Added TagHelperContext.UniqueId:

- The ID is created at view compilation time and is unique per TagHelperExecutionContext and thus per HTML element in the source for which Tag Helpers will run
- #241

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

@@ -14,14 +14,21 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         /// Instantiates a new <see cref="TagHelperContext"/>.
         /// </summary>
         /// <param name="allAttributes">Every attribute associated with the current HTML element.</param>
-        public TagHelperContext([NotNull] IDictionary<string, object> allAttributes)
+        /// <param name="uniqueId">The unique identifier for the source element this <see cref="TagHelperContext" /> applies to.</param>
+        public TagHelperContext([NotNull] IDictionary<string, object> allAttributes, [NotNull] string uniqueId)
         {
             AllAttributes = allAttributes;
+            UniqueId = uniqueId;
         }
 
         /// <summary>
         /// Every attribute associated with the current HTML element.
         /// </summary>
         public IDictionary<string, object> AllAttributes { get; private set; }
+
+        /// <summary>
+        /// An identifier unique to the HTML element this context is for.
+        /// </summary>
+        public string UniqueId { get; private set; }
     }
 }

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

@@ -17,12 +17,22 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         /// Instantiates a new <see cref="TagHelperExecutionContext"/>.
         /// </summary>
         /// <param name="tagName">The HTML tag name in the Razor source.</param>
-        public TagHelperExecutionContext([NotNull] string tagName)
+        public TagHelperExecutionContext([NotNull] string tagName, [NotNull] string uniqueId)
         {
             AllAttributes = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
             HTMLAttributes = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             _tagHelpers = new List<ITagHelper>();
             TagName = tagName;
+            UniqueId = uniqueId;
+        }
+
+        /// <summary>
+        /// Internal for testing purposes only.
+        /// </summary>
+        internal TagHelperExecutionContext([NotNull] string tagName)
+            : this(tagName, string.Empty)
+        {
+
         }
 
         /// <summary>
@@ -35,6 +45,11 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         /// </summary>
         public IDictionary<string, object> AllAttributes { get; private set; }
 
+        /// <summary>
+        /// An identifier unique to the HTML element this context is for.
+        /// </summary>
+        public string UniqueId { get; private set; }
+
         /// <summary>
         /// <see cref="ITagHelper"/>s that should be run.
         /// </summary>

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

@@ -37,7 +37,7 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
 
         private async Task<TagHelperOutput> RunAsyncCore(TagHelperExecutionContext executionContext, string outputContent)
         {
-            var tagHelperContext = new TagHelperContext(executionContext.AllAttributes);
+            var tagHelperContext = new TagHelperContext(executionContext.AllAttributes, executionContext.UniqueId);
             var tagHelperOutput = new TagHelperOutput(executionContext.TagName,
                                                       executionContext.HTMLAttributes,
                                                       outputContent);

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

@@ -25,10 +25,11 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         /// Starts a <see cref="TagHelperExecutionContext"/> scope.
         /// </summary>
         /// <param name="tagName">The HTML tag name that the scope is associated with.</param>
+        /// <param name="uniqueId">An identifier unique to the HTML element this scope is for.</param>
         /// <returns>A <see cref="TagHelperExecutionContext"/> to use.</returns>
-        public TagHelperExecutionContext Begin(string tagName)
+        public TagHelperExecutionContext Begin(string tagName, string uniqueId)
         {
-            var executionContext = new TagHelperExecutionContext(tagName);
+            var executionContext = new TagHelperExecutionContext(tagName, uniqueId);
 
             _executionScopes.Push(executionContext);
 

src/Microsoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/CSharpTagHelperCodeRenderer.cs

@@ -135,10 +135,26 @@ namespace Microsoft.AspNet.Razor.Generator.Compiler.CSharp
             _writer.WriteStartAssignment(ExecutionContextVariableName)
                    .WriteStartInstanceMethodInvocation(ScopeManagerVariableName,
                                                        _tagHelperContext.ScopeManagerBeginMethodName);
+
+            // Assign a unique ID for this instance of the source HTML tag. This must be unique
+            // per call site, e.g. if the tag is on the view twice, there should be two IDs.
             _writer.WriteStringLiteral(tagName)
+                   .WriteParameterSeparator()
+                   .WriteStringLiteral(GenerateUniqueId())
                    .WriteEndMethodInvocation();
         }
 
+        /// <summary>
+        /// Generates a unique ID for an HTML element.
+        /// </summary>
+        /// <returns>
+        /// A globally unique ID.
+        /// </returns>
+        protected virtual string GenerateUniqueId()
+        {
+            return Guid.NewGuid().ToString("N");
+        }
+
         private void RenderTagHelpersCreation(TagHelperChunk chunk)
         {
             var tagHelperDescriptors = chunk.Descriptors;

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

@@ -16,7 +16,7 @@ namespace Microsoft.AspNet.Razor.Runtime.Test.TagHelpers
             var scopeManager = new TagHelperScopeManager();
 
             // Act
-            var executionContext = scopeManager.Begin("p");
+            var executionContext = scopeManager.Begin("p", string.Empty);
 
             // Assert
             Assert.Equal("p", executionContext.TagName);
@@ -29,8 +29,8 @@ namespace Microsoft.AspNet.Razor.Runtime.Test.TagHelpers
             var scopeManager = new TagHelperScopeManager();
 
             // Act
-            var executionContext = scopeManager.Begin("p");
+            var executionContext = scopeManager.Begin("p", string.Empty);
-            executionContext = scopeManager.Begin("div");
+            executionContext = scopeManager.Begin("div", string.Empty);
 
             // Assert
             Assert.Equal("div", executionContext.TagName);
@@ -43,8 +43,8 @@ namespace Microsoft.AspNet.Razor.Runtime.Test.TagHelpers
             var scopeManager = new TagHelperScopeManager();
 
             // Act
-            var executionContext = scopeManager.Begin("p");
+            var executionContext = scopeManager.Begin("p", string.Empty);
-            executionContext = scopeManager.Begin("div");
+            executionContext = scopeManager.Begin("div", string.Empty);
             executionContext = scopeManager.End();
 
             // Assert
@@ -58,8 +58,8 @@ namespace Microsoft.AspNet.Razor.Runtime.Test.TagHelpers
             var scopeManager = new TagHelperScopeManager();
 
             // Act
-            var executionContext = scopeManager.Begin("p");
+            var executionContext = scopeManager.Begin("p", string.Empty);
-            executionContext = scopeManager.Begin("div");
+            executionContext = scopeManager.Begin("div", string.Empty);
             executionContext = scopeManager.End();
             executionContext = scopeManager.End();
 

test/Microsoft.AspNet.Razor.Test/Generator/CSharpTagHelperRenderingUnitTest.cs

@@ -0,0 +1,187 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.AspNet.Razor.Generator;
+using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
+using Microsoft.AspNet.Razor.TagHelpers;
+using Xunit;
+
+namespace Microsoft.AspNet.Razor.Test.Generator
+{
+    public class CSharpTagHelperRenderingUnitTest
+    {
+        [Fact]
+        public void CreatesAUniqueIdForSingleTagHelperChunk()
+        {
+            // Arrange
+            var chunk = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(chunk);
+
+            // Assert
+            Assert.Equal(1, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        [Fact]
+        public void UsesTheSameUniqueIdForTagHelperChunkWithMultipleTagHelpers()
+        {
+            // Arrange
+            var chunk = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None),
+                new TagHelperDescriptor("div", "Div2TagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(chunk);
+
+            // Assert
+            Assert.Equal(1, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        [Fact]
+        public void UsesDifferentUniqueIdForMultipleTagHelperChunksForSameTagHelper()
+        {
+            // Arrange
+            var chunk1 = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var chunk2 = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(chunk1);
+            codeRenderer.RenderTagHelper(chunk2);
+
+            // Assert
+            Assert.Equal(2, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        [Fact]
+        public void UsesDifferentUniqueIdForNestedTagHelperChunksForSameTagHelper()
+        {
+            // Arrange
+            var parentChunk = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var childChunk = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            parentChunk.Children.Add(childChunk);
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(parentChunk);
+
+            // Assert
+            Assert.Equal(2, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        [Fact]
+        public void UsesDifferentUniqueIdForMultipleTagHelperChunksForDifferentTagHelpers()
+        {
+            // Arrange
+            var divChunk = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var spanChunk = CreateTagHelperChunk("span", new[] {
+                new TagHelperDescriptor("span", "SpanTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(divChunk);
+            codeRenderer.RenderTagHelper(spanChunk);
+
+            // Assert
+            Assert.Equal(2, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        [Fact]
+        public void UsesCorrectUniqueIdForMultipleTagHelperChunksSomeWithSameSameTagHelpersSomeWithDifferentTagHelpers()
+        {
+            // Arrange
+            var chunk1 = CreateTagHelperChunk("div", new[] {
+                new TagHelperDescriptor("div", "DivTagHelper", "FakeAssemblyName", ContentBehavior.None),
+                new TagHelperDescriptor("div", "Div2TagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var chunk2 = CreateTagHelperChunk("span", new[] {
+                new TagHelperDescriptor("span", "SpanTagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var chunk3 = CreateTagHelperChunk("span", new[] {
+                new TagHelperDescriptor("span", "SpanTagHelper", "FakeAssemblyName", ContentBehavior.None),
+                new TagHelperDescriptor("span", "Span2TagHelper", "FakeAssemblyName", ContentBehavior.None)
+            });
+            var codeRenderer = CreateCodeRenderer();
+
+            // Act
+            codeRenderer.RenderTagHelper(chunk1);
+            codeRenderer.RenderTagHelper(chunk2);
+            codeRenderer.RenderTagHelper(chunk3);
+
+            // Assert
+            Assert.Equal(3, codeRenderer.GenerateUniqueIdCount);
+        }
+
+        private static TagHelperChunk CreateTagHelperChunk(string tagName, IEnumerable<TagHelperDescriptor> tagHelperDescriptors)
+        {
+            return new TagHelperChunk
+            {
+                TagName = tagName,
+                Descriptors = tagHelperDescriptors,
+                Children = new List<Chunk>(),
+                Attributes = new Dictionary<string, Chunk>()
+            };
+        }
+
+        private static TrackingUniqueIdsTagHelperCodeRenderer CreateCodeRenderer()
+        {
+            var writer = new CSharpCodeWriter();
+            var codeBuilderContext = CreateContext();
+            var visitor = new CSharpCodeVisitor(writer, codeBuilderContext);
+            var codeRenderer = new TrackingUniqueIdsTagHelperCodeRenderer(
+                visitor,
+                writer,
+                codeBuilderContext);
+            visitor.TagHelperRenderer = codeRenderer;
+            return codeRenderer;
+        }
+
+        private static CodeBuilderContext CreateContext()
+        {
+            return new CodeBuilderContext(
+                new CodeGeneratorContext(
+                    new RazorEngineHost(new CSharpRazorCodeLanguage()),
+                    "MyClass",
+                    "MyNamespace",
+                    string.Empty,
+                    shouldGenerateLinePragmas: true));
+        }
+
+        private class TrackingUniqueIdsTagHelperCodeRenderer : CSharpTagHelperCodeRenderer
+        {
+            public TrackingUniqueIdsTagHelperCodeRenderer(
+                IChunkVisitor bodyVisitor,
+                CSharpCodeWriter writer,
+                CodeBuilderContext context)
+                : base(bodyVisitor, writer, context)
+            {
+
+            }
+
+            protected override string GenerateUniqueId()
+            {
+                GenerateUniqueIdCount++;
+                return "test";
+            }
+
+            public int GenerateUniqueIdCount { get; private set; }
+        }
+    }
+}

test/Microsoft.AspNet.Razor.Test/Generator/TagHelperAttributeValueCodeRendererTest.cs

@@ -65,7 +65,7 @@ namespace Microsoft.AspNet.Razor.Test.Generator
             }
         }
 
-        private class AttributeCodeGeneratorReplacingCodeBuilder : CSharpCodeBuilder
+        private class AttributeCodeGeneratorReplacingCodeBuilder : TestCSharpCodeBuilder
         {
             public AttributeCodeGeneratorReplacingCodeBuilder(CodeBuilderContext context)
                 : base(context)

test/Microsoft.AspNet.Razor.Test/Generator/TagHelperTestBase.cs

@@ -5,7 +5,9 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
 using Microsoft.AspNet.Razor.Parser;
 using Microsoft.AspNet.Razor.TagHelpers;
 using Xunit;
@@ -78,6 +80,11 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                 _tagHelperDescriptors = tagHelperDescriptors;
             }
 
+            protected internal override CodeBuilder CreateCodeBuilder(CodeBuilderContext context)
+            {
+                return Host.DecorateCodeBuilder(new TestCSharpCodeBuilder(context), context);
+            }
+
             protected internal override RazorParser CreateParser(string fileName)
             {
                 var parser = base.CreateParser(fileName);
@@ -87,5 +94,37 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                                        new CustomTagHelperDescriptorResolver(_tagHelperDescriptors));
             }
         }
+
+        protected class TestCSharpCodeBuilder : CSharpCodeBuilder
+        {
+            public TestCSharpCodeBuilder(CodeBuilderContext context)
+                : base(context)
+            {
+
+            }
+
+            protected override CSharpCodeVisitor CreateCSharpCodeVisitor(CSharpCodeWriter writer, CodeBuilderContext context)
+            {
+                var visitor = base.CreateCSharpCodeVisitor(writer, context);
+                visitor.TagHelperRenderer = new NoUniqueIdsTagHelperCodeRenderer(visitor, writer, context);
+                return visitor;
+            }
+
+            private class NoUniqueIdsTagHelperCodeRenderer : CSharpTagHelperCodeRenderer
+            {
+                public NoUniqueIdsTagHelperCodeRenderer(IChunkVisitor bodyVisitor,
+                                                        CSharpCodeWriter writer,
+                                                        CodeBuilderContext context)
+                    : base(bodyVisitor, writer, context)
+                {
+
+                }
+
+                protected override string GenerateUniqueId()
+                {
+                    return "test";
+                }
+            }
+        }
     }
 }

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/BasicTagHelpers.CustomAttributeCodeGenerator.cs

@@ -25,7 +25,7 @@ namespace TestOutput
             Instrumentation.BeginContext(27, 49, true);
             WriteLiteral("\r\n<div class=\"randomNonTagHelperAttribute\">\r\n    ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.AddHtmlAttribute("class", "Hello World");
@@ -34,7 +34,7 @@ namespace TestOutput
             Instrumentation.BeginContext(99, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
@@ -44,7 +44,7 @@ namespace TestOutput
             Instrumentation.BeginContext(116, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             __InputTagHelper.Type = **From custom attribute code renderer**: "text";
@@ -59,7 +59,7 @@ namespace TestOutput
             Instrumentation.BeginContext(147, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             __InputTagHelper.Type = **From custom attribute code renderer**: "checkbox";

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/BasicTagHelpers.cs

@@ -26,7 +26,7 @@ namespace TestOutput
             Instrumentation.BeginContext(27, 49, true);
             WriteLiteral("\r\n<div class=\"randomNonTagHelperAttribute\">\r\n    ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.AddHtmlAttribute("class", "Hello World");
@@ -35,7 +35,7 @@ namespace TestOutput
             Instrumentation.BeginContext(99, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
@@ -45,7 +45,7 @@ namespace TestOutput
             Instrumentation.BeginContext(116, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             __InputTagHelper.Type = "text";
@@ -60,7 +60,7 @@ namespace TestOutput
             Instrumentation.BeginContext(147, 10, true);
             WriteLiteral("\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             __InputTagHelper.Type = "checkbox";

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/ComplexTagHelpers.cs

@@ -38,7 +38,7 @@ namespace TestOutput
             Instrumentation.BeginContext(78, 55, true);
             WriteLiteral("    <div class=\"randomNonTagHelperAttribute\">\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             StartWritingScope();
@@ -71,7 +71,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(245, 16, true);
             WriteLiteral("                ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
@@ -79,7 +79,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(264, 10, true);
             WriteLiteral("New Time: ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             __InputTagHelper.Type = "text";
@@ -109,7 +109,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(394, 16, true);
             WriteLiteral("                ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
@@ -117,7 +117,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(413, 14, true);
             WriteLiteral("Current Time: ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             StartWritingScope();
@@ -143,7 +143,7 @@ Write(checkbox);
             Instrumentation.BeginContext(468, 18, true);
             WriteLiteral("\r\n                ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             StartWritingScope();
@@ -165,7 +165,7 @@ Write(true ? "checkbox" : "anything");
             Instrumentation.BeginContext(536, 18, true);
             WriteLiteral("\r\n                ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input", "test");
             __InputTagHelper = CreateTagHelper<InputTagHelper>();
             __tagHelperExecutionContext.Add(__InputTagHelper);
             StartWritingScope();

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/ContentBehaviorTagHelpers.cs

@@ -28,31 +28,31 @@ namespace TestOutput
             Instrumentation.BeginContext(27, 2, true);
             WriteLiteral("\r\n");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("modify");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("modify", "test");
             __ModifyTagHelper = CreateTagHelper<ModifyTagHelper>();
             __tagHelperExecutionContext.Add(__ModifyTagHelper);
             StartWritingScope();
             WriteLiteral("\r\n    ");
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("none");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("none", "test");
             __NoneTagHelper = CreateTagHelper<NoneTagHelper>();
             __tagHelperExecutionContext.Add(__NoneTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
             WriteLiteral(__tagHelperExecutionContext.Output.GenerateStartTag());
             WriteLiteral("\r\n        ");
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("append");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("append", "test");
             __AppendTagHelper = CreateTagHelper<AppendTagHelper>();
             __tagHelperExecutionContext.Add(__AppendTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
             WriteLiteral(__tagHelperExecutionContext.Output.GenerateStartTag());
             WriteLiteral("\r\n            ");
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("prepend");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("prepend", "test");
             __PrependTagHelper = CreateTagHelper<PrependTagHelper>();
             __tagHelperExecutionContext.Add(__PrependTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
             WriteLiteral(__tagHelperExecutionContext.Output.GenerateStartTag());
             WriteLiteral(__tagHelperExecutionContext.Output.GenerateContent());
             WriteLiteral("\r\n                ");
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("replace");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("replace", "test");
             __ReplaceTagHelper = CreateTagHelper<ReplaceTagHelper>();
             __tagHelperExecutionContext.Add(__ReplaceTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/SingleTagHelper.cs

@@ -24,7 +24,7 @@ namespace TestOutput
             Instrumentation.BeginContext(27, 2, true);
             WriteLiteral("\r\n");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", "test");
             __PTagHelper = CreateTagHelper<PTagHelper>();
             __tagHelperExecutionContext.Add(__PTagHelper);
             __PTagHelper.Age = 1337;

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/TagHelpersInHelper.cs

@@ -24,7 +24,7 @@ MyHelper(string val)
             Instrumentation.BeginContext(62, 19, true);
             WriteLiteralTo(__razor_helper_writer, "    <div>\r\n        ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper", "test");
             __MyTagHelper = CreateTagHelper<MyTagHelper>();
             __tagHelperExecutionContext.Add(__MyTagHelper);
             StartWritingScope();
@@ -51,7 +51,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(184, 52, true);
             WriteLiteralTo(__razor_helper_writer, "\r\n            In None ContentBehavior.\r\n            ");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper", "test");
             __NestedTagHelper = CreateTagHelper<NestedTagHelper>();
             __tagHelperExecutionContext.Add(__NestedTagHelper);
             StartWritingScope();
@@ -106,7 +106,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(27, 2, true);
             WriteLiteral("\r\n");
             Instrumentation.EndContext();
-            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper");
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper", "test");
             __MyTagHelper = CreateTagHelper<MyTagHelper>();
             __tagHelperExecutionContext.Add(__MyTagHelper);
             __tagHelperExecutionContext.Output = __tagHelperRunner.RunAsync(__tagHelperExecutionContext).Result;
@@ -114,7 +114,7 @@ Write(DateTime.Now);
             Instrumentation.BeginContext(367, 9, false);
 #line 12 "TagHelpersInHelper.cshtml"
 Write(MyHelper(item => new Template((__razor_template_writer) => {
-    __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper");
+    __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper", "test");
     __NestedTagHelper = CreateTagHelper<NestedTagHelper>();
     __tagHelperExecutionContext.Add(__NestedTagHelper);
     StartWritingScope();

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/TagHelpersInSection.cs

@@ -38,7 +38,7 @@ namespace TestOutput
                 Instrumentation.BeginContext(87, 21, true);
                 WriteLiteralTo(__razor_template_writer, "\r\n    <div>\r\n        ");
                 Instrumentation.EndContext();
-                __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper");
+                __tagHelperExecutionContext = __tagHelperScopeManager.Begin("mytaghelper", "test");
                 __MyTagHelper = CreateTagHelper<MyTagHelper>();
                 __tagHelperExecutionContext.Add(__MyTagHelper);
                 StartWritingScope();
@@ -65,7 +65,7 @@ Write(DateTime.Now);
                 Instrumentation.BeginContext(211, 52, true);
                 WriteLiteralTo(__razor_template_writer, "\r\n            In None ContentBehavior.\r\n            ");
                 Instrumentation.EndContext();
-                __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper");
+                __tagHelperExecutionContext = __tagHelperScopeManager.Begin("nestedtaghelper", "test");
                 __NestedTagHelper = CreateTagHelper<NestedTagHelper>();
                 __tagHelperExecutionContext.Add(__NestedTagHelper);
                 StartWritingScope();