Modify IViewComponentHelper to remove method selection ambiguity.

Fixes #612

samples/TagHelperSample.Web/Components/FeaturedMoviesComponent.cs

@@ -38,18 +38,5 @@ namespace TagHelperSample.Web.Components
 
             return View(movies);
         }
-
-        public IViewComponentResult Invoke(string movieName)
-        {
-            string quote;
-            if (!_cache.TryGetValue(movieName, out quote))
-            {
-                IChangeToken expirationToken;
-                quote = _moviesService.GetCriticsQuote(out expirationToken);
-                _cache.Set(movieName, quote, new MemoryCacheEntryOptions().AddExpirationToken(expirationToken));
-            }
-
-            return Content(quote);
-        }
     }
 }

samples/TagHelperSample.Web/Components/MoviesComponent.cs

@@ -0,0 +1,36 @@
+// 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 Microsoft.AspNet.Mvc;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Primitives;
+using TagHelperSample.Web.Services;
+
+namespace TagHelperSample.Web.Components
+{
+    [ViewComponent(Name = "Movies")]
+    public class MoviesComponent : ViewComponent
+    {
+        private readonly IMemoryCache _cache;
+        private readonly MoviesService _moviesService;
+
+        public MoviesComponent(MoviesService moviesService, IMemoryCache cache)
+        {
+            _moviesService = moviesService;
+            _cache = cache;
+        }
+
+        public IViewComponentResult Invoke(string movieName)
+        {
+            string quote;
+            if (!_cache.TryGetValue(movieName, out quote))
+            {
+                IChangeToken expirationToken;
+                quote = _moviesService.GetCriticsQuote(out expirationToken);
+                _cache.Set(movieName, quote, new MemoryCacheEntryOptions().AddExpirationToken(expirationToken));
+            }
+
+            return Content(quote);
+        }
+    }
+}

samples/TagHelperSample.Web/Views/Movies/Index.cshtml

@@ -35,7 +35,7 @@
     </div>
     <div class="sidebar">
         <cache expires-after="TimeSpan.FromMinutes(20)">
-            @Component.Invoke("FeaturedMovies")
+            @await Component.InvokeAsync("FeaturedMovies")
         </cache>
     </div>
     <div style="clear: left"></div>

samples/TagHelperSample.Web/Views/Shared/Components/FeaturedMovies/Default.cshtml

@@ -10,7 +10,7 @@
             </div>
             <em>Critics say:</em>
             <cache vary-by="@movie.Name">
-                @Component.Invoke("FeaturedMovies", movie.Name)
+                @await Component.InvokeAsync("Movies", new { movieName = movie.Name })
             </cache>
         </dd>
     }

src/Microsoft.AspNet.Mvc.ViewFeatures/IViewComponentHelper.cs

@@ -7,22 +7,27 @@ using Microsoft.AspNet.Html;
 
 namespace Microsoft.AspNet.Mvc
 {
+    /// <summary>
+    /// Supports the rendering of view components in a view.
+    /// </summary>
     public interface IViewComponentHelper
     {
-        IHtmlContent Invoke(string name, params object[] args);
+        /// <summary>
+        /// Invokes a view component with the specified <paramref name="name"/>.
+        /// </summary>
+        /// <param name="name">The name of the view component.</param>
+        /// <param name="arguments">Arguments to be passed to the invoked view component method.</param>
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
+        /// </returns>
+        Task<IHtmlContent> InvokeAsync(string name, object arguments);
 
-        IHtmlContent Invoke(Type componentType, params object[] args);
+        /// <summary>
-
+        /// Invokes a view component of type <paramref name="componentType" />.
-        void RenderInvoke(string name, params object[] args);
+        /// </summary>
-
+        /// <param name="componentType">The view component <see cref="Type"/>.</param>
-        void RenderInvoke(Type componentType, params object[] args);
+        /// <param name="arguments">Arguments to be passed to the invoked view component method.</param>
-
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
-        Task<IHtmlContent> InvokeAsync(string name, params object[] args);
+        /// </returns>
-
+        Task<IHtmlContent> InvokeAsync(Type componentType, object arguments);
-        Task<IHtmlContent> InvokeAsync(Type componentType, params object[] args);
-
-        Task RenderInvokeAsync(string name, params object[] args);
-
-        Task RenderInvokeAsync(Type componentType, params object[] args);
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/Logging/DefaultViewComponentInvokerLoggerExtensions.cs

@@ -10,15 +10,21 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Logging
 {
     public static class DefaultViewComponentInvokerLoggerExtensions
     {
-        private static readonly Action<ILogger, string, Exception> _viewComponentExecuting;
+        private static readonly string[] EmptyArguments =
+#if NET451
+            new string[0];
+#else
+            Array.Empty<string>();
+#endif
+        private static readonly Action<ILogger, string, string[], Exception> _viewComponentExecuting;
         private static readonly Action<ILogger, string, double, string, Exception> _viewComponentExecuted;
 
         static DefaultViewComponentInvokerLoggerExtensions()
         {
-            _viewComponentExecuting = LoggerMessage.Define<string>(
+            _viewComponentExecuting = LoggerMessage.Define<string, string[]>(
                 LogLevel.Debug,
                 1,
-                "Executing view component {ViewComponentName}");
+                "Executing view component {ViewComponentName} with arguments ({Arguments}).");
 
             _viewComponentExecuted = LoggerMessage.Define<string, double, string>(
                 LogLevel.Debug,
@@ -32,9 +38,29 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Logging
             return logger.BeginScopeImpl(new ViewComponentLogScope(context.ViewComponentDescriptor));
         }
 
-        public static void ViewComponentExecuting(this ILogger logger, ViewComponentContext context)
+        public static void ViewComponentExecuting(
+            this ILogger logger,
+            ViewComponentContext context,
+            object[] arguments)
         {
-            _viewComponentExecuting(logger, context.ViewComponentDescriptor.DisplayName, null);
+            var formattedArguments = GetFormattedArguments(arguments);
+            _viewComponentExecuting(logger, context.ViewComponentDescriptor.DisplayName, formattedArguments, null);
+        }
+
+        private static string[] GetFormattedArguments(object[] arguments)
+        {
+            if (arguments == null || arguments.Length == 0)
+            {
+                return EmptyArguments;
+            }
+
+            var formattedArguments = new string[arguments.Length];
+            for (var i = 0; i < formattedArguments.Length; i++)
+            {
+                formattedArguments[i] = Convert.ToString(arguments[i]);
+            }
+
+            return formattedArguments;
         }
 
         public static void ViewComponentExecuted(

src/Microsoft.AspNet.Mvc.ViewFeatures/Logging/ViewComponentResultLoggerExtensions.cs

@@ -8,41 +8,29 @@ namespace Microsoft.AspNet.Mvc.Logging
 {
     public static class ViewComponentResultLoggerExtensions
     {
-        private static readonly Action<ILogger, string, string[], Exception> _viewComponentResultExecuting;
+        private static readonly Action<ILogger, string, Exception> _viewComponentResultExecuting;
 
         static ViewComponentResultLoggerExtensions()
         {
-            _viewComponentResultExecuting = LoggerMessage.Define<string, string[]>(
+            _viewComponentResultExecuting = LoggerMessage.Define<string>(
                 LogLevel.Information,
                 1,
-                "Executing ViewComponentResult, running {ViewComponentName} with arguments ({Arguments}).");
+                "Executing ViewComponentResult, running {ViewComponentName}.");
         }
 
-        public static void ViewComponentResultExecuting(this ILogger logger, string viewComponentName, object[] arguments)
+        public static void ViewComponentResultExecuting(this ILogger logger, string viewComponentName)
         {
             if (logger.IsEnabled(LogLevel.Information))
             {
-                var formattedArguments = new string[arguments.Length];
+                _viewComponentResultExecuting(logger, viewComponentName, null);
-                for (var i = 0; i < arguments.Length; i++)
-                {
-                    formattedArguments[i] = Convert.ToString(arguments[i]);
-                }
-
-                _viewComponentResultExecuting(logger, viewComponentName, formattedArguments, null);
             }
         }
 
-        public static void ViewComponentResultExecuting(this ILogger logger, Type viewComponentType, object[] arguments)
+        public static void ViewComponentResultExecuting(this ILogger logger, Type viewComponentType)
         {
             if (logger.IsEnabled(LogLevel.Information))
             {
-                var formattedArguments = new string[arguments.Length];
+                _viewComponentResultExecuting(logger, viewComponentType.Name, null);
-                for (var i = 0; i < arguments.Length; i++)
-                {
-                    formattedArguments[i] = Convert.ToString(arguments[i]);
-                }
-
-                _viewComponentResultExecuting(logger, viewComponentType.Name, formattedArguments, null);
             }
         }
     }

src/Microsoft.AspNet.Mvc.ViewFeatures/Microsoft.AspNet.Mvc.ViewFeatures.xproj

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">14.0</VisualStudioVersion>
     <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+    <DisabledCustomTools>.resx</DisabledCustomTools>
   </PropertyGroup>
   <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.Props" Condition="'$(VSToolsPath)' != ''" />
   <PropertyGroup Label="Globals">

src/Microsoft.AspNet.Mvc.ViewFeatures/Properties/Resources.Designer.cs

@@ -27,7 +27,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The async view component method '{0}' should be declared to return Task&lt;T&gt;.
+        /// Method '{0}' of view component '{1}' should be declared to return {2}&lt;T&gt;.
         /// </summary>
         internal static string ViewComponent_AsyncMethod_ShouldReturnTask
         {
@@ -35,11 +35,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The async view component method '{0}' should be declared to return Task&lt;T&gt;.
+        /// Method '{0}' of view component '{1}' should be declared to return {2}&lt;T&gt;.
         /// </summary>
-        internal static string FormatViewComponent_AsyncMethod_ShouldReturnTask(object p0)
+        internal static string FormatViewComponent_AsyncMethod_ShouldReturnTask(object p0, object p1, object p2)
         {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_AsyncMethod_ShouldReturnTask"), p0);
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_AsyncMethod_ShouldReturnTask"), p0, p1, p2);
         }
 
         /// <summary>
@@ -59,7 +59,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view component method '{0}' should be declared to return a value.
+        /// Method '{0}' of view component '{1}' should be declared to return a value.
         /// </summary>
         internal static string ViewComponent_SyncMethod_ShouldReturnValue
         {
@@ -67,11 +67,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view component method '{0}' should be declared to return a value.
+        /// Method '{0}' of view component '{1}' should be declared to return a value.
         /// </summary>
-        internal static string FormatViewComponent_SyncMethod_ShouldReturnValue(object p0)
+        internal static string FormatViewComponent_SyncMethod_ShouldReturnValue(object p0, object p1)
         {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_SyncMethod_ShouldReturnValue"), p0);
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_SyncMethod_ShouldReturnValue"), p0, p1);
         }
 
         /// <summary>
@@ -107,7 +107,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// Could not find an '{0}' method matching the parameters.
+        /// Could not find an '{0}' or '{1}' method for the view component '{2}'.
         /// </summary>
         internal static string ViewComponent_CannotFindMethod
         {
@@ -115,27 +115,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// Could not find an '{0}' method matching the parameters.
+        /// Could not find an '{0}' or '{1}' method for the view component '{2}'.
         /// </summary>
-        internal static string FormatViewComponent_CannotFindMethod(object p0)
+        internal static string FormatViewComponent_CannotFindMethod(object p0, object p1, object p2)
         {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_CannotFindMethod"), p0);
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_CannotFindMethod"), p0, p1, p2);
-        }
-
-        /// <summary>
-        /// Could not find an '{0}' or '{1}' method matching the parameters.
-        /// </summary>
-        internal static string ViewComponent_CannotFindMethod_WithFallback
-        {
-            get { return GetString("ViewComponent_CannotFindMethod_WithFallback"); }
-        }
-
-        /// <summary>
-        /// Could not find an '{0}' or '{1}' method matching the parameters.
-        /// </summary>
-        internal static string FormatViewComponent_CannotFindMethod_WithFallback(object p0, object p1)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_CannotFindMethod_WithFallback"), p0, p1);
         }
 
         /// <summary>
@@ -859,7 +843,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view component method '{0}' cannot return a {1}.
+        /// Method '{0}' of view component '{1}' cannot return a {2}.
         /// </summary>
         internal static string ViewComponent_SyncMethod_CannotReturnTask
         {
@@ -867,11 +851,27 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view component method '{0}' cannot return a {1}.
+        /// Method '{0}' of view component '{1}' cannot return a {2}.
         /// </summary>
-        internal static string FormatViewComponent_SyncMethod_CannotReturnTask(object p0, object p1)
+        internal static string FormatViewComponent_SyncMethod_CannotReturnTask(object p0, object p1, object p2)
         {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_SyncMethod_CannotReturnTask"), p0, p1);
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_SyncMethod_CannotReturnTask"), p0, p1, p2);
+        }
+
+        /// <summary>
+        /// View component '{0}' must have exactly one public method named '{1}' or '{2}'.
+        /// </summary>
+        internal static string ViewComponent_AmbiguousMethods
+        {
+            get { return GetString("ViewComponent_AmbiguousMethods"); }
+        }
+
+        /// <summary>
+        /// View component '{0}' must have exactly one public method named '{1}' or '{2}'.
+        /// </summary>
+        internal static string FormatViewComponent_AmbiguousMethods(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewComponent_AmbiguousMethods"), p0, p1, p2);
         }
 
         private static string GetString(string name, params string[] formatterNames)

src/Microsoft.AspNet.Mvc.ViewFeatures/Rendering/ViewComponentHelperExtensions.cs

@@ -7,48 +7,76 @@ using Microsoft.AspNet.Html;
 
 namespace Microsoft.AspNet.Mvc.Rendering
 {
+    /// <summary>
+    /// Extension methods for <see cref="IViewComponentHelper"/>.
+    /// </summary>
     public static class ViewComponentHelperExtensions
     {
-        public static IHtmlContent Invoke<TComponent>(this IViewComponentHelper helper, params object[] args)
+        /// <summary>
+        /// Invokes a view component with the specified <paramref name="name"/>.
+        /// </summary>
+        /// <param name="name">The name of the view component.</param>
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
+        /// </returns>
+        public static Task<IHtmlContent> InvokeAsync(this IViewComponentHelper helper, string name)
         {
             if (helper == null)
             {
                 throw new ArgumentNullException(nameof(helper));
             }
 
-            return helper.Invoke(typeof(TComponent), args);
+            return helper.InvokeAsync(name, arguments: null);
         }
 
-        public static void RenderInvoke<TComponent>(this IViewComponentHelper helper, params object[] args)
+        /// <summary>
+        /// Invokes a view component of type <paramref name="componentType" />.
+        /// </summary>
+        /// <param name="componentType">The view component <see cref="Type"/>.</param>
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
+        /// </returns>
+        public static Task<IHtmlContent> InvokeAsync(this IViewComponentHelper helper, Type componentType)
         {
             if (helper == null)
             {
                 throw new ArgumentNullException(nameof(helper));
             }
 
-            helper.RenderInvoke(typeof(TComponent), args);
+            return helper.InvokeAsync(componentType, arguments: null);
         }
 
-        public static Task<IHtmlContent> InvokeAsync<TComponent>(
+        /// <summary>
-            this IViewComponentHelper helper,
+        /// Invokes a view component of type <typeparam name="TComponent"/>.
-            params object[] args)
+        /// </summary>
+        /// <param name="helper">The <see cref="IViewComponentHelper"/>.</param>
+        /// <param name="arguments">Arguments to be passed to the invoked view component method.</param>
+        /// <typeparam name="TComponent">The <see cref="Type"/> of the view component.</typeparam>
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
+        /// </returns>
+        public static Task<IHtmlContent> InvokeAsync<TComponent>(this IViewComponentHelper helper, object arguments)
         {
             if (helper == null)
             {
                 throw new ArgumentNullException(nameof(helper));
             }
 
-            return helper.InvokeAsync(typeof(TComponent), args);
+            return helper.InvokeAsync(typeof(TComponent), arguments);
         }
 
-        public static Task RenderInvokeAsync<TComponent>(this IViewComponentHelper helper, params object[] args)
+        /// <summary>
+        /// Invokes a view component of type <typeparam name="TComponent"/>.
+        /// </summary>
+        /// <param name="helper">The <see cref="IViewComponentHelper"/>.</param>
+        /// <typeparam name="TComponent">The <see cref="Type"/> of the view component.</typeparam>
+        /// <returns>A <see cref="Task"/> that on completion returns the rendered <see cref="IHtmlContent" />.
+        /// </returns>
+        public static Task<IHtmlContent> InvokeAsync<TComponent>(this IViewComponentHelper helper)
         {
             if (helper == null)
             {
                 throw new ArgumentNullException(nameof(helper));
             }
 
-            return helper.RenderInvokeAsync(typeof(TComponent), args);
+            return helper.InvokeAsync(typeof(TComponent), arguments: null);
         }
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/Resources.resx

@@ -122,13 +122,13 @@
     <comment>{1} is the newline character</comment>
   </data>
   <data name="ViewComponent_AsyncMethod_ShouldReturnTask" xml:space="preserve">
-    <value>The async view component method '{0}' should be declared to return Task&lt;T&gt;.</value>
+    <value>Method '{0}' of view component '{1}' should be declared to return {2}&lt;T&gt;.</value>
   </data>
   <data name="ViewComponent_MustReturnValue" xml:space="preserve">
     <value>A view component must return a non-null value.</value>
   </data>
   <data name="ViewComponent_SyncMethod_ShouldReturnValue" xml:space="preserve">
-    <value>The view component method '{0}' should be declared to return a value.</value>
+    <value>Method '{0}' of view component '{1}' should be declared to return a value.</value>
   </data>
   <data name="ViewComponent_CannotFindComponent" xml:space="preserve">
     <value>A view component named '{0}' could not be found.</value>
@@ -137,10 +137,7 @@
     <value>An invoker could not be created for the view component '{0}'.</value>
   </data>
   <data name="ViewComponent_CannotFindMethod" xml:space="preserve">
-    <value>Could not find an '{0}' method matching the parameters.</value>
+    <value>Could not find an '{0}' or '{1}' method for the view component '{2}'.</value>
-  </data>
-  <data name="ViewComponent_CannotFindMethod_WithFallback" xml:space="preserve">
-    <value>Could not find an '{0}' or '{1}' method matching the parameters.</value>
   </data>
   <data name="ViewComponent_InvalidReturnValue" xml:space="preserve">
     <value>View components only support returning {0}, {1} or {2}.</value>
@@ -278,6 +275,9 @@
     <value>The collection already contains an entry with key '{0}'.</value>
   </data>
   <data name="ViewComponent_SyncMethod_CannotReturnTask" xml:space="preserve">
-    <value>The view component method '{0}' cannot return a {1}.</value>
+    <value>Method '{0}' of view component '{1}' cannot return a {2}.</value>
+  </data>
+  <data name="ViewComponent_AmbiguousMethods" xml:space="preserve">
+    <value>View component '{0}' must have exactly one public method named '{1}' or '{2}'.</value>
   </data>
 </root>

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponentResult.cs

@@ -3,7 +3,9 @@
 
 using System;
 using System.Text;
+using System.Text.Encodings.Web;
 using System.Threading.Tasks;
+using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Internal;
 using Microsoft.AspNet.Mvc.Logging;
 using Microsoft.AspNet.Mvc.ModelBinding;
@@ -26,7 +28,7 @@ namespace Microsoft.AspNet.Mvc
         /// <summary>
         /// Gets or sets the arguments provided to the view component.
         /// </summary>
-        public object[] Arguments { get; set; }
+        public object Arguments { get; set; }
 
         /// <summary>
         /// Gets or sets the <see cref="MediaTypeHeaderValue"/> representing the Content-Type header of the response.
@@ -77,6 +79,7 @@ namespace Microsoft.AspNet.Mvc
 
             var loggerFactory = services.GetRequiredService<ILoggerFactory>();
             var logger = loggerFactory.CreateLogger<ViewComponentResult>();
+            var htmlEncoder = services.GetRequiredService<HtmlEncoder>();
 
             var viewData = ViewData;
             if (viewData == null)
@@ -119,23 +122,29 @@ namespace Microsoft.AspNet.Mvc
                     htmlHelperOptions);
 
                 (viewComponentHelper as ICanHasViewContext)?.Contextualize(viewContext);
+                var result = await GetViewComponentResult(viewComponentHelper, logger);
 
-                if (ViewComponentType == null && ViewComponentName == null)
+                result.WriteTo(writer, htmlEncoder);
-                {
+            }
-                    throw new InvalidOperationException(Resources.FormatViewComponentResult_NameOrTypeMustBeSet(
+        }
-                        nameof(ViewComponentName),
+
-                        nameof(ViewComponentType)));
+        private Task<IHtmlContent> GetViewComponentResult(IViewComponentHelper viewComponentHelper, ILogger logger)
-                }
+        {
-                else if (ViewComponentType == null)
+            if (ViewComponentType == null && ViewComponentName == null)
-                {
+            {
-                    logger.ViewComponentResultExecuting(ViewComponentName, Arguments);
+                throw new InvalidOperationException(Resources.FormatViewComponentResult_NameOrTypeMustBeSet(
-                    await viewComponentHelper.RenderInvokeAsync(ViewComponentName, Arguments);
+                    nameof(ViewComponentName),
-                }
+                    nameof(ViewComponentType)));
-                else
+            }
-                {
+            else if (ViewComponentType == null)
-                    logger.ViewComponentResultExecuting(ViewComponentType, Arguments);
+            {
-                    await viewComponentHelper.RenderInvokeAsync(ViewComponentType, Arguments);
+                logger.ViewComponentResultExecuting(ViewComponentName);
-                }
+                return viewComponentHelper.InvokeAsync(ViewComponentName, Arguments);
+            }
+            else
+            {
+                logger.ViewComponentResultExecuting(ViewComponentType);
+                return viewComponentHelper.InvokeAsync(ViewComponentType, Arguments);
             }
         }
     }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/DefaultViewComponentDescriptorProvider.cs

@@ -5,7 +5,9 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Infrastructure;
+using Microsoft.AspNet.Mvc.ViewFeatures;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
@@ -14,6 +16,8 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
     /// </summary>
     public class DefaultViewComponentDescriptorProvider : IViewComponentDescriptorProvider
     {
+        private const string AsyncMethodName = "InvokeAsync";
+        private const string SyncMethodName = "Invoke";
         private readonly IAssemblyProvider _assemblyProvider;
 
         /// <summary>
@@ -32,7 +36,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             return types
                 .Where(IsViewComponentType)
-                .Select(CreateCandidate);
+                .Select(CreateDescriptor);
         }
 
         /// <summary>
@@ -47,11 +51,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         }
 
         /// <summary>
-        /// Determines whether or not the given <see cref="TypeInfo"/> is a View Component class.
+        /// Determines whether or not the given <see cref="TypeInfo"/> is a view component class.
         /// </summary>
         /// <param name="typeInfo">The <see cref="TypeInfo"/>.</param>
         /// <returns>
-        /// <c>true</c> if <paramref name="typeInfo"/>represents a View Component class, otherwise <c>false</c>.
+        /// <c>true</c> if <paramref name="typeInfo"/>represents a view component class, otherwise <c>false</c>.
         /// </returns>
         protected virtual bool IsViewComponentType(TypeInfo typeInfo)
         {
@@ -63,16 +67,70 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             return ViewComponentConventions.IsComponent(typeInfo);
         }
 
-        private static ViewComponentDescriptor CreateCandidate(TypeInfo typeInfo)
+        private static ViewComponentDescriptor CreateDescriptor(TypeInfo typeInfo)
         {
-            var candidate = new ViewComponentDescriptor()
+            var type = typeInfo.AsType();
+            var candidate = new ViewComponentDescriptor
             {
                 FullName = ViewComponentConventions.GetComponentFullName(typeInfo),
                 ShortName = ViewComponentConventions.GetComponentName(typeInfo),
-                Type = typeInfo.AsType(),
+                Type = type,
+                MethodInfo = FindMethod(type)
             };
 
             return candidate;
         }
+
+        private static MethodInfo FindMethod(Type componentType)
+        {
+            var componentName = componentType.FullName;
+            var methods = componentType.GetMethods(BindingFlags.Public | BindingFlags.Instance)
+                .Where(method =>
+                    string.Equals(method.Name, AsyncMethodName, StringComparison.Ordinal) ||
+                    string.Equals(method.Name, SyncMethodName, StringComparison.Ordinal))
+                .ToArray();
+
+            if (methods.Length == 0)
+            {
+                throw new InvalidOperationException(
+                    Resources.FormatViewComponent_CannotFindMethod(SyncMethodName, AsyncMethodName, componentName));
+            }
+            else if (methods.Length > 1)
+            {
+                throw new InvalidOperationException(
+                    Resources.FormatViewComponent_AmbiguousMethods(componentName, AsyncMethodName, SyncMethodName));
+            }
+
+            var selectedMethod = methods[0];
+            if (string.Equals(selectedMethod.Name, AsyncMethodName, StringComparison.Ordinal))
+            {
+                if (!selectedMethod.ReturnType.GetTypeInfo().IsGenericType ||
+                    selectedMethod.ReturnType.GetGenericTypeDefinition() != typeof(Task<>))
+                {
+                    throw new InvalidOperationException(Resources.FormatViewComponent_AsyncMethod_ShouldReturnTask(
+                        AsyncMethodName,
+                        componentName,
+                        nameof(Task)));
+                }
+            }
+            else
+            {
+                if (selectedMethod.ReturnType == typeof(void))
+                {
+                    throw new InvalidOperationException(Resources.FormatViewComponent_SyncMethod_ShouldReturnValue(
+                        SyncMethodName,
+                        componentName));
+                }
+                else if (selectedMethod.ReturnType.IsAssignableFrom(typeof(Task)))
+                {
+                    throw new InvalidOperationException(Resources.FormatViewComponent_SyncMethod_CannotReturnTask(
+                        SyncMethodName,
+                        componentName,
+                        nameof(Task)));
+                }
+            }
+
+            return selectedMethod;
+        }
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/DefaultViewComponentHelper.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.IO;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Html;
@@ -10,9 +9,13 @@ using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures;
 using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
+    /// <summary>
+    /// Default implementation for <see cref="IViewComponentHelper"/>.
+    /// </summary>
     public class DefaultViewComponentHelper : IViewComponentHelper, ICanHasViewContext
     {
         private readonly IViewComponentDescriptorCollectionProvider _descriptorProvider;
@@ -22,6 +25,16 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         private readonly IViewBufferScope _viewBufferScope;
         private ViewContext _viewContext;
 
+        /// <summary>
+        /// Initializes a new instance of <see cref="DefaultViewComponentHelper"/>.
+        /// </summary>
+        /// <param name="descriptorProvider">The <see cref="IViewComponentDescriptorCollectionProvider"/>
+        /// used to locate view components.</param>
+        /// <param name="htmlEncoder">The <see cref="HtmlEncoder"/>.</param>
+        /// <param name="selector">The <see cref="IViewComponentSelector"/>.</param>
+        /// <param name="invokerFactory">The <see cref="IViewComponentInvokerFactory"/>.</param>
+        /// <param name="viewBufferScope">The <see cref="IViewBufferScope"/> that manages the lifetime of
+        /// <see cref="ViewBuffer"/> instances.</param>
         public DefaultViewComponentHelper(
             IViewComponentDescriptorCollectionProvider descriptorProvider,
             HtmlEncoder htmlEncoder,
@@ -61,6 +74,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             _viewBufferScope = viewBufferScope;
         }
 
+        /// <inheritdoc />
         public void Contextualize(ViewContext viewContext)
         {
             if (viewContext == null)
@@ -71,133 +85,41 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             _viewContext = viewContext;
         }
 
-        public IHtmlContent Invoke(string name, params object[] arguments)
+        /// <inheritdoc />
+        public Task<IHtmlContent> InvokeAsync(string name, object arguments)
         {
             if (name == null)
             {
                 throw new ArgumentNullException(nameof(name));
             }
 
-            var descriptor = SelectComponent(name);
-
-            var viewBuffer = new ViewBuffer(_viewBufferScope, name);
-            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
-            {
-                InvokeCore(writer, descriptor, arguments);
-                return writer.ContentBuilder;
-            }
-        }
-
-        public IHtmlContent Invoke(Type componentType, params object[] arguments)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var descriptor = SelectComponent(componentType);
-            var viewBuffer = new ViewBuffer(_viewBufferScope, componentType.Name);
-            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
-            {
-                InvokeCore(writer, descriptor, arguments);
-                return writer.ContentBuilder;
-            }
-        }
-
-        public void RenderInvoke(string name, params object[] arguments)
-        {
-            if (name == null)
-            {
-                throw new ArgumentNullException(nameof(name));
-            }
-
-            var descriptor = SelectComponent(name);
-            InvokeCore(_viewContext.Writer, descriptor, arguments);
-        }
-
-        public void RenderInvoke(Type componentType, params object[] arguments)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var descriptor = SelectComponent(componentType);
-            InvokeCore(_viewContext.Writer, descriptor, arguments);
-        }
-
-        public async Task<IHtmlContent> InvokeAsync(string name, params object[] arguments)
-        {
-            if (name == null)
-            {
-                throw new ArgumentNullException(nameof(name));
-            }
-
-            var descriptor = SelectComponent(name);
-
-            var viewBuffer = new ViewBuffer(_viewBufferScope, name);
-            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
-            {
-                await InvokeCoreAsync(writer, descriptor, arguments);
-                return writer.ContentBuilder;
-            }
-        }
-
-        public async Task<IHtmlContent> InvokeAsync(Type componentType, params object[] arguments)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var descriptor = SelectComponent(componentType);
-
-            var viewBuffer = new ViewBuffer(_viewBufferScope, componentType.Name);
-            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
-            {
-                await InvokeCoreAsync(writer, descriptor, arguments);
-                return writer.ContentBuilder;
-            }
-        }
-
-        public Task RenderInvokeAsync(string name, params object[] arguments)
-        {
-            if (name == null)
-            {
-                throw new ArgumentNullException(nameof(name));
-            }
-
-            var descriptor = SelectComponent(name);
-            return InvokeCoreAsync(_viewContext.Writer, descriptor, arguments);
-        }
-
-        public Task RenderInvokeAsync(Type componentType, params object[] arguments)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var descriptor = SelectComponent(componentType);
-            return InvokeCoreAsync(_viewContext.Writer, descriptor, arguments);
-        }
-
-        private ViewComponentDescriptor SelectComponent(string name)
-        {
             var descriptor = _selector.SelectComponent(name);
             if (descriptor == null)
             {
                 throw new InvalidOperationException(Resources.FormatViewComponent_CannotFindComponent(name));
             }
 
-            return descriptor;
+            return InvokeCoreAsync(descriptor, arguments);
+        }
+
+        /// <inheritdoc />
+        public Task<IHtmlContent> InvokeAsync(Type componentType, object arguments)
+        {
+            if (componentType == null)
+            {
+                throw new ArgumentNullException(nameof(componentType));
+            }
+
+            var descriptor = SelectComponent(componentType);
+            return InvokeCoreAsync(descriptor, arguments);
         }
 
         private ViewComponentDescriptor SelectComponent(Type componentType)
         {
             var descriptors = _descriptorProvider.ViewComponents;
-            foreach (var descriptor in descriptors.Items)
+            for (var i = 0; i < descriptors.Items.Count; i++)
             {
+                var descriptor = descriptors.Items[i];
                 if (descriptor.Type == componentType)
                 {
                     return descriptor;
@@ -208,58 +130,30 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                 componentType.FullName));
         }
 
-        private Task InvokeCoreAsync(
+        private async Task<IHtmlContent> InvokeCoreAsync(
-            TextWriter writer,
             ViewComponentDescriptor descriptor,
-            object[] arguments)
+            object arguments)
         {
-            if (writer == null)
+            var viewBuffer = new ViewBuffer(_viewBufferScope, descriptor.FullName);
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
             {
-                throw new ArgumentNullException(nameof(writer));
+                var context = new ViewComponentContext(
+                    descriptor,
+                    PropertyHelper.ObjectToDictionary(arguments),
+                    _htmlEncoder,
+                    _viewContext,
+                    writer);
+
+                var invoker = _invokerFactory.CreateInstance(context);
+                if (invoker == null)
+                {
+                    throw new InvalidOperationException(
+                        Resources.FormatViewComponent_IViewComponentFactory_ReturnedNull(descriptor.FullName));
+                }
+
+                await invoker.InvokeAsync(context);
+                return writer.ContentBuilder;
             }
-
-            if (descriptor == null)
-            {
-                throw new ArgumentNullException(nameof(descriptor));
-            }
-
-            var context = new ViewComponentContext(descriptor, arguments, _htmlEncoder, _viewContext, writer);
-
-            var invoker = _invokerFactory.CreateInstance(context);
-            if (invoker == null)
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_IViewComponentFactory_ReturnedNull(descriptor.Type.FullName));
-            }
-
-            return invoker.InvokeAsync(context);
-        }
-
-        private void InvokeCore(
-            TextWriter writer,
-            ViewComponentDescriptor descriptor,
-            object[] arguments)
-        {
-            if (writer == null)
-            {
-                throw new ArgumentNullException(nameof(writer));
-            }
-
-            if (descriptor == null)
-            {
-                throw new ArgumentNullException(nameof(descriptor));
-            }
-
-            var context = new ViewComponentContext(descriptor, arguments, _htmlEncoder, _viewContext, writer);
-
-            var invoker = _invokerFactory.CreateInstance(context);
-            if (invoker == null)
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_IViewComponentFactory_ReturnedNull(descriptor.Type.FullName));
-            }
-
-            invoker.Invoke(context);
         }
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/DefaultViewComponentInvoker.cs

@@ -16,6 +16,9 @@ using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
+    /// <summary>
+    /// Default implementation for <see cref="IViewComponentInvoker"/>.
+    /// </summary>
     public class DefaultViewComponentInvoker : IViewComponentInvoker
     {
         private readonly ITypeActivatorCache _typeActivatorCache;
@@ -23,6 +26,13 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         private readonly DiagnosticSource _diagnosticSource;
         private readonly ILogger _logger;
 
+        /// <summary>
+        /// Initializes a new instance of <see cref="DefaultViewComponentInvoker"/>.
+        /// </summary>
+        /// <param name="typeActivatorCache">Caches factories for instantiating view component instances.</param>
+        /// <param name="viewComponentActivator">The <see cref="IViewComponentActivator"/>.</param>
+        /// <param name="diagnosticSource">The <see cref="DiagnosticSource"/>.</param>
+        /// <param name="logger">The <see cref="ILogger"/>.</param>
         public DefaultViewComponentInvoker(
             ITypeActivatorCache typeActivatorCache,
             IViewComponentActivator viewComponentActivator,
@@ -55,27 +65,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             _logger = logger;
         }
 
-        public void Invoke(ViewComponentContext context)
+        /// <inheritdoc />
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            var method = ViewComponentMethodSelector.FindSyncMethod(
-                context.ViewComponentDescriptor.Type.GetTypeInfo(),
-                context.Arguments);
-            if (method == null)
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_CannotFindMethod(ViewComponentMethodSelector.SyncMethodName));
-            }
-
-            var result = InvokeSyncCore(method, context);
-
-            result.Execute(context);
-        }
-
         public async Task InvokeAsync(ViewComponentContext context)
         {
             if (context == null)
@@ -83,32 +73,25 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                 throw new ArgumentNullException(nameof(context));
             }
 
-            IViewComponentResult result;
+            var methodInfo = context.ViewComponentDescriptor?.MethodInfo;
-
+            if (methodInfo == null)
-            var asyncMethod = ViewComponentMethodSelector.FindAsyncMethod(
-                context.ViewComponentDescriptor.Type.GetTypeInfo(),
-                context.Arguments);
-            if (asyncMethod == null)
             {
-                // We support falling back to synchronous if there is no InvokeAsync method, in this case we'll still
+                throw new InvalidOperationException(Resources.FormatPropertyOfTypeCannotBeNull(
-                // execute the IViewResult asynchronously.
+                    nameof(ViewComponentDescriptor.MethodInfo),
-                var syncMethod = ViewComponentMethodSelector.FindSyncMethod(
+                    nameof(ViewComponentDescriptor)));
-                    context.ViewComponentDescriptor.Type.GetTypeInfo(),
+            }
-                    context.Arguments);
+
-                if (syncMethod == null)
+            var isAsync = typeof(Task).GetTypeInfo().IsAssignableFrom(methodInfo.ReturnType.GetTypeInfo());
-                {
+            IViewComponentResult result;
-                    throw new InvalidOperationException(
+            if (isAsync)
-                        Resources.FormatViewComponent_CannotFindMethod_WithFallback(
+            {
-                        ViewComponentMethodSelector.SyncMethodName, ViewComponentMethodSelector.AsyncMethodName));
+                result = await InvokeAsyncCore(context);
-                }
-                else
-                {
-                    result = InvokeSyncCore(syncMethod, context);
-                }
             }
             else
             {
-                result = await InvokeAsyncCore(asyncMethod, context);
+                // We support falling back to synchronous if there is no InvokeAsync method, in this case we'll still
+                // execute the IViewResult asynchronously.
+                result = InvokeSyncCore(context);
             }
 
             await result.ExecuteAsync(context);
@@ -129,29 +112,20 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             return component;
         }
 
-        private async Task<IViewComponentResult> InvokeAsyncCore(
+        private async Task<IViewComponentResult> InvokeAsyncCore(ViewComponentContext context)
-            MethodInfo method,
-            ViewComponentContext context)
         {
-            if (method == null)
-            {
-                throw new ArgumentNullException(nameof(method));
-            }
-
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var component = CreateComponent(context);
 
             using (_logger.ViewComponentScope(context))
             {
+                var method = context.ViewComponentDescriptor.MethodInfo;
+                var arguments = ControllerActionExecutor.PrepareArguments(context.Arguments, method.GetParameters());
+
                 _diagnosticSource.BeforeViewComponent(context, component);
-                _logger.ViewComponentExecuting(context);
+                _logger.ViewComponentExecuting(context, arguments);
 
                 var startTime = Environment.TickCount;
-                var result = await ControllerActionExecutor.ExecuteAsync(method, component, context.Arguments);
+                var result = await ControllerActionExecutor.ExecuteAsync(method, component, arguments);
 
                 var viewComponentResult = CoerceToViewComponentResult(result);
                 _logger.ViewComponentExecuted(context, startTime, viewComponentResult);
@@ -161,35 +135,25 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             }
         }
 
-        public IViewComponentResult InvokeSyncCore(MethodInfo method, ViewComponentContext context)
+        private IViewComponentResult InvokeSyncCore(ViewComponentContext context)
         {
-            if (method == null)
-            {
-                throw new ArgumentNullException(nameof(method));
-            }
-
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var component = CreateComponent(context);
 
             using (_logger.ViewComponentScope(context))
             {
-                _diagnosticSource.BeforeViewComponent(context, component);
+                var method = context.ViewComponentDescriptor.MethodInfo;
-                _logger.ViewComponentExecuting(context);
+                var arguments = ControllerActionExecutor.PrepareArguments(
+                    context.Arguments,
+                    method.GetParameters());
 
+                _diagnosticSource.BeforeViewComponent(context, component);
+                _logger.ViewComponentExecuting(context, arguments);
+
+                var startTime = Environment.TickCount;
+                object result;
                 try
                 {
-                    var startTime = Environment.TickCount;
+                    result = method.Invoke(component, arguments);
-                    var result = method.Invoke(component, context.Arguments);
-
-                    var viewComponentResult = CoerceToViewComponentResult(result);
-                    _logger.ViewComponentExecuted(context, startTime, viewComponentResult);
-                    _diagnosticSource.AfterViewComponent(context, viewComponentResult, component);
-
-                    return viewComponentResult;
                 }
                 catch (TargetInvocationException ex)
                 {
@@ -198,6 +162,12 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                     exceptionInfo.Throw();
                     return null; // Unreachable
                 }
+
+                var viewComponentResult = CoerceToViewComponentResult(result);
+                _logger.ViewComponentExecuted(context, startTime, viewComponentResult);
+                _diagnosticSource.AfterViewComponent(context, viewComponentResult, component);
+
+                return viewComponentResult;
             }
         }
 

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/IViewComponentDescriptorProvider.cs

@@ -6,7 +6,7 @@ using System.Collections.Generic;
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
     /// <summary>
-    /// Discovers the View Components in the application.
+    /// Discovers the view components in the application.
     /// </summary>
     public interface IViewComponentDescriptorProvider
     {

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/IViewComponentInvoker.cs

@@ -5,10 +5,17 @@ using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
+    /// <summary>
+    /// Specifies the contract for execution of a view component.
+    /// </summary>
     public interface IViewComponentInvoker
     {
-        void Invoke(ViewComponentContext context);
+        /// <summary>
-
+        /// Executes the view component specified by <see cref="ViewComponentContext.ViewComponentDescriptor"/>
+        /// of <paramref name="context"/> and writes the result to <see cref="ViewComponentContext.Writer"/>.
+        /// </summary>
+        /// <param name="context">The <see cref="ViewComponentContext"/>.</param>
+        /// <returns>A <see cref="Task"/> that represents the asynchronous operation of execution.</returns>
         Task InvokeAsync(ViewComponentContext context);
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/IViewComponentSelector.cs

@@ -4,14 +4,14 @@
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
     /// <summary>
-    /// Selects a View Component based on a View Component name.
+    /// Selects a view component based on a view component name.
     /// </summary>
     public interface IViewComponentSelector
     {
         /// <summary>
-        /// Selects a View Component based on <paramref name="componentName"/>.
+        /// Selects a view component based on <paramref name="componentName"/>.
         /// </summary>
-        /// <param name="componentName">The View Component name.</param>
+        /// <param name="componentName">The view component name.</param>
         /// <returns>A <see cref="ViewComponentDescriptor"/>, or <c>null</c> if no match is found.</returns>
         ViewComponentDescriptor SelectComponent(string componentName);
     }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/ViewComponentContext.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.IO;
 using System.Text.Encodings.Web;
 using Microsoft.AspNet.Mvc.Rendering;
@@ -10,7 +11,7 @@ using Microsoft.AspNet.Mvc.ViewFeatures;
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
     /// <summary>
-    /// A context for View Components.
+    /// A context for view components.
     /// </summary>
     public class ViewComponentContext
     {
@@ -23,7 +24,6 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         public ViewComponentContext()
         {
             ViewComponentDescriptor = new ViewComponentDescriptor();
-            Arguments = new object[0];
             ViewContext = new ViewContext();
         }
 
@@ -31,14 +31,14 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         /// Creates a new <see cref="ViewComponentContext"/>.
         /// </summary>
         /// <param name="viewComponentDescriptor">
-        /// The <see cref="ViewComponentContext"/> for the View Component being invoked.
+        /// The <see cref="ViewComponentContext"/> for the view component being invoked.
         /// </param>
-        /// <param name="arguments">The View Component arguments.</param>
+        /// <param name="arguments">The view component arguments.</param>
         /// <param name="viewContext">The <see cref="ViewContext"/>.</param>
         /// <param name="writer">The <see cref="TextWriter"/> for writing output.</param>
         public ViewComponentContext(
             ViewComponentDescriptor viewComponentDescriptor,
-            object[] arguments,
+            IDictionary<string, object> arguments,
             HtmlEncoder htmlEncoder,
             ViewContext viewContext,
             TextWriter writer)
@@ -82,15 +82,15 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         }
 
         /// <summary>
-        /// Gets or sets the View Component arguments.
+        /// Gets or sets the view component arguments.
         /// </summary>
         /// <remarks>
         /// The property setter is provided for unit test purposes only.
         /// </remarks>
-        public object[] Arguments { get; set; }
+        public IDictionary<string, object> Arguments { get; set; }
 
         /// <summary>
-        /// Gets or sets the <see cref="HtmlEncoder"/>.
+        /// Gets or sets the <see cref="System.Text.Encodings.Web.HtmlEncoder"/>.
         /// </summary>
         /// <remarks>
         /// The property setter is provided for unit test purposes only.
@@ -98,7 +98,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         public HtmlEncoder HtmlEncoder { get; set; }
 
         /// <summary>
-        /// Gets or sets the <see cref="ViewComponentDescriptor"/> for the View Component being invoked.
+        /// Gets or sets the <see cref="ViewComponents.ViewComponentDescriptor"/> for the view component being invoked.
         /// </summary>
         /// <remarks>
         /// The property setter is provided for unit test purposes only.
@@ -106,7 +106,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         public ViewComponentDescriptor ViewComponentDescriptor { get; set; }
 
         /// <summary>
-        /// Gets or sets the <see cref="ViewContext"/>.
+        /// Gets or sets the <see cref="Rendering.ViewContext"/>.
         /// </summary>
         /// <remarks>
         /// The property setter is provided for unit test purposes only.

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/ViewComponentDescriptor.cs

@@ -3,11 +3,12 @@
 
 using System;
 using System.Diagnostics;
+using System.Reflection;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
 {
     /// <summary>
-    /// A descriptor for a View Component.
+    /// A descriptor for a view component.
     /// </summary>
     [DebuggerDisplay("{DisplayName}")]
     public class ViewComponentDescriptor
@@ -23,7 +24,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         }
 
         /// <summary>
-        /// Gets or sets the display name of the View Component.
+        /// Gets or sets the display name of the view component.
         /// </summary>
         public string DisplayName
         {
@@ -53,8 +54,8 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         /// </summary>
         /// <remarks>
         /// <para>
-        /// The full name is defaulted to the full namespace of the View Component class, prepended to
+        /// The full name is defaulted to the full namespace of the view component class, prepended to
-        /// the the class name with a '.' character as the separator. If the View Component class uses
+        /// the the class name with a '.' character as the separator. If the view component class uses
         /// <code>ViewComponent</code> as a suffix, the suffix will be omitted from the <see cref="FullName"/>.
         /// </para>
         /// <example>
@@ -89,7 +90,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         /// </summary>
         /// <remarks>
         /// <para>
-        /// The short name is defaulted to the name of the View Component class. If the View Component class uses
+        /// The short name is defaulted to the name of the view component class. If the view component class uses
         /// <code>ViewComponent</code> as a suffix, the suffix will be omitted from the <see cref="ShortName"/>.
         /// </para>
         /// <example>
@@ -115,8 +116,13 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         public string ShortName { get; set; }
 
         /// <summary>
-        /// Gets or sets the <see cref="Type"/>.
+        /// Gets or sets the <see cref="System.Type"/>.
         /// </summary>
         public Type Type { get; set; }
+
+        /// <summary>
+        /// Gets or sets the <see cref="System.Reflection.MethodInfo"/> to invoke.
+        /// </summary>
+        public MethodInfo MethodInfo { get; set; }
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/ViewComponentMethodSelector.cs

@@ -1,98 +0,0 @@
-// 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.Linq.Expressions;
-using System.Reflection;
-using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.ViewFeatures;
-
-namespace Microsoft.AspNet.Mvc.ViewComponents
-{
-    public static class ViewComponentMethodSelector
-    {
-        public const string AsyncMethodName = "InvokeAsync";
-        public const string SyncMethodName = "Invoke";
-
-        public static MethodInfo FindAsyncMethod(TypeInfo componentType, object[] args)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var method = GetMethod(componentType, args, AsyncMethodName);
-            if (method == null)
-            {
-                return null;
-            }
-
-            if (!method.ReturnType.GetTypeInfo().IsGenericType ||
-                method.ReturnType.GetGenericTypeDefinition() != typeof(Task<>))
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_AsyncMethod_ShouldReturnTask(AsyncMethodName));
-            }
-
-            return method;
-        }
-
-        public static MethodInfo FindSyncMethod(TypeInfo componentType, object[] args)
-        {
-            if (componentType == null)
-            {
-                throw new ArgumentNullException(nameof(componentType));
-            }
-
-            var method = GetMethod(componentType, args, SyncMethodName);
-            if (method == null)
-            {
-                return null;
-            }
-
-            if (method.ReturnType == typeof(void))
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_SyncMethod_ShouldReturnValue(SyncMethodName));
-            }
-            else if (method.ReturnType.IsAssignableFrom(typeof(Task)))
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatViewComponent_SyncMethod_CannotReturnTask(SyncMethodName, nameof(Task)));
-            }
-
-            return method;
-        }
-
-        private static MethodInfo GetMethod(TypeInfo componentType, object[] args, string methodName)
-        {
-            Type[] types;
-            if (args == null || args.Length == 0)
-            {
-                types = Type.EmptyTypes;
-            }
-            else
-            {
-                types = new Type[args.Length];
-                for (var i = 0; i < args.Length; i++)
-                {
-                    types[i] = args[i]?.GetType() ?? typeof(object);
-                }
-            }
-
-#if NET451
-            return componentType.AsType().GetMethod(
-                methodName,
-                BindingFlags.Public | BindingFlags.Instance,
-                binder: null,
-                types: types,
-                modifiers: null);
-#else
-            var method = componentType.AsType().GetMethod(methodName, types: types);
-            // At most one method (including static and instance methods) with the same parameter types can exist
-            // per type.
-            return method != null && method.IsStatic ? null : method;
-#endif
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponentResultTest.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Reflection;
 using System.Text;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
@@ -42,13 +43,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewData = null,
                 TempData = null,
                 ViewComponentName = "Text"
@@ -132,13 +134,43 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
+                ViewComponentName = "Text",
+                TempData = _tempDataDictionary,
+            };
+
+            // Act
+            await viewComponentResult.ExecuteResultAsync(actionContext);
+
+            // Assert
+            var body = ReadBody(actionContext.HttpContext.Response);
+            Assert.Equal("Hello, World!", body);
+        }
+
+        [Fact]
+        public async Task ExecuteResultAsync_UsesDictionaryArguments()
+        {
+            // Arrange
+            var descriptor = new ViewComponentDescriptor()
+            {
+                FullName = "Full.Name.Text",
+                ShortName = "Text",
+                Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
+            };
+
+            var actionContext = CreateActionContext(descriptor);
+
+            var viewComponentResult = new ViewComponentResult()
+            {
+                Arguments = new Dictionary<string, object> { ["name"] = "World!" },
                 ViewComponentName = "Text",
                 TempData = _tempDataDictionary,
             };
@@ -160,13 +192,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.AsyncText",
                 ShortName = "AsyncText",
                 Type = typeof(AsyncTextViewComponent),
+                MethodInfo = typeof(AsyncTextViewComponent).GetMethod(nameof(AsyncTextViewComponent.InvokeAsync)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "AsyncText",
                 TempData = _tempDataDictionary,
             };
@@ -188,6 +221,7 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var adapter = new TestDiagnosticListener();
@@ -196,7 +230,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Text",
                 TempData = _tempDataDictionary,
             };
@@ -226,13 +260,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Text",
                 TempData = _tempDataDictionary,
             };
@@ -254,13 +289,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Full.Name.Text",
                 TempData = _tempDataDictionary,
             };
@@ -282,13 +318,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentType = typeof(TextViewComponent),
                 TempData = _tempDataDictionary,
             };
@@ -310,13 +347,14 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke))
             };
 
             var actionContext = CreateActionContext(descriptor);
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentType = typeof(TextViewComponent),
                 StatusCode = 404,
                 TempData = _tempDataDictionary,
@@ -367,6 +405,7 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
@@ -375,7 +414,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Text",
                 ContentType = contentType,
                 TempData = _tempDataDictionary,
@@ -403,6 +442,7 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
@@ -412,7 +452,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Text",
                 ContentType = new MediaTypeHeaderValue("text/html") { Encoding = Encoding.UTF8 },
                 TempData = _tempDataDictionary,
@@ -439,6 +479,7 @@ namespace Microsoft.AspNet.Mvc
                 FullName = "Full.Name.Text",
                 ShortName = "Text",
                 Type = typeof(TextViewComponent),
+                MethodInfo = typeof(TextViewComponent).GetMethod(nameof(TextViewComponent.Invoke)),
             };
 
             var actionContext = CreateActionContext(descriptor);
@@ -447,7 +488,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentResult = new ViewComponentResult()
             {
-                Arguments = new object[] { "World!" },
+                Arguments = new { name = "World!" },
                 ViewComponentName = "Text",
                 TempData = _tempDataDictionary,
             };
@@ -459,7 +500,10 @@ namespace Microsoft.AspNet.Mvc
             Assert.Equal(expectedContentType, actionContext.HttpContext.Response.ContentType);
         }
 
-        private IServiceCollection CreateServices(object diagnosticListener, HttpContext context, params ViewComponentDescriptor[] descriptors)
+        private IServiceCollection CreateServices(
+            object diagnosticListener,
+            HttpContext context,
+            params ViewComponentDescriptor[] descriptors)
         {
             var httpContext = new DefaultHttpContext();
             var diagnosticSource = new DiagnosticListener("Microsoft.AspNet");
@@ -535,12 +579,6 @@ namespace Microsoft.AspNet.Mvc
 
         private class AsyncTextViewComponent : ViewComponent
         {
-            public HtmlString Invoke()
-            {
-                // Should never run.
-                throw null;
-            }
-
             public Task<HtmlString> InvokeAsync(string name)
             {
                 return Task.FromResult(new HtmlString("Hello-Async, " + name));

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/ContentViewComponentResultTest.cs

@@ -1,6 +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.Collections.Generic;
 using System.IO;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
@@ -57,7 +58,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentContext = new ViewComponentContext(
                 viewComponentDescriptor,
-                new object[0],
+                new Dictionary<string, object>(),
                 new HtmlTestEncoder(),
                 viewContext,
                 writer);

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/DefaultViewComponentActivatorTests.cs

@@ -2,13 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.IO;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Http.Internal;
-using Microsoft.AspNet.Mvc.ModelBinding;
-using Microsoft.AspNet.Mvc.Rendering;
-using Microsoft.AspNet.Routing;
-using Moq;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/DefaultViewComponentDescriptorProviderTest.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Infrastructure;
 using Xunit;
 
@@ -23,9 +24,10 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             // Assert
             var descriptor = Assert.Single(descriptors);
-            Assert.Equal(typeof(ConventionsViewComponent), descriptor.Type);
+            Assert.Same(typeof(ConventionsViewComponent), descriptor.Type);
             Assert.Equal("Microsoft.AspNet.Mvc.ViewComponents.Conventions", descriptor.FullName);
             Assert.Equal("Conventions", descriptor.ShortName);
+            Assert.Same(typeof(ConventionsViewComponent).GetMethod("Invoke"), descriptor.MethodInfo);
         }
 
         [Fact]
@@ -42,15 +44,156 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             Assert.Equal(typeof(AttributeViewComponent), descriptor.Type);
             Assert.Equal("AttributesAreGreat", descriptor.FullName);
             Assert.Equal("AttributesAreGreat", descriptor.ShortName);
+            Assert.Same(typeof(AttributeViewComponent).GetMethod("InvokeAsync"), descriptor.MethodInfo);
+        }
+
+        [Theory]
+        [InlineData(typeof(NoMethodsViewComponent))]
+        [InlineData(typeof(NonPublicInvokeAsyncViewComponent))]
+        [InlineData(typeof(NonPublicInvokeViewComponent))]
+        public void GetViewComponents_ThrowsIfTypeHasNoInvocationMethods(Type type)
+        {
+            // Arrange
+            var expected = $"Could not find an 'Invoke' or 'InvokeAsync' method for the view component '{type}'.";
+            var provider = CreateProvider(type);
+
+            // Act
+            var ex = Assert.Throws<InvalidOperationException>(() => provider.GetViewComponents().ToArray());
+            Assert.Equal(expected, ex.Message);
+        }
+
+        [Theory]
+        [InlineData(typeof(MultipleInvokeViewComponent))]
+        [InlineData(typeof(MultipleInvokeAsyncViewComponent))]
+        [InlineData(typeof(InvokeAndInvokeAsyncViewComponent))]
+        public void GetViewComponents_ThrowsIfTypeHasAmbiguousInvocationMethods(Type type)
+        {
+            // Arrange
+            var expected = $"View component '{type}' must have exactly one public method named " +
+                "'InvokeAsync' or 'Invoke'.";
+            var provider = CreateProvider(type);
+
+            // Act
+            var ex = Assert.Throws<InvalidOperationException>(() => provider.GetViewComponents().ToArray());
+            Assert.Equal(expected, ex.Message);
+        }
+
+        [Theory]
+        [InlineData(typeof(NonGenericTaskReturningInvokeAsyncViewComponent))]
+        [InlineData(typeof(VoidReturningInvokeAsyncViewComponent))]
+        [InlineData(typeof(NonTaskReturningInvokeAsyncViewComponent))]
+        public void GetViewComponents_ThrowsIfInvokeAsyncDoesNotHaveCorrectReturnType(Type type)
+        {
+            // Arrange
+            var expected = $"Method 'InvokeAsync' of view component '{type}' should be declared to return Task<T>.";
+            var provider = CreateProvider(type);
+
+            // Act and Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => provider.GetViewComponents().ToArray());
+            Assert.Equal(expected, ex.Message);
+        }
+
+        [Fact]
+        public void GetViewComponents_ThrowsIfInvokeReturnsATask()
+        {
+            // Arrange
+            var type = typeof(TaskReturningInvokeViewComponent);
+            var expected = $"Method 'Invoke' of view component '{type}' cannot return a Task.";
+            var provider = CreateProvider(type);
+
+            // Act and Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => provider.GetViewComponents().ToArray());
+            Assert.Equal(expected, ex.Message);
+        }
+
+        [Fact]
+        public void GetViewComponents_ThrowsIfInvokeIsVoidReturning()
+        {
+            // Arrange
+            var type = typeof(VoidReturningInvokeViewComponent);
+            var expected = $"Method 'Invoke' of view component '{type}' should be declared to return a value.";
+            var provider = CreateProvider(type);
+
+            // Act and Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => provider.GetViewComponents().ToArray());
+            Assert.Equal(expected, ex.Message);
         }
 
         private class ConventionsViewComponent
         {
+            public string Invoke() => "Hello world";
         }
 
         [ViewComponent(Name = "AttributesAreGreat")]
         private class AttributeViewComponent
         {
+            public Task<string> InvokeAsync() => Task.FromResult("Hello world");
+        }
+
+        private class MultipleInvokeViewComponent
+        {
+            public IViewComponentResult Invoke() => null;
+
+            public IViewComponentResult Invoke(int a) => null;
+        }
+
+        private class NoMethodsViewComponent
+        {
+        }
+
+        private class NonPublicInvokeViewComponent
+        {
+            private IViewComponentResult Invoke() => null;
+        }
+
+        private class NonPublicInvokeAsyncViewComponent
+        {
+            protected Task<IViewComponentResult> InvokeAsync() => null;
+        }
+
+        private class MultipleInvokeAsyncViewComponent
+        {
+            public Task<IViewComponentResult> InvokeAsync(string a) => null;
+
+            public Task<IViewComponentResult> InvokeAsync(int a) => null;
+
+            public Task<IViewComponentResult> InvokeAsync(int a, int b) => null;
+        }
+
+        private class InvokeAndInvokeAsyncViewComponent
+        {
+            public Task<IViewComponentResult> InvokeAsync(string a) => null;
+
+            public string InvokeAsync(int a) => null;
+        }
+
+        private class NonGenericTaskReturningInvokeAsyncViewComponent
+        {
+            public Task InvokeAsync() => Task.FromResult(0);
+        }
+
+        private class VoidReturningInvokeAsyncViewComponent
+        {
+            public void InvokeAsync()
+            {
+            }
+        }
+
+        public class NonTaskReturningInvokeAsyncViewComponent
+        {
+            public long InvokeAsync() => 0L;
+        }
+
+        public class TaskReturningInvokeViewComponent
+        {
+            public Task Invoke() => Task.FromResult(0);
+        }
+
+        public class VoidReturningInvokeViewComponent
+        {
+            public void Invoke(int x)
+            {
+            }
         }
 
         private DefaultViewComponentDescriptorProvider CreateProvider(Type componentType)
@@ -80,11 +223,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                 return
                     GetAssemblyProvider()
                     .CandidateAssemblies
-                    .SelectMany(a => a.DefinedTypes)
+                    .SelectMany(a => a.DefinedTypes);
-#if DNX451
-                    .Select(t => t.GetTypeInfo())
-#endif
-                    ;
             }
 
             private static IAssemblyProvider GetAssemblyProvider()

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/DefaultViewComponentSelectorTest.cs

@@ -12,6 +12,8 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 {
     public class DefaultViewComponentSelectorTest
     {
+        private static readonly string Namespace = typeof(DefaultViewComponentSelectorTest).Namespace;
+
         [Fact]
         public void SelectComponent_ByShortNameWithSuffix()
         {
@@ -22,7 +24,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent("Suffix");
 
             // Assert
-            Assert.Equal(typeof(SuffixViewComponent), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.SuffixViewComponent), result.Type);
         }
 
         [Fact]
@@ -32,10 +34,10 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var selector = CreateSelector();
 
             // Act
-            var result = selector.SelectComponent("Microsoft.AspNet.Mvc.ViewComponents.Suffix");
+            var result = selector.SelectComponent($"{Namespace}.Suffix");
 
             // Assert
-            Assert.Equal(typeof(SuffixViewComponent), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.SuffixViewComponent), result.Type);
         }
 
         [Fact]
@@ -48,7 +50,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent("WithoutSuffix");
 
             // Assert
-            Assert.Equal(typeof(WithoutSuffix), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.WithoutSuffix), result.Type);
         }
 
         [Fact]
@@ -58,10 +60,10 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var selector = CreateSelector();
 
             // Act
-            var result = selector.SelectComponent("Microsoft.AspNet.Mvc.ViewComponents.WithoutSuffix");
+            var result = selector.SelectComponent($"{Namespace}.WithoutSuffix");
 
             // Assert
-            Assert.Equal(typeof(WithoutSuffix), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.WithoutSuffix), result.Type);
         }
 
         [Fact]
@@ -74,7 +76,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent("ByAttribute");
 
             // Assert
-            Assert.Equal(typeof(ByAttribute), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.ByAttribute), result.Type);
         }
 
         [Fact]
@@ -87,7 +89,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent("ByNamingConvention");
 
             // Assert
-            Assert.Equal(typeof(ByNamingConventionViewComponent), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.ByNamingConventionViewComponent), result.Type);
         }
 
         [Fact]
@@ -98,9 +100,9 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             var expected =
                 "The view component name 'Ambiguous' matched multiple types:" + Environment.NewLine +
-                "Type: 'Microsoft.AspNet.Mvc.ViewComponents.DefaultViewComponentSelectorTest+Ambiguous1' - " +
+                $"Type: '{typeof(ViewComponentContainer.Ambiguous1)}' - " +
                 "Name: 'Namespace1.Ambiguous'" + Environment.NewLine +
-                "Type: 'Microsoft.AspNet.Mvc.ViewComponents.DefaultViewComponentSelectorTest+Ambiguous2' - " +
+                $"Type: '{typeof(ViewComponentContainer.Ambiguous2)}' - " +
                 "Name: 'Namespace2.Ambiguous'";
 
             // Act
@@ -120,7 +122,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent("Namespace1.Ambiguous");
 
             // Assert
-            Assert.Equal(typeof(Ambiguous1), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.Ambiguous1), result.Type);
         }
 
         [Theory]
@@ -135,44 +137,56 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var result = selector.SelectComponent(name);
 
             // Assert
-            Assert.Equal(typeof(FullNameInAttribute), result.Type);
+            Assert.Same(typeof(ViewComponentContainer.FullNameInAttribute), result.Type);
         }
 
         private IViewComponentSelector CreateSelector()
         {
-            return new FilteredViewComponentSelector();
+            var provider = new DefaultViewComponentDescriptorCollectionProvider(
+                    new FilteredViewComponentDescriptorProvider());
+            return new DefaultViewComponentSelector(provider);
         }
 
-        private class SuffixViewComponent : ViewComponent
+        private class ViewComponentContainer
         {
-        }
+            public class SuffixViewComponent : ViewComponent
+            {
+                public string Invoke() => "Hello";
+            }
 
-        private class WithoutSuffix : ViewComponent
+            public class WithoutSuffix : ViewComponent
-        {
+            {
-        }
+                public string Invoke() => "Hello";
+            }
 
-        private class ByNamingConventionViewComponent
+            public class ByNamingConventionViewComponent
-        {
+            {
-        }
+                public string Invoke() => "Hello";
+            }
 
-        [ViewComponent]
+            [ViewComponent]
-        private class ByAttribute
+            public class ByAttribute
-        {
+            {
-        }
+                public string Invoke() => "Hello";
+            }
 
-        [ViewComponent(Name = "Namespace1.Ambiguous")]
+            [ViewComponent(Name = "Namespace1.Ambiguous")]
-        private class Ambiguous1
+            public class Ambiguous1
-        {
+            {
-        }
+                public string Invoke() => "Hello";
+            }
 
-        [ViewComponent(Name = "Namespace2.Ambiguous")]
+            [ViewComponent(Name = "Namespace2.Ambiguous")]
-        private class Ambiguous2
+            public class Ambiguous2
-        {
+            {
-        }
+                public string Invoke() => "Hello";
+            }
 
-        [ViewComponent(Name = "CoolNameSpace.FullNameInAttribute")]
+            [ViewComponent(Name = "CoolNameSpace.FullNameInAttribute")]
-        private class FullNameInAttribute
+            public class FullNameInAttribute
-        {
+            {
+                public string Invoke() => "Hello";
+            }
         }
 
         // This will only consider types nested inside this class as ViewComponent classes
@@ -181,10 +195,10 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             public FilteredViewComponentDescriptorProvider()
                 : base(GetAssemblyProvider())
             {
-                AllowedTypes = typeof(DefaultViewComponentSelectorTest).GetNestedTypes(BindingFlags.NonPublic);
+                AllowedTypes = typeof(ViewComponentContainer).GetNestedTypes(bindingAttr: BindingFlags.Public);
             }
 
-            public Type[] AllowedTypes { get; private set; }
+            public Type[] AllowedTypes { get; }
 
             protected override bool IsViewComponentType(TypeInfo typeInfo)
             {
@@ -208,19 +222,10 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             {
                 var assemblyProvider = new StaticAssemblyProvider();
                 assemblyProvider.CandidateAssemblies.Add(
-                    typeof(FilteredViewComponentSelector).GetTypeInfo().Assembly);
+                    typeof(ViewComponentContainer).GetTypeInfo().Assembly);
 
                 return assemblyProvider;
             }
         }
-
-        // This will only consider types nested inside this class as ViewComponent classes
-        private class FilteredViewComponentSelector : DefaultViewComponentSelector
-        {
-            public FilteredViewComponentSelector()
-                : base(new DefaultViewComponentDescriptorCollectionProvider(new FilteredViewComponentDescriptorProvider()))
-            {
-            }
-        }
     }
 }

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/HtmlContentViewComponentResultTest.cs

@@ -1,7 +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.
 
-#if MOCK_SUPPORT
+using System.Collections.Generic;
 using System.IO;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
@@ -57,7 +57,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentContext = new ViewComponentContext(
                 viewComponentDescriptor,
-                new object[0],
+                new Dictionary<string, object>(),
                 new HtmlTestEncoder(),
                 viewContext,
                 writer);
@@ -66,4 +66,3 @@ namespace Microsoft.AspNet.Mvc
         }
     }
 }
-#endif

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/JsonViewComponentResultTest.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.IO;
 using System.Text;
 using Microsoft.AspNet.Http;
@@ -85,7 +86,7 @@ namespace Microsoft.AspNet.Mvc
 
             var viewComponentContext = new ViewComponentContext(
                 viewComponentDescriptor,
-                new object[0],
+                new Dictionary<string, object>(),
                 new HtmlTestEncoder(),
                 viewContext,
                 writer);

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/ViewComponentMethodSelectorTest.cs

@@ -1,282 +0,0 @@
-// 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.Globalization;
-using System.Reflection;
-using System.Threading.Tasks;
-using Xunit;
-
-namespace Microsoft.AspNet.Mvc.ViewComponents
-{
-    public class ViewComponentMethodSelectorTest
-    {
-        [Theory]
-        [InlineData(typeof(ViewComponentWithSyncInvoke), new object[] { "" })]
-        [InlineData(typeof(ViewComponentWithAsyncInvoke), new object[] { 42, false })]
-        [InlineData(typeof(ViewComponentWithNonPublicNonInstanceInvokes), new object[] { })]
-        [InlineData(typeof(ViewComponentWithNonPublicNonInstanceInvokes), new object[] { "" })]
-        public void FindAsyncMethod_ReturnsNull_IfMatchCannotBeFound(Type type, object[] args)
-        {
-            // Arrange
-            var typeInfo = type.GetTypeInfo();
-
-            // Act
-            var method = ViewComponentMethodSelector.FindAsyncMethod(typeInfo, args);
-
-            // Assert
-            Assert.Null(method);
-        }
-
-        [Theory]
-        [InlineData(typeof(ViewComponentWithAsyncInvoke), new object[0])]
-        [InlineData(typeof(ViewComponentWithSyncInvoke), new object[] { "" })]
-        [InlineData(typeof(ViewComponentWithAsyncInvoke), new object[] { "" })]
-        [InlineData(typeof(ViewComponentWithSyncInvoke), new object[] { 42 })]
-        [InlineData(typeof(ViewComponentWithAsyncInvoke), new object[] { "", 42 })]
-        [InlineData(typeof(ViewComponentWithNonPublicNonInstanceInvokes), new object[] { })]
-        [InlineData(typeof(ViewComponentWithNonPublicNonInstanceInvokes), new object[] { "" })]
-        [InlineData(typeof(BaseClass), new object[] { })]
-        public void FindSyncMethod_ReturnsNull_IfMatchCannotBeFound(Type type, object[] args)
-        {
-            // Arrange
-            var typeInfo = type.GetTypeInfo();
-
-            // Act
-            var method = ViewComponentMethodSelector.FindSyncMethod(typeInfo, args);
-
-            // Assert
-            Assert.Null(method);
-        }
-
-        [Theory]
-        [InlineData(new object[] { new object[] { "Hello" } })]
-        [InlineData(new object[] { new object[] { 4 } })]
-        [InlineData(new object[] { new object[] { "", 5 } })]
-        public void FindAsyncMethod_ThrowsIfInvokeAsyncDoesNotHaveCorrectReturnType(object[] args)
-        {
-            // Arrange
-            var typeInfo = typeof(TypeWithInvalidInvokeAsync).GetTypeInfo();
-
-            // Act and Assert
-            var ex = Assert.Throws<InvalidOperationException>(
-                () => ViewComponentMethodSelector.FindAsyncMethod(typeInfo, args));
-            Assert.Equal("The async view component method 'InvokeAsync' should be declared to return Task<T>.",
-                ex.Message);
-        }
-
-        [Fact]
-        public void FindSyncMethod_ThrowsIfInvokeSyncIsAVoidMethod()
-        {
-            // Arrange
-            var expectedMessage = "The view component method 'Invoke' should be declared to return a value.";
-            var typeInfo = typeof(TypeWithInvalidInvokeSync).GetTypeInfo();
-
-            // Act and Assert
-            var ex = Assert.Throws<InvalidOperationException>(
-                () => ViewComponentMethodSelector.FindSyncMethod(typeInfo, new object[] { 4 }));
-            Assert.Equal(expectedMessage, ex.Message);
-        }
-
-        [Fact]
-        public void FindSyncMethod_ThrowsIfInvokeSyncReturnsTask()
-        {
-            // Arrange
-            var expectedMessage = "The view component method 'Invoke' cannot return a Task.";
-            var typeInfo = typeof(TypeWithInvalidInvokeSync).GetTypeInfo();
-
-            // Act and Assert
-            var ex = Assert.Throws<InvalidOperationException>(
-                () => ViewComponentMethodSelector.FindSyncMethod(typeInfo, new object[] { "" }));
-            Assert.Equal(expectedMessage, ex.Message);
-        }
-
-        public static TheoryData FindAsyncMethod_ReturnsMethodMatchingParametersData
-        {
-            get
-            {
-                var derivedClass = new DerivedClass();
-
-                return new TheoryData<Type, object[], string>
-                {
-                    { typeof(ViewComponentWithAsyncInvoke), new object[] { "", }, "1" },
-                    { typeof(ViewComponentWithAsyncInvoke), new object[] { "", 2 }, "2" },
-                    { typeof(ViewComponentWithAsyncInvoke), new object[] { "", 0, 1 }, "3" },
-                    { typeof(ViewComponentWithAsyncInvoke), new object[] { 1, false, 1 }, "4" },
-                    { typeof(MethodsWithValueConversions), new object[] { 2, (byte)1, (byte)2 }, "2" },
-                    { typeof(MethodsWithValueConversions), new object[] { derivedClass, derivedClass }, "4" },
-                    { typeof(MethodsWithValueConversions), new object[] { CultureInfo.InvariantCulture }, "6" },
-                };
-            }
-        }
-
-        [Theory]
-        [MemberData(nameof(FindAsyncMethod_ReturnsMethodMatchingParametersData))]
-        public void FindAsyncMethod_ReturnsMethodMatchingParameters(Type type, object[] args, string expectedId)
-        {
-            // Arrange
-            var typeInfo = type.GetTypeInfo();
-
-            // Act
-            var method = ViewComponentMethodSelector.FindAsyncMethod(typeInfo, args);
-
-            // Assert
-            Assert.NotNull(method);
-            var data = method.GetCustomAttribute<MethodDataAttribute>();
-            Assert.Equal(expectedId, data.Data);
-        }
-
-        public static TheoryData FindSyncMethod_ReturnsMethodMatchingParametersData
-        {
-            get
-            {
-                var derivedClass = new DerivedAgain();
-
-                return new TheoryData<Type, object[], string>
-                {
-                    { typeof(ViewComponentWithSyncInvoke), new object[] { }, "1" },
-                    { typeof(ViewComponentWithSyncInvoke), new object[] { 2, 3 }, "2" },
-                    { typeof(ViewComponentWithSyncInvoke), new object[] { "", 0, true }, "3" },
-                    { typeof(MethodsWithValueConversions), new object[] { 1, (byte)2, 3.0f }, "1" },
-                    { typeof(MethodsWithValueConversions), new object[] { derivedClass, derivedClass }, "3" },
-                    { typeof(MethodsWithValueConversions), new object[] { "Hello world" }, "5" },
-                    { typeof(DerivedClass), new object[] { }, "Derived1" },
-#if !DNXCORE50
-                    { typeof(DerivedAgain), new object[] { "" }, "Derived2" },
-#endif
-                };
-            }
-        }
-
-        [Theory]
-        [MemberData(nameof(FindSyncMethod_ReturnsMethodMatchingParametersData))]
-        public void FindSyncMethod_ReturnsMethodMatchingParameters(Type type, object[] args, string expectedId)
-        {
-            // Arrange
-            var typeInfo = type.GetTypeInfo();
-
-            // Act
-            var method = ViewComponentMethodSelector.FindSyncMethod(typeInfo, args);
-
-            // Assert
-            Assert.NotNull(method);
-            var data = method.GetCustomAttribute<MethodDataAttribute>();
-            Assert.Equal(expectedId, data.Data);
-        }
-
-        private class ViewComponentWithSyncInvoke
-        {
-            [MethodData("1")]
-            public int Invoke() => 3;
-
-            [MethodData("2")]
-            public int Invoke(int a, int? b) => a + b.Value;
-
-            [MethodData("3")]
-            public int Invoke(string a, int b, bool? c) => 3;
-        }
-
-        private class ViewComponentWithAsyncInvoke
-        {
-            [MethodData("1")]
-            public Task<string> InvokeAsync(string value) => Task.FromResult(value.ToUpperInvariant());
-
-            [MethodData("2")]
-            public Task<string> InvokeAsync(string a, int b) => Task.FromResult(a + b);
-
-            [MethodData("3")]
-            public Task<string> InvokeAsync(string a, int? b, int c) => Task.FromResult(a + b + c);
-
-            [MethodData("4")]
-            public Task<string> InvokeAsync(int? a, bool? b, int c) => Task.FromResult(a.ToString() + b + c);
-
-            [MethodData("5")]
-            public Task<string> InvokeAsync(object value) => Task.FromResult(value.ToString());
-        }
-
-        public class MethodsWithValueConversions
-        {
-            [MethodData("1")]
-            public int Invoke(long a, char b, double c) => 1;
-
-            [MethodData("2")]
-            public Task<int> InvokeAsync(float a, float b, byte c) => Task.FromResult(1);
-
-            [MethodData("3")]
-            public int Invoke(BaseClass a, DerivedClass b) => 1;
-
-            [MethodData("4")]
-            public Task<int> InvokeAsync(BaseClass a, DerivedClass b) => Task.FromResult(1);
-
-            [MethodData("5")]
-            public int Invoke(IEnumerable<char> value) => 1;
-
-            [MethodData("6")]
-            public Task<int> InvokeAsync(IFormatProvider formatProvider) => Task.FromResult(1);
-        }
-
-        private class ViewComponentWithNonPublicNonInstanceInvokes
-        {
-            public static int Invoke() => 1;
-
-            private int Invoke(string a) => 2;
-
-            public static Task<int> InvokeAsync() => Task.FromResult(3);
-
-            protected Task<string> InvokeAsync(string a) => Task.FromResult(a);
-        }
-
-        public class BaseClass
-        {
-            [MethodData("Base")]
-            public static int Invoke() => 1;
-        }
-
-        public class DerivedClass : BaseClass
-        {
-            [MethodData("Derived1")]
-            public new int Invoke() => 1;
-
-            [MethodData("Derived2")]
-            public int Invoke(string x) => 2;
-        }
-
-        public class DerivedAgain : DerivedClass
-        {
-            [MethodData("DerivedAgain")]
-            public new static int Invoke(string x) => 2;
-        }
-
-        private class TypeWithInvalidInvokeAsync
-        {
-            public Task InvokeAsync(string value) => Task.FromResult(value);
-
-            public void InvokeAsync(int value)
-            {
-
-            }
-
-            public long InvokeAsync(string a, int b) => b;
-        }
-
-        private class TypeWithInvalidInvokeSync
-        {
-            public Task Invoke(string value) => Task.FromResult(value);
-
-            public void Invoke(int value)
-            {
-            }
-        }
-
-        private class MethodDataAttribute : Attribute
-        {
-            public MethodDataAttribute(string data)
-            {
-                Data = data;
-            }
-
-            public string Data { get; }
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/ViewViewComponentResultTest.cs

@@ -2,9 +2,11 @@
 // 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.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
@@ -147,9 +149,9 @@ namespace Microsoft.AspNet.Mvc
         {
             // Arrange
             var expected = string.Join(Environment.NewLine,
-                        "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
+                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
-                        "location1",
+                "location1",
-                        "location2");
+                "location2");
 
             var view = Mock.Of<IView>();
 
@@ -185,9 +187,9 @@ namespace Microsoft.AspNet.Mvc
         {
             // Arrange
             var expected = string.Join(Environment.NewLine,
-                        "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
+                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
-                        "location1",
+                "location1",
-                        "location2");
+                "location2");
 
             var view = Mock.Of<IView>();
 
@@ -223,11 +225,11 @@ namespace Microsoft.AspNet.Mvc
         {
             // Arrange
             var expected = string.Join(Environment.NewLine,
-                        "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
+                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
-                        "location1",
+                "location1",
-                        "location2",
+                "location2",
-                        "location3",
+                "location3",
-                        "location4");
+                "location4");
 
             var view = Mock.Of<IView>();
 
@@ -535,11 +537,12 @@ namespace Microsoft.AspNet.Mvc
             {
                 ShortName = "Invoke",
                 Type = typeof(object),
+                MethodInfo = typeof(object).GetTypeInfo().DeclaredMethods.First()
             };
 
             var viewComponentContext = new ViewComponentContext(
                 viewComponentDescriptor,
-                new object[0],
+                new Dictionary<string, object>(),
                 new HtmlTestEncoder(),
                 viewContext,
                 TextWriter.Null);

test/WebSites/BasicWebSite/Views/Home/JsonTextInView.cshtml

@@ -1 +1 @@
-@Component.Invoke("JsonTextInView")
+@await Component.InvokeAsync("JsonTextInView")

test/WebSites/BasicWebSite/Views/RequestScopedService/ViewComponent.cshtml

@@ -1 +1 @@
-@Component.Invoke("RequestId")
+@await Component.InvokeAsync("RequestId")

test/WebSites/RazorWebSite/Views/InheritingInherits/Index.cshtml

@@ -1,3 +1,3 @@
 @model Person
 <h1>@Model.Name</h1>
-@Component.Invoke("InheritingViewComponent", Model.Address)
+@await Component.InvokeAsync("InheritingViewComponent", new { address = Model.Address })

test/WebSites/RazorWebSite/Views/ViewEngine/ViewWithRelativePath.cshtml

@@ -12,4 +12,4 @@
 }
 ViewWithRelativePath-content
 <partial>@await Html.PartialAsync("../Shared/_PartialThatSetsTitle.cshtml")</partial>
-@await Component.InvokeAsync("ComponentWithRelativePath", person)
+@await Component.InvokeAsync("ComponentWithRelativePath", new { person })

test/WebSites/RazorWebSite/Views/ViewEngine/ViewWithTitle.cshtml

@@ -2,6 +2,6 @@
     ViewData["Title"] = "Page title";
     // The invoked partial sets a title, but this shouldn't override the current page's ViewData \ ViewBag.
     await Html.RenderPartialAsync("_PartialThatSetsTitle");
-    await Component.RenderInvokeAsync("ComponentThatSetsTitle");
+    @await Component.InvokeAsync("ComponentThatSetsTitle")
     Layout = "/Views/Shared/_LayoutWithTitle.cshtml";
 }

test/WebSites/RazorWebSite/Views/ViewWithPaths/Index.cshtml

@@ -1,6 +1,6 @@
 <Index>
     @ViewContext.ExecutingFilePath
     @ViewContext.View.Path
-    @Component.Invoke("ComponentForViewWithPaths")
+    @await Component.InvokeAsync("ComponentForViewWithPaths")
     @Html.Partial("_Partial")
 </Index>

test/WebSites/TagHelpersWebSite/TagHelpers/TagCloudViewComponentTagHelper.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.IO;
 using System.Linq;
 using System.Text.Encodings.Web;
@@ -58,7 +59,7 @@ namespace MvcSample.Web.Components
 
             await result.ExecuteAsync(new ViewComponentContext(
                 viewComponentDescriptor,
-                new object[0],
+                new Dictionary<string, object>(),
                 _htmlEncoder,
                 ViewContext,
                 writer));

test/WebSites/TagHelpersWebSite/Views/Home/Index.cshtml

@@ -35,7 +35,7 @@
     <h3>Current Tag Cloud from Tag Helper</h3>
     <tag-cloud count="Model.TagsToShow" surround="div" />
     <h3>Current Tag Cloud from ViewComponentHelper:</h3>
-    <section bold>@await Component.InvokeAsync("Tags", 15)</section>
+    <section bold>@await Component.InvokeAsync("Tags", new { count = 15 })</section>
     @{
         RenderTemplate(
             "Tag Cloud from Template: ",