Mapper优化

doc/GenMapper版本日志.md

@@ -2,6 +2,29 @@
 
 ## v0.1.0
 - ⚡️升级`.NET10`
+- 🛠优化生成器代码
+- ⚡️支持生成扩展方法
+
+```csharp
+internal static partial class MapperExtensions
+{
+    [GenMapper]
+    [MapBetween([nameof(Product.Name), nameof(Product.Category)], nameof(ProductDto.Name), By = nameof(MapToDtoName))]
+    [MapBetween(nameof(Product.SplitValue), [nameof(ProductDto.S1), nameof(ProductDto.S2)], By = nameof(MapOneToMultiTest))]
+    public static partial ProductDto ToDto(this Product product, Action<Product, ProductDto>? action = null);
+
+    public static string MapToDtoName(string name, string category)
+    {
+        return $"{name}-{category}";
+    }
+
+    public static (string, string) MapOneToMultiTest(string value)
+    {
+        var val = value.Split(',');
+        return (val[0], val[1]);
+    }
+}
+```
 
 ## v0.0.9
 

src/AutoGenMapper.Roslyn/AutoMapperExtensionGenerator.cs

@@ -0,0 +1,72 @@
+using Generators.Shared;
+using Generators.Shared.Builder;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.Collections.Generic;
+using System.Linq;
+using static AutoGenMapperGenerator.Helper;
+namespace AutoGenMapperGenerator;
+
+[Generator(LanguageNames.CSharp)]
+public class AutoMapperExtensionGenerator : IIncrementalGenerator
+{
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        var map = context.SyntaxProvider.ForAttributeWithMetadataName(GenMapperAttributeFullName
+            , static (node, _) => node is MethodDeclarationSyntax
+            {
+                ParameterList.Parameters:
+                {
+                    Count: var psCount
+                } ps
+            } && psCount > 0 && ps[0].Type is not null
+            , static (source, _) => CollectMapperContext(source));
+
+        context.RegisterSourceOutput(map, static (context, source) =>
+        {
+            if (source.Item2 is not null)
+            {
+                context.ReportDiagnostic(source.Item2);
+                return;
+            }
+            if (source.Item1 is null) return;
+            var file = CreateCodeFile(source.Item1);
+#if DEBUG
+            var ss = file?.ToString();
+#endif
+            context.AddSource(file);
+        });
+    }
+    static (MapperContext?, Diagnostic?) CollectMapperContext(GeneratorAttributeSyntaxContext context)
+    {
+        var location = context.TargetNode.GetLocation();
+        var mapBetweens = CollectSpecificBetweenInfo(context.TargetSymbol).ToArray();
+        var mapperTargets = CollectMapTargets(context.TargetSymbol);
+        var mapContext = new MapperContext(context.TargetSymbol)
+        {
+            Targets = mapperTargets
+        };
+        var error = Helper.CollectMapperContext(mapContext, mapBetweens, location);
+        return (mapContext, error);
+    }
+    static CodeFile? CreateCodeFile(MapperContext context)
+    {
+        INamedTypeSymbol classSymbol = context.ContainingType!;
+        var cb = ClassBuilder.Default.Modifiers("static partial").ClassName(classSymbol.Name)
+            .AddGeneratedCodeAttribute(typeof(AutoMapperGenerator));
+        List<MethodBuilder> methods = [];
+        foreach (var ctx in context.Targets)
+        {
+            var m = BuildAutoMapClass.GenerateExtensionMethod(context, ctx);
+            methods.Add(m);
+        }
+
+        cb.AddMembers([.. methods]);
+        var ns = NamespaceBuilder.Default.Namespace(classSymbol.ContainingNamespace.ToDisplayString());
+        return CodeFile.New($"{classSymbol.FormatFileName()}.AutoMap.Ex.g.cs")
+            //.AddUsings("using System.Linq;")
+            //.AddUsings("using AutoGenMapperGenerator;")
+            .AddUsings(classSymbol.GetTargetUsings())
+            .AddMembers(ns.AddMembers(cb));
+    }
+}