#138 Make anonymous roots lightweight

Author: NikolayPianikov

src/Pure.DI.Core/Components/Api.g.cs

@@ -10,14 +10,22 @@ namespace System
     internal delegate TResult Func<out TResult>();
 #endif
 #if NET20 || NET35
-    internal delegate TResult Func<in T, out TResult>(T arg);
-    internal delegate TResult Func<in T, in T1, out TResult>(T arg, T1 arg1);
-    internal delegate TResult Func<in T, in T1, in T2, out TResult>(T arg, T1 arg1, T2 arg2);
-    internal delegate TResult Func<in T, in T1, in T2, in T3, out TResult>(T arg, T1 arg1, T2 arg2, T3 arg3);
-    internal delegate TResult Func<in T, in T1, in T2, in T3, in T4, out TResult>(T arg, T1 arg1, T2 arg2, T3 arg3, T4 arg4);
-    internal delegate TResult Func<in T, in T1, in T2, in T3, in T4, in T5, out TResult>(T arg, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5);
-    internal delegate TResult Func<in T, in T1, in T2, in T3, in T4, in T5, in T6, out TResult>(T arg, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6);
-    internal delegate TResult Func<in T, in T1, in T2, in T3, in T4, in T5, in T6, in T7, out TResult>(T arg, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7);
+    internal delegate TResult Func<in T1, out TResult>(T1 arg1);
+    internal delegate TResult Func<in T1, in T2, out TResult>(T1 arg1, T2 arg2);
+    internal delegate TResult Func<in T1, in T2, in T3, out TResult>(T1 arg1, T2 arg2, T3 arg3);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, in T14, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13, T14 arg14);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, in T14, in T15, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13, T14 arg14, T15 arg15);
+    internal delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, in T14, in T15, in T16, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13, T14 arg14, T15 arg15, T16 arg16);
 #endif
 }
 #endif
@@ -8310,6 +8318,9 @@ internal interface IResolver<TComposite, out T>
         T ResolveByTag(TComposite composite, object tag);
     }
 
+    /// <summary>
+    /// Lightweight composition root. Does not create a separate composition object for instance creation, uses a common one for all lightweight roots and a delegate to create the type instance.
+    /// </summary>
     internal class LightweightRoot { }
 
     /// <summary>

src/Pure.DI.Core/Components/Api.g.tt

@@ -22,10 +22,10 @@ namespace System
     internal delegate TResult Func<out TResult>();
 #endif
 #if NET20 || NET35
-<#for(var i = 0; i < baseCount; i ++)
+<#for(var i = 1; i <= 16; i ++)
 {
-var typeArgs = string.Join(", ", GetSuffixes(0, i).Select(suffix => $"in T{suffix}"));
-var args = string.Join(", ", GetSuffixes(0, i).Select(suffix => $"T{suffix} arg{suffix}"));
+var typeArgs = string.Join(", ", GetSuffixes(1, i).Select(suffix => $"in T{suffix}"));
+var args = string.Join(", ", GetSuffixes(1, i).Select(suffix => $"T{suffix} arg{suffix}"));
 #>
     internal delegate TResult Func<<#=typeArgs#>, out TResult>(<#=args#>);
 <#
@@ -3580,6 +3580,9 @@ var typeArgs = string.Join(", ", GetSuffixes(1, i + 1).Select(suffix => $"T{suff
         T ResolveByTag(TComposite composite, object tag);
     }
 
+    /// <summary>
+    /// Lightweight composition root. Does not create a separate composition object for instance creation, uses a common one for all lightweight roots and a delegate to create the type instance.
+    /// </summary>
     internal class LightweightRoot { }
 
     /// <summary>

src/Pure.DI.Core/Core/Code/ResolversBuilder.cs

@@ -7,7 +7,7 @@ sealed class ResolversBuilder(ITypeResolver typeResolver)
 {
     public IEnumerable<ResolverInfo> Build(RootsContext ctx) =>
         ctx.Roots
-            .Where(i => i.RootArgs.IsEmpty && !i.Source.IsLightweightRootMethod)
+            .Where(i => i.RootArgs.IsEmpty && i.Source.LightweightKind is not LightweightKind.TransientComposition)
             .Where(i => !i.Injection.Type.IsRefLikeType)
             .Where(i => !ReferenceEquals(i.Injection.Tag, MdTag.ContextTag))
             .Where(i => typeResolver.Resolve(ctx.Setup, i.Injection.Type).TypeArgs.Count == 0)

src/Pure.DI.Core/Core/Code/VariableNameProvider.cs

@@ -24,9 +24,7 @@ public string GetLocalUniqueVariableName(string baseName) =>
         uniqueNameProvider.GetUniqueName($"{Names.LocalVariablePrefix}{ToTitleCase(baseName)}{Names.Salt}");
 
     public string GetUniqueRootName(string name, ITypeSymbol rootType) =>
-        string.IsNullOrWhiteSpace(name)
-            ? uniqueNameProvider.GetUniqueName(ToTitleCase(rootType.Name))
-            : name;
+        uniqueNameProvider.GetUniqueName(string.IsNullOrWhiteSpace(name) ? ToTitleCase(rootType.Name) : name);
 
     private static string GetVariableName(string prefix, string baseName, int id) =>
         $"{prefix}{ToTitleCase(baseName)}{Names.Salt}{(id != 0 ? id.ToString() : "")}";

src/Pure.DI.Core/Core/LifetimesValidator.cs

@@ -16,7 +16,6 @@ public bool Validate(DependencyGraph dependencyGraph)
         }
 
         var errors = new HashSet<object>();
-        var graph = dependencyGraph.Graph;
         foreach (var root in dependencyGraph.Roots)
         {
             graphWalker.Walk(

src/Pure.DI.Core/Core/Models/LightweightKind.cs

@@ -0,0 +1,8 @@
+namespace Pure.DI.Core.Models;
+
+public enum LightweightKind
+{
+    None,
+    TransientRoot,
+    TransientComposition
+}

src/Pure.DI.Core/Core/Models/MdRoot.cs

@@ -13,7 +13,7 @@ record MdRoot(
     ITypeSymbol RootContractType,
     bool IsBuilder,
     ImmutableArray<MdRoot> BuilderRoots = default,
-    bool IsLightweightRootMethod = false)
+    LightweightKind LightweightKind = LightweightKind.None)
 {
     public override string ToString() => $"Root<{RootType}>(\"{Name}\", {Tag.ToString()})";
 }

src/Pure.DI.Core/Core/RootDependencyNodeBuilder.cs

@@ -57,7 +57,7 @@ public IEnumerable<DependencyNode> Build(DependencyNodeBuildContext ctx)
                 rootType,
                 false,
                 ImmutableArray<MdRoot>.Empty,
-                IsLightweightRootMethod: true);
+                LightweightKind: LightweightKind.TransientComposition);
 
             var binding = bindingsFactory.CreateLightweightRootBinding(setup, root);
 

src/Pure.DI.Core/Core/RootValidator.cs

@@ -16,7 +16,7 @@ public bool Validate(CompositionCode composition)
         }
 
         var invalidRoots = composition.PublicRoots
-            .Where(root => root.Source is { IsBuilder: false, IsLightweightRootMethod: false })
+            .Where(root => root.Source is { IsBuilder: false, LightweightKind: not LightweightKind.TransientComposition })
             .Where(root => !root.RootArgs.IsDefaultOrEmpty && root.TypeDescription.TypeArgs.Count == 0)
             .GroupBy(root => root.Node.Binding.Id)
             .Select(root => root.First());

tests/Pure.DI.IntegrationTests/LightweightRootsTests.cs

@@ -126,4 +126,77 @@ public static void Main()
         result.Success.ShouldBeTrue(result);
         result.StdOut.ShouldBe(["Initialize 1 Abc"], result);
     }
+
+    [Fact]
+    public async Task ShouldSupportSeveralLightweightRoots()
+    {
+        // Given
+
+        // When
+        var result = await """
+                           using System;
+                           using Pure.DI;
+
+                           namespace Sample
+                           {
+                               interface IDependency {}
+                           
+                               class Dependency: IDependency
+                               {
+                               }
+                           
+                               interface IService
+                               {
+                                   IDependency? Dep { get; }
+                               }
+                           
+                               class Service: IService 
+                               {
+                                   [Ordinal(1)]
+                                   internal void Initialize([Tag(374)] string depName)
+                                   {
+                                       Console.WriteLine($"Initialize 1 {depName}");
+                                   }
+                           
+                                   [Ordinal(0)]
+                                   public IDependency? Dep { get; set; }
+                               }
+                               
+                               class Xyz
+                               {
+                                    public Xyz()
+                                    {
+                                        Console.WriteLine("Xyz");
+                                    }
+                               }
+                           
+                               static class Setup
+                               {
+                                   private static void SetupComposition()
+                                   {
+                                       DI.Setup("Composition")
+                                           .Bind(374).To(_ => "Abc")
+                                           .Bind().As(Lifetime.PerResolve).To<Dependency>()
+                                           .Root<Service>("Root", kind: RootKinds.Light)
+                                           .Root<Xyz>("Xyz", kind: RootKinds.Light);
+                                   }
+                               }
+                           
+                               public class Program
+                               {
+                                   public static void Main()
+                                   {
+                                       var composition = new Composition();
+                                       var service1 = composition.Root;
+                                       var service2 = composition.Resolve<Service>();
+                                       var xyz = composition.Xyz;
+                                   }
+                               }
+                           }
+                           """.RunAsync();
+
+        // Then
+        result.Success.ShouldBeTrue(result);
+        result.StdOut.ShouldBe(["Initialize 1 Abc", "Initialize 1 Abc", "Xyz"], result);
+    }
 }