Add support for get-only indexer properties

- #399
- move invalid `HtmlAttributeNameAttribute.Name` checking to `TagHelperDescriptorFactory`
- add a few new error cases
 - but does not cover all the new error cases e.g. `[HtmlAttributeName(...)]` on a get-only `int` property

nit:
- `resx` target removed some older resources from `RazorResources.Designer.cs`

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

@@ -234,6 +234,22 @@ namespace Microsoft.AspNet.Razor.Runtime
             return GetString("TagHelperDescriptorFactory_Tag");
         }
 
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. An '{2}' must not be associated with a property with no public setter unless its type implements '{3}'.
+        /// </summary>
+        internal static string TagHelperDescriptorFactory_InvalidAttributeNameAttribute
+        {
+            get { return GetString("TagHelperDescriptorFactory_InvalidAttributeNameAttribute"); }
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. An '{2}' must not be associated with a property with no public setter unless its type implements '{3}'.
+        /// </summary>
+        internal static string FormatTagHelperDescriptorFactory_InvalidAttributeNameAttribute(object p0, object p1, object p2, object p3)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributeNameAttribute"), p0, p1, p2, p3);
+        }
+
         /// <summary>
         /// Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with {2} '{3}' because {2} contains a '{4}' character.
         /// </summary>
@@ -283,19 +299,67 @@ namespace Microsoft.AspNet.Razor.Runtime
         }
 
         /// <summary>
-        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null unless property type implements '{4}'.
+        /// Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with a null or empty name.
         /// </summary>
-        internal static string TagHelperDescriptorFactory_InvalidAttributePrefix
+        internal static string TagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty
         {
-            get { return GetString("TagHelperDescriptorFactory_InvalidAttributePrefix"); }
+            get { return GetString("TagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty"); }
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with a null or empty name.
+        /// </summary>
+        internal static string FormatTagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty(object p0, object p1)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty"), p0, p1);
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null or empty if property has no public setter.
+        /// </summary>
+        internal static string TagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty
+        {
+            get { return GetString("TagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty"); }
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null or empty if property has no public setter.
+        /// </summary>
+        internal static string FormatTagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty(object p0, object p1, object p2, object p3)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty"), p0, p1, p2, p3);
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must not be null if property has no public setter and its type implements '{4}'.
+        /// </summary>
+        internal static string TagHelperDescriptorFactory_InvalidAttributePrefixNull
+        {
+            get { return GetString("TagHelperDescriptorFactory_InvalidAttributePrefixNull"); }
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must not be null if property has no public setter and its type implements '{4}'.
+        /// </summary>
+        internal static string FormatTagHelperDescriptorFactory_InvalidAttributePrefixNull(object p0, object p1, object p2, object p3, object p4)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributePrefixNull"), p0, p1, p2, p3, p4);
         }
 
         /// <summary>
         /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null unless property type implements '{4}'.
         /// </summary>
-        internal static string FormatTagHelperDescriptorFactory_InvalidAttributePrefix(object p0, object p1, object p2, object p3, object p4)
+        internal static string TagHelperDescriptorFactory_InvalidAttributePrefixNotNull
         {
-            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributePrefix"), p0, p1, p2, p3, p4);
+            get { return GetString("TagHelperDescriptorFactory_InvalidAttributePrefixNotNull"); }
+        }
+
+        /// <summary>
+        /// Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null unless property type implements '{4}'.
+        /// </summary>
+        internal static string FormatTagHelperDescriptorFactory_InvalidAttributePrefixNotNull(object p0, object p1, object p2, object p3, object p4)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("TagHelperDescriptorFactory_InvalidAttributePrefixNotNull"), p0, p1, p2, p3, p4);
         }
 
         /// <summary>

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

@@ -159,6 +159,9 @@
   <data name="TagHelperDescriptorFactory_Tag" xml:space="preserve">
     <value>Tag</value>
   </data>
+  <data name="TagHelperDescriptorFactory_InvalidAttributeNameAttribute" xml:space="preserve">
+    <value>Invalid tag helper bound property '{0}.{1}'. An '{2}' must not be associated with a property with no public setter unless its type implements '{3}'.</value>
+  </data>
   <data name="TagHelperDescriptorFactory_InvalidAttributeNameOrPrefixCharacter" xml:space="preserve">
     <value>Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with {2} '{3}' because {2} contains a '{4}' character.</value>
   </data>
@@ -168,7 +171,16 @@
   <data name="TagHelperDescriptorFactory_InvalidAttributeNameOrPrefixWhitespace" xml:space="preserve">
     <value>Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with a whitespace {2}.</value>
   </data>
-  <data name="TagHelperDescriptorFactory_InvalidAttributePrefix" xml:space="preserve">
+  <data name="TagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty" xml:space="preserve">
+    <value>Invalid tag helper bound property '{0}.{1}'. Tag helpers cannot bind to HTML attributes with a null or empty name.</value>
+  </data>
+  <data name="TagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty" xml:space="preserve">
+    <value>Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null or empty if property has no public setter.</value>
+  </data>
+  <data name="TagHelperDescriptorFactory_InvalidAttributePrefixNull" xml:space="preserve">
+    <value>Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must not be null if property has no public setter and its type implements '{4}'.</value>
+  </data>
+  <data name="TagHelperDescriptorFactory_InvalidAttributePrefixNotNull" xml:space="preserve">
     <value>Invalid tag helper bound property '{0}.{1}'. '{2}.{3}' must be null unless property type implements '{4}'.</value>
   </data>
   <data name="TagHelperAttributeList_CannotAddWithNullName" xml:space="preserve">

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

@@ -13,23 +13,41 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
     {
         private string _dictionaryAttributePrefix;
 
+        /// <summary>
+        /// Instantiates a new instance of the <see cref="HtmlAttributeNameAttribute"/> class with <see cref="Name"/>
+        /// equal to <c>null</c>.
+        /// </summary>
+        /// <remarks>
+        /// Associated property must not have a public setter and must be compatible with
+        /// <see cref="System.Collections.Generic.IDictionary{TKey, TValue}"/> where <c>TKey</c> is
+        /// <see cref="string"/>.
+        /// </remarks>
+        public HtmlAttributeNameAttribute()
+        {
+        }
+
         /// <summary>
         /// Instantiates a new instance of the <see cref="HtmlAttributeNameAttribute"/> class.
         /// </summary>
-        /// <param name="name">HTML attribute name for the associated property.</param>
+        /// <param name="name">
+        /// HTML attribute name for the associated property. Must be <c>null</c> or empty if associated property does
+        /// not have a public setter and is compatible with
+        /// <see cref="System.Collections.Generic.IDictionary{TKey, TValue}"/> where <c>TKey</c> is
+        /// <see cref="string"/>. Otherwise must not be <c>null</c> or empty.
+        /// </param>
         public HtmlAttributeNameAttribute(string name)
         {
-            if (string.IsNullOrEmpty(name))
-            {
-                throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(name));
-            }
-
             Name = name;
         }
 
         /// <summary>
         /// HTML attribute name of the associated property.
         /// </summary>
+        /// <value>
+        /// <c>null</c> or empty if and only if associated property does not have a public setter and is compatible
+        /// with <see cref="System.Collections.Generic.IDictionary{TKey, TValue}"/> where <c>TKey</c> is
+        /// <see cref="string"/>.
+        /// </value>
         public string Name { get; }
 
         /// <summary>
@@ -42,9 +60,14 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         /// <see cref="string"/>.
         /// </remarks>
         /// <value>
+        /// <para>
         /// If associated property is compatible with
         /// <see cref="System.Collections.Generic.IDictionary{TKey, TValue}"/>, default value is <c>Name + "-"</c>.
+        /// <see cref="Name"/> must not be <c>null</c> or empty in this case.
+        /// </para>
+        /// <para>
         /// Otherwise default value is <c>null</c>.
+        /// </para>
         /// </value>
         public string DictionaryAttributePrefix
         {

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

@@ -256,45 +256,72 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             bool designTime,
             ErrorSink errorSink)
         {
-            var accessibleProperties = type.GetRuntimeProperties().Where(IsAccessibleProperty);
             var attributeDescriptors = new List<TagHelperAttributeDescriptor>();
 
             // Keep indexer descriptors separate to avoid sorting the combined list later.
             var indexerDescriptors = new List<TagHelperAttributeDescriptor>();
 
+            var accessibleProperties = type.GetRuntimeProperties().Where(IsAccessibleProperty);
             foreach (var property in accessibleProperties)
             {
                 var attributeNameAttribute = property.GetCustomAttribute<HtmlAttributeNameAttribute>(inherit: false);
-                var descriptor = ToAttributeDescriptor(property, attributeNameAttribute, designTime);
+                var hasExplicitName =
-                if (ValidateTagHelperAttributeDescriptor(descriptor, type, errorSink))
+                    attributeNameAttribute != null && !string.IsNullOrEmpty(attributeNameAttribute.Name);
+                var attributeName = hasExplicitName ? attributeNameAttribute.Name : ToHtmlCase(property.Name);
+
+                TagHelperAttributeDescriptor mainDescriptor = null;
+                if (property.SetMethod?.IsPublic == true)
                 {
-                    bool isInvalid;
+                    mainDescriptor = ToAttributeDescriptor(property, attributeName, designTime);
-                    var indexerDescriptor = ToIndexerAttributeDescriptor(
+                    if (!ValidateTagHelperAttributeDescriptor(mainDescriptor, type, errorSink))
-                        property,
-                        attributeNameAttribute,
-                        parentType: type,
-                        errorSink: errorSink,
-                        defaultPrefix: descriptor.Name + "-",
-                        designTime: designTime,
-                        isInvalid: out isInvalid);
-
-                    if (indexerDescriptor != null &&
-                        !ValidateTagHelperAttributeDescriptor(indexerDescriptor, type, errorSink))
                     {
-                        isInvalid = true;
+                        // HtmlAttributeNameAttribute.Name is invalid. Ignore this property completely.
-                    }
-
-                    if (isInvalid)
-                    {
-                        // HtmlAttributeNameAttribute was not valid. Ignore this property completely.
                         continue;
                     }
+                }
+                else if (hasExplicitName)
+                {
+                    // Specified HtmlAttributeNameAttribute.Name though property has no public setter.
+                    errorSink.OnError(
+                        SourceLocation.Zero,
+                        Resources.FormatTagHelperDescriptorFactory_InvalidAttributeNameNotNullOrEmpty(
+                            type.FullName,
+                            property.Name,
+                            typeof(HtmlAttributeNameAttribute).FullName,
+                            nameof(HtmlAttributeNameAttribute.Name)));
+                    continue;
+                }
 
-                    attributeDescriptors.Add(descriptor);
+                bool isInvalid;
-                    if (indexerDescriptor != null)
+                var indexerDescriptor = ToIndexerAttributeDescriptor(
-                    {
+                    property,
-                        indexerDescriptors.Add(indexerDescriptor);
+                    attributeNameAttribute,
-                    }
+                    parentType: type,
+                    errorSink: errorSink,
+                    defaultPrefix: attributeName + "-",
+                    designTime: designTime,
+                    isInvalid: out isInvalid);
+                if (indexerDescriptor != null &&
+                    !ValidateTagHelperAttributeDescriptor(indexerDescriptor, type, errorSink))
+                {
+                    isInvalid = true;
+                }
+
+                if (isInvalid)
+                {
+                    // The property type or HtmlAttributeNameAttribute.DictionaryAttributePrefix (or perhaps the
+                    // HTML-casing of the property name) is invalid. Ignore this property completely.
+                    continue;
+                }
+
+                if (mainDescriptor != null)
+                {
+                    attributeDescriptors.Add(mainDescriptor);
+                }
+
+                if (indexerDescriptor != null)
+                {
+                    indexerDescriptors.Add(indexerDescriptor);
                 }
             }
 
@@ -309,9 +336,26 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             Type parentType,
             ErrorSink errorSink)
         {
-            var nameOrPrefix = attributeDescriptor.IsIndexer ?
+            string nameOrPrefix;
-                Resources.TagHelperDescriptorFactory_Prefix :
+            if (attributeDescriptor.IsIndexer)
-                Resources.TagHelperDescriptorFactory_Name;
+            {
+                nameOrPrefix = Resources.TagHelperDescriptorFactory_Prefix;
+            }
+            else if (string.IsNullOrEmpty(attributeDescriptor.Name))
+            {
+                errorSink.OnError(
+                    SourceLocation.Zero,
+                    Resources.FormatTagHelperDescriptorFactory_InvalidAttributeNameNullOrEmpty(
+                        parentType.FullName,
+                        attributeDescriptor.PropertyName));
+
+                return false;
+            }
+            else
+            {
+                nameOrPrefix = Resources.TagHelperDescriptorFactory_Name;
+            }
+
             return ValidateTagHelperAttributeNameOrPrefix(
                 attributeDescriptor.Name,
                 parentType,
@@ -329,8 +373,9 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         {
             if (string.IsNullOrEmpty(attributeNameOrPrefix))
             {
-                // HtmlAttributeNameAttribute validates Name is non-null and non-empty. Both are valid for
+                // ValidateTagHelperAttributeDescriptor validates Name is non-null and non-empty. The empty string is
-                // DictionaryAttributePrefix. (Empty DictionaryAttributePrefix is a corner case which would bind every
+                // valid for DictionaryAttributePrefix and null is impossible at this point because it means "don't
+                // create a descriptor". (Empty DictionaryAttributePrefix is a corner case which would bind every
                 // attribute of a target element. Likely not particularly useful but unclear what minimum length
                 // should be required and what scenarios a minimum length would break.)
                 return true;
@@ -388,13 +433,9 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
         private static TagHelperAttributeDescriptor ToAttributeDescriptor(
             PropertyInfo property,
-            HtmlAttributeNameAttribute attributeNameAttribute,
+            string attributeName,
             bool designTime)
         {
-            var attributeName = attributeNameAttribute != null ?
-                                attributeNameAttribute.Name :
-                                ToHtmlCase(property.Name);
-
             return ToAttributeDescriptor(
                 property,
                 attributeName,
@@ -413,6 +454,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             out bool isInvalid)
         {
             isInvalid = false;
+            var hasPublicSetter = property.SetMethod?.IsPublic == true;
             var dictionaryTypeArguments = ClosedGenericMatcher.ExtractGenericInterface(
                     property.PropertyType,
                     typeof(IDictionary<,>))
@@ -426,13 +468,44 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
                     isInvalid = true;
                     errorSink.OnError(
                         SourceLocation.Zero,
-                        Resources.FormatTagHelperDescriptorFactory_InvalidAttributePrefix(
+                        Resources.FormatTagHelperDescriptorFactory_InvalidAttributePrefixNotNull(
                             parentType.FullName,
                             property.Name,
                             nameof(HtmlAttributeNameAttribute),
                             nameof(HtmlAttributeNameAttribute.DictionaryAttributePrefix),
                             "IDictionary<string, TValue>"));
                 }
+                else if (attributeNameAttribute != null && !hasPublicSetter)
+                {
+                    // Associated an HtmlAttributeNameAttribute with a non-dictionary property that lacks a public
+                    // setter.
+                    isInvalid = true;
+                    errorSink.OnError(
+                        SourceLocation.Zero,
+                        Resources.FormatTagHelperDescriptorFactory_InvalidAttributeNameAttribute(
+                            parentType.FullName,
+                            property.Name,
+                            nameof(HtmlAttributeNameAttribute),
+                            "IDictionary<string, TValue>"));
+                }
+
+                return null;
+            }
+            else if (!hasPublicSetter &&
+                attributeNameAttribute != null &&
+                !attributeNameAttribute.DictionaryAttributePrefixSet)
+            {
+                // Must set DictionaryAttributePrefix when using HtmlAttributeNameAttribute with a dictionary property
+                // that lacks a public setter.
+                isInvalid = true;
+                errorSink.OnError(
+                    SourceLocation.Zero,
+                    Resources.FormatTagHelperDescriptorFactory_InvalidAttributePrefixNull(
+                        parentType.FullName,
+                        property.Name,
+                        nameof(HtmlAttributeNameAttribute),
+                        nameof(HtmlAttributeNameAttribute.DictionaryAttributePrefix),
+                        "IDictionary<string, TValue>"));
 
                 return null;
             }
@@ -482,9 +555,8 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
         private static bool IsAccessibleProperty(PropertyInfo property)
         {
-            // Accessible properties are those with public getters and setters and without [HtmlAttributeNotBound].
+            // Accessible properties are those with public getters and without [HtmlAttributeNotBound].
             return property.GetMethod?.IsPublic == true &&
-                property.SetMethod?.IsPublic == true &&
                 property.GetCustomAttribute<HtmlAttributeNotBoundAttribute>(inherit: false) == null;
         }
 

src/Microsoft.AspNet.Razor/Properties/RazorResources.Designer.cs

@@ -1286,22 +1286,6 @@ namespace Microsoft.AspNet.Razor
             return string.Format(CultureInfo.CurrentCulture, GetString("TagHelpers_CannotHaveCSharpInTagDeclaration"), p0);
         }
 
-        /// <summary>
-        /// A TagHelperChunkGenerator must only be used with TagHelperBlocks.
-        /// </summary>
-        internal static string TagHelpers_TagHelperCodeGeneartorMustBeAssociatedWithATagHelperBlock
-        {
-            get { return GetString("TagHelpers_TagHelperCodeGeneartorMustBeAssociatedWithATagHelperBlock"); }
-        }
-
-        /// <summary>
-        /// A TagHelperChunkGenerator must only be used with TagHelperBlocks.
-        /// </summary>
-        internal static string FormatTagHelpers_TagHelperCodeGeneartorMustBeAssociatedWithATagHelperBlock()
-        {
-            return GetString("TagHelpers_TagHelperCodeGeneartorMustBeAssociatedWithATagHelperBlock");
-        }
-
         /// <summary>
         /// Directive '{0}' must have a value.
         /// </summary>

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

@@ -958,7 +958,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
                                 isStringProperty: false,
                                 designTimeDescriptor: null),
                             new TagHelperAttributeDescriptor(
-                                name: "valid-prefix",
+                                name: "valid-name-",
                                 propertyName: nameof(SingleValidHtmlAttributePrefix.DictionaryProperty),
                                 typeName: typeof(string).FullName,
                                 isIndexer: true,
@@ -1048,6 +1048,20 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
                                 isIndexer: true,
                                 isStringProperty: false,
                                 designTimeDescriptor: null),
+                            new TagHelperAttributeDescriptor(
+                                name: "get-only-dictionary-property-",
+                                propertyName: nameof(MultipleValidHtmlAttributePrefix.GetOnlyDictionaryProperty),
+                                typeName: typeof(int).FullName,
+                                isIndexer: true,
+                                isStringProperty: false,
+                                designTimeDescriptor: null),
+                            new TagHelperAttributeDescriptor(
+                                name: "valid-prefix6",
+                                propertyName: nameof(MultipleValidHtmlAttributePrefix.GetOnlyDictionaryPropertyWithAttributePrefix),
+                                typeName: typeof(string).FullName,
+                                isIndexer: true,
+                                isStringProperty: true,
+                                designTimeDescriptor: null),
                         },
                         new string[0]
                     },
@@ -1087,6 +1101,14 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
                             onError(
                                 typeof(MultipleInvalidHtmlAttributePrefix).FullName,
                                 nameof(MultipleInvalidHtmlAttributePrefix.DictionaryOfIntSubclassProperty)),
+                            onError(
+                                typeof(MultipleInvalidHtmlAttributePrefix).FullName,
+                                nameof(MultipleInvalidHtmlAttributePrefix.GetOnlyDictionaryAttributePrefix)),
+                            $"Invalid tag helper bound property '{ typeof(MultipleInvalidHtmlAttributePrefix).FullName }." +
+                            $"{ nameof(MultipleInvalidHtmlAttributePrefix.GetOnlyDictionaryPropertyWithAttributeName) }'. " +
+                            $"'{ typeof(HtmlAttributeNameAttribute).FullName }." +
+                            $"{ nameof(HtmlAttributeNameAttribute.Name) }' must be null or empty if property has " +
+                            "no public setter.",
                         }
                     },
                 };
@@ -1128,14 +1150,12 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
                 TagHelperAttributeDescriptorComparer.Default);
         }
 
-        public static TheoryData<string> ValidAttributeNameOrPrefixData
+        public static TheoryData<string> ValidAttributeNameData
         {
             get
             {
                 return new TheoryData<string>
                 {
-                    null,
-                    string.Empty,
                     "data",
                     "dataa-",
                     "ValidName",
@@ -1147,7 +1167,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         }
 
         [Theory]
-        [MemberData(nameof(ValidAttributeNameOrPrefixData))]
+        [MemberData(nameof(ValidAttributeNameData))]
         public void ValidateTagHelperAttributeDescriptor_WithValidName_ReturnsTrue(string name)
         {
             // Arrange
@@ -1170,8 +1190,25 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
             Assert.Empty(errorSink.Errors);
         }
 
+        public static TheoryData<string> ValidAttributePrefixData
+        {
+            get
+            {
+                return new TheoryData<string>
+                {
+                    string.Empty,
+                    "data",
+                    "dataa-",
+                    "ValidName",
+                    "valid-name",
+                    "--valid--name--",
+                    ",,--__..oddly.valid::;;",
+                };
+            }
+        }
+
         [Theory]
-        [MemberData(nameof(ValidAttributeNameOrPrefixData))]
+        [MemberData(nameof(ValidAttributePrefixData))]
         public void ValidateTagHelperAttributeDescriptor_WithValidPrefix_ReturnsTrue(string prefix)
         {
             // Arrange
@@ -1732,7 +1769,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
         private class SingleValidHtmlAttributePrefix : TagHelper
         {
-            [HtmlAttributeName("valid-name", DictionaryAttributePrefix = "valid-prefix")]
+            [HtmlAttributeName("valid-name")]
             public IDictionary<string, string> DictionaryProperty { get; set; }
         }
 
@@ -1755,6 +1792,11 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
             [HtmlAttributeName("valid-name6")]
             public string StringProperty { get; set; }
+
+            public IDictionary<string, int> GetOnlyDictionaryProperty { get; }
+
+            [HtmlAttributeName(DictionaryAttributePrefix = "valid-prefix6")]
+            public IDictionary<string, string> GetOnlyDictionaryPropertyWithAttributePrefix { get; }
         }
 
         private class SingleInvalidHtmlAttributePrefix : TagHelper
@@ -1779,6 +1821,12 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
             [HtmlAttributeName("valid-name5", DictionaryAttributePrefix = "valid-prefix5-")]
             public DictionaryOfIntSubclass DictionaryOfIntSubclassProperty { get; set; }
+
+            [HtmlAttributeName(DictionaryAttributePrefix = "valid-prefix6")]
+            public IDictionary<int, string> GetOnlyDictionaryAttributePrefix { get; }
+
+            [HtmlAttributeName("invalid-name7")]
+            public IDictionary<string, object> GetOnlyDictionaryPropertyWithAttributeName { get; }
         }
 
         private class DictionarySubclass : Dictionary<string, string>