escape quotes in event handler attribute content

src/Microsoft.AspNetCore.Blazor.Razor.Extensions/EventHandlerLoweringPass.cs

@@ -199,7 +199,7 @@ namespace Microsoft.AspNetCore.Blazor.Razor
                 // an expression.
                 var tokens = htmlContentNode.FindDescendantNodes<IntermediateToken>();
 
-                var content = "\"" + string.Join(string.Empty, tokens.Select(t => t.Content))+ "\"";
+                var content = "\"" + string.Join(string.Empty, tokens.Select(t => t.Content.Replace("\"", "\\\""))) + "\"";
                 return new[] { new IntermediateToken() { Content = content, Kind = TokenKind.CSharp, } };
             }
             else

test/Microsoft.AspNetCore.Blazor.Build.Test/CodeGenerationTestBase.cs

@@ -2443,6 +2443,20 @@ Welcome to your new app.
             CompileToAssembly(generated);
         }
 
+        [Fact]
+        public void EventHandlerTagHelper_EscapeQuotes()
+        {
+            // Act
+            var generated = CompileToCSharp(@"
+<input onfocus='alert(""Test"");' />
+");
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(generated.CodeDocument);
+            AssertCSharpDocumentMatchesBaseline(generated.CodeDocument);
+            CompileToAssembly(generated);
+        }
+
         #endregion
     }
 }

test/Microsoft.AspNetCore.Blazor.Build.Test/TestFiles/DesignTimeCodeGenerationTest/EventHandlerTagHelper_EscapeQuotes/TestComponent.codegen.cs

@@ -0,0 +1,30 @@
+// <auto-generated/>
+#pragma warning disable 1591
+namespace Test
+{
+    #line hidden
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Threading.Tasks;
+    using Microsoft.AspNetCore.Blazor;
+    using Microsoft.AspNetCore.Blazor.Components;
+    public class TestComponent : Microsoft.AspNetCore.Blazor.Components.BlazorComponent
+    {
+        #pragma warning disable 219
+        private void __RazorDirectiveTokenHelpers__() {
+        }
+        #pragma warning restore 219
+        #pragma warning disable 0414
+        private static System.Object __o = null;
+        #pragma warning restore 0414
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(Microsoft.AspNetCore.Blazor.RenderTree.RenderTreeBuilder builder)
+        {
+            base.BuildRenderTree(builder);
+            __o = Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIFocusEventArgs>("alert(\"Test\");");
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591

test/Microsoft.AspNetCore.Blazor.Build.Test/TestFiles/DesignTimeCodeGenerationTest/EventHandlerTagHelper_EscapeQuotes/TestComponent.ir.txt

@@ -0,0 +1,29 @@
+Document - 
+    NamespaceDeclaration -  - Test
+        UsingDirective - (3:1,1 [12] ) - System
+        UsingDirective - (18:2,1 [32] ) - System.Collections.Generic
+        UsingDirective - (53:3,1 [17] ) - System.Linq
+        UsingDirective - (73:4,1 [28] ) - System.Threading.Tasks
+        UsingDirective - (104:5,1 [33] ) - Microsoft.AspNetCore.Blazor
+        UsingDirective - (140:6,1 [44] ) - Microsoft.AspNetCore.Blazor.Components
+        ClassDeclaration -  - public - TestComponent - Microsoft.AspNetCore.Blazor.Components.BlazorComponent - 
+            DesignTimeDirective - 
+                DirectiveToken - (14:0,14 [32] ) - "*, Microsoft.AspNetCore.Blazor"
+                DirectiveToken - (14:0,14 [9] ) - "*, Test"
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning disable 0414
+            CSharpCode - 
+                IntermediateToken -  - CSharp - private static System.Object __o = null;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning restore 0414
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                CSharpCode - 
+                    IntermediateToken -  - CSharp - base.BuildRenderTree(builder);
+                HtmlElement - (0:0,0 [34] x:\dir\subdir\Test\TestComponent.cshtml) - input
+                    HtmlAttribute - (16:0,16 [14] x:\dir\subdir\Test\TestComponent.cshtml) - onfocus=" - "
+                        CSharpExpressionAttributeValue -  - 
+                            IntermediateToken -  - CSharp - Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIFocusEventArgs>(
+                            IntermediateToken -  - CSharp - "alert(\"Test\");"
+                            IntermediateToken -  - CSharp - )
+                HtmlContent - (34:0,34 [2] x:\dir\subdir\Test\TestComponent.cshtml)
+                    IntermediateToken - (34:0,34 [2] x:\dir\subdir\Test\TestComponent.cshtml) - Html - \n

test/Microsoft.AspNetCore.Blazor.Build.Test/TestFiles/RuntimeCodeGenerationTest/EventHandlerTagHelper_EscapeQuotes/TestComponent.codegen.cs

@@ -0,0 +1,25 @@
+// <auto-generated/>
+#pragma warning disable 1591
+namespace Test
+{
+    #line hidden
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Threading.Tasks;
+    using Microsoft.AspNetCore.Blazor;
+    using Microsoft.AspNetCore.Blazor.Components;
+    public class TestComponent : Microsoft.AspNetCore.Blazor.Components.BlazorComponent
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(Microsoft.AspNetCore.Blazor.RenderTree.RenderTreeBuilder builder)
+        {
+            base.BuildRenderTree(builder);
+            builder.OpenElement(0, "input");
+            builder.AddAttribute(1, "onfocus", Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIFocusEventArgs>("alert(\"Test\");"));
+            builder.CloseElement();
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591

test/Microsoft.AspNetCore.Blazor.Build.Test/TestFiles/RuntimeCodeGenerationTest/EventHandlerTagHelper_EscapeQuotes/TestComponent.ir.txt

@@ -0,0 +1,18 @@
+Document - 
+    NamespaceDeclaration -  - Test
+        UsingDirective - (3:1,1 [14] ) - System
+        UsingDirective - (18:2,1 [34] ) - System.Collections.Generic
+        UsingDirective - (53:3,1 [19] ) - System.Linq
+        UsingDirective - (73:4,1 [30] ) - System.Threading.Tasks
+        UsingDirective - (104:5,1 [35] ) - Microsoft.AspNetCore.Blazor
+        UsingDirective - (140:6,1 [46] ) - Microsoft.AspNetCore.Blazor.Components
+        ClassDeclaration -  - public - TestComponent - Microsoft.AspNetCore.Blazor.Components.BlazorComponent - 
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                CSharpCode - 
+                    IntermediateToken -  - CSharp - base.BuildRenderTree(builder);
+                HtmlElement - (0:0,0 [34] x:\dir\subdir\Test\TestComponent.cshtml) - input
+                    HtmlAttribute - (16:0,16 [14] x:\dir\subdir\Test\TestComponent.cshtml) - onfocus=" - "
+                        CSharpExpressionAttributeValue -  - 
+                            IntermediateToken -  - CSharp - Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIFocusEventArgs>(
+                            IntermediateToken -  - CSharp - "alert(\"Test\");"
+                            IntermediateToken -  - CSharp - )