Rewrite of code rendering context

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/CodeRenderingContext.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 Microsoft.AspNetCore.Razor.Language.Intermediate;
 
 namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 {
@@ -10,91 +11,49 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         internal static readonly object NewLineString = "NewLineString";
         internal static readonly object SuppressUniqueIds = "SuppressUniqueIds";
 
-        public static CodeRenderingContext Create(RazorCodeDocument codeDocument, RazorCodeGenerationOptions options)
-        {
-            if (codeDocument == null)
-            {
-                throw new ArgumentNullException(nameof(codeDocument));
-            }
-
-            if (options == null)
-            {
-                throw new ArgumentNullException(nameof(options));
-            }
-
-            IntermediateNodeWriter nodeWriter;
-            TagHelperWriter tagHelperWriter;
-
-            if (options.DesignTime)
-            {
-                nodeWriter = new DesignTimeNodeWriter();
-                tagHelperWriter = new DesignTimeTagHelperWriter();
-            }
-            else
-            {
-                nodeWriter = new RuntimeNodeWriter();
-                tagHelperWriter = new RuntimeTagHelperWriter();
-            }
-
-            var documentKind = codeDocument.GetDocumentIntermediateNode()?.DocumentKind;
-            var codeWriter = new CodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, documentKind, codeDocument.Source, options)
-            {
-                TagHelperWriter = tagHelperWriter
-            };
-
-            var newLineString = codeDocument.Items[NewLineString];
-            if (newLineString != null)
-            {
-                // Set new line character to a specific string regardless of platform, for testing purposes.
-                codeWriter.NewLine = (string)newLineString;
-            }
-
-            context.Items[SuppressUniqueIds] = codeDocument.Items[SuppressUniqueIds];
-
-            return context;
-        }
-
         public abstract CodeWriter CodeWriter { get; }
 
-        public abstract IntermediateNodeWriter NodeWriter { get; protected set; }
-
-        public abstract RazorSourceDocument SourceDocument { get; }
-
-        public abstract RazorCodeGenerationOptions Options { get; }
-
         public abstract RazorDiagnosticCollection Diagnostics { get; }
 
-        public abstract ItemCollection Items { get; }
-
         public abstract string DocumentKind { get; }
 
-        public abstract IntermediateNodeWriterScope Push(IntermediateNodeWriter writer);
+        public abstract ItemCollection Items { get; }
 
-        public struct IntermediateNodeWriterScope : IDisposable
+        public abstract IntermediateNodeWriter NodeWriter { get; }
+
+        public abstract RazorCodeGenerationOptions Options { get; }
+
+        public abstract RazorSourceDocument SourceDocument { get; }
+
+        public abstract Scope CreateScope();
+
+        public abstract Scope CreateScope(IntermediateNodeWriter writer);
+
+        public abstract void EndScope();
+
+        public abstract void RenderNode(IntermediateNode node);
+
+        public abstract void RenderChildren(IntermediateNode node);
+
+        public abstract void AddLineMappingFor(IntermediateNode node);
+
+        public struct Scope : IDisposable
         {
             private readonly CodeRenderingContext _context;
-            private readonly IntermediateNodeWriter _writer;
 
-            public IntermediateNodeWriterScope(CodeRenderingContext context, IntermediateNodeWriter writer)
+            public Scope(CodeRenderingContext context)
             {
                 if (context == null)
                 {
                     throw new ArgumentNullException(nameof(context));
                 }
 
-                if (writer == null)
-                {
-                    throw new ArgumentNullException(nameof(writer));
-                }
-
                 _context = context;
-                _writer = writer;
             }
 
             public void Dispose()
             {
-                _context.NodeWriter = _writer;
+                _context.EndScope();
             }
         }
 
@@ -102,22 +61,9 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         // All bits below here are temporary
 
         #region Temporary TagHelper bits
-        internal TagHelperWriter TagHelperWriter { get; set; }
 
         internal TagHelperRenderingContext TagHelperRenderingContext { get; set; }
 
-        internal TagHelperWriterScope Push(TagHelperWriter writer)
-        {
-            if (writer == null)
-            {
-                throw new ArgumentNullException(nameof(writer));
-            }
-
-            var scope = new TagHelperWriterScope(this, TagHelperWriter);
-            TagHelperWriter = writer;
-            return scope;
-        }
-
         internal TagHelperRenderingContextScope Push(TagHelperRenderingContext context)
         {
             if (context == null)
@@ -130,33 +76,6 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             return scope;
         }
 
-        internal struct TagHelperWriterScope : IDisposable
-        {
-            private readonly CodeRenderingContext _context;
-            private readonly TagHelperWriter _writer;
-
-            public TagHelperWriterScope(CodeRenderingContext context, TagHelperWriter writer)
-            {
-                if (context == null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
-                if (writer == null)
-                {
-                    throw new ArgumentNullException(nameof(writer));
-                }
-
-                _context = context;
-                _writer = writer;
-            }
-
-            public void Dispose()
-            {
-                _context.TagHelperWriter = _writer;
-            }
-        }
-
         internal struct TagHelperRenderingContextScope : IDisposable
         {
             private readonly CodeRenderingContext _context;

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/CodeRenderingContextExtensions.cs

@@ -1,126 +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 Microsoft.AspNetCore.Razor.Language.Intermediate;
-
-namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
-{
-    public static class CodeRenderingContextExtensions
-    {
-        private static readonly object RenderNodeKey = new object();
-        private static readonly object RenderChildrenKey = new object();
-        private static readonly object LineMappingsKey = new object();
-
-        public static void SetRenderNode(this CodeRenderingContext context, Action<IntermediateNode> renderNode)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            context.Items[RenderNodeKey] = renderNode;
-        }
-
-        public static void RenderNode(this CodeRenderingContext context, IntermediateNode node)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            if (node == null)
-            {
-                throw new ArgumentNullException(nameof(node));
-            }
-
-            var renderNode = (Action<IntermediateNode>)context.Items[RenderNodeKey];
-
-            if (renderNode == null)
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatRenderingContextRequiresDelegate(nameof(CodeRenderingContext), nameof(RenderNode)));
-            }
-
-            renderNode(node);
-        }
-
-        public static void SetRenderChildren(this CodeRenderingContext context, Action<IntermediateNode> renderChildren)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            context.Items[RenderChildrenKey] = renderChildren;
-        }
-
-        public static void RenderChildren(this CodeRenderingContext context, IntermediateNode node)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            if (node == null)
-            {
-                throw new ArgumentNullException(nameof(node));
-            }
-
-            var renderChildren = (Action<IntermediateNode>)context.Items[RenderChildrenKey];
-            if (renderChildren == null)
-            {
-                throw new InvalidOperationException(
-                    Resources.FormatRenderingContextRequiresDelegate(nameof(CodeRenderingContext), nameof(RenderChildren)));
-            }
-
-            renderChildren(node);
-        }
-
-        public static void AddLineMappingFor(this CodeRenderingContext context, IntermediateNode node)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            if (node == null)
-            {
-                throw new ArgumentNullException(nameof(node));
-            }
-
-            var lineMappings = (List<LineMapping>)context.Items[LineMappingsKey];
-            if (lineMappings == null)
-            {
-                lineMappings = new List<LineMapping>();
-                context.Items[LineMappingsKey] = lineMappings;
-            }
-
-            if (node.Source == null)
-            {
-                return;
-            }
-
-            if (context.SourceDocument.FilePath != null &&
-                !string.Equals(context.SourceDocument.FilePath, node.Source.Value.FilePath, StringComparison.OrdinalIgnoreCase))
-            {
-                // We don't want to generate line mappings for imports.
-                return;
-            }
-
-            var source = node.Source.Value;
-            var generatedLocation = new SourceSpan(context.CodeWriter.Location, source.Length);
-            var lineMapping = new LineMapping(source, generatedLocation);
-
-            lineMappings.Add(lineMapping);
-        }
-
-        public static IReadOnlyList<LineMapping> GetLineMappings(this CodeRenderingContext context)
-        {
-            var lineMappings = (IReadOnlyList<LineMapping>)context.Items[LineMappingsKey] ?? Array.Empty<LineMapping>();
-
-            return lineMappings;
-        }
-    }
-}

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/CodeTarget.cs

@@ -86,7 +86,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 
         }
 
-        public abstract DocumentWriter CreateWriter(CodeRenderingContext context);
+        public abstract IntermediateNodeWriter CreateNodeWriter();
 
         public abstract TExtension GetExtension<TExtension>() where TExtension : class, ICodeTargetExtension;
 

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DefaultCodeRenderingContext.cs

@@ -3,61 +3,181 @@
 // 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 Microsoft.AspNetCore.Razor.Language.Intermediate;
 
 namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 {
     internal class DefaultCodeRenderingContext : CodeRenderingContext
     {
-        // Internal for unit testing
+        private readonly RazorCodeDocument _codeDocument;
-        internal DefaultCodeRenderingContext(
+        private readonly DocumentIntermediateNode _documentNode;
-            CodeWriter codeWriter,
+
-            IntermediateNodeWriter nodeWriter,
+        private readonly List<ScopeInternal> _scopes;
-            RazorSourceDocument sourceDocument,
-            RazorCodeGenerationOptions options)
-            : this (codeWriter, nodeWriter, null, sourceDocument, options)
-        {
-        }
 
         public DefaultCodeRenderingContext(
             CodeWriter codeWriter,
             IntermediateNodeWriter nodeWriter,
-            string documentKind,
+            RazorCodeDocument codeDocument,
-            RazorSourceDocument sourceDocument,
+            DocumentIntermediateNode documentNode,
             RazorCodeGenerationOptions options)
         {
+            if (codeWriter == null)
+            {
+                throw new ArgumentNullException(nameof(codeWriter));
+            }
+
+            if (nodeWriter == null)
+            {
+                throw new ArgumentNullException(nameof(nodeWriter));
+            }
+
+            if (codeDocument == null)
+            {
+                throw new ArgumentNullException(nameof(codeDocument));
+            }
+
+            if (documentNode == null)
+            {
+                throw new ArgumentNullException(nameof(documentNode));
+            }
+
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
             CodeWriter = codeWriter;
-            NodeWriter = nodeWriter;
+            _codeDocument = codeDocument;
-            DocumentKind = documentKind;
+            _documentNode = documentNode;
-            SourceDocument = sourceDocument;
             Options = options;
+
             Diagnostics = new DefaultRazorDiagnosticCollection();
             Items = new DefaultItemCollection();
+            LineMappings = new List<LineMapping>();
+
+            TagHelperRenderingContext = new TagHelperRenderingContext();
+
+            var diagnostics = _documentNode.GetAllDiagnostics();
+            for (var i = 0; i < diagnostics.Count; i++)
+            {
+                Diagnostics.Add(diagnostics[i]);
+            }
+
+            var newLineString = codeDocument.Items[NewLineString];
+            if (newLineString != null)
+            {
+                // Set new line character to a specific string regardless of platform, for testing purposes.
+                codeWriter.NewLine = (string)newLineString;
+            }
+
+            Items[NewLineString] = codeDocument.Items[NewLineString];
+            Items[SuppressUniqueIds] = codeDocument.Items[SuppressUniqueIds];
+
+            _scopes = new List<ScopeInternal>();
+            _scopes.Add(new ScopeInternal(nodeWriter));
         }
 
+        // This will be initialized by the document writer when the context is 'live'.
+        public IntermediateNodeVisitor Visitor { get; set; }
+
         public override CodeWriter CodeWriter { get; }
 
-        public override IntermediateNodeWriter NodeWriter { get; protected set; }
-
-        public override RazorSourceDocument SourceDocument { get; }
-
-        public override RazorCodeGenerationOptions Options { get; }
-
         public override RazorDiagnosticCollection Diagnostics { get; }
 
-        public override ItemCollection Items { get; }
-
         public override string DocumentKind { get; }
 
-        public override IntermediateNodeWriterScope Push(IntermediateNodeWriter writer)
+        public override ItemCollection Items { get; }
+
+        public List<LineMapping> LineMappings { get; }
+
+        public override IntermediateNodeWriter NodeWriter => Current.Writer;
+
+        public override RazorCodeGenerationOptions Options { get; }
+
+        public override RazorSourceDocument SourceDocument => _codeDocument.Source;
+
+        private ScopeInternal Current => _scopes[_scopes.Count - 1];
+
+        public override void AddLineMappingFor(IntermediateNode node)
+        {
+            if (node == null)
+            {
+                throw new ArgumentNullException(nameof(node));
+            }
+
+            if (node.Source == null)
+            {
+                return;
+            }
+
+            if (SourceDocument.FilePath != null &&
+                !string.Equals(SourceDocument.FilePath, node.Source.Value.FilePath, StringComparison.OrdinalIgnoreCase))
+            {
+                // We don't want to generate line mappings for imports.
+                return;
+            }
+
+            var source = node.Source.Value;
+            var generatedLocation = new SourceSpan(CodeWriter.Location, source.Length);
+            var lineMapping = new LineMapping(source, generatedLocation);
+
+            LineMappings.Add(lineMapping);
+        }
+
+        public override Scope CreateScope()
+        {
+            CreateScope(Current.Writer);
+            return new Scope(this);
+        }
+
+        public override Scope CreateScope(IntermediateNodeWriter writer)
         {
             if (writer == null)
             {
                 throw new ArgumentNullException(nameof(writer));
             }
 
-            var scope = new IntermediateNodeWriterScope(this, NodeWriter);
+            _scopes.Add(new ScopeInternal(writer));
-            NodeWriter = writer;
+            return new Scope(this);
-            return scope;
+        }
+
+        public override void EndScope()
+        {
+            _scopes.RemoveAt(_scopes.Count - 1);
+        }
+
+        public override void RenderChildren(IntermediateNode node)
+        {
+            if (node == null)
+            {
+                throw new ArgumentNullException(nameof(node));
+            }
+
+            for (var i = 0; i < node.Children.Count; i++)
+            {
+                Visitor.Visit(node.Children[i]);
+            }
+        }
+
+        public override void RenderNode(IntermediateNode node)
+        {
+            if (node == null)
+            {
+                throw new ArgumentNullException(nameof(node));
+            }
+
+            Visitor.Visit(node);
+        }
+
+        private struct ScopeInternal
+        {
+            public ScopeInternal(IntermediateNodeWriter writer)
+            {
+                Writer = writer;
+            }
+
+            public IntermediateNodeWriter Writer { get; }
         }
     }
 }

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DefaultCodeTarget.cs

@@ -18,9 +18,9 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 
         public ICodeTargetExtension[] Extensions { get; }
 
-        public override DocumentWriter CreateWriter(CodeRenderingContext context)
+        public override IntermediateNodeWriter CreateNodeWriter()
         {
-            return new DefaultDocumentWriter(this, context);
+            return _options.DesignTime ? (IntermediateNodeWriter)new DesignTimeNodeWriter() : new RuntimeNodeWriter();
         }
 
         public override TExtension GetExtension<TExtension>()

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DefaultDocumentWriter.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.Linq;
 using System.Text;
 using Microsoft.AspNetCore.Razor.Language.Intermediate;
 
@@ -9,63 +10,57 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 {
     internal class DefaultDocumentWriter : DocumentWriter
     {
-        private readonly CodeRenderingContext _context;
+        private readonly CodeTarget _codeTarget;
-        private readonly CodeTarget _target;
+        private readonly RazorCodeGenerationOptions _options;
 
-        public DefaultDocumentWriter(CodeTarget target, CodeRenderingContext context)
+        public DefaultDocumentWriter(CodeTarget codeTarget, RazorCodeGenerationOptions options)
         {
-            if (target == null)
+            _codeTarget = codeTarget;
-            {
+            _options = options;
-                throw new ArgumentNullException(nameof(target));
-            }
-
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            _target = target;
-            _context = context;
         }
 
-        public override void WriteDocument(DocumentIntermediateNode node)
+        public override RazorCSharpDocument WriteDocument(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
-            if (node == null)
+            if (codeDocument == null)
             {
-                throw new ArgumentNullException(nameof(node));
+                throw new ArgumentNullException(nameof(codeDocument));
             }
 
-            var visitor = new Visitor(_target, _context);
+            if (documentNode == null)
-            _context.SetRenderNode(visitor.Visit);
+            {
-            _context.SetRenderChildren(visitor.RenderChildren);
+                throw new ArgumentNullException(nameof(documentNode));
+            }
 
-            visitor.VisitDocument(node);
+            var context = new DefaultCodeRenderingContext(
+                new CodeWriter(),
+                _codeTarget.CreateNodeWriter(),
+                codeDocument,
+                documentNode,
+                _options);
+            context.Visitor = new Visitor(_codeTarget, context);
 
-            _context.SetRenderChildren(null);
+            context.Visitor.VisitDocument(documentNode);
-            _context.SetRenderNode(null);
+
+            var cSharp = context.CodeWriter.GenerateCode();
+            return new DefaultRazorCSharpDocument(
+                cSharp,
+                _options,
+                context.Diagnostics.ToArray(),
+                context.LineMappings.ToArray());
         }
 
         private class Visitor : IntermediateNodeVisitor
         {
-            private readonly CodeRenderingContext _context;
+            private readonly DefaultCodeRenderingContext _context;
             private readonly CodeTarget _target;
 
-            public Visitor(CodeTarget target, CodeRenderingContext context)
+            public Visitor(CodeTarget target, DefaultCodeRenderingContext context)
             {
                 _target = target;
                 _context = context;
             }
 
-            private CodeRenderingContext Context => _context;
+            private DefaultCodeRenderingContext Context => _context;
-
-            public void RenderChildren(IntermediateNode node)
-            {
-                for (var i = 0; i < node.Children.Count; i++)
-                {
-                    var child = node.Children[i];
-                    Visit(child);
-                }
-            }
 
             public override void VisitDocument(DocumentIntermediateNode node)
             {
@@ -102,7 +97,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
                     .WriteLine("// <auto-generated/>")
                     .WriteLine("#pragma warning disable 1591");
 
-                RenderChildren(node);
+                VisitDefault(node);
 
                 Context.CodeWriter.WriteLine("#pragma warning restore 1591");
             }
@@ -117,7 +112,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
                 using (Context.CodeWriter.BuildNamespace(node.Content))
                 {
                     Context.CodeWriter.WriteLine("#line hidden");
-                    RenderChildren(node);
+                    VisitDefault(node);
                 }
             }
 
@@ -125,7 +120,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             {
                 using (Context.CodeWriter.BuildClassDeclaration(node.Modifiers, node.Name, node.BaseType, node.Interfaces))
                 {
-                    RenderChildren(node);
+                    VisitDefault(node);
                 }
             }
 
@@ -147,7 +142,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 
                 using (Context.CodeWriter.BuildScope())
                 {
-                    RenderChildren(node);
+                    VisitDefault(node);
                 }
 
                 Context.CodeWriter.WriteLine("#pragma warning restore 1998");
@@ -209,7 +204,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 
                 using (Context.Push(tagHelperRenderingContext))
                 {
-                    RenderChildren(node);
+                    VisitDefault(node);
                 }
             }
 

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DesignTimeTagHelperWriter.cs

@@ -1,16 +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;
-using System.Text;
-using Microsoft.AspNetCore.Razor.Language.Extensions;
-using Microsoft.AspNetCore.Razor.Language.Intermediate;
-using Microsoft.AspNetCore.Razor.Language.Legacy;
-
-namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
-{
-    internal class DesignTimeTagHelperWriter : TagHelperWriter
-    {
-    }
-}

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DocumentWriter.cs

@@ -1,12 +1,28 @@
 // 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 Microsoft.AspNetCore.Razor.Language.Intermediate;
 
 namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 {
     public abstract class DocumentWriter
     {
-        public abstract void WriteDocument(DocumentIntermediateNode node);
+        public DocumentWriter Create(CodeTarget codeTarget, RazorCodeGenerationOptions options)
+        {
+            if (codeTarget == null)
+            {
+                throw new ArgumentNullException(nameof(codeTarget));
+            }
+
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
+            return new DefaultDocumentWriter(codeTarget, options);
+        }
+
+        public abstract RazorCSharpDocument WriteDocument(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode);
     }
 }

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/RuntimeTagHelperWriter.cs

@@ -1,16 +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.Globalization;
-using System.Linq;
-using Microsoft.AspNetCore.Razor.Language.Extensions;
-using Microsoft.AspNetCore.Razor.Language.Intermediate;
-using Microsoft.AspNetCore.Razor.Language.Legacy;
-
-namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
-{
-    internal class RuntimeTagHelperWriter : TagHelperWriter
-    {
-    }
-}

src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/TagHelperWriter.cs

@@ -1,11 +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.AspNetCore.Razor.Language.Intermediate;
-
-namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
-{
-    internal abstract class TagHelperWriter
-    {
-    }
-}

src/Microsoft.AspNetCore.Razor.Language/DefaultRazorCSharpLoweringPhase.cs

@@ -12,34 +12,22 @@ namespace Microsoft.AspNetCore.Razor.Language
     {
         protected override void ExecuteCore(RazorCodeDocument codeDocument)
         {
-            var irDocument = codeDocument.GetDocumentIntermediateNode();
+            var documentNode = codeDocument.GetDocumentIntermediateNode();
-            ThrowForMissingDocumentDependency(irDocument);
+            ThrowForMissingDocumentDependency(documentNode);
 
-            var target = irDocument.Target;
+            var target = documentNode.Target;
             if (target == null)
             {
                 var message = Resources.FormatDocumentMissingTarget(
-                    irDocument.DocumentKind,
+                    documentNode.DocumentKind,
                     nameof(CodeTarget),
                     nameof(DocumentIntermediateNode.Target));
                 throw new InvalidOperationException(message);
             }
 
-            var context = CodeRenderingContext.Create(codeDocument, irDocument.Options);
+            var writer = new DefaultDocumentWriter(documentNode.Target, documentNode.Options);
-            var documentWriter = target.CreateWriter(context);
+            var cSharpDocument = writer.WriteDocument(codeDocument, documentNode);
-            documentWriter.WriteDocument(irDocument);
+            codeDocument.SetCSharpDocument(cSharpDocument);
-
-            var diagnostics = new List<RazorDiagnostic>();
-            diagnostics.AddRange(irDocument.GetAllDiagnostics());
-            diagnostics.AddRange(context.Diagnostics);
-
-            var lineMappings = context.GetLineMappings();
-            var csharpDocument = RazorCSharpDocument.Create(
-                context.CodeWriter.GenerateCode(),
-                irDocument.Options,
-                diagnostics,
-                lineMappings);
-            codeDocument.SetCSharpDocument(csharpDocument);
         }
     }
 }

src/Microsoft.AspNetCore.Razor.Language/Extensions/DefaultTagHelperTargetExtension.cs

@@ -107,8 +107,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                     .WriteParameterSeparator();
 
                 // We remove and redirect writers so TagHelper authors can retrieve content.
-                using (context.Push(new RuntimeNodeWriter()))
+                using (context.CreateScope(new RuntimeNodeWriter()))
-                using (context.Push(new RuntimeTagHelperWriter()))
                 {
                     using (context.CodeWriter.BuildAsyncLambda())
                     {
@@ -215,7 +214,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                         .Write(attributeValueStyleParameter)
                         .WriteEndMethodInvocation();
 
-                    using (context.Push(new TagHelperHtmlAttributeRuntimeNodeWriter()))
+                    using (context.CreateScope(new TagHelperHtmlAttributeRuntimeNodeWriter()))
                     {
                         context.RenderChildren(node);
                     }
@@ -237,8 +236,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                     // We're building a writing scope around the provided chunks which captures everything written from the
                     // page. Therefore, we do not want to write to any other buffer since we're using the pages buffer to
                     // ensure we capture all content that's written, directly or indirectly.
-                    using (context.Push(new RuntimeNodeWriter()))
+                    using (context.CreateScope(new RuntimeNodeWriter()))
-                    using (context.Push(new RuntimeTagHelperWriter()))
                     {
                         context.RenderChildren(node);
                     }
@@ -335,7 +333,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 {
                     context.CodeWriter.WriteMethodInvocation(BeginWriteTagHelperAttributeMethodName);
 
-                    using (context.Push(new LiteralRuntimeNodeWriter()))
+                    using (context.CreateScope(new LiteralRuntimeNodeWriter()))
                     {
                         context.RenderChildren(node);
                     }

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/InjectTargetExtensionTest.cs

@@ -4,6 +4,7 @@
 using System;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.CodeGeneration;
+using Microsoft.AspNetCore.Razor.Language.Intermediate;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Xunit;
 
@@ -15,7 +16,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InjectDirectiveTargetExtension_WritesProperty()
         {
             // Arrange
-            var context = GetRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
             var target = new InjectTargetExtension();
             var node = new InjectIntermediateNode()
             {
@@ -37,7 +38,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InjectDirectiveTargetExtension_WritesPropertyWithLinePragma_WhenSourceIsSet()
         {
             // Arrange
-            var context = GetRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
             var target = new InjectTargetExtension();
             var node = new InjectIntermediateNode()
             {
@@ -63,15 +64,5 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 "#line hidden" + Environment.NewLine,
                 context.CodeWriter.Builder.ToString());
         }
-
-        private CodeRenderingContext GetRenderingContext()
-        {
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
-
-            return context;
-        }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/DefaultCodeTargetTest.cs

@@ -28,20 +28,31 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         }
 
         [Fact]
-        public void CreateWriter_CreatesDefaultDocumentWriter()
+        public void CreateWriter_DesignTime_CreatesDesignTimeNodeWriter()
         {
             // Arrange
-            var codeWriter = new CodeWriter();
+            var options = RazorCodeGenerationOptions.CreateDesignTimeDefault();
-            var codeDocument = TestRazorCodeDocument.Create(string.Empty);
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = CodeRenderingContext.Create(codeDocument, options);
             var target = new DefaultCodeTarget(options, Enumerable.Empty<ICodeTargetExtension>());
 
             // Act
-            var writer = target.CreateWriter(context);
+            var writer = target.CreateNodeWriter();
 
             // Assert
-            Assert.IsType<DefaultDocumentWriter>(writer);
+            Assert.IsType<DesignTimeNodeWriter>(writer);
+        }
+
+        [Fact]
+        public void CreateWriter_Runtime_CreatesRuntimeNodeWriter()
+        {
+            // Arrange
+            var options = RazorCodeGenerationOptions.CreateDefault();
+            var target = new DefaultCodeTarget(options, Enumerable.Empty<ICodeTargetExtension>());
+
+            // Act
+            var writer = target.CreateNodeWriter();
+
+            // Assert
+            Assert.IsType<RuntimeNodeWriter>(writer);
         }
 
         [Fact]

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/DefaultDocumentWriterTest.cs

@@ -13,24 +13,19 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         public void WriteDocument_Empty_WritesChecksumAndMarksAutoGenerated()
         {
             // Arrange
+            var document = new DocumentIntermediateNode();
+
             var codeDocument = TestRazorCodeDocument.CreateEmpty();
             var options = RazorCodeGenerationOptions.CreateDefault();
 
             var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
+            var writer = new DefaultDocumentWriter(target, options);
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-
-            var writer = new DefaultDocumentWriter(target, context);
-
-            var document = new DocumentIntermediateNode();
-            var builder = IntermediateNodeBuilder.Create(document);
 
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
@@ -45,6 +40,8 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         public void WriteDocument_Empty_SuppressChecksumTrue_DoesnotWriteChecksum()
         {
             // Arrange
+            var document = new DocumentIntermediateNode();
+
             var codeDocument = TestRazorCodeDocument.CreateEmpty();
             var optionsBuilder = new DefaultRazorCodeGenerationOptionsBuilder()
             {
@@ -53,20 +50,13 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             var options = optionsBuilder.Build();
 
             var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
+            var writer = new DefaultDocumentWriter(target, options);
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-
-            var writer = new DefaultDocumentWriter(target, context);
-
-            var document = new DocumentIntermediateNode();
-            var builder = IntermediateNodeBuilder.Create(document);
 
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"// <auto-generated/>
 #pragma warning disable 1591
@@ -80,16 +70,6 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         public void WriteDocument_WritesNamespace()
         {
             // Arrange
-            var codeDocument = TestRazorCodeDocument.CreateEmpty();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-
-            var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-
-            var writer = new DefaultDocumentWriter(target, context);
-
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new NamespaceDeclarationIntermediateNode()
@@ -97,11 +77,17 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
                 Content = "TestNamespace",
             });
 
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            var target = CodeTarget.CreateDefault(codeDocument, options);
+            var writer = new DefaultDocumentWriter(target, options);
+
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
@@ -120,15 +106,6 @@ namespace TestNamespace
         public void WriteDocument_WritesClass()
         {
             // Arrange
-            var codeDocument = TestRazorCodeDocument.CreateEmpty();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-
-            var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-            var writer = new DefaultDocumentWriter(target, context);
-
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new ClassDeclarationIntermediateNode()
@@ -142,11 +119,17 @@ namespace TestNamespace
                 Name = "TestClass",
             });
 
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            var target = CodeTarget.CreateDefault(codeDocument, options);
+            var writer = new DefaultDocumentWriter(target, options);
+
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
@@ -164,15 +147,6 @@ internal class TestClass : TestBase, IFoo, IBar
         public void WriteDocument_WritesMethod()
         {
             // Arrange
-            var codeDocument = TestRazorCodeDocument.CreateEmpty();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-
-            var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-            var writer = new DefaultDocumentWriter(target, context);
-
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new MethodDeclarationIntermediateNode()
@@ -187,11 +161,17 @@ internal class TestClass : TestBase, IFoo, IBar
                 ReturnType = "string",
             });
 
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            var target = CodeTarget.CreateDefault(codeDocument, options);
+            var writer = new DefaultDocumentWriter(target, options);
+
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
@@ -211,15 +191,6 @@ internal virtual async string TestMethod()
         public void WriteDocument_WritesField()
         {
             // Arrange
-            var codeDocument = TestRazorCodeDocument.CreateEmpty();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-
-            var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-            var writer = new DefaultDocumentWriter(target, context);
-
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new FieldDeclarationIntermediateNode()
@@ -233,11 +204,17 @@ internal virtual async string TestMethod()
                 Type = "string",
             });
 
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            var target = CodeTarget.CreateDefault(codeDocument, options);
+            var writer = new DefaultDocumentWriter(target, options);
+
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
@@ -253,15 +230,6 @@ internal readonly string _foo;
         public void WriteDocument_WritesProperty()
         {
             // Arrange
-            var codeDocument = TestRazorCodeDocument.CreateEmpty();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-
-            var target = CodeTarget.CreateDefault(codeDocument, options);
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument.Source, options);
-            var writer = new DefaultDocumentWriter(target, context);
-
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new PropertyDeclarationIntermediateNode()
@@ -275,11 +243,17 @@ internal readonly string _foo;
                 Type = "string",
             });
 
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            var target = CodeTarget.CreateDefault(codeDocument, options);
+            var writer = new DefaultDocumentWriter(target, options);
+
             // Act
-            writer.WriteDocument(document);
+            var result = writer.WriteDocument(codeDocument, document);
 
             // Assert
-            var csharp = context.CodeWriter.Builder.ToString();
+            var csharp = result.GeneratedCode;
             Assert.Equal(
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/DesignTimeNodeWriterTest.cs

@@ -15,9 +15,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new UsingDirectiveIntermediateNode()
             {
@@ -42,9 +40,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             // Arrange
             var writer = new DesignTimeNodeWriter();
             var sourceDocument = TestRazorSourceDocument.Create("@using System;");
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
 
             var originalSpan = new SourceSpan("test.cshtml", 0, 0, 0, 6);
             var generatedSpan = new SourceSpan(null, 21 + Environment.NewLine.Length, 1, 0, 6);
@@ -59,7 +55,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             writer.WriteUsingDirective(context, node);
 
             // Assert
-            var mapping = Assert.Single(context.GetLineMappings());
+            var mapping = Assert.Single(((DefaultCodeRenderingContext)context).LineMappings);
             Assert.Equal(expectedLineMapping, mapping);
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
@@ -78,9 +74,7 @@ using System;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(node);
@@ -107,9 +101,7 @@ using System;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode()
             {
@@ -143,9 +135,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(node);
@@ -161,15 +151,14 @@ __o = i++;
                 Kind = IntermediateToken.TokenKind.CSharp,
             });
 
-            context.SetRenderNode((n) => Assert.IsType<MyExtensionIntermediateNode>(n));
-
             // Act
             writer.WriteCSharpExpression(context, node);
 
             // Assert
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
-@"__o = i++;
+@"__o = iRender Children
+++;
 ",
                 csharp,
                 ignoreLineEndingDifferences: true);
@@ -180,10 +169,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var sourceDocument = TestRazorSourceDocument.Create("       @i++");
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var codeWriter = new CodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
 
             var node = new CSharpExpressionIntermediateNode()
             {
@@ -202,8 +188,6 @@ __o = i++;
                 Kind = IntermediateToken.TokenKind.CSharp,
             });
 
-            context.SetRenderNode((n) => Assert.IsType<MyExtensionIntermediateNode>(n));
-
             // Act
             writer.WriteCSharpExpression(context, node);
 
@@ -211,7 +195,8 @@ __o = i++;
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
 @"#line 1 ""test.cshtml""
-  __o = i++;
+  __o = iRender Children
+++;
 
 #line default
 #line hidden
@@ -225,9 +210,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode();
             IntermediateNodeBuilder.Create(node)
@@ -250,9 +233,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode()
             {
@@ -282,9 +263,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode();
             IntermediateNodeBuilder.Create(node)
@@ -311,9 +290,7 @@ __o = i++;
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode()
             {
@@ -347,9 +324,7 @@ if (true) { }
         {
             // Arrange
             var writer = new DesignTimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode()
             {
@@ -386,9 +361,10 @@ if (true) { }
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateDesignTime(source: sourceDocument);
 
             // Act
             writer.WriteCSharpExpressionAttributeValue(context, node);
@@ -413,9 +389,10 @@ if (true) { }
             var content = "<input checked=\"hello-world @if(@true){ }\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateDesignTime(source: sourceDocument);
 
             // Act
             writer.WriteCSharpCodeAttributeValue(context, node);
@@ -440,9 +417,10 @@ if (true) { }
             var content = "<input checked=\"hello-world @if(@true){ @false }\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateDesignTime(source: sourceDocument);
 
             // Act
             writer.WriteCSharpCodeAttributeValue(context, node);
@@ -455,7 +433,7 @@ if (true) { }
 
 #line default
 #line hidden
-Render Node - CSharpExpressionIntermediateNode
+Render Children
 #line 1 ""test.cshtml""
                                                }
 
@@ -466,19 +444,6 @@ Render Node - CSharpExpressionIntermediateNode
                 ignoreLineEndingDifferences: true);
         }
 
-        private static CodeRenderingContext GetCodeRenderingContext(IntermediateNodeWriter writer, RazorSourceDocument sourceDocument)
-        {
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var codeWriter = new CodeWriter();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
-            context.SetRenderNode(n =>
-            {
-                codeWriter.WriteLine($"Render Node - {n.GetType().Name}");
-            });
-
-            return context;
-        }
-
         private static DocumentIntermediateNode Lower(RazorCodeDocument codeDocument)
         {
             var engine = RazorEngine.Create();
@@ -499,10 +464,10 @@ Render Node - CSharpExpressionIntermediateNode
                 }
             }
 
-            var irDocument = codeDocument.GetDocumentIntermediateNode();
+            var documentNode = codeDocument.GetDocumentIntermediateNode();
-            Assert.NotNull(irDocument);
+            Assert.NotNull(documentNode);
 
-            return irDocument;
+            return documentNode;
         }
 
         private class MyExtensionIntermediateNode : ExtensionIntermediateNode
@@ -511,12 +476,12 @@ Render Node - CSharpExpressionIntermediateNode
 
             public override void Accept(IntermediateNodeVisitor visitor)
             {
-                throw new NotImplementedException();
+                visitor.VisitDefault(this);
             }
 
             public override void WriteNode(CodeTarget target, CodeRenderingContext context)
             {
-                throw new NotImplementedException();
+                context.CodeWriter.WriteLine("MyExtensionNode");
             }
         }
     }

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/LiteralRuntimeNodeWriterTest.cs

@@ -13,9 +13,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
         {
             // Arrange
             var writer = new LiteralRuntimeNodeWriter();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode()
             {

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/RuntimeNodeWriterTest.cs

@@ -16,8 +16,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new UsingDirectiveIntermediateNode()
             {
@@ -42,8 +41,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new UsingDirectiveIntermediateNode()
             {
@@ -76,8 +74,7 @@ using System;
             {
                 WriteCSharpExpressionMethod = "Test",
             };
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(node);
@@ -108,8 +105,7 @@ using System;
             {
                 WriteCSharpExpressionMethod = "Test",
             };
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode()
             {
@@ -147,8 +143,7 @@ Test(i++);
             {
                 WriteCSharpExpressionMethod = "Test",
             };
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpExpressionIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(node);
@@ -164,15 +159,14 @@ Test(i++);
                 Kind = IntermediateToken.TokenKind.CSharp,
             });
 
-            context.SetRenderNode((n) => Assert.IsType<MyExtensionIntermediateNode>(n));
-
             // Act
             writer.WriteCSharpExpression(context, node);
 
             // Assert
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
-@"Test(i++);
+@"Test(iRender Children
+++);
 ",
                 csharp,
                 ignoreLineEndingDifferences: true);
@@ -187,9 +181,7 @@ Test(i++);
             {
                 WriteCSharpExpressionMethod = "Test",
             };
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var sourceDocument = TestRazorSourceDocument.Create("       @i++");
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
 
             var node = new CSharpExpressionIntermediateNode()
             {
@@ -208,8 +200,6 @@ Test(i++);
                 Kind = IntermediateToken.TokenKind.CSharp,
             });
 
-            context.SetRenderNode((n) => Assert.IsType<MyExtensionIntermediateNode>(n));
-
             // Act
             writer.WriteCSharpExpression(context, node);
 
@@ -217,7 +207,8 @@ Test(i++);
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
 @"#line 1 ""test.cshtml""
-   Test(i++);
+   Test(iRender Children
+++);
 
 #line default
 #line hidden
@@ -232,8 +223,7 @@ Test(i++);
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode();
             IntermediateNodeBuilder.Create(node)
@@ -257,8 +247,7 @@ Test(i++);
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode();
             IntermediateNodeBuilder.Create(node)
@@ -286,8 +275,7 @@ Test(i++);
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode()
             {
@@ -322,8 +310,7 @@ if (true) { }
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new CSharpCodeIntermediateNode()
             {
@@ -358,8 +345,7 @@ if (true) { }
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
 
             var node = new HtmlContentIntermediateNode();
             node.Children.Add(new IntermediateToken()
@@ -386,9 +372,7 @@ if (true) { }
             // Arrange
             var codeWriter = new CodeWriter();
             var writer = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument: null, options: options);
-
 
             var node = new HtmlContentIntermediateNode();
             node.Children.Add(new IntermediateToken()
@@ -418,9 +402,10 @@ WriteLiteral(@""{1}"");
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single();
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single();
+
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.WriteHtmlAttribute(context, node);
@@ -430,6 +415,7 @@ WriteLiteral(@""{1}"");
             Assert.Equal(
 @"BeginWriteAttribute(""checked"", "" checked=\"""", 6, ""\"""", 34, 2);
 Render Children
+Render Children
 EndWriteAttribute();
 ",
                 csharp,
@@ -444,9 +430,10 @@ EndWriteAttribute();
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[0] as HtmlAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[0] as HtmlAttributeValueIntermediateNode;
+            
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.WriteHtmlAttributeValue(context, node);
@@ -468,9 +455,10 @@ EndWriteAttribute();
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.WriteCSharpExpressionAttributeValue(context, node);
@@ -497,9 +485,10 @@ WriteAttributeValue("" "", 27, false, 28, 6, false);
             var content = "<input checked=\"hello-world @if(@true){ }\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateRuntime(source: sourceDocument);
 
             // Act
             writer.WriteCSharpCodeAttributeValue(context, node);
@@ -530,7 +519,7 @@ WriteAttributeValue("" "", 27, false, 28, 6, false);
             {
                 PushWriterMethod = "TestPushWriter"
             };
-            var context = GetCodeRenderingContext(writer, null);
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.BeginWriterScope(context, "MyWriter");
@@ -552,7 +541,7 @@ WriteAttributeValue("" "", 27, false, 28, 6, false);
             {
                 PopWriterMethod = "TestPopWriter"
             };
-            var context = GetCodeRenderingContext(writer, null);
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.EndWriterScope(context);
@@ -566,19 +555,6 @@ WriteAttributeValue("" "", 27, false, 28, 6, false);
                 ignoreLineEndingDifferences: true);
         }
 
-        private static CodeRenderingContext GetCodeRenderingContext(IntermediateNodeWriter writer, RazorSourceDocument sourceDocument)
-        {
-            var codeWriter = new CodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
-            context.SetRenderChildren(n =>
-            {
-                codeWriter.WriteLine("Render Children");
-            });
-
-            return context;
-        }
-
         private static DocumentIntermediateNode Lower(RazorCodeDocument codeDocument)
         {
             var engine = RazorEngine.Create();
@@ -611,7 +587,7 @@ WriteAttributeValue("" "", 27, false, 28, 6, false);
 
             public override void Accept(IntermediateNodeVisitor visitor)
             {
-                throw new NotImplementedException();
+                visitor.VisitDefault(this);
             }
 
             public override void WriteNode(CodeTarget target, CodeRenderingContext context)

test/Microsoft.AspNetCore.Razor.Language.Test/CodeGeneration/TagHelperHtmlAttributeRuntimeNodeWriterTest.cs

@@ -17,9 +17,10 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[0] as HtmlAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[0] as HtmlAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.WriteHtmlAttributeValue(context, node);
@@ -40,9 +41,10 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             var content = "<input checked=\"hello-world @false\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpExpressionAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             // Act
             writer.WriteCSharpExpressionAttributeValue(context, node);
@@ -68,9 +70,10 @@ AddHtmlAttributeValue("" "", 27, false, 28, 6, false);
             var content = "<input checked=\"hello-world @if(@true){ }\" />";
             var sourceDocument = TestRazorSourceDocument.Create(content);
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
-            var context = GetCodeRenderingContext(writer, sourceDocument);
+            var documentNode = Lower(codeDocument);
-            var irDocument = Lower(codeDocument);
+            var node = documentNode.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
-            var node = irDocument.Children.OfType<HtmlAttributeIntermediateNode>().Single().Children[1] as CSharpCodeAttributeValueIntermediateNode;
+
+            var context = TestCodeRenderingContext.CreateRuntime(source: sourceDocument);
 
             // Act
             writer.WriteCSharpCodeAttributeValue(context, node);
@@ -93,19 +96,6 @@ AddHtmlAttributeValue("" "", 27, false, 28, 6, false);
                 ignoreLineEndingDifferences: true);
         }
 
-        private static CodeRenderingContext GetCodeRenderingContext(IntermediateNodeWriter writer, RazorSourceDocument sourceDocument)
-        {
-            var codeWriter = new CodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, writer, sourceDocument, options);
-            context.SetRenderChildren(_ =>
-            {
-                codeWriter.WriteLine("Render Children");
-            });
-
-            return context;
-        }
-
         private static DocumentIntermediateNode Lower(RazorCodeDocument codeDocument)
         {
             var engine = RazorEngine.Create();
@@ -126,10 +116,10 @@ AddHtmlAttributeValue("" "", 27, false, 28, 6, false);
                 }
             }
 
-            var irDocument = codeDocument.GetDocumentIntermediateNode();
+            var documentNode = codeDocument.GetDocumentIntermediateNode();
-            Assert.NotNull(irDocument);
+            Assert.NotNull(documentNode);
 
-            return irDocument;
+            return documentNode;
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/Extensions/DefaultTagHelperTargetExtensionTest.cs

@@ -69,9 +69,15 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
-            var node = new DefaultTagHelperBodyIntermediateNode();
+            var node = new DefaultTagHelperBodyIntermediateNode()
+            {
+                Children =
+                {
+                    new CSharpExpressionIntermediateNode(),
+                }
+            };
 
             // Act
             extension.WriteTagHelperBody(context, node);
@@ -90,10 +96,14 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperBodyIntermediateNode()
             {
+                Children =
+                {
+                    new CSharpExpressionIntermediateNode(),
+                },
                 TagMode = TagMode.SelfClosing,
                 TagName = "p",
             };
@@ -118,7 +128,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperCreateIntermediateNode()
             {
@@ -143,7 +153,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperCreateIntermediateNode()
             {
@@ -169,7 +179,7 @@ __tagHelperExecutionContext.Add(__TestNamespace_MyTagHelper);
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperExecuteIntermediateNode();
 
@@ -189,7 +199,7 @@ __tagHelperExecutionContext.Add(__TestNamespace_MyTagHelper);
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperExecuteIntermediateNode();
 
@@ -216,7 +226,7 @@ __tagHelperExecutionContext = __tagHelperScopeManager.End();
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperHtmlAttributeIntermediateNode()
             {
@@ -242,6 +252,7 @@ __tagHelperExecutionContext = __tagHelperScopeManager.End();
             var csharp = context.CodeWriter.Builder.ToString();
             Assert.Equal(
 @"Render Children
+Render Children
 ",
                 csharp,
                 ignoreLineEndingDifferences: true);
@@ -252,7 +263,7 @@ __tagHelperExecutionContext = __tagHelperScopeManager.End();
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperHtmlAttributeIntermediateNode()
             {
@@ -287,7 +298,7 @@ __tagHelperExecutionContext.AddHtmlAttribute(""name"", Html.Raw(__tagHelperStrin
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperHtmlAttributeIntermediateNode()
             {
@@ -314,6 +325,7 @@ __tagHelperExecutionContext.AddHtmlAttribute(""name"", Html.Raw(__tagHelperStrin
             Assert.Equal(
 @"BeginAddHtmlAttributeValues(__tagHelperExecutionContext, ""name"", 2, global::Microsoft.AspNetCore.Razor.TagHelpers.HtmlAttributeValueStyle.DoubleQuotes);
 Render Children
+Render Children
 EndAddHtmlAttributeValues(__tagHelperExecutionContext);
 ",
                 csharp,
@@ -325,7 +337,7 @@ EndAddHtmlAttributeValues(__tagHelperExecutionContext);
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -363,7 +375,7 @@ __InputTagHelper.StringProp = ""value"";
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -401,7 +413,7 @@ __InputTagHelper.StringProp = string.Empty;
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -443,7 +455,7 @@ __InputTagHelper.IntProp = 32;
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -480,7 +492,7 @@ __InputTagHelper.IntProp = 32;
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -522,7 +534,7 @@ __InputTagHelper.IntIndexer[""bound""] = 32;
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -559,7 +571,7 @@ __InputTagHelper.IntIndexer[""bound""] = 32;
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -602,7 +614,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""bound"", __InputTagHelper.St
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -645,7 +657,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""bound"", __InputTagHelper.In
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -683,7 +695,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""bound"", __InputTagHelper.In
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -730,7 +742,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""foo-bound"", __InputTagHelpe
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperPropertyIntermediateNode()
             {
@@ -772,7 +784,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""foo-bound"", __InputTagHelpe
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
-            var context = GetDesignTimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateDesignTime();
 
             var node = new DefaultTagHelperRuntimeIntermediateNode();
 
@@ -792,7 +804,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""foo-bound"", __InputTagHelpe
         {
             // Arrange
             var extension = new DefaultTagHelperTargetExtension();
-            var context = GetRuntimeCodeRenderingContext();
+            var context = TestCodeRenderingContext.CreateRuntime();
 
             var node = new DefaultTagHelperRuntimeIntermediateNode();
 
@@ -825,50 +837,6 @@ private global::Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperScopeMana
                 ignoreLineEndingDifferences: true);
         }
 
-        private static CodeRenderingContext GetRuntimeCodeRenderingContext()
-        {
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, null, options)
-            {
-                Items =
-                {
-                    { CodeRenderingContext.SuppressUniqueIds, "test" },
-                },
-                TagHelperWriter = new RuntimeTagHelperWriter(),
-                TagHelperRenderingContext = new TagHelperRenderingContext()
-            };
-            context.SetRenderChildren(n =>
-            {
-                codeWriter.WriteLine("Render Children");
-            });
-
-            return context;
-        }
-
-        private static CodeRenderingContext GetDesignTimeCodeRenderingContext()
-        {
-            var codeWriter = new CodeWriter();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDesignTimeDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, null, options)
-            {
-                Items =
-                {
-                    { CodeRenderingContext.SuppressUniqueIds, "test" },
-                },
-                TagHelperWriter = new DesignTimeTagHelperWriter(),
-                TagHelperRenderingContext = new TagHelperRenderingContext()
-            };
-            context.SetRenderChildren(n =>
-            {
-                codeWriter.WriteLine("Render Children");
-            });
-
-            return context;
-        }
-
         private static DocumentIntermediateNode Lower(RazorCodeDocument codeDocument)
         {
             var engine = RazorEngine.Create();

test/Microsoft.AspNetCore.Razor.Language.Test/Extensions/DesignTimeDirectiveTargetExtensionTest.cs

@@ -14,10 +14,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
 
@@ -41,11 +38,7 @@ private void __RazorDirectiveTokenHelpers__() {
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var sourceDocument = RazorSourceDocument.Create("test content", "test.cshtml");
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument, options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
             var token = new DirectiveTokenIntermediateNode()
@@ -80,11 +73,7 @@ System.String __typeHelper = default(System.String);
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var sourceDocument = RazorSourceDocument.Create("test content", "test.cshtml");
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument, options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
             var token = new DirectiveTokenIntermediateNode()
@@ -119,11 +108,7 @@ global::System.Object __typeHelper = nameof(System.Collections.Generic);
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var sourceDocument = RazorSourceDocument.Create("test content", "test.cshtml");
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument, options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
             var token = new DirectiveTokenIntermediateNode()
@@ -158,11 +143,7 @@ global::System.Object Foo = null;
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var sourceDocument = RazorSourceDocument.Create("test content", "test.cshtml");
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument, options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
             var token = new DirectiveTokenIntermediateNode()
@@ -208,11 +189,7 @@ global::System.Object __typeHelper = ""Value"";
         {
             // Arrange
             var extension = new DesignTimeDirectiveTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new DesignTimeNodeWriter();
-            var sourceDocument = RazorSourceDocument.Create("test content", "test.cshtml");
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument, options);
 
             var node = new DesignTimeDirectiveIntermediateNode();
             var token = new DirectiveTokenIntermediateNode()

test/Microsoft.AspNetCore.Razor.Language.Test/Extensions/PreallocatedAttributeTargetExtensionTest.cs

@@ -13,10 +13,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var node = new PreallocatedTagHelperHtmlAttributeValueIntermediateNode()
             {
@@ -43,10 +40,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var node = new PreallocatedTagHelperHtmlAttributeValueIntermediateNode()
             {
@@ -73,10 +67,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var node = new PreallocatedTagHelperHtmlAttributeIntermediateNode()
             {
@@ -100,10 +91,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var node = new PreallocatedTagHelperPropertyValueIntermediateNode()
             {
@@ -130,10 +118,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options);
 
             var tagHelperBuilder = new DefaultTagHelperDescriptorBuilder(TagHelperConventions.DefaultKind, "FooTagHelper", "Test");
             tagHelperBuilder.TypeName("FooTagHelper");
@@ -173,13 +158,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(_tagHelper1);
         {
             // Arrange
             var extension = new PreallocatedAttributeTargetExtension();
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options)
-            {
-                TagHelperRenderingContext = new TagHelperRenderingContext()
-            };
 
             var tagHelperBuilder = new DefaultTagHelperDescriptorBuilder(TagHelperConventions.DefaultKind, "FooTagHelper", "Test");
             tagHelperBuilder.TypeName("FooTagHelper");

test/Microsoft.AspNetCore.Razor.Language.Test/Extensions/SectionTargetExtensionTest.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using Microsoft.AspNetCore.Razor.Language.CodeGeneration;
+using Microsoft.AspNetCore.Razor.Language.Intermediate;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Xunit;
 using static Microsoft.AspNetCore.Razor.Language.Intermediate.IntermediateNodeAssert;
@@ -16,6 +17,10 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             // Arrange
             var node = new SectionIntermediateNode()
             {
+                Children =
+                {
+                    new CSharpExpressionIntermediateNode(),
+                },
                 Name = "MySection"
             };
 
@@ -24,26 +29,14 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 SectionMethodName = "CreateSection"
             };
 
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateRuntime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options)
-            { 
-                TagHelperWriter = new RuntimeTagHelperWriter(),
-            };
-
-            context.SetRenderChildren((n) =>
-            {
-                Assert.Same(node, n);
-                context.CodeWriter.WriteLine(" var s = \"Inside\"");
-            });
 
             // Act
             extension.WriteSection(context, node);
 
             // Assert
             var expected = @"CreateSection(""MySection"", async() => {
-     var s = ""Inside""
+    Render Children
 }
 );
 ";
@@ -58,6 +51,10 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             // Arrange
             var node = new SectionIntermediateNode()
             {
+                Children =
+                {
+                    new CSharpExpressionIntermediateNode(),
+                },
                 Name = "MySection"
             };
 
@@ -66,26 +63,14 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 SectionMethodName = "CreateSection"
             };
 
-            var codeWriter = new CodeWriter();
+            var context = TestCodeRenderingContext.CreateDesignTime();
-            var nodeWriter = new RuntimeNodeWriter();
-            var options = RazorCodeGenerationOptions.Create(false, 4, true, false);
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options)
-            {
-                TagHelperWriter = new RuntimeTagHelperWriter(),
-            };
-
-            context.SetRenderChildren((n) =>
-            {
-                Assert.Same(node, n);
-                context.CodeWriter.WriteLine(" var s = \"Inside\"");
-            });
 
             // Act
             extension.WriteSection(context, node);
 
             // Assert
             var expected = @"CreateSection(""MySection"", async(__razor_section_writer) => {
-     var s = ""Inside""
+    Render Children
 }
 );
 ";

test/Microsoft.AspNetCore.Razor.Language.Test/Extensions/TemplateTargetExtensionTest.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using Microsoft.AspNetCore.Razor.Language.CodeGeneration;
+using Microsoft.AspNetCore.Razor.Language.Intermediate;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.Extensions
@@ -12,29 +13,25 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         public void WriteTemplate_WritesTemplateCode()
         {
             // Arrange
-            var node = new TemplateIntermediateNode();
+            var node = new TemplateIntermediateNode()
+            {
+                Children =
+                {
+                    new CSharpExpressionIntermediateNode()
+                }
+            };
             var extension = new TemplateTargetExtension()
             {
                 TemplateTypeName = "global::TestTemplate"
             };
             
-            var codeWriter = new CodeWriter();
             var nodeWriter = new RuntimeNodeWriter()
             {
                 PushWriterMethod = "TestPushWriter",
                 PopWriterMethod = "TestPopWriter"
             };
-            var options = RazorCodeGenerationOptions.CreateDefault();
-            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, sourceDocument: null, options: options)
-            {
-                TagHelperWriter = new RuntimeTagHelperWriter(),
-            };
 
-            context.SetRenderChildren((n) =>
+            var context = TestCodeRenderingContext.CreateRuntime(nodeWriter: nodeWriter);
-            {
-                Assert.Same(node, n);
-                context.CodeWriter.WriteLine(" var s = \"Inside\"");
-            });
 
             // Act
             extension.WriteTemplate(context, node);
@@ -42,7 +39,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             // Assert
             var expected = @"item => new global::TestTemplate(async(__razor_template_writer) => {
     TestPushWriter(__razor_template_writer);
-     var s = ""Inside""
+    Render Children
     TestPopWriter();
 }
 )";

test/Microsoft.AspNetCore.Razor.Test.Common/Language/CodeGeneration/TestCodeRenderingContext.cs

@@ -0,0 +1,99 @@
+// 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.AspNetCore.Razor.Language.Intermediate;
+
+namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
+{
+    public static class TestCodeRenderingContext
+    {
+        public static CodeRenderingContext CreateDesignTime(
+            string newLineString = null,
+            string suppressUniqueIds = "test",
+            RazorSourceDocument source = null,
+            IntermediateNodeWriter nodeWriter = null)
+        {
+            var codeWriter = new CodeWriter();
+            var documentNode = new DocumentIntermediateNode();
+            var options = RazorCodeGenerationOptions.CreateDesignTimeDefault();
+
+            if (source == null)
+            {
+                source = TestRazorSourceDocument.Create(); 
+            }
+
+            var codeDocument = RazorCodeDocument.Create(source);
+            if (newLineString != null)
+            {
+                codeDocument.Items[CodeRenderingContext.NewLineString] = newLineString;
+            }
+
+            if (suppressUniqueIds != null)
+            {
+                codeDocument.Items[CodeRenderingContext.SuppressUniqueIds] = suppressUniqueIds;
+            }
+
+            if (nodeWriter == null)
+            {
+                nodeWriter = new DesignTimeNodeWriter();
+            }
+
+            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument, documentNode, options);
+            context.Visitor = new RenderChildrenVisitor(context);
+
+            return context;
+        }
+
+        public static CodeRenderingContext CreateRuntime(
+            string newLineString = null,
+            string suppressUniqueIds = "test",
+            RazorSourceDocument source = null,
+            IntermediateNodeWriter nodeWriter = null)
+        {
+            var codeWriter = new CodeWriter();
+            var documentNode = new DocumentIntermediateNode();
+            var options = RazorCodeGenerationOptions.CreateDefault();
+
+            if (source == null)
+            {
+                source = TestRazorSourceDocument.Create();
+            }
+
+            var codeDocument = RazorCodeDocument.Create(source);
+            if (newLineString != null)
+            {
+                codeDocument.Items[CodeRenderingContext.NewLineString] = newLineString;
+            }
+
+            if (suppressUniqueIds != null)
+            {
+                codeDocument.Items[CodeRenderingContext.SuppressUniqueIds] = suppressUniqueIds;
+            }
+
+            if (nodeWriter == null)
+            {
+                nodeWriter = new RuntimeNodeWriter();
+            }
+
+            var context = new DefaultCodeRenderingContext(codeWriter, nodeWriter, codeDocument, documentNode, options);
+            context.Visitor = new RenderChildrenVisitor(context);
+
+            return context;
+        }
+
+        private class RenderChildrenVisitor : IntermediateNodeVisitor
+        {
+            private readonly CodeRenderingContext _context;
+            public RenderChildrenVisitor(CodeRenderingContext context)
+            {
+                _context = context;
+            }
+
+            public override void VisitDefault(IntermediateNode node)
+            {
+                _context.CodeWriter.WriteLine("Render Children");
+            }
+        }
+
+    }
+}