Dig through nested csharp expressions for design time generation

src/Compiler/Microsoft.AspNetCore.Razor.Language/src/Components/ComponentDesignTimeNodeWriter.cs

@@ -717,16 +717,25 @@ private void WritePropertyAccess(CodeRenderingContext context, ComponentAttribut
                         context.CodeWriter.Write(", ");
                     }
 
-                    foreach (var token in typeArgumentNode.Children.OfType<IntermediateToken>())
+                    writeTypeArgument(typeArgumentNode.Children);
+
+                    void writeTypeArgument(IntermediateNodeCollection typeArgumentComponents)
                     {
-                        // As per WriteComponentTypeArgument, we expect every token to be C#, but check just in case
-                        if (token.IsCSharp)
-                        {
-                            context.CodeWriter.Write(token.Content);
-                        }
-                        else
+                        foreach (var typeArgumentNodeComponent in typeArgumentComponents)
                         {
-                            Debug.Fail($"Unexpected non-C# content in a generic type parameter: '{token.Content}'");
+                            switch (typeArgumentNodeComponent)
+                            {
+                                case IntermediateToken { IsCSharp: true } token:
+                                    context.CodeWriter.Write(token.Content);
+                                    break;
+                                case CSharpExpressionIntermediateNode cSharpExpression:
+                                    writeTypeArgument(cSharpExpression.Children);
+                                    break;
+                                default:
+                                    // As per WriteComponentTypeArgument, we expect every token to be C#, but check just in case
+                                    Debug.Fail($"Unexpected non-C# content in a generic type parameter: '{typeArgumentNodeComponent}'");
+                                    break;
+                            }
                         }
                     }
                 }

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/IntegrationTests/ComponentCodeGenerationTestBase.cs

@@ -5886,6 +5886,27 @@ public class MyComponent<TItem> : ComponentBase
         CompileToAssembly(generated);
     }
 
+    [Fact, WorkItem("https://github.com/dotnet/razor/issues/8467")]
+    public void ChildComponent_AtSpecifiedInRazorFileForTypeParameter()
+    {
+        AdditionalSyntaxTrees.Add(Parse("""
+            using Microsoft.AspNetCore.Components;
+            namespace Test
+            {
+                public class C<T> : ComponentBase
+                {
+                    [Parameter] public int Item { get; set; }
+                }
+            }
+            """));
+
+        var generated = CompileToCSharp("""<C T="@string" Item="1" />""");
+
+        AssertDocumentNodeMatchesBaseline(generated.CodeDocument);
+        AssertCSharpDocumentMatchesBaseline(generated.CodeDocument);
+        CompileToAssembly(generated);
+    }
+
     [Fact]
     public void GenericComponent_NonPrimitiveType()
     {

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/ChildComponent_AtSpecifiedInRazorFileForTypeParameter/TestComponent.codegen.cs

@@ -0,0 +1,66 @@
+// <auto-generated/>
+#pragma warning disable 1591
+namespace Test
+{
+    #line hidden
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    public partial class TestComponent : global::Microsoft.AspNetCore.Components.ComponentBase
+    {
+        #pragma warning disable 219
+        private void __RazorDirectiveTokenHelpers__() {
+        }
+        #pragma warning restore 219
+        #pragma warning disable 0414
+        private static object __o = null;
+        #pragma warning restore 0414
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __o = typeof(
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+       string
+
+#line default
+#line hidden
+#nullable disable
+            );
+            __o = global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.TypeCheck<global::System.Int32>(
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+                     1
+
+#line default
+#line hidden
+#nullable disable
+            );
+            __builder.AddAttribute(-1, "ChildContent", (global::Microsoft.AspNetCore.Components.RenderFragment)((__builder2) => {
+            }
+            ));
+            #pragma warning disable BL0005
+            ((global::Test.C<string>)default).
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+               Item
+
+#line default
+#line hidden
+#nullable disable
+             = default;
+            #pragma warning restore BL0005
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+__o = typeof(global::Test.C<>);
+
+#line default
+#line hidden
+#nullable disable
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/ChildComponent_AtSpecifiedInRazorFileForTypeParameter/TestComponent.ir.txt

@@ -0,0 +1,22 @@
+Document - 
+    NamespaceDeclaration -  - Test
+        UsingDirective - (3:1,1 [20] ) - global::System
+        UsingDirective - (26:2,1 [40] ) - global::System.Collections.Generic
+        UsingDirective - (69:3,1 [25] ) - global::System.Linq
+        UsingDirective - (97:4,1 [36] ) - global::System.Threading.Tasks
+        UsingDirective - (136:5,1 [45] ) - global::Microsoft.AspNetCore.Components
+        ClassDeclaration -  - public partial - TestComponent - global::Microsoft.AspNetCore.Components.ComponentBase - 
+            DesignTimeDirective - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning disable 0414
+            CSharpCode - 
+                IntermediateToken -  - CSharp - private static object __o = null;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning restore 0414
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                Component - (0:0,0 [26] x:\dir\subdir\Test\TestComponent.cshtml) - C
+                    ComponentTypeArgument - (6:0,6 [7] x:\dir\subdir\Test\TestComponent.cshtml) - T
+                        CSharpExpression - (7:0,7 [6] x:\dir\subdir\Test\TestComponent.cshtml)
+                            LazyIntermediateToken - (7:0,7 [6] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - string
+                    ComponentAttribute - (21:0,21 [1] x:\dir\subdir\Test\TestComponent.cshtml) - Item - Item - AttributeStructure.DoubleQuotes
+                        LazyIntermediateToken - (21:0,21 [1] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - 1

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/ChildComponent_AtSpecifiedInRazorFileForTypeParameter/TestComponent.mappings.txt

@@ -0,0 +1,15 @@
+Source Location: (7:0,7 [6] x:\dir\subdir\Test\TestComponent.cshtml)
+|string|
+Generated Location: (935:25,7 [6] )
+|string|
+
+Source Location: (21:0,21 [1] x:\dir\subdir\Test\TestComponent.cshtml)
+|1|
+Generated Location: (1224:34,21 [1] )
+|1|
+
+Source Location: (15:0,15 [4] x:\dir\subdir\Test\TestComponent.cshtml)
+|Item|
+Generated Location: (1633:47,15 [4] )
+|Item|
+

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/ChildComponent_AtSpecifiedInRazorFileForTypeParameter/TestComponent.codegen.cs

@@ -0,0 +1,31 @@
+// <auto-generated/>
+#pragma warning disable 1591
+namespace Test
+{
+    #line hidden
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    public partial class TestComponent : global::Microsoft.AspNetCore.Components.ComponentBase
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.OpenComponent<global::Test.C<string>>(0);
+            __builder.AddComponentParameter(1, "Item", global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.TypeCheck<global::System.Int32>(
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+                     1
+
+#line default
+#line hidden
+#nullable disable
+            ));
+            __builder.CloseComponent();
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/ChildComponent_AtSpecifiedInRazorFileForTypeParameter/TestComponent.ir.txt

@@ -0,0 +1,15 @@
+Document - 
+    NamespaceDeclaration -  - Test
+        UsingDirective - (3:1,1 [22] ) - global::System
+        UsingDirective - (26:2,1 [42] ) - global::System.Collections.Generic
+        UsingDirective - (69:3,1 [27] ) - global::System.Linq
+        UsingDirective - (97:4,1 [38] ) - global::System.Threading.Tasks
+        UsingDirective - (136:5,1 [47] ) - global::Microsoft.AspNetCore.Components
+        ClassDeclaration -  - public partial - TestComponent - global::Microsoft.AspNetCore.Components.ComponentBase - 
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                Component - (0:0,0 [26] x:\dir\subdir\Test\TestComponent.cshtml) - C
+                    ComponentTypeArgument - (6:0,6 [7] x:\dir\subdir\Test\TestComponent.cshtml) - T
+                        CSharpExpression - (7:0,7 [6] x:\dir\subdir\Test\TestComponent.cshtml)
+                            LazyIntermediateToken - (7:0,7 [6] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - string
+                    ComponentAttribute - (21:0,21 [1] x:\dir\subdir\Test\TestComponent.cshtml) - Item - Item - AttributeStructure.DoubleQuotes
+                        LazyIntermediateToken - (21:0,21 [1] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - 1