Introduce source generators package

Update dependencies
2026-07-18 15:29:30 +00:00 · 2024-08-28 15:24:18 +02:00
parent 00459fc59b
commit 552b72b1b9
9 changed files with 307 additions and 11 deletions
@@ -0,0 +1,173 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Sybil;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace System.Extensions;
+#nullable enable
+[Generator(LanguageNames.CSharp)]
+public class NotifyPropertyChangedGenerator : IIncrementalGenerator
+{
+    private const string AttributeNamespace = "System.Windows.Extensions";
+    private const string AttributeName = "GenerateNotifyPropertyChangedAttribute";
+    private const string AttributeShortName = "GenerateNotifyPropertyChanged";
+    private const string PropertyChangedEventHandler = "PropertyChangedEventHandler";
+    private const string NullablePropertyChangedEventHandler = "PropertyChangedEventHandler?";
+    private const string PropertyChanged = "PropertyChanged";
+    private const string Partial = "partial";
+    private const string Public = "public";
+
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        context.RegisterPostInitializationOutput(context =>
+        {
+            var compilationUnitBuilder = SyntaxBuilder.CreateCompilationUnit()
+                .WithNamespace(
+                SyntaxBuilder.CreateNamespace(AttributeNamespace)
+                    .WithClass(SyntaxBuilder.CreateClass(AttributeName)
+                        .WithModifier(Public)
+                    .WithConstructor(SyntaxBuilder.CreateConstructor(AttributeName)
+                        .WithModifier(Public))
+                    .WithAttribute(SyntaxBuilder.CreateAttribute("AttributeUsage")
+                        .WithArgument(AttributeTargets.Field)
+                        .WithArgument("Inherited", false)
+                        .WithArgument("AllowMultiple", false))
+                    .WithBaseClass(nameof(Attribute))));
+            var compilationUnitSyntax = compilationUnitBuilder.Build();
+            var source = compilationUnitSyntax.ToFullString();
+            context.AddSource($"{AttributeName}.g", source);
+        });
+
+        var classDeclarations = context.SyntaxProvider.CreateSyntaxProvider(
+            predicate: static (s, _) => s is FieldDeclarationSyntax,
+            transform: static (ctx, _) => GetFilteredFieldDeclarationSyntax(ctx)).Where(static c => c is not null);
+
+        var compilationAndClasses = context.CompilationProvider.Combine(classDeclarations.Collect());
+        context.RegisterSourceOutput(compilationAndClasses, (sourceProductionContext, tuple) => Execute(tuple.Left, tuple.Right, sourceProductionContext));
+    }
+
+    private static ClassDeclarationSyntax? GetFilteredFieldDeclarationSyntax(GeneratorSyntaxContext context)
+    {
+        var fieldDeclarationSyntax = (FieldDeclarationSyntax)context.Node;
+        if (fieldDeclarationSyntax.AttributeLists
+            .SelectMany(l => l.Attributes)
+            .OfType<AttributeSyntax>()
+            .Any(s => s.Name.ToString() == AttributeName || s.Name.ToString() == AttributeShortName))
+        {
+            return fieldDeclarationSyntax.Parent as ClassDeclarationSyntax;
+        }
+
+        return default;
+    }
+
+    private static void Execute(Compilation compilation, ImmutableArray<ClassDeclarationSyntax?> classes, SourceProductionContext sourceProductionContext)
+    {
+        if (classes.IsDefaultOrEmpty)
+        {
+            return;
+        }
+
+        var maybeLanguageVersion = (compilation.SyntaxTrees.FirstOrDefault()?.Options as CSharpParseOptions)?.LanguageVersion;
+        if (!maybeLanguageVersion.HasValue)
+        {
+            return;
+        }
+
+        var languageVersion = maybeLanguageVersion.Value;
+        var distinctClasses = classes.Distinct();
+        foreach (var c in distinctClasses.OfType<ClassDeclarationSyntax>())
+        {
+            var className = c.Identifier.ToFullString();
+            if (!c.Modifiers.Any(m => m.ToString() == Partial))
+            {
+                Diagnostics.ClassNotPartial(className);
+                continue;
+            }
+
+            var originalNamespaceSyntax = GetParentOfType<BaseNamespaceDeclarationSyntax>(c);
+            if (originalNamespaceSyntax is null)
+            {
+                Diagnostics.ClassNotInNamespace(className);
+                continue;
+            }
+
+            if (!c.Members
+                .OfType<EventFieldDeclarationSyntax>()
+                .Any(eventField =>
+                    (eventField.Declaration.Variables.Any(variable => variable.Identifier.Text == PropertyChanged) &&
+                    eventField.Modifiers.Any(modifier => modifier.Text == Public) &&
+                    eventField.Declaration.Type.ToString() == PropertyChangedEventHandler) ||
+                    eventField.Declaration.Type.ToString() == NullablePropertyChangedEventHandler))
+            {
+                Diagnostics.ClassDoesNotImplementINotifyPropertyChanged(className);
+                continue;
+            }
+
+            var generatedClassBuilder = SyntaxBuilder.CreateClass(className)
+                .WithModifiers(string.Join(" ", c.Modifiers.Select(m => m.ToFullString())));
+            var compilationUnitBuilder = SyntaxBuilder.CreateCompilationUnit()
+                .WithNamespace(
+                    (languageVersion >= LanguageVersion.CSharp10 ?
+                    SyntaxBuilder.CreateFileScopedNamespace(originalNamespaceSyntax.Name.ToFullString()) :
+                    SyntaxBuilder.CreateNamespace(originalNamespaceSyntax.Name.ToFullString()))
+                    .WithClass(generatedClassBuilder));
+            
+            foreach (var field in c.DescendantNodes().OfType<FieldDeclarationSyntax>())
+            {
+                if (field.AttributeLists
+                    .SelectMany(l => l.Attributes)
+                    .OfType<AttributeSyntax>()
+                    .Any(s => s.Name.ToString() == AttributeName ||
+                        s.Name.ToString() == AttributeShortName) is false)
+                {
+                    continue;
+                }
+
+                var fieldName = field.Declaration.Variables.First().Identifier.ToFullString();
+                var propertyName = fieldName.TrimStart('_');
+                propertyName = $"{char.ToUpper(propertyName[0])}{propertyName.Substring(1)}";
+                var propertyBuilder = SyntaxBuilder.CreateProperty(field.Declaration.Type.ToFullString(), propertyName)
+                    .WithModifier(Public)
+                    .WithAccessor(SyntaxBuilder.CreateGetter()
+                        .WithBody($"return this.{fieldName};"))
+                    .WithAccessor(SyntaxBuilder.CreateSetter()
+                        .WithBody($"this.{fieldName} = value;\r\nthis.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof({propertyName})));"));
+                generatedClassBuilder.WithProperty(propertyBuilder);
+            }
+
+            var generatedSyntax = compilationUnitBuilder.Build();
+            if (originalNamespaceSyntax.Usings.Count != 0)
+            {
+                generatedSyntax = generatedSyntax.AddUsings([.. originalNamespaceSyntax.Usings]);
+            }
+            else
+            {
+                if (originalNamespaceSyntax.Parent is CompilationUnitSyntax compilationUnit)
+                {
+                    generatedSyntax = generatedSyntax.AddUsings([.. compilationUnit.Usings]);
+                }
+            }
+
+            var fileSource = generatedSyntax.ToFullString();
+            sourceProductionContext.AddSource($"{className}.g", fileSource);
+        }
+    }
+
+    private static T? GetParentOfType<T>(SyntaxNode syntaxNode)
+    {
+        if (syntaxNode.Parent is null)
+        {
+            return default;
+        }
+
+        if (syntaxNode.Parent is T parentNode)
+        {
+            return parentNode;
+        }
+
+        return GetParentOfType<T>(syntaxNode.Parent);
+    }
+}
+#nullable disable