In RazorCompiler, support attribute values of type UIEventHandler

src/Microsoft.Blazor/RenderTree/UIEventHandler.cs

@@ -6,5 +6,5 @@ namespace Microsoft.Blazor.RenderTree
     /// <summary>
     /// Handles an event raised for a <see cref="RenderTreeNode"/>.
     /// </summary>
-    public delegate void UIEventHandler(UIEventArgs eventInfo);
+    public delegate void UIEventHandler(UIEventArgs eventArgs);
 }

test/Microsoft.Blazor.Build.Test/RazorCompilerTest.cs

@@ -179,7 +179,7 @@ namespace Microsoft.Blazor.Build.Test
                 + "<elem attr=@myValue />");
 
             // Assert
-            Assert.Collection(GetRenderTree(component).Where(NotWhitespace),
+            Assert.Collection(GetRenderTree(component),
                 node => AssertNode.Element(node, "elem", 1),
                 node => AssertNode.Attribute(node, "attr", "My string"));
         }
@@ -193,7 +193,7 @@ namespace Microsoft.Blazor.Build.Test
                 + "<elem attr=@myValue />");
 
             // Assert
-            Assert.Collection(GetRenderTree(component).Where(NotWhitespace),
+            Assert.Collection(GetRenderTree(component),
                 node => AssertNode.Element(node, "elem", 1),
                 node => AssertNode.Attribute(node, "attr", "123"));
         }
@@ -207,11 +207,31 @@ namespace Microsoft.Blazor.Build.Test
                 + "<elem attr=\"Hello, @myValue.ToUpperInvariant()    with number @(myNum*2)!\" />");
 
             // Assert
-            Assert.Collection(GetRenderTree(component).Where(NotWhitespace),
+            Assert.Collection(GetRenderTree(component),
                 node => AssertNode.Element(node, "elem", 1),
                 node => AssertNode.Attribute(node, "attr", "Hello, WORLD    with number 246!"));
         }
 
+        [Fact]
+        public void SupportsAttributesWithEventHandlerValues()
+        {
+            // Arrange/Act
+            var component = CompileToComponent(
+                "<elem attr=@MyHandleEvent />"
+                + @"@functions {
+                        void MyHandleEvent(Microsoft.Blazor.RenderTree.UIEventArgs eventArgs) {}
+                    }");
+
+            // Assert
+            Assert.Collection(GetRenderTree(component),
+                node => AssertNode.Element(node, "elem", 1),
+                node =>
+                {
+                    Assert.Equal(RenderTreeNodeType.Attribute, node.NodeType);
+                    Assert.NotNull(node.AttributeEventHandlerValue);
+                });
+        }
+
         private static bool NotWhitespace(RenderTreeNode node)
             => node.NodeType != RenderTreeNodeType.Text
             || !string.IsNullOrWhiteSpace(node.TextContent);

test/testapps/BasicTestApp/CounterComponent.cs

@@ -1,35 +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 Microsoft.Blazor.Components;
-using Microsoft.Blazor.RenderTree;
-
-namespace BasicTestApp
-{
-    public class CounterComponent : IComponent
-    {
-        private int currentCount = 0;
-
-        public void BuildRenderTree(RenderTreeBuilder builder)
-        {
-            builder.OpenElement("h1");
-            builder.AddText("Counter");
-            builder.CloseElement();
-
-            builder.OpenElement("p");
-            builder.AddText("Current count: ");
-            builder.AddText(currentCount.ToString());
-            builder.CloseElement();
-
-            builder.OpenElement("button");
-            builder.AddAttribute("onclick", OnButtonClicked);
-            builder.AddText("Click me");
-            builder.CloseElement();
-        }
-
-        private void OnButtonClicked(UIEventArgs eventInfo)
-        {
-            currentCount++;
-        }
-    }
-}

test/testapps/BasicTestApp/CounterComponent.cshtml

@@ -0,0 +1,12 @@
+<h1>Counter</h1>
+<p>Current count: @currentCount.ToString()</p>
+<button onclick=@OnButtonClicked>Click me</button>
+
+@functions {
+    int currentCount = 0;
+
+    void OnButtonClicked(Microsoft.Blazor.RenderTree.UIEventArgs eventArgs)
+    {
+        currentCount++;
+    }
+}