Make ViewComponentTagHelper's bound attribute display names nicer.

- Went from `typeName __Generated__SomeViewComponentTagHelper.PropertyName` to `typeName SomeViewComponentTagHelper.PropertyName`.
- Updated `TagHelperBoundDescriptorBuilder` to allow setting of `DisplayName`.
- Added `TagHelperBoundAttributeDescriptorBuilderTest` class to verify new `DisplayName` additions.
- Updated `ViewComponentTagHelperDescriptorFactoryTest` expectations.

#1251

src/Microsoft.AspNetCore.Razor.Language/BoundAttributeDescriptorBuilder.cs

@@ -31,6 +31,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             [typeof(decimal).FullName] = "decimal",
         };
 
+        private string _displayName;
         private bool _isEnum;
         private bool _hasIndexer;
         private string _indexerValueTypeName;
@@ -113,6 +114,18 @@ namespace Microsoft.AspNetCore.Razor.Language
             return this;
         }
 
+        public BoundAttributeDescriptorBuilder DisplayName(string displayName)
+        {
+            if (displayName == null)
+            {
+                throw new ArgumentNullException(nameof(displayName));
+            }
+
+            _displayName = displayName;
+
+            return this;
+        }
+
         public BoundAttributeDescriptor Build()
         {
             var validationDiagnostics = Validate();
@@ -122,12 +135,17 @@ namespace Microsoft.AspNetCore.Razor.Language
                 diagnostics.UnionWith(_diagnostics);
             }
 
-            if (!PrimitiveDisplayTypeNameLookups.TryGetValue(_typeName, out var simpleName))
+            var displayName = _displayName;
+            if (displayName == null)
             {
-                simpleName = _typeName;
+                if (!PrimitiveDisplayTypeNameLookups.TryGetValue(_typeName, out var simpleName))
+                {
+                    simpleName = _typeName;
+                }
+
+                displayName = $"{simpleName} {_containingTypeName}.{_propertyName}";
             }
 
-            var displayName = $"{simpleName} {_containingTypeName}.{_propertyName}";
             var descriptor = new ITagHelperBoundAttributeDescriptor(
                 _isEnum,
                 _name,

src/Microsoft.CodeAnalysis.Razor/ViewComponentTagHelperDescriptorFactory.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language;
@@ -20,6 +21,25 @@ namespace Microsoft.CodeAnalysis.Razor
                 .WithGlobalNamespaceStyle(SymbolDisplayGlobalNamespaceStyle.Omitted)
                 .WithMiscellaneousOptions(SymbolDisplayFormat.FullyQualifiedFormat.MiscellaneousOptions & (~SymbolDisplayMiscellaneousOptions.UseSpecialTypes));
 
+        private static readonly IReadOnlyDictionary<string, string> PrimitiveDisplayTypeNameLookups = new Dictionary<string, string>(StringComparer.Ordinal)
+        {
+            [typeof(byte).FullName] = "byte",
+            [typeof(sbyte).FullName] = "sbyte",
+            [typeof(int).FullName] = "int",
+            [typeof(uint).FullName] = "uint",
+            [typeof(short).FullName] = "short",
+            [typeof(ushort).FullName] = "ushort",
+            [typeof(long).FullName] = "long",
+            [typeof(ulong).FullName] = "ulong",
+            [typeof(float).FullName] = "float",
+            [typeof(double).FullName] = "double",
+            [typeof(char).FullName] = "char",
+            [typeof(bool).FullName] = "bool",
+            [typeof(object).FullName] = "object",
+            [typeof(string).FullName] = "string",
+            [typeof(decimal).FullName] = "decimal",
+        };
+
         public ViewComponentTagHelperDescriptorFactory(Compilation compilation)
         {
             _viewComponentAttributeSymbol = compilation.GetTypeByMetadataName(ViewComponentTypes.ViewComponentAttribute);
@@ -47,7 +67,7 @@ namespace Microsoft.CodeAnalysis.Razor
                     AddRequiredAttributes(methodParameters, ruleBuilder);
                 });
 
-                AddBoundAttributes(methodParameters, descriptorBuilder);
+                AddBoundAttributes(methodParameters, displayName, descriptorBuilder);
             }
             else
             {
@@ -148,18 +168,25 @@ namespace Microsoft.CodeAnalysis.Razor
             }
         }
 
-        private void AddBoundAttributes(ImmutableArray<IParameterSymbol> methodParameters, TagHelperDescriptorBuilder builder)
+        private void AddBoundAttributes(ImmutableArray<IParameterSymbol> methodParameters, string containingDisplayName, TagHelperDescriptorBuilder builder)
         {
             foreach (var parameter in methodParameters)
             {
                 var lowerKebabName = HtmlConventions.ToHtmlCase(parameter.Name);
                 var typeName = parameter.Type.ToDisplayString(FullNameTypeDisplayFormat);
+
+                if (!PrimitiveDisplayTypeNameLookups.TryGetValue(typeName, out var simpleName))
+                {
+                    simpleName = typeName;
+                }
+
                 builder.BindAttribute(attributeBuilder =>
                 {
                     attributeBuilder
                         .Name(lowerKebabName)
                         .PropertyName(parameter.Name)
-                        .TypeName(typeName);
+                        .TypeName(typeName)
+                        .DisplayName($"{simpleName} {containingDisplayName}.{parameter.Name}");
 
                     if (parameter.Type.TypeKind == TypeKind.Enum)
                     {

test/Microsoft.AspNetCore.Razor.Language.Test/BoundAttributeDescriptorBuilderTest.cs

@@ -0,0 +1,39 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Xunit;
+
+namespace Microsoft.AspNetCore.Razor.Language
+{
+    public class BoundAttributeDescriptorBuilderTest
+    {
+        [Fact]
+        public void DisplayName_SetsDescriptorsDisplayName()
+        {
+            // Arrange
+            var expectedDisplayName = "ExpectedDisplayName";
+            var builder = BoundAttributeDescriptorBuilder.Create("TestTagHelper");
+
+            // Act
+            var descriptor = builder.DisplayName(expectedDisplayName).Build();
+
+            // Assert
+            Assert.Equal(expectedDisplayName, descriptor.DisplayName);
+        }
+
+        [Fact]
+        public void DisplayName_DefaultsToPropertyLookingDisplayName()
+        {
+            // Arrange
+            var builder = BoundAttributeDescriptorBuilder.Create("TestTagHelper")
+                .TypeName(typeof(int).FullName)
+                .PropertyName("SomeProperty");
+
+            // Act
+            var descriptor = builder.Build();
+
+            // Assert
+            Assert.Equal("int TestTagHelper.SomeProperty", descriptor.DisplayName);
+        }
+    }
+}

test/Microsoft.CodeAnalysis.Razor.Test/ViewComponentTagHelperDescriptorFactoryTest.cs

@@ -31,12 +31,14 @@ namespace Microsoft.CodeAnalysis.Razor.Workspaces
                     attribute
                     .Name("foo")
                     .PropertyName("foo")
-                    .TypeName(typeof(string).FullName))
+                    .TypeName(typeof(string).FullName)
+                    .DisplayName("string StringParameterViewComponentTagHelper.foo"))
                 .BindAttribute(attribute =>
                     attribute
                     .Name("bar")
                     .PropertyName("bar")
-                    .TypeName(typeof(string).FullName))
+                    .TypeName(typeof(string).FullName)
+                    .DisplayName("string StringParameterViewComponentTagHelper.bar"))
                 .AddMetadata(ViewComponentTypes.ViewComponentNameKey, "StringParameter")
                 .Build();
 
@@ -69,17 +71,20 @@ namespace Microsoft.CodeAnalysis.Razor.Workspaces
                     .Name("test-enum")
                     .PropertyName("testEnum")
                     .TypeName(typeof(VariousParameterViewComponent).FullName + "." + nameof(VariousParameterViewComponent.TestEnum))
-                    .AsEnum())
+                    .AsEnum()
+                    .DisplayName(typeof(VariousParameterViewComponent).FullName + "." + nameof(VariousParameterViewComponent.TestEnum) + " VariousParameterViewComponentTagHelper.testEnum"))
                 .BindAttribute(attribute =>
                     attribute
                     .Name("test-string")
                     .PropertyName("testString")
-                    .TypeName(typeof(string).FullName))
+                    .TypeName(typeof(string).FullName)
+                    .DisplayName("string VariousParameterViewComponentTagHelper.testString"))
                 .BindAttribute(attribute =>
                     attribute
                     .Name("baz")
                     .PropertyName("baz")
-                    .TypeName(typeof(int).FullName))
+                    .TypeName(typeof(int).FullName)
+                    .DisplayName("int VariousParameterViewComponentTagHelper.baz"))
                 .AddMetadata(ViewComponentTypes.ViewComponentNameKey, "VariousParameter")
                 .Build();
 
@@ -109,13 +114,15 @@ namespace Microsoft.CodeAnalysis.Razor.Workspaces
                     attribute
                     .Name("foo")
                     .PropertyName("Foo")
-                    .TypeName("System.Collections.Generic.List<System.String>"))
+                    .TypeName("System.Collections.Generic.List<System.String>")
+                    .DisplayName("System.Collections.Generic.List<System.String> GenericParameterViewComponentTagHelper.Foo"))
                 .BindAttribute(attribute =>
                     attribute
                     .Name("bar")
                     .PropertyName("Bar")
                     .TypeName("System.Collections.Generic.Dictionary<System.String, System.Int32>")
-                    .AsDictionary("bar-", typeof(int).FullName))
+                    .AsDictionary("bar-", typeof(int).FullName)
+                    .DisplayName("System.Collections.Generic.Dictionary<System.String, System.Int32> GenericParameterViewComponentTagHelper.Bar"))
                 .AddMetadata(ViewComponentTypes.ViewComponentNameKey, "GenericParameter")
                 .Build();
 

test/Microsoft.CodeAnalysis.Razor.Test/ViewComponentTagHelperDescriptorProviderTest.cs

@@ -1,10 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
@@ -49,12 +46,14 @@ namespace Microsoft.CodeAnalysis.Razor
                     attribute
                     .Name("foo")
                     .PropertyName("foo")
-                    .TypeName(typeof(string).FullName))
+                    .TypeName(typeof(string).FullName)
+                    .DisplayName("string StringParameterViewComponentTagHelper.foo"))
                 .BindAttribute(attribute =>
                     attribute
                     .Name("bar")
                     .PropertyName("bar")
-                    .TypeName(typeof(string).FullName))
+                    .TypeName(typeof(string).FullName)
+                    .DisplayName("string StringParameterViewComponentTagHelper.bar"))
                 .AddMetadata(ViewComponentTypes.ViewComponentNameKey, "StringParameter")
                 .Build();