Change ITypeInfo.IsTagHelper to ITypeInfo.ImplementsInterface(ITypeInfo)

Fixes #511

src/Microsoft.AspNet.Razor.Runtime.Precompilation/CodeAnalysisSymbolBasedTypeInfo.cs

@@ -18,13 +18,8 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
     [DebuggerDisplay("{Name}")]
     public class CodeAnalysisSymbolBasedTypeInfo : ITypeInfo
     {
-        /// <summary>
+        private static readonly System.Reflection.TypeInfo OpenGenericDictionaryTypeInfo =
-        /// The <see cref="System.Reflection.TypeInfo"/> for <see cref="IDictionary{TKey, TValue}"/>.
-        /// </summary>
-        public static readonly System.Reflection.TypeInfo OpenGenericDictionaryTypeInfo =
             typeof(IDictionary<,>).GetTypeInfo();
-        private static readonly System.Reflection.TypeInfo TagHelperTypeInfo =
-            typeof(ITagHelper).GetTypeInfo();
         private readonly ITypeSymbol _type;
         private readonly ITypeSymbol _underlyingType;
         private string _fullName;
@@ -120,13 +115,33 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
         }
 
         /// <inheritdoc />
-        public bool IsTagHelper
+        public bool ImplementsInterface(ITypeInfo interfaceTypeInfo)
         {
-            get
+            if (interfaceTypeInfo == null)
             {
-                return _type.AllInterfaces.Any(
+                throw new ArgumentNullException(nameof(interfaceTypeInfo));
-                    implementedInterface => IsType(implementedInterface, TagHelperTypeInfo));
             }
+
+            var runtimeTypeInfo = interfaceTypeInfo as RuntimeTypeInfo;
+            if (runtimeTypeInfo != null)
+            {
+                return runtimeTypeInfo.TypeInfo.IsInterface &&
+                    _type.AllInterfaces.Any(implementedInterface => IsType(implementedInterface, runtimeTypeInfo.TypeInfo));
+            }
+
+            var codeAnalysisTypeInfo = interfaceTypeInfo as CodeAnalysisSymbolBasedTypeInfo;
+            if (codeAnalysisTypeInfo != null)
+            {
+                return codeAnalysisTypeInfo.TypeSymbol.TypeKind == TypeKind.Interface &&
+                    _type.AllInterfaces.Any(
+                        implementedInterface => implementedInterface == codeAnalysisTypeInfo.TypeSymbol);
+            }
+
+            throw new ArgumentException(
+                Resources.FormatArgumentMustBeAnInstanceOf(
+                    typeof(RuntimeTypeInfo).FullName,
+                    typeof(CodeAnalysisSymbolBasedTypeInfo).FullName),
+                nameof(interfaceTypeInfo));
         }
 
         private string SanitizedFullName
@@ -193,8 +208,8 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
             System.Reflection.TypeInfo targetTypeInfo)
         {
             return string.Equals(
-                targetTypeInfo.FullName,
+                RuntimeTypeInfo.SanitizeFullName(targetTypeInfo.FullName),
-                GetFullName(sourceTypeSymbol),
+                RuntimeTypeInfo.SanitizeFullName(GetFullName(sourceTypeSymbol)),
                 StringComparison.Ordinal);
         }
 

src/Microsoft.AspNet.Razor.Runtime.Precompilation/Properties/Resources.Designer.cs

@@ -10,6 +10,22 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
         private static readonly ResourceManager _resourceManager
             = new ResourceManager("Microsoft.AspNet.Razor.Runtime.Precompilation.Resources", typeof(Resources).GetTypeInfo().Assembly);
 
+        /// <summary>
+        /// Argument must be an instance of '{0}' or '{1}'.
+        /// </summary>
+        internal static string ArgumentMustBeAnInstanceOf
+        {
+            get { return GetString("ArgumentMustBeAnInstanceOf"); }
+        }
+
+        /// <summary>
+        /// Argument must be an instance of '{0}' or '{1}'.
+        /// </summary>
+        internal static string FormatArgumentMustBeAnInstanceOf(object p0, object p1)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ArgumentMustBeAnInstanceOf"), p0, p1);
+        }
+
         /// <summary>
         /// Unable to find a suitable constructor for type '{0}'.
         /// </summary>

src/Microsoft.AspNet.Razor.Runtime.Precompilation/Resources.resx

@@ -117,6 +117,9 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
+  <data name="ArgumentMustBeAnInstanceOf" xml:space="preserve">
+    <value>Argument must be an instance of '{0}' or '{1}'.</value>
+  </data>
   <data name="CodeAnalysisConstructorNotFound" xml:space="preserve">
     <value>Unable to find a suitable constructor for type '{0}'.</value>
   </data>

src/Microsoft.AspNet.Razor.Runtime/Properties/Resources.Designer.cs

@@ -442,6 +442,22 @@ namespace Microsoft.AspNet.Razor.Runtime
             return GetString("TagHelperDescriptorFactory_ParentTag");
         }
 
+        /// <summary>
+        /// Argument must be an instance of '{0}'.
+        /// </summary>
+        internal static string ArgumentMustBeAnInstanceOf
+        {
+            get { return GetString("ArgumentMustBeAnInstanceOf"); }
+        }
+
+        /// <summary>
+        /// Argument must be an instance of '{0}'.
+        /// </summary>
+        internal static string FormatArgumentMustBeAnInstanceOf(object p0)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ArgumentMustBeAnInstanceOf"), p0);
+        }
+
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

src/Microsoft.AspNet.Razor.Runtime/Resources.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!--
+  <!-- 
-    Microsoft ResX Schema
+    Microsoft ResX Schema 
-
+    
     Version 2.0
-
+    
-    The primary goals of this format is to allow a simple XML format
+    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the
+    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes
+    various data types are done through the TypeConverter classes 
     associated with the data types.
-
+    
     Example:
-
+    
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-
+                
-    There are any number of "resheader" rows that contain simple
+    There are any number of "resheader" rows that contain simple 
     name/value pairs.
-
+    
-    Each data row contains a name, and value. The row also contains a
+    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support
+    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture.
+    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the
+    Classes that don't support this are serialized and stored with the 
     mimetype set.
-
+    
-    The mimetype is used for serialized objects, and tells the
+    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not
+    ResXResourceReader how to depersist the object. This is currently not 
     extensible. For a given mimetype the value must be set accordingly:
-
+    
-    Note - application/x-microsoft.net.object.binary.base64 is the format
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can
+    that the ResXResourceWriter will generate, however the reader can 
     read any of the formats listed below.
-
+    
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-
+    
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array
+    value   : The object must be serialized into a byte array 
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -198,4 +198,7 @@
   <data name="TagHelperDescriptorFactory_ParentTag" xml:space="preserve">
     <value>Parent Tag</value>
   </data>
+  <data name="ArgumentMustBeAnInstanceOf" xml:space="preserve">
+    <value>Argument must be an instance of '{0}'.</value>
+  </data>
 </root>

src/Microsoft.AspNet.Razor.Runtime/TagHelpers/ITypeInfo.cs

@@ -49,9 +49,9 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         bool IsGenericType { get; }
 
         /// <summary>
-        /// Gets a value indicating whether the type implements the <see cref="ITagHelper"/> interface.
+        /// Gets a value indicating whether the type implements the <param name="interfaceTypeInfo"/> interface.
         /// </summary>
-        bool IsTagHelper { get; }
+        bool ImplementsInterface(ITypeInfo interfaceTypeInfo);
 
         /// <summary>
         /// Gets the <see cref="ITypeInfo[]"/> for the <c>TKey</c> and <c>TValue</c> parameters of

src/Microsoft.AspNet.Razor.Runtime/TagHelpers/RuntimeTypeInfo.cs

@@ -77,7 +77,23 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         }
 
         /// <inheritdoc />
-        public bool IsTagHelper => TagHelperTypeInfo.IsAssignableFrom(TypeInfo);
+        public bool ImplementsInterface(ITypeInfo interfaceTypeInfo)
+        {
+            if (interfaceTypeInfo == null)
+            {
+                throw new ArgumentNullException(nameof(interfaceTypeInfo));
+            }
+
+            var runtimeTypeInfo = interfaceTypeInfo as RuntimeTypeInfo;
+            if (runtimeTypeInfo == null)
+            {
+                throw new ArgumentException(
+                    Resources.FormatArgumentMustBeAnInstanceOf(typeof(RuntimeTypeInfo).FullName),
+                    nameof(interfaceTypeInfo));
+            }
+
+            return runtimeTypeInfo.TypeInfo.IsInterface && runtimeTypeInfo.TypeInfo.IsAssignableFrom(TypeInfo);
+        }
 
         private string SanitizedFullName
         {

src/Microsoft.AspNet.Razor.Runtime/TagHelpers/TagHelperTypeResolver.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
     /// </summary>
     public class TagHelperTypeResolver
     {
-        private static readonly TypeInfo ITagHelperTypeInfo = typeof(ITagHelper).GetTypeInfo();
+        private static readonly ITypeInfo ITagHelperTypeInfo = new RuntimeTypeInfo(typeof(ITagHelper).GetTypeInfo());
 
         /// <summary>
         /// Locates valid <see cref="ITagHelper"/> types from the <see cref="Assembly"/> named <paramref name="name"/>.
@@ -109,7 +109,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             return typeInfo.IsPublic &&
                    !typeInfo.IsAbstract &&
                    !typeInfo.IsGenericType &&
-                   typeInfo.IsTagHelper;
+                   typeInfo.ImplementsInterface(ITagHelperTypeInfo);
         }
     }
 }

test/Microsoft.AspNet.Razor.Runtime.Precompilation.Files/DerivingFromIList.cs

@@ -0,0 +1,38 @@
+// 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;
+using System.Collections.Generic;
+
+namespace Microsoft.AspNet.Razor.Runtime
+{
+    public class DerivingFromIList : IReadOnlyList<string>
+    {
+        public string this[int index]
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public int Count
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public IEnumerator<string> GetEnumerator()
+        {
+            throw new NotImplementedException();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

test/Microsoft.AspNet.Razor.Runtime.Precompilation.Files/DerivingFromList.cs

@@ -0,0 +1,11 @@
+// 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.Collections.Generic;
+
+namespace Microsoft.AspNet.Razor.Runtime
+{
+    public class DerivingFromList : List<string>
+    {
+    }
+}

test/Microsoft.AspNet.Razor.Runtime.Precompilation.Test/PrecompilationTagHelperTypeResolverTest.cs

@@ -8,6 +8,7 @@ using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Reflection;
 using Microsoft.AspNet.Razor.Runtime.TagHelpers;
+using Microsoft.AspNet.Testing;
 using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 
@@ -15,7 +16,7 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
 {
     public class PrecompilationTagHelperTypeResolverTest
     {
-        private static readonly TypeInfo TagHelperTypeInfo = typeof(ITagHelper).GetTypeInfo();
+        private static readonly ITypeInfo TagHelperTypeInfo = new RuntimeTypeInfo(typeof(ITagHelper).GetTypeInfo());
 
         [Theory]
         [InlineData(typeof(TypeDerivingFromITagHelper))]
@@ -35,6 +36,60 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
             AssertEqual(expected, actual);
         }
 
+        [Fact]
+        public void ImplementsInterface_ThrowsIfPassedInParameterIsNotRuntimeTypeOrCodeAnalysisBasedTypeInfo()
+        {
+            // Arrange
+            var interfaceType = new TestTypeInfo();
+            var compilation = CompilationUtility.GetCompilation(nameof(DerivingFromList));
+            var tagHelperResolver = new PrecompilationTagHelperTypeResolver(compilation);
+
+            // Act
+            var exportedTypes = tagHelperResolver.GetExportedTypes(compilation.AssemblyName);
+
+            // Assert
+            var actual = Assert.Single(exportedTypes);
+            ExceptionAssert.ThrowsArgument(() => actual.ImplementsInterface(interfaceType),
+                "interfaceTypeInfo",
+                $"Argument must be an instance of '{typeof(RuntimeTypeInfo)}' or '{typeof(CodeAnalysisSymbolBasedTypeInfo)}'.");
+        }
+
+        [Theory]
+        [InlineData(typeof(DerivingFromList))]
+        [InlineData(typeof(DerivingFromIList))]
+        public void ImplementsInterface_ReturnsTrueIfTypeDerivesFromInterface(Type expected)
+        {
+            // Arrange
+            var interfaceType = new RuntimeTypeInfo(typeof(IEnumerable<string>).GetTypeInfo());
+            var compilation = CompilationUtility.GetCompilation(expected.Name);
+            var tagHelperResolver = new PrecompilationTagHelperTypeResolver(compilation);
+
+            // Act
+            var exportedTypes = tagHelperResolver.GetExportedTypes(compilation.AssemblyName);
+
+            // Assert
+            var actual = Assert.Single(exportedTypes);
+            Assert.True(actual.ImplementsInterface(interfaceType));
+        }
+
+        [Theory]
+        [InlineData(typeof(TagHelper))]
+        [InlineData(typeof(IEnumerable<string>))]
+        public void ImplementsInterface_ReturnsFalseIfTypeDoesNotDerivesFromInterface(Type interfaceType)
+        {
+            // Arrange
+            var interfaceTypeInfo = new RuntimeTypeInfo(interfaceType.GetTypeInfo());
+            var compilation = CompilationUtility.GetCompilation("TagHelperDescriptorFactoryTagHelpers");
+            var tagHelperResolver = new PrecompilationTagHelperTypeResolver(compilation);
+
+            // Act
+            var exportedTypes = tagHelperResolver.GetExportedTypes(compilation.AssemblyName);
+
+            // Assert
+            var actual = Assert.Single(exportedTypes, type => type.Name == nameof(RequiredParentTagHelper));
+            Assert.False(actual.ImplementsInterface(interfaceTypeInfo));
+        }
+
         [Fact]
         public void PropertyNamesForComplexPropertiesAreGeneratedCorrectly()
         {
@@ -472,7 +527,7 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
 
             // Assert
             var type = Assert.Single(exportedTypes);
-            Assert.False(type.IsTagHelper);
+            Assert.False(type.ImplementsInterface(TagHelperTypeInfo));
         }
 
         private static void AssertAttributes<TAttribute>(
@@ -481,7 +536,7 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
             Action<TAttribute, TAttribute> assertItem)
             where TAttribute : Attribute
         {
-            AssertAttributes<TAttribute>(expected, actual, assertItem, attributes => attributes);
+            AssertAttributes(expected, actual, assertItem, attributes => attributes);
         }
 
         private static void AssertAttributes<TAttribute>(
@@ -519,7 +574,9 @@ namespace Microsoft.AspNet.Razor.Runtime.Precompilation
             Assert.Equal(expected.IsPublic, actual.IsPublic);
             Assert.Equal(expected.IsAbstract, actual.IsAbstract);
             Assert.Equal(expected.IsGenericType, actual.IsGenericType);
-            Assert.Equal(expected.IsTagHelper, actual.IsTagHelper);
+            Assert.Equal(
+                expected.ImplementsInterface(TagHelperTypeInfo),
+                actual.ImplementsInterface(TagHelperTypeInfo));
             Assert.Equal(
                 expected.GetGenericDictionaryParameters(),
                 actual.GetGenericDictionaryParameters(),

test/Microsoft.AspNet.Razor.Runtime.Test/TagHelpers/RuntimeTypeInfoTest.cs

@@ -7,6 +7,7 @@ using System.Collections.Generic;
 using System.ComponentModel;
 using System.Reflection;
 using System.Threading.Tasks;
+using Microsoft.AspNet.Testing;
 using Xunit;
 
 namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
@@ -110,35 +111,58 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             Assert.Empty(actual);
         }
 
-        [Theory]
+        [Fact]
-        [InlineData(typeof(ITagHelper))]
+        public void ImplementsInterface_ThrowsIfArgumentIsNotRuntimeType()
-        [InlineData(typeof(TagHelper))]
-        [InlineData(typeof(ImplementsITagHelper))]
-        [InlineData(typeof(DerivesFromTagHelper))]
-        [InlineData(typeof(Fake.ImplementsRealITagHelper))]
-        public void IsTagHelper_ReturnsTrueIfTypeImplementsTagHelper(Type type)
         {
             // Arrange
-            var runtimeTypeInfo = new RuntimeTypeInfo(type.GetTypeInfo());
+            var typeInfo = new RuntimeTypeInfo(typeof(object).GetTypeInfo());
+            var interfaceTypeInfo = new TestTypeInfo();
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => typeInfo.ImplementsInterface(interfaceTypeInfo),
+                "interfaceTypeInfo",
+                $"Argument must be an instance of '{typeof(RuntimeTypeInfo)}'.");
+        }
+
+        [Theory]
+        [InlineData(typeof(ITagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(TagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(ImplementsITagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(DerivesFromTagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(Fake.ImplementsRealITagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(string), typeof(IEnumerable<char>))]
+        [InlineData(typeof(Dictionary<string, string>), typeof(IDictionary<string, string>))]
+        [InlineData(typeof(List<string>), typeof(IList<string>))]
+        [InlineData(typeof(IList<string>), typeof(IEnumerable<string>))]
+        public void ImplementsInterface_ReturnsTrueIfTypeImplementsInterface(Type runtimeType, Type interfaceType)
+        {
+            // Arrange
+            var runtimeTypeInfo = new RuntimeTypeInfo(runtimeType.GetTypeInfo());
+            var interfaceTypeInfo = new RuntimeTypeInfo(interfaceType.GetTypeInfo());
 
             // Act
-            var result = runtimeTypeInfo.IsTagHelper;
+            var result = runtimeTypeInfo.ImplementsInterface(interfaceTypeInfo);
 
             // Assert
             Assert.True(result);
         }
 
         [Theory]
-        [InlineData(typeof(string))]
+        [InlineData(typeof(string), typeof(object))]
-        [InlineData(typeof(SubType))]
+        [InlineData(typeof(DerivesFromTagHelper), typeof(TagHelper))]
-        [InlineData(typeof(Fake.DoesNotImplementRealITagHelper))]
+        [InlineData(typeof(string), typeof(ITagHelper))]
-        public void IsTagHelper_ReturnsFalseIfTypeDoesNotImplementTagHelper(Type type)
+        [InlineData(typeof(string), typeof(IList<char>))]
+        [InlineData(typeof(SubType), typeof(ITagHelper))]
+        [InlineData(typeof(Fake.DoesNotImplementRealITagHelper), typeof(ITagHelper))]
+        [InlineData(typeof(IDictionary<,>), typeof(IDictionary<string, string>))]
+        public void ImplementsInterface_ReturnsTrueIfTypeDoesNotImplementInterface(Type runtimeType, Type interfaceType)
         {
             // Arrange
-            var runtimeTypeInfo = new RuntimeTypeInfo(type.GetTypeInfo());
+            var runtimeTypeInfo = new RuntimeTypeInfo(runtimeType.GetTypeInfo());
+            var interfaceTypeInfo = new RuntimeTypeInfo(interfaceType.GetTypeInfo());
 
             // Act
-            var result = runtimeTypeInfo.IsTagHelper;
+            var result = runtimeTypeInfo.ImplementsInterface(interfaceTypeInfo);
 
             // Assert
             Assert.False(result);
@@ -502,73 +526,5 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         private class CustomType
         {
         }
-
-        private class TestTypeInfo : ITypeInfo
-        {
-            public string FullName { get; set; }
-
-            public bool IsAbstract
-            {
-                get
-                {
-                    throw new NotImplementedException();
-    }
-}
-
-            public bool IsGenericType
-            {
-                get
-                {
-                    throw new NotImplementedException();
-                }
-            }
-
-            public bool IsPublic
-            {
-                get
-                {
-                    throw new NotImplementedException();
-                }
-            }
-
-            public bool IsTagHelper
-            {
-                get
-                {
-                    throw new NotImplementedException();
-                }
-            }
-
-            public string Name
-            {
-                get
-                {
-                    throw new NotImplementedException();
-                }
-            }
-
-            public IEnumerable<IPropertyInfo> Properties
-            {
-                get
-                {
-                    throw new NotImplementedException();
-                }
-            }
-
-            public bool Equals(ITypeInfo other)
-            {
-                throw new NotImplementedException();
-            }
-
-            public IEnumerable<TAttribute> GetCustomAttributes<TAttribute>() where TAttribute : Attribute
-            {
-                throw new NotImplementedException();
-            }
-
-            public ITypeInfo[] GetGenericDictionaryParameters()
-            {
-                throw new NotImplementedException();
-            }
-        }
     }
 }

test/Microsoft.AspNet.Razor.Runtime.Test/TagHelpers/TestTagHelpers/TestTypeInfo.cs

@@ -0,0 +1,73 @@
+// 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;
+
+namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
+{
+    public class TestTypeInfo : ITypeInfo
+    {
+        public string FullName { get; set; }
+
+        public bool IsAbstract
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public bool IsGenericType
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public bool IsPublic
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public bool ImplementsInterface(ITypeInfo other)
+        {
+            throw new NotImplementedException();
+        }
+
+        public string Name
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public IEnumerable<IPropertyInfo> Properties
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public bool Equals(ITypeInfo other)
+        {
+            throw new NotImplementedException();
+        }
+
+        public IEnumerable<TAttribute> GetCustomAttributes<TAttribute>() where TAttribute : Attribute
+        {
+            throw new NotImplementedException();
+        }
+
+        public ITypeInfo[] GetGenericDictionaryParameters()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}