Add missing `RenderPartial(...)` overload

- #7127
- also remove some redundant `null` checks

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Rendering/HtmlHelperPartialExtensions.cs

@@ -115,20 +115,8 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
         /// This method synchronously calls and blocks on
         /// <see cref="IHtmlHelper.PartialAsync(string, object, ViewDataDictionary)"/>
         /// </remarks>
-        public static IHtmlContent Partial(
+        public static IHtmlContent Partial(this IHtmlHelper htmlHelper, string partialViewName)
-            this IHtmlHelper htmlHelper,
-            string partialViewName)
         {
-            if (htmlHelper == null)
-            {
-                throw new ArgumentNullException(nameof(htmlHelper));
-            }
-
-            if (partialViewName == null)
-            {
-                throw new ArgumentNullException(nameof(partialViewName));
-            }
-
             return Partial(htmlHelper, partialViewName, htmlHelper.ViewData.Model, viewData: null);
         }
 
@@ -152,16 +140,6 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
             string partialViewName,
             ViewDataDictionary viewData)
         {
-            if (htmlHelper == null)
-            {
-                throw new ArgumentNullException(nameof(htmlHelper));
-            }
-
-            if (partialViewName == null)
-            {
-                throw new ArgumentNullException(nameof(partialViewName));
-            }
-
             return Partial(htmlHelper, partialViewName, htmlHelper.ViewData.Model, viewData);
         }
 
@@ -180,21 +158,8 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
         /// This method synchronously calls and blocks on
         /// <see cref="IHtmlHelper.PartialAsync(string, object, ViewDataDictionary)"/>
         /// </remarks>
-        public static IHtmlContent Partial(
+        public static IHtmlContent Partial(this IHtmlHelper htmlHelper, string partialViewName, object model)
-            this IHtmlHelper htmlHelper,
-            string partialViewName,
-            object model)
         {
-            if (htmlHelper == null)
-            {
-                throw new ArgumentNullException(nameof(htmlHelper));
-            }
-
-            if (partialViewName == null)
-            {
-                throw new ArgumentNullException(nameof(partialViewName));
-            }
-
             return Partial(htmlHelper, partialViewName, model, viewData: null);
         }
 
@@ -244,22 +209,9 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
         /// <remarks>
         /// In this context, "renders" means the method writes its output using <see cref="ViewContext.Writer"/>.
         /// </remarks>
-        public static void RenderPartial(
+        public static void RenderPartial(this IHtmlHelper htmlHelper, string partialViewName)
-            this IHtmlHelper htmlHelper,
-            string partialViewName)
         {
-            if (htmlHelper == null)
+            RenderPartial(htmlHelper, partialViewName, htmlHelper.ViewData.Model, viewData: null);
-            {
-                throw new ArgumentNullException(nameof(htmlHelper));
-            }
-
-            if (partialViewName == null)
-            {
-                throw new ArgumentNullException(nameof(partialViewName));
-            }
-
-            var result = htmlHelper.RenderPartialAsync(partialViewName, htmlHelper.ViewData.Model, viewData: null);
-            result.GetAwaiter().GetResult();
         }
 
         /// <summary>
@@ -278,18 +230,7 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
             string partialViewName,
             ViewDataDictionary viewData)
         {
-            if (htmlHelper == null)
+            RenderPartial(htmlHelper, partialViewName, htmlHelper.ViewData.Model, viewData);
-            {
-                throw new ArgumentNullException(nameof(htmlHelper));
-            }
-
-            if (partialViewName == null)
-            {
-                throw new ArgumentNullException(nameof(partialViewName));
-            }
-
-            var result = htmlHelper.RenderPartialAsync(partialViewName, htmlHelper.ViewData.Model, viewData);
-            result.GetAwaiter().GetResult();
         }
 
         /// <summary>
@@ -303,10 +244,28 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
         /// <remarks>
         /// In this context, "renders" means the method writes its output using <see cref="ViewContext.Writer"/>.
         /// </remarks>
+        public static void RenderPartial(this IHtmlHelper htmlHelper, string partialViewName, object model)
+        {
+            RenderPartial(htmlHelper, partialViewName, model, viewData: null);
+        }
+
+        /// <summary>
+        /// Renders HTML markup for the specified partial view.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="IHtmlHelper"/> instance this method extends.</param>
+        /// <param name="partialViewName">
+        /// The name or path of the partial view used to create the HTML markup. Must not be <c>null</c>.
+        /// </param>
+        /// <param name="model">A model to pass into the partial view.</param>
+        /// <param name="viewData">A <see cref="ViewDataDictionary"/> to pass into the partial view.</param>
+        /// <remarks>
+        /// In this context, "renders" means the method writes its output using <see cref="ViewContext.Writer"/>.
+        /// </remarks>
         public static void RenderPartial(
             this IHtmlHelper htmlHelper,
             string partialViewName,
-            object model)
+            object model,
+            ViewDataDictionary viewData)
         {
             if (htmlHelper == null)
             {
@@ -318,7 +277,7 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
                 throw new ArgumentNullException(nameof(partialViewName));
             }
 
-            var result = htmlHelper.RenderPartialAsync(partialViewName, model, viewData: null);
+            var result = htmlHelper.RenderPartialAsync(partialViewName, model, viewData);
             result.GetAwaiter().GetResult();
         }
 

test/Microsoft.AspNetCore.Mvc.ViewFeatures.Test/Rendering/HtmlHelperPartialExtensionsTest.cs

@@ -152,6 +152,7 @@ namespace Microsoft.AspNetCore.Mvc.Rendering
                     { helper => helper.RenderPartial("test"), null, null },
                     { helper => helper.RenderPartial("test", model), model, null },
                     { helper => helper.RenderPartial("test", viewData), null, viewData },
+                    { helper => helper.RenderPartial("test", model, viewData), model, viewData },
                 };
             }
         }