adds a new source file to a target <see cref="SourceProductionContext"/> instance.
+    /// </summary>
+    /// <param name="context">The input <see cref="SourceProductionContext"/> instance to use.</param>
+    /// <param name="name">The name of the source file to add.</param>
+    /// <param name="compilationUnit">The <see cref="CompilationUnitSyntax"/> instance representing the syntax tree to add.</param>
+    public static void AddSource(this SourceProductionContext context, string name, CompilationUnitSyntax compilationUnit)
+    {
+#if !ROSLYN_4_3_1_OR_GREATER
+        // We're fine with the extra allocation in the few cases where adjusting the filename is necessary.
+        // This will only ever be done when code generation is executed again anyway, which is a slow path.
+        name = name.Replace('+', '.').Replace('`', '_');
+#endif
+
+        // Add the UTF8 text for the input compilation unit
+        context.AddSource(name, compilationUnit.GetText(Encoding.UTF8));
+    }
+}

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

@@ -4,7 +4,6 @@
 
 using System.Collections.Immutable;
 using System.Linq;
-using System.Text;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using CommunityToolkit.Mvvm.SourceGenerators.Input.Models;
 using CommunityToolkit.Mvvm.SourceGenerators.Models;
@@ -61,7 +60,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             ImmutableArray<MemberDeclarationSyntax> memberDeclarations = Execute.GetSyntax(item.Info.Value);
             CompilationUnitSyntax compilationUnit = item.Hierarchy.GetCompilationUnit(memberDeclarations);
 
-            context.AddSource($"{item.Hierarchy.FilenameHint}.{item.Info.Value.MethodName}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.Hierarchy.FilenameHint}.{item.Info.Value.MethodName}.g.cs", compilationUnit);
         });
     }
 }

src/CommunityToolkit.Mvvm.SourceGenerators/Messaging/IMessengerRegisterAllGenerator.cs

@@ -4,7 +4,6 @@
 
 using System.Collections.Immutable;
 using System.Linq;
-using System.Text;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using CommunityToolkit.Mvvm.SourceGenerators.Messaging.Models;
 using Microsoft.CodeAnalysis;
@@ -84,15 +83,15 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         {
             CompilationUnitSyntax compilationUnit = Execute.GetSyntax(item);
 
-            context.AddSource("__IMessengerExtensions.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource("__IMessengerExtensions.g.cs", compilationUnit);
         });
 
         // Generate the class with all registration methods
         context.RegisterImplementationSourceOutput(recipientInfo, static (context, item) =>
         {
             CompilationUnitSyntax compilationUnit = Execute.GetSyntax(item);
 
-            context.AddSource($"{item.FilenameHint}.g.cs", compilationUnit.GetText(Encoding.UTF8));
+            context.AddSource($"{item.FilenameHint}.g.cs", compilationUnit);
         });
     }
 }

tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn401.UnitTests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn401.UnitTests.csproj

@@ -8,7 +8,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.MSTest" Version="1.1.1" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="1.1.1" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing.MSTest" Version="1.1.1" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.4.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.0.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.1" />
     <PackageReference Include="MSTest.TestAdapter" Version="3.0.1" />
     <PackageReference Include="MSTest.TestFramework" Version="3.0.1" />

tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn431.UnitTests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn431.UnitTests.csproj

@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>net472;net6.0;net7.0</TargetFrameworks>
+    <DefineConstants>$(DefineConstants);ROSLYN_4_3_1_OR_GREATER</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>

tests/CommunityToolkit.Mvvm.SourceGenerators.UnitTests/Test_SourceGeneratorsCodegen.cs

@@ -193,6 +193,92 @@ public object? A
         VerifyGenerateSources(source, new[] { new ObservablePropertyGenerator() }, ("MyApp.MyViewModel.g.cs", result));
     }
 
+    [TestMethod]
+    public void ObservablePropertyWithinGenericAndNestedTypes()
+    {
+        string source = """
+            using System.ComponentModel;
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            #nullable enable
+
+            namespace MyApp;
+
+            partial class Foo
+            {
+                partial class MyViewModel<T> : ObservableObject
+                {
+                    [ObservableProperty]
+                    private string? a;
+                }
+            }
+            """;
+
+        string result = """
+            // <auto-generated/>
+            #pragma warning disable
+            #nullable enable
+            namespace MyApp
+            {
+                partial class Foo
+                {
+                    partial class MyViewModel<T>
+                    {
+                        /// <inheritdoc cref="a"/>
+                        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.1.0.0")]
+                        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+                        public string? A
+                        {
+                            get => a;
+                            set
+                            {
+                                if (!global::System.Collections.Generic.EqualityComparer<string?>.Default.Equals(a, value))
+                                {
+                                    OnAChanging(value);
+                                    OnAChanging(default, value);
+                                    OnPropertyChanging(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangingArgs.A);
+                                    a = value;
+                                    OnAChanged(value);
+                                    OnAChanged(default, value);
+                                    OnPropertyChanged(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedArgs.A);
+                                }
+                            }
+                        }
+
+                        /// <summary>Executes the logic for when <see cref="A"/> is changing.</summary>
+                        /// <param name="value">The new property value being set.</param>
+                        /// <remarks>This method is invoked right before the value of <see cref="A"/> is changed.</remarks>
+                        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.1.0.0")]
+                        partial void OnAChanging(string? value);
+                        /// <summary>Executes the logic for when <see cref="A"/> is changing.</summary>
+                        /// <param name="oldValue">The previous property value that is being replaced.</param>
+                        /// <param name="newValue">The new property value being set.</param>
+                        /// <remarks>This method is invoked right before the value of <see cref="A"/> is changed.</remarks>
+                        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.1.0.0")]
+                        partial void OnAChanging(string? oldValue, string? newValue);
+                        /// <summary>Executes the logic for when <see cref="A"/> just changed.</summary>
+                        /// <param name="value">The new property value that was set.</param>
+                        /// <remarks>This method is invoked right after the value of <see cref="A"/> is changed.</remarks>
+                        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.1.0.0")]
+                        partial void OnAChanged(string? value);
+                        /// <summary>Executes the logic for when <see cref="A"/> just changed.</summary>
+                        /// <param name="oldValue">The previous property value that was replaced.</param>
+                        /// <param name="newValue">The new property value that was set.</param>
+                        /// <remarks>This method is invoked right after the value of <see cref="A"/> is changed.</remarks>
+                        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.1.0.0")]
+                        partial void OnAChanged(string? oldValue, string? newValue);
+                    }
+                }
+            }
+            """;
+
+#if ROSLYN_4_3_1_OR_GREATER
+        VerifyGenerateSources(source, new[] { new ObservablePropertyGenerator() }, ("MyApp.Foo+MyViewModel`1.g.cs", result));
+#else
+        VerifyGenerateSources(source, new[] { new ObservablePropertyGenerator() }, ("MyApp.Foo.MyViewModel_1.g.cs", result));
+#endif
+    }
+
     /// <summary>
     /// Generates the requested sources
     /// </summary>
@@ -212,7 +298,7 @@ from assembly in AppDomain.CurrentDomain.GetAssemblies()
             let reference = MetadataReference.CreateFromFile(assembly.Location)
             select reference;
 
-        SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(source, CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp11));
+        SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(source, CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp10));
 
         // Create a syntax tree with the input source
         CSharpCompilation compilation = CSharpCompilation.Create(