Fix parsing of type arguments in arrays

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

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 #nullable disable
@@ -5397,6 +5397,36 @@ public class MyType
         Assert.Collection(result.Diagnostics, d => { Assert.Equal("CS0411", d.Id); });
     }
 
+    [Fact, WorkItem("https://github.com/dotnet/aspnetcore/issues/48526")]
+    public void EventCallbackOfT_Array()
+    {
+        // Arrange
+        AdditionalSyntaxTrees.Add(Parse("""
+            using Microsoft.AspNetCore.Components.Forms;
+
+            namespace Test;
+
+            public class MyComponent<TItem> : InputBase<TItem[]>
+            {
+                protected override bool TryParseValueFromString(string value, out TItem[] result, out string validationErrorMessage) => throw null;
+            }
+            """));
+
+        // Act
+        var generated = CompileToCSharp("""
+            <MyComponent @bind-Value="Selected" />
+
+            @code {
+                string[] Selected { get; set; } = Array.Empty<string>();
+            }
+            """);
+
+        // Assert
+        AssertDocumentNodeMatchesBaseline(generated.CodeDocument);
+        AssertCSharpDocumentMatchesBaseline(generated.CodeDocument);
+        CompileToAssembly(generated);
+    }
+
     #endregion
 
     #region Event Handlers

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

@@ -0,0 +1,79 @@
+// <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)
+        {
+            var __typeInference_CreateMyComponent_0 = global::__Blazor.Test.TestComponent.TypeInference.CreateMyComponent_0(__builder, -1, -1, 
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+                          Selected
+
+#line default
+#line hidden
+#nullable disable
+            , -1, global::Microsoft.AspNetCore.Components.EventCallback.Factory.Create(this, 
+            global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.CreateInferredEventCallback(this, __value => Selected = __value, Selected)), -1, () => Selected);
+            #pragma warning disable BL0005
+            __typeInference_CreateMyComponent_0.
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+                   Value
+
+#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.MyComponent<>);
+
+#line default
+#line hidden
+#nullable disable
+        }
+        #pragma warning restore 1998
+#nullable restore
+#line 3 "x:\dir\subdir\Test\TestComponent.cshtml"
+
+    string[] Selected { get; set; } = Array.Empty<string>();
+
+#line default
+#line hidden
+#nullable disable
+    }
+}
+namespace __Blazor.Test.TestComponent
+{
+    #line hidden
+    internal static class TypeInference
+    {
+        public static global::Test.MyComponent<TItem> CreateMyComponent_0<TItem>(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder, int seq, int __seq0, TItem[] __arg0, int __seq1, global::Microsoft.AspNetCore.Components.EventCallback<TItem[]> __arg1, int __seq2, global::System.Linq.Expressions.Expression<global::System.Func<TItem[]>> __arg2)
+        {
+        __builder.OpenComponent<global::Test.MyComponent<TItem>>(seq);
+        __builder.AddComponentParameter(__seq0, "Value", __arg0);
+        __builder.AddComponentParameter(__seq1, "ValueChanged", __arg1);
+        __builder.AddComponentParameter(__seq2, "ValueExpression", __arg2);
+        __builder.CloseComponent();
+        return default;
+        }
+    }
+}
+#pragma warning restore 1591

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

@@ -0,0 +1,35 @@
+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 [38] x:\dir\subdir\Test\TestComponent.cshtml) - MyComponent
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - Value - Value - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            LazyIntermediateToken - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - Selected
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - ValueChanged - ValueChanged - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            IntermediateToken -  - CSharp - global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.CreateInferredEventCallback(this, 
+                            IntermediateToken -  - CSharp - __value => Selected = __value
+                            IntermediateToken -  - CSharp - , Selected)
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - ValueExpression - ValueExpression - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            IntermediateToken -  - CSharp - () => Selected
+                HtmlContent - (38:0,38 [4] x:\dir\subdir\Test\TestComponent.cshtml)
+                    LazyIntermediateToken - (38:0,38 [4] x:\dir\subdir\Test\TestComponent.cshtml) - Html - \n\n
+            CSharpCode - (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml)
+                LazyIntermediateToken - (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - \n    string[] Selected { get; set; } = Array.Empty<string>();\n
+    NamespaceDeclaration -  - __Blazor.Test.TestComponent
+        ClassDeclaration -  - internal static - TypeInference -  - 
+            ComponentTypeInferenceMethod -  - __Blazor.Test.TestComponent.TypeInference - CreateMyComponent_0

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

@@ -0,0 +1,19 @@
+Source Location: (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml)
+|Selected|
+Generated Location: (1072:25,26 [8] )
+|Selected|
+
+Source Location: (19:0,19 [5] x:\dir\subdir\Test\TestComponent.cshtml)
+|Value|
+Generated Location: (1593:36,19 [5] )
+|Value|
+
+Source Location: (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml)
+|
+    string[] Selected { get; set; } = Array.Empty<string>();
+|
+Generated Location: (2008:54,7 [64] )
+|
+    string[] Selected { get; set; } = Array.Empty<string>();
+|
+

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

@@ -0,0 +1,52 @@
+// <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)
+        {
+            global::__Blazor.Test.TestComponent.TypeInference.CreateMyComponent_0(__builder, 0, 1, 
+#nullable restore
+#line 1 "x:\dir\subdir\Test\TestComponent.cshtml"
+                          Selected
+
+#line default
+#line hidden
+#nullable disable
+            , 2, global::Microsoft.AspNetCore.Components.EventCallback.Factory.Create(this, global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.CreateInferredEventCallback(this, __value => Selected = __value, Selected)), 3, () => Selected);
+        }
+        #pragma warning restore 1998
+#nullable restore
+#line 3 "x:\dir\subdir\Test\TestComponent.cshtml"
+
+    string[] Selected { get; set; } = Array.Empty<string>();
+
+#line default
+#line hidden
+#nullable disable
+    }
+}
+namespace __Blazor.Test.TestComponent
+{
+    #line hidden
+    internal static class TypeInference
+    {
+        public static void CreateMyComponent_0<TItem>(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder, int seq, int __seq0, TItem[] __arg0, int __seq1, global::Microsoft.AspNetCore.Components.EventCallback<TItem[]> __arg1, int __seq2, global::System.Linq.Expressions.Expression<global::System.Func<TItem[]>> __arg2)
+        {
+        __builder.OpenComponent<global::Test.MyComponent<TItem>>(seq);
+        __builder.AddComponentParameter(__seq0, "Value", __arg0);
+        __builder.AddComponentParameter(__seq1, "ValueChanged", __arg1);
+        __builder.AddComponentParameter(__seq2, "ValueExpression", __arg2);
+        __builder.CloseComponent();
+        }
+    }
+}
+#pragma warning restore 1591

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

@@ -0,0 +1,26 @@
+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 [38] x:\dir\subdir\Test\TestComponent.cshtml) - MyComponent
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - Value - Value - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            LazyIntermediateToken - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - Selected
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - ValueChanged - ValueChanged - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            IntermediateToken -  - CSharp - global::Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.CreateInferredEventCallback(this, 
+                            IntermediateToken -  - CSharp - __value => Selected = __value
+                            IntermediateToken -  - CSharp - , Selected)
+                    ComponentAttribute - (26:0,26 [8] x:\dir\subdir\Test\TestComponent.cshtml) - ValueExpression - ValueExpression - AttributeStructure.DoubleQuotes
+                        CSharpExpression - 
+                            IntermediateToken -  - CSharp - () => Selected
+            CSharpCode - (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml)
+                LazyIntermediateToken - (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml) - CSharp - \n    string[] Selected { get; set; } = Array.Empty<string>();\n
+    NamespaceDeclaration -  - __Blazor.Test.TestComponent
+        ClassDeclaration -  - internal static - TypeInference -  - 
+            ComponentTypeInferenceMethod -  - __Blazor.Test.TestComponent.TypeInference - CreateMyComponent_0

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EventCallbackOfT_Array/TestComponent.mappings.txt

@@ -0,0 +1,9 @@
+Source Location: (49:2,7 [64] x:\dir\subdir\Test\TestComponent.cshtml)
+|
+    string[] Selected { get; set; } = Array.Empty<string>();
+|
+Generated Location: (1215:28,7 [64] )
+|
+    string[] Selected { get; set; } = Array.Empty<string>();
+|
+

src/Compiler/Microsoft.CodeAnalysis.Razor/src/DefaultTypeNameFeature.cs

@@ -22,24 +22,45 @@ public override IReadOnlyList<string> ParseTypeParameters(string typeName)
         }
 
         var parsed = SyntaxFactory.ParseTypeName(typeName);
+
         if (parsed is IdentifierNameSyntax identifier)
         {
             return Array.Empty<string>();
         }
-        else if (parsed is ArrayTypeSyntax array)
+
+        if (TryParseCore(parsed) is { } list)
         {
-            return new[] { array.ElementType.ToString() };
+            return list;
         }
-        else if (parsed is TupleTypeSyntax tuple)
+
+        return parsed.DescendantNodesAndSelf()
+            .OfType<TypeArgumentListSyntax>()
+            .SelectMany(arg => arg.Arguments)
+            .SelectMany(ParseCore).ToArray();
+
+        static IReadOnlyList<string> TryParseCore(TypeSyntax parsed)
         {
-            return tuple.Elements.Select(a => a.ToString()).ToList();
+            if (parsed is ArrayTypeSyntax array)
+            {
+                return ParseCore(array.ElementType);
+            }
+
+            if (parsed is TupleTypeSyntax tuple)
+            {
+                return tuple.Elements.SelectMany(a => ParseCore(a.Type)).ToList();
+            }
+
+            return null;
         }
-        else
+
+        static IReadOnlyList<string> ParseCore(TypeSyntax parsed)
         {
-            return parsed.DescendantNodesAndSelf()
-                .OfType<TypeArgumentListSyntax>()
-                .SelectMany(arg => arg.Arguments)
-                .Select(a => a.ToString()).ToList();
+            if (TryParseCore(parsed) is { } list)
+            {
+                return list;
+            }
+
+            return new[] { parsed.ToString() };
         }
     }
 

src/Compiler/Microsoft.CodeAnalysis.Razor/test/DefaultTypeNameFeatureTest.cs

@@ -0,0 +1,38 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Linq;
+using Xunit;
+
+namespace Microsoft.CodeAnalysis.Razor;
+
+public class DefaultTypeNameFeatureTest
+{
+    [Theory]
+    [InlineData("C", 0)]
+    [InlineData("T", 0)]
+    [InlineData("T[]", 1)]
+    [InlineData("T[][]", 1)]
+    [InlineData("(T, T)[]", 2)]
+    [InlineData("(T X, T Y)[]", 2)]
+    [InlineData("(T[], T)[]", 2)]
+    [InlineData("(T[] X, T Y)[]", 2)]
+    [InlineData("C<T>", 1)]
+    [InlineData("C<T[]>", 1)]
+    [InlineData("C<T[][]>", 1)]
+    [InlineData("C<(T, T)[]>", 2)]
+    [InlineData("C<(T X, T Y)[]>", 2)]
+    [InlineData("C<(T[], T)[]>", 2)]
+    [InlineData("C<(T[] X, T Y)[]>", 2)]
+    public void ParseTypeParameters(string input, int expectedNumberOfTs)
+    {
+        // Arrange.
+        var feature = new DefaultTypeNameFeature();
+
+        // Act.
+        var parsed = feature.ParseTypeParameters(input);
+
+        // Assert.
+        Assert.Equal(Enumerable.Repeat("T", expectedNumberOfTs), parsed);
+    }
+}