Adding support for inheriting chunks from _ViewStarts as part of host

parsing.

Fixes #881

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/ChunkHelper.cs

@@ -0,0 +1,83 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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 Microsoft.AspNet.Mvc.Razor.Host;
+using Microsoft.AspNet.Razor.Generator.Compiler;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// Contains helper methods for dealing with Chunks
+    /// </summary>
+    public static class ChunkHelper
+    {
+        private const string TModelToken = "<TModel>";
+
+        /// <summary>
+        /// Attempts to cast the passed in <see cref="Chunk"/> to type <typeparamref name="TChunk"/> and throws if the
+        /// cast fails.
+        /// </summary>
+        /// <typeparam name="TChunk">The type to cast to.</typeparam>
+        /// <param name="chunk">The chunk to cast.</param>
+        /// <returns>The <paramref name="Chunk"/> cast to <typeparamref name="TChunk"/>.</returns>
+        /// <exception cref="ArgumentException"><paramref name="chunk"/> is not an instance of
+        /// <typeparamref name="TChunk"/>.</exception>
+        public static TChunk EnsureChunk<TChunk>([NotNull] Chunk chunk)
+            where TChunk : Chunk
+        {
+            var chunkOfT = chunk as TChunk;
+            if (chunkOfT == null)
+            {
+                var message = Resources.FormatArgumentMustBeOfType(typeof(TChunk).FullName);
+                throw new ArgumentException(message, "chunk");
+            }
+
+            return chunkOfT;
+        }
+
+        /// <summary>
+        /// Returns the <see cref="ModelChunk"/> used to determine the model name for the page generated
+        /// using the specified <paramref name="codeTree"/>
+        /// </summary>
+        /// <param name="codeTree">The <see cref="CodeTree"/> to scan for <see cref="ModelChunk"/>s in.</param>
+        /// <returns>The last <see cref="ModelChunk"/> in the <see cref="CodeTree"/> if found, null otherwise.
+        /// </returns>
+        public static ModelChunk GetModelChunk([NotNull] CodeTree codeTree)
+        {
+            // If there's more than 1 model chunk there will be a Razor error BUT we want intellisense to show up on
+            // the current model chunk that the user is typing.
+            return codeTree.Chunks
+                           .OfType<ModelChunk>()
+                           .LastOrDefault();
+        }
+
+        /// <summary>
+        /// Returns the type name of the Model specified via a <see cref="ModelChunk"/> in the
+        /// <paramref name="codeTree"/> if specified or the default model type.
+        /// </summary>
+        /// <param name="codeTree">The <see cref="CodeTree"/> to scan for <see cref="ModelChunk"/>s in.</param>
+        /// <param name="defaultModelName">The <see cref="Type"/> name of the default model.</param>
+        /// <returns>The model type name for the generated page.</returns>
+        public static string GetModelTypeName([NotNull] CodeTree codeTree,
+                                              [NotNull] string defaultModelName)
+        {
+            var modelChunk = GetModelChunk(codeTree);
+            return modelChunk != null ? modelChunk.ModelType : defaultModelName;
+        }
+
+        /// <summary>
+        /// Returns a string with the &lt;TModel&gt; token replaced with the value specified in 
+        /// <paramref name="modelName"/>.
+        /// </summary>
+        /// <param name="value">The string to replace the token in.</param>
+        /// <param name="modelName">The model name to replace with.</param>
+        /// <returns>A string with the token replaced.</returns>
+        public static string ReplaceTModel([NotNull] string value,
+                                           [NotNull] string modelName)
+        {
+            return value.Replace(TModelToken, modelName);
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/ChunkInheritanceUtility.cs

@@ -0,0 +1,147 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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 System.IO;
+using System.Linq;
+using Microsoft.AspNet.FileSystems;
+using Microsoft.AspNet.Razor;
+using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Razor.Parser;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// A utility type for supporting inheritance of chunks into a page from _ViewStart pages that apply to it.
+    /// </summary>
+    public class ChunkInheritanceUtility
+    {
+        private readonly IReadOnlyList<Chunk> _defaultInheritedChunks;
+
+        /// <summary>
+        /// Instantiates a new instance of <see cref="ChunkInheritanceUtility"/>.
+        /// </summary>
+        /// <param name="codeTree">The <see cref="CodeTree"/> instance to add <see cref="Chunk"/>s to.</param>
+        /// <param name="defaultInheritedChunks">The list of <see cref="Chunk"/>s inherited by default.</param>
+        /// <param name="defaultModel">The model type used in the event no model is specified via the
+        /// <c>@model</c> keyword.</param>
+        public ChunkInheritanceUtility([NotNull] CodeTree codeTree,
+                                       [NotNull] IReadOnlyList<Chunk> defaultInheritedChunks,
+                                       [NotNull] string defaultModel)
+        {
+            CodeTree = codeTree;
+            _defaultInheritedChunks = defaultInheritedChunks;
+            ChunkMergers = GetMergerMappings(codeTree, defaultModel);
+        }
+
+        /// <summary>
+        /// Gets the CodeTree to add inherited <see cref="Chunk"/> instances to.
+        /// </summary>
+        public CodeTree CodeTree { get; private set; }
+
+        /// <summary>
+        /// Gets a dictionary mapping <see cref="Chunk"/> type to the <see cref="IChunkMerger"/> used to merge
+        /// chunks of that type.
+        /// </summary>
+        public IDictionary<Type, IChunkMerger> ChunkMergers { get; private set; }
+
+        /// <summary>
+        /// Gets the list of chunks that are to be inherited by a specified page.
+        /// Chunks are inherited from _ViewStarts that are applicable to the page.
+        /// </summary>
+        /// <param name="razorHost">The <see cref="MvcRazorHost"/> used to parse _ViewStart pages.</param>
+        /// <param name="fileSystem">The filesystem that represents the application.</param>
+        /// <param name="appRoot">The root of the application.</param>
+        /// <param name="pagePath">The path of the page to locate inherited chunks for.</param>
+        /// <returns>A list of chunks that are applicable to the given page.</returns>
+        public List<Chunk> GetInheritedChunks([NotNull] MvcRazorHost razorHost,
+                                              [NotNull] IFileSystem fileSystem,
+                                              [NotNull] string appRoot,
+                                              [NotNull] string pagePath)
+        {
+            var inheritedChunks = new List<Chunk>();
+
+            var templateEngine = new RazorTemplateEngine(razorHost);
+            foreach (var viewStart in ViewStartUtility.GetViewStartLocations(appRoot, pagePath))
+            {
+                IFileInfo fileInfo;
+                if (fileSystem.TryGetFileInfo(viewStart, out fileInfo))
+                {
+                    var parsedTree = ParseViewFile(templateEngine, fileInfo);
+                    var chunksToAdd = parsedTree.Chunks
+                                                .Where(chunk => ChunkMergers.ContainsKey(chunk.GetType()));
+                    inheritedChunks.AddRange(chunksToAdd);
+                }
+            }
+
+            inheritedChunks.AddRange(_defaultInheritedChunks);
+
+            return inheritedChunks;
+        }
+
+        /// <summary>
+        /// Merges a list of chunks into the <see cref="CodeTree"/> instance.
+        /// </summary>
+        /// <param name="inherited">The list of chunks to merge.</param>
+        public void MergeInheritedChunks(List<Chunk> inherited)
+        {
+            var current = CodeTree.Chunks;
+
+            // We merge chunks into the codeTree in two passes. In the first pass, we traverse the CodeTree visiting
+            // a mapped IChunkMerger for types that are registered.
+            foreach (var chunk in current)
+            {
+                if (ChunkMergers.TryGetValue(chunk.GetType(), out var merger))
+                {
+                    merger.VisitChunk(chunk);
+                }
+            }
+
+            // In the second phase we invoke IChunkMerger.Merge for each chunk that has a mapped merger.
+            // During this phase, the merger can either add to the CodeTree or ignore the chunk based on the merging
+            // rules.
+            foreach (var chunk in inherited)
+            {
+                if (ChunkMergers.TryGetValue(chunk.GetType(), out var merger))
+                {
+                    // TODO: When mapping chunks, we should remove mapping information since it would be incorrect
+                    // to generate it in the page that inherits it. Tracked by #945
+                    merger.Merge(CodeTree, chunk);
+                }
+            }
+        }
+
+        private static Dictionary<Type, IChunkMerger> GetMergerMappings(CodeTree codeTree, string defaultModel)
+        {
+            var modelType = ChunkHelper.GetModelTypeName(codeTree, defaultModel);
+            return new Dictionary<Type, IChunkMerger>
+            {
+                { typeof(UsingChunk), new UsingChunkMerger() },
+                { typeof(InjectChunk), new InjectChunkMerger(modelType) },
+                { typeof(SetBaseTypeChunk), new SetBaseTypeChunkMerger(modelType) }
+            };
+        }
+
+        // TODO: This needs to be cached (#1016)
+        private CodeTree ParseViewFile(RazorTemplateEngine engine,
+                                       IFileInfo fileInfo)
+        {
+            using (var stream = fileInfo.CreateReadStream())
+            {
+                using (var streamReader = new StreamReader(stream))
+                {
+                    var parseResults = engine.ParseTemplate(streamReader);
+                    var className = ParserHelpers.SanitizeClassName(fileInfo.Name);
+                    var language = engine.Host.CodeLanguage;
+                    var codeGenerator = language.CreateCodeGenerator(className,
+                                                                     engine.Host.DefaultNamespace,
+                                                                     fileInfo.PhysicalPath,
+                                                                     engine.Host);
+                    codeGenerator.Visit(parseResults);
+                    return codeGenerator.Context.CodeTreeBuilder.CodeTree;
+                }
+            }
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/IChunkMerger.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Generator.Compiler;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// Defines the contract for merging <see cref="Chunk"/> instances from _ViewStart files.
+    /// </summary>
+    public interface IChunkMerger
+    {
+        /// <summary>
+        /// Visits a <see cref="Chunk"/> from the <see cref="CodeTree"/> to merge into.
+        /// </summary>
+        /// <param name="chunk">A <see cref="Chunk"/> from the tree.</param>
+        void VisitChunk(Chunk chunk);
+
+        /// <summary>
+        /// Merges an inherited <see cref="Chunk"/> into the <see cref="CodeTree"/>.
+        /// </summary>
+        /// <param name="codeTree">The <see cref="CodeTree"/> to merge into.</param>
+        /// <param name="chunk">The <see cref="Chunk"/> to merge.</param>
+        void Merge(CodeTree codeTree, Chunk chunk);
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/InjectChunkMerger.cs

@@ -0,0 +1,61 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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 System.Linq;
+using Microsoft.AspNet.Razor.Generator.Compiler;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// A <see cref="IChunkMerger"/> that merges <see cref="InjectChunk"/> instances.
+    /// </summary>
+    public class InjectChunkMerger : IChunkMerger
+    {
+        private readonly HashSet<string> _addedMemberNames = new HashSet<string>(StringComparer.Ordinal);
+        private string _modelType;
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="InjectChunkMerger"/>.
+        /// </summary>
+        /// <param name="modelType">The model type to be used to replace &lt;TModel&gt; tokens.</param>
+        public InjectChunkMerger([NotNull] string modelType)
+        {
+            _modelType = '<' + modelType + '>';
+        }
+
+        /// <inheritdoc />
+        public void VisitChunk([NotNull] Chunk chunk)
+        {
+            var injectChunk = ChunkHelper.EnsureChunk<InjectChunk>(chunk);
+            injectChunk.TypeName = ChunkHelper.ReplaceTModel(injectChunk.TypeName, _modelType);
+            _addedMemberNames.Add(injectChunk.MemberName);
+        }
+
+        /// <inheritdoc />
+        public void Merge([NotNull] CodeTree codeTree, [NotNull] Chunk chunk)
+        {
+            var injectChunk = ChunkHelper.EnsureChunk<InjectChunk>(chunk);
+            if (!_addedMemberNames.Contains(injectChunk.MemberName))
+            {
+                _addedMemberNames.Add(injectChunk.MemberName);
+                codeTree.Chunks.Add(TransformChunk(injectChunk));
+            }
+        }
+
+        private InjectChunk TransformChunk(InjectChunk injectChunk)
+        {
+            var typeName = ChunkHelper.ReplaceTModel(injectChunk.TypeName, _modelType);
+            if (typeName != injectChunk.TypeName)
+            {
+                return new InjectChunk(typeName, injectChunk.MemberName)
+                {
+                    Start = injectChunk.Start,
+                    Association = injectChunk.Association
+                };
+            }
+            return injectChunk;
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/SetBaseTypeChunkMerger.cs

@@ -0,0 +1,62 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Generator.Compiler;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// A <see cref="IChunkMerger"/> that merges <see cref="SetBaseTypeChunk"/> instances.
+    /// </summary>
+    public class SetBaseTypeChunkMerger : IChunkMerger
+    {
+        private readonly string _modelType;
+        private bool _isBaseTypeSet;
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="SetBaseTypeChunkMerger"/>.
+        /// </summary>
+        /// <param name="defaultModelType">The type name of the model used by default.</param>
+        public SetBaseTypeChunkMerger(string modelType)
+        {
+            _modelType = '<' + modelType + '>';
+        }
+
+        /// <inheritdoc />
+        public void VisitChunk([NotNull] Chunk chunk)
+        {
+            var setBaseTypeChunk = ChunkHelper.EnsureChunk<SetBaseTypeChunk>(chunk);
+            setBaseTypeChunk.TypeName = ChunkHelper.ReplaceTModel(setBaseTypeChunk.TypeName, _modelType);
+            _isBaseTypeSet = true;
+        }
+
+        /// <inheritdoc />
+        public void Merge([NotNull] CodeTree codeTree, [NotNull] Chunk chunk)
+        {
+            if (!_isBaseTypeSet)
+            {
+                var baseTypeChunk = ChunkHelper.EnsureChunk<SetBaseTypeChunk>(chunk);
+
+                // The base type can set exactly once and the first one we encounter wins.
+                _isBaseTypeSet = true;
+
+                codeTree.Chunks.Add(TransformChunk(baseTypeChunk));
+            }
+        }
+
+        private SetBaseTypeChunk TransformChunk(SetBaseTypeChunk setBaseTypeChunk)
+        {
+            var typeName = ChunkHelper.ReplaceTModel(setBaseTypeChunk.TypeName, _modelType);
+            if (typeName != setBaseTypeChunk.TypeName)
+            {
+                return new SetBaseTypeChunk
+                {
+                    TypeName = typeName,
+                    Start = setBaseTypeChunk.Start,
+                    Association = setBaseTypeChunk.Association
+                };
+            }
+            return setBaseTypeChunk;
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/Directives/UsingChunkMerger.cs

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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.AspNet.Razor.Generator.Compiler;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    /// <summary>
+    /// A <see cref="IChunkMerger"/> that merges <see cref="UsingChunk"/> instances.
+    /// </summary>
+    public class UsingChunkMerger : IChunkMerger
+    {
+        private readonly HashSet<string> _currentUsings = new HashSet<string>(StringComparer.Ordinal);
+
+        /// <inheritdoc />
+        public void VisitChunk([NotNull] Chunk chunk)
+        {
+            var namespaceChunk = ChunkHelper.EnsureChunk<UsingChunk>(chunk);
+            _currentUsings.Add(namespaceChunk.Namespace);
+        }
+
+        /// <inheritdoc />
+        public void Merge([NotNull] CodeTree codeTree, [NotNull] Chunk chunk)
+        {
+            var namespaceChunk = ChunkHelper.EnsureChunk<UsingChunk>(chunk);
+
+            if (!_currentUsings.Contains(namespaceChunk.Namespace))
+            {
+                _currentUsings.Add(namespaceChunk.Namespace);
+                codeTree.Chunks.Add(namespaceChunk);
+            }
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/InjectChunk.cs

@@ -10,8 +10,8 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// <summary>
         /// Represents the chunk for an @inject statement.
         /// </summary>
-        /// <param name="typeName">The type of object that would be injected</param>
-        /// <param name="propertyName">The member name the field is exposed to the page as.</param>
+        /// <param name="typeName">The type name of the property to be injected</param>
+        /// <param name="propertyName">The member name of the property to be injected.</param>
         public InjectChunk(string typeName,
                            string propertyName)
         {
@@ -19,8 +19,14 @@ namespace Microsoft.AspNet.Mvc.Razor
             MemberName = propertyName;
         }
 
-        public string TypeName { get; private set; }
+        /// <summary>
+        /// Gets or sets the type name of the property to be injected.
+        /// </summary>
+        public string TypeName { get; set; }
 
-        public string MemberName { get; private set; }
+        /// <summary>
+        /// Gets or sets the name of the property to be injected.
+        /// </summary>
+        public string MemberName { get; set; }
     }
 }

src/Microsoft.AspNet.Mvc.Razor.Host/MvcCSharpCodeBuilder.cs

@@ -1,10 +1,8 @@
 // Copyright (c) Microsoft Open Technologies, Inc. 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 System.Globalization;
-using System.Linq;
+using Microsoft.AspNet.Mvc.Razor.Directives;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
@@ -13,13 +11,16 @@ namespace Microsoft.AspNet.Mvc.Razor
 {
     public class MvcCSharpCodeBuilder : CSharpCodeBuilder
     {
-        private readonly MvcRazorHostOptions _hostOptions;
+        private readonly string _defaultModel;
+        private readonly string _activateAttribute;
 
-        public MvcCSharpCodeBuilder([NotNull] CodeGeneratorContext context, 
-                                    [NotNull] MvcRazorHostOptions hostOptions)
+        public MvcCSharpCodeBuilder([NotNull] CodeGeneratorContext context,
+                                    [NotNull] string defaultModel,
+                                    [NotNull] string activateAttribute)
             : base(context)
         {
-            _hostOptions = hostOptions;
+            _defaultModel = defaultModel;
+            _activateAttribute = activateAttribute;
         }
 
         private string Model { get; set; }
@@ -27,12 +28,9 @@ namespace Microsoft.AspNet.Mvc.Razor
         protected override CSharpCodeWritingScope BuildClassDeclaration(CSharpCodeWriter writer)
         {
             // Grab the last model chunk so it gets intellisense.
-            // NOTE: If there's more than 1 model chunk there will be a Razor error BUT we want intellisense to 
-            // show up on the current model chunk that the user is typing.
-            var modelChunk = Context.CodeTreeBuilder.CodeTree.Chunks.OfType<ModelChunk>()
-                                                                    .LastOrDefault();
+            var modelChunk = ChunkHelper.GetModelChunk(Context.CodeTreeBuilder.CodeTree);
 
-            Model = modelChunk != null ? modelChunk.ModelType : _hostOptions.DefaultModel;
+            Model = modelChunk != null ? modelChunk.ModelType : _defaultModel;
 
             // If there were any model chunks then we need to modify the class declaration signature.
             if (modelChunk != null)
@@ -62,7 +60,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             writer.WriteLineHiddenDirective();
 
-            var injectVisitor = new InjectChunkVisitor(writer, Context, _hostOptions.ActivateAttributeName);
+            var injectVisitor = new InjectChunkVisitor(writer, Context, _activateAttribute);
             injectVisitor.Accept(Context.CodeTreeBuilder.CodeTree.Chunks);
 
             writer.WriteLine();

src/Microsoft.AspNet.Mvc.Razor.Host/MvcRazorHost.cs

@@ -1,49 +1,71 @@
 // Copyright (c) Microsoft Open Technologies, Inc. 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 System.IO;
-using System.Linq;
+using Microsoft.AspNet.FileSystems;
+using Microsoft.AspNet.Mvc.Razor.Directives;
 using Microsoft.AspNet.Razor;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Parser;
+using Microsoft.Framework.Runtime;
 
 namespace Microsoft.AspNet.Mvc.Razor
 {
     public class MvcRazorHost : RazorEngineHost, IMvcRazorHost
     {
-        private const string ViewNamespace = "ASP";
-
-        private static readonly string[] _defaultNamespaces = new[] 
-        { 
+        private const string BaseType = "Microsoft.AspNet.Mvc.Razor.RazorPage";
+        private static readonly string[] _defaultNamespaces = new[]
+        {
             "System",
             "System.Linq",
             "System.Collections.Generic",
             "Microsoft.AspNet.Mvc",
             "Microsoft.AspNet.Mvc.Rendering",
         };
+        private static readonly Chunk[] _defaultInheritedChunks = new[]
+        {
+            new InjectChunk("Microsoft.AspNet.Mvc.Rendering.IHtmlHelper<TModel>", "Html"),
+            new InjectChunk("Microsoft.AspNet.Mvc.IViewComponentHelper", "Component"),
+            new InjectChunk("Microsoft.AspNet.Mvc.IUrlHelper", "Url"),
+        };
 
-        private readonly MvcRazorHostOptions _hostOptions;
-
+        private readonly string _appRoot;
+        private readonly IFileSystem _fileSystem;
         // CodeGenerationContext.DefaultBaseClass is set to MyBaseType<dynamic>. 
         // This field holds the type name without the generic decoration (MyBaseType)
         private readonly string _baseType;
 
-        public MvcRazorHost(Type baseType)
-            : this(baseType.FullName)
+        /// <summary>
+        /// Initializes a new instance of <see cref="MvcRazorHost"/> with the specified
+        /// <param name="appEnvironment"/>.
+        /// </summary>
+        /// <param name="appEnvironment">Contains information about the executing application.</param>
+        public MvcRazorHost(IApplicationEnvironment appEnvironment)
+            : this(appEnvironment.ApplicationBasePath,
+                   new PhysicalFileSystem(appEnvironment.ApplicationBasePath))
         {
         }
 
-        public MvcRazorHost(string baseType)
+        /// <summary>
+        /// Initializes a new instance of <see cref="MvcRazorHost"/> at the specified application root
+        /// and <paramref name="fileSystem"/>.
+        /// </summary>
+        /// <param name="applicationBasePath">The base path of the application.</param>
+        /// <param name="fileSystem">
+        /// A <see cref="IFileSystem"/> rooted at the <paramref name="applicationBasePath"/>.
+        /// </param>
+        protected internal MvcRazorHost(string applicationBasePath,
+                                        IFileSystem fileSystem)
             : base(new CSharpRazorCodeLanguage())
         {
-            // TODO: this needs to flow from the application rather than being initialized here.
-            // Tracked by #774
-            _hostOptions = new MvcRazorHostOptions();
-            _baseType = baseType;
-            DefaultBaseClass = baseType + '<' + _hostOptions.DefaultModel + '>';
+            _appRoot = applicationBasePath;
+            _fileSystem = fileSystem;
+            _baseType = BaseType;
+
+            DefaultBaseClass = BaseType + '<' + DefaultModel + '>';
+            DefaultNamespace = "Asp";
             GeneratedClassContext = new GeneratedClassContext(
                 executeMethodName: "ExecuteAsync",
                 writeMethodName: "Write",
@@ -62,51 +84,64 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
         }
 
+        /// <summary>
+        /// Gets the model type used by default when no model is specified.
+        /// </summary>
+        /// <remarks>This value is used as the generic type argument for the base type </remarks>
+        public virtual string DefaultModel
+        {
+            get { return "dynamic"; }
+        }
+
+        /// <summary>
+        /// Gets the list of chunks that are injected by default by this host.
+        /// </summary>
+        public virtual IReadOnlyList<Chunk> DefaultInheritedChunks
+        {
+            get { return _defaultInheritedChunks; }
+        }
+
+        /// <summary>
+        /// Gets or sets the name attribute that is used to decorate properties that are injected and need to be
+        /// activated.
+        /// </summary>
+        public virtual string ActivateAttribute
+        {
+            get { return "Microsoft.AspNet.Mvc.ActivateAttribute"; }
+        }
+
+        /// <inheritdoc />
         public GeneratorResults GenerateCode(string rootRelativePath, Stream inputStream)
         {
             var className = ParserHelpers.SanitizeClassName(rootRelativePath);
             using (var reader = new StreamReader(inputStream))
             {
                 var engine = new RazorTemplateEngine(this);
-                return engine.GenerateCode(reader, className, ViewNamespace, rootRelativePath);
+                return engine.GenerateCode(reader, className, DefaultNamespace, rootRelativePath);
             }
         }
 
-        public override ParserBase DecorateCodeParser(ParserBase incomingCodeParser)
+        /// <inheritdoc />
+        public override ParserBase DecorateCodeParser([NotNull] ParserBase incomingCodeParser)
         {
             return new MvcRazorCodeParser(_baseType);
         }
 
-        public override CodeBuilder DecorateCodeBuilder(CodeBuilder incomingBuilder, CodeGeneratorContext context)
+        /// <inheritdoc />
+        public override CodeBuilder DecorateCodeBuilder([NotNull] CodeBuilder incomingBuilder,
+                                                        [NotNull] CodeGeneratorContext context)
         {
             UpdateCodeBuilder(context);
-            return new MvcCSharpCodeBuilder(context, _hostOptions);
+            return new MvcCSharpCodeBuilder(context, DefaultModel, ActivateAttribute);
         }
 
         private void UpdateCodeBuilder(CodeGeneratorContext context)
         {
-            var currentChunks = context.CodeTreeBuilder.CodeTree.Chunks;
-            var existingInjects = new HashSet<string>(currentChunks.OfType<InjectChunk>()
-                                                                   .Select(c => c.MemberName),
-                                                      StringComparer.Ordinal);
-
-            var modelChunk = currentChunks.OfType<ModelChunk>()
-                                          .LastOrDefault();
-            var model = _hostOptions.DefaultModel;
-            if (modelChunk != null)
-            {
-                model = modelChunk.ModelType;
-            }
-            model = '<' + model + '>';
-
-            // Locate properties by name that haven't already been injected in to the View.
-            var propertiesToAdd = _hostOptions.DefaultInjectedProperties
-                                              .Where(c => !existingInjects.Contains(c.MemberName));
-            foreach (var property in propertiesToAdd)
-            {
-                var typeName = property.TypeName.Replace("<TModel>", model);
-                currentChunks.Add(new InjectChunk(typeName, property.MemberName));
-            }
+            var chunkUtility = new ChunkInheritanceUtility(context.CodeTreeBuilder.CodeTree,
+                                                           DefaultInheritedChunks,
+                                                           DefaultModel);
+            var inheritedChunks = chunkUtility.GetInheritedChunks(this, _fileSystem, _appRoot, context.SourceFile);
+            chunkUtility.MergeInheritedChunks(inheritedChunks);
         }
     }
 }

src/Microsoft.AspNet.Mvc.Razor.Host/MvcRazorHostOptions.cs

@@ -1,42 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Represents configuration options for the Razor Host
-    /// </summary>
-    public class MvcRazorHostOptions
-    {
-        public MvcRazorHostOptions()
-        {
-            DefaultModel = "dynamic";
-            ActivateAttributeName = "Microsoft.AspNet.Mvc.ActivateAttribute";
-            DefaultInjectedProperties = new List<InjectDescriptor>()
-            {
-                new InjectDescriptor("Microsoft.AspNet.Mvc.Rendering.IHtmlHelper<TModel>", "Html"),
-                new InjectDescriptor("Microsoft.AspNet.Mvc.IViewComponentHelper", "Component"),
-                new InjectDescriptor("Microsoft.AspNet.Mvc.IUrlHelper", "Url"),
-            };
-        }
-
-        /// <summary>
-        /// Gets or sets the model that is used by default for generated views
-        /// when no model is explicily specified. Defaults to dynamic.
-        /// </summary>
-        public string DefaultModel { get; set; }
-
-        /// <summary>
-        /// Gets or sets the attribue that is used to decorate properties that are injected and need to
-        /// be activated.
-        /// </summary>
-        public string ActivateAttributeName { get; set; }
-
-        /// <summary>
-        /// Gets the list of properties that are injected by default.
-        /// </summary>
-        public IList<InjectDescriptor> DefaultInjectedProperties { get; private set; }
-    }
-}

src/Microsoft.AspNet.Mvc.Razor.Host/Properties/AssemblyInfo.cs

@@ -0,0 +1,6 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("Microsoft.AspNet.Mvc.Razor.Host.Test")]

src/Microsoft.AspNet.Mvc.Razor.Host/Properties/Resources.Designer.cs

@@ -26,6 +26,22 @@ namespace Microsoft.AspNet.Mvc.Razor.Host
             return GetString("ArgumentCannotBeNullOrEmpy");
         }
 
+        /// <summary>
+        /// Argument must be an instance of type '{0}'.
+        /// </summary>
+        internal static string ArgumentMustBeOfType
+        {
+            get { return GetString("ArgumentMustBeOfType"); }
+        }
+
+        /// <summary>
+        /// Argument must be an instance of type '{0}'.
+        /// </summary>
+        internal static string FormatArgumentMustBeOfType(object p0)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ArgumentMustBeOfType"), p0);
+        }
+
         /// <summary>
         /// The 'inherits' keyword is not allowed when a '{0}' keyword is used.
         /// </summary>

src/Microsoft.AspNet.Mvc.Razor.Host/Resources.resx

@@ -120,6 +120,9 @@
   <data name="ArgumentCannotBeNullOrEmpy" xml:space="preserve">
     <value>Argument cannot be null or empty.</value>
   </data>
+  <data name="ArgumentMustBeOfType" xml:space="preserve">
+    <value>Argument must be an instance of '{0}'.</value>
+  </data>
   <data name="MvcRazorCodeParser_CannotHaveModelAndInheritsKeyword" xml:space="preserve">
     <value>The 'inherits' keyword is not allowed when a '{0}' keyword is used.</value>
   </data>

src/Microsoft.AspNet.Mvc.Razor.Host/ViewStartUtility.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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 System.IO;
+using System.Linq;
+
+namespace Microsoft.AspNet.Mvc.Razor
+{
+    public static class ViewStartUtility
+    {
+        private const string ViewStartFileName = "_viewstart.cshtml";
+
+        /// <summary>
+        /// Determines if the given path represents a view start file.
+        /// </summary>
+        /// <param name="path">The path to inspect.</param>
+        /// <returns>True if the path is a view start file, false otherwise.</returns>
+        public static bool IsViewStart([NotNull] string path)
+        {
+            var fileName = Path.GetFileName(path);
+            return string.Equals(ViewStartFileName, fileName, StringComparison.OrdinalIgnoreCase);
+        }
+
+        /// <summary>
+        /// Gets the view start locations that are applicable to the specified path.
+        /// </summary>
+        /// <param name="applicationBase">The base of the application.</param>
+        /// <param name="path">The path to locate view starts for.</param>
+        /// <returns>A sequence of paths that represent potential view start locations.</returns>
+        /// <remarks>
+        /// This method returns paths starting from the directory of <paramref name="path"/> and moves
+        /// upwards until it hits the application root.
+        /// e.g.
+        /// /Views/Home/View.cshtml -> [ /Views/Home/_ViewStart.cshtml, /Views/_ViewStart.cshtml, /_ViewStart.cshtml ]
+        /// </remarks>
+        public static IEnumerable<string> GetViewStartLocations(string applicationBase, string path)
+        {
+            if (string.IsNullOrEmpty(path))
+            {
+                return Enumerable.Empty<string>();
+            }
+
+            applicationBase = TrimTrailingSlash(applicationBase);
+            var viewStartLocations = new List<string>();
+            var currentDir = GetViewDirectory(applicationBase, path);
+            while (IsSubDirectory(applicationBase, currentDir))
+            {
+                viewStartLocations.Add(Path.Combine(currentDir, ViewStartFileName));
+                currentDir = Path.GetDirectoryName(currentDir);
+            }
+
+            return viewStartLocations;
+        }
+
+        private static bool IsSubDirectory(string appRoot, string currentDir)
+        {
+            return currentDir.StartsWith(appRoot, StringComparison.OrdinalIgnoreCase);
+        }
+
+        private static string GetViewDirectory(string appRoot, string viewPath)
+        {
+            if (viewPath.StartsWith("~/"))
+            {
+                viewPath = viewPath.Substring(2);
+            }
+            else if (viewPath[0] == Path.DirectorySeparatorChar ||
+                     viewPath[0] == Path.AltDirectorySeparatorChar)
+            {
+                viewPath = viewPath.Substring(1);
+            }
+
+            var viewDir = Path.GetDirectoryName(viewPath);
+            return Path.GetFullPath(Path.Combine(appRoot, viewDir));
+        }
+
+        private static string TrimTrailingSlash(string path)
+        {
+            if (path.Length > 0 &&
+                path[path.Length - 1] == Path.DirectorySeparatorChar)
+            {
+                return path.Substring(0, path.Length - 1);
+            }
+
+            return path;
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Razor.Host/project.json

@@ -4,8 +4,10 @@
     "warningsAsErrors": true
   },
   "dependencies": {
+    "Microsoft.AspNet.FileSystems": "1.0.0-*",
     "Microsoft.AspNet.Mvc.Common": "",
-    "Microsoft.AspNet.Razor": "4.0.0-*"
+    "Microsoft.AspNet.Razor": "4.0.0-*",
+    "Microsoft.Framework.Runtime.Interfaces":  "1.0.0-*"
   },
   "frameworks": {
     "net45": {

src/Microsoft.AspNet.Mvc.Razor/RazorPage.cs

@@ -99,11 +99,26 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// <inheritdoc />
         public abstract Task ExecuteAsync();
 
+        /// <summary>
+        /// Writes the specified <paramref name="value"/> with HTML encoding to <see cref="Output"/>.
+        /// </summary>
+        /// <param name="value">The <see cref="object"/> to write.</param>
         public virtual void Write(object value)
         {
             WriteTo(Output, value);
         }
 
+        /// <summary>
+        /// Writes the specified <paramref name="value"/> with HTML encoding to <paramref name="writer"/>.
+        /// </summary>
+        /// <param name="writer">The <see cref="TextWriter"/> instance to write to.</param>
+        /// <param name="value">The <see cref="object"/> to write.</param>
+        /// <remarks>
+        /// <paramref name="value"/>s of type <see cref="HtmlString"/> are written without encoding and the
+        /// <see cref="HelperResult.WriteTo(TextWriter)"/> is invoked for <see cref="HelperResult"/> types.
+        /// For all other types, the encoded result of <see cref="object.ToString"/> is written to the
+        /// <paramref name="writer"/>.
+        /// </remarks>
         public virtual void WriteTo(TextWriter writer, object content)
         {
             if (content != null)
@@ -128,11 +143,20 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
         }
 
-        public void WriteLiteral(object value)
+        /// <summary>
+        /// Writes the specified <paramref name="value"/> without HTML encoding to <see cref="Output"/>.
+        /// </summary>
+        /// <param name="value">The <see cref="object"/> to write.</param>
+        public virtual void WriteLiteral(object value)
         {
             WriteLiteralTo(Output, value);
         }
 
+        /// <summary>
+        /// Writes the specified <paramref name="value"/> without HTML encoding to the <paramref name="writer"/>.
+        /// </summary>
+        /// <param name="writer">The <see cref="TextWriter"/> instance to write to.</param>
+        /// <param name="value">The <see cref="object"/> to write.</param>
         public virtual void WriteLiteralTo(TextWriter writer, object text)
         {
             if (text != null)

src/Microsoft.AspNet.Mvc.Razor/ViewStartProvider.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using Microsoft.Framework.Runtime;
 
@@ -12,21 +11,20 @@ namespace Microsoft.AspNet.Mvc.Razor
     /// <inheritdoc />
     public class ViewStartProvider : IViewStartProvider
     {
-        private const string ViewStartFileName = "_ViewStart.cshtml";
         private readonly string _appRoot;
         private readonly IRazorPageFactory _pageFactory;
 
         public ViewStartProvider(IApplicationEnvironment appEnv,
                                  IRazorPageFactory pageFactory)
         {
-            _appRoot = TrimTrailingSlash(appEnv.ApplicationBasePath);
+            _appRoot = appEnv.ApplicationBasePath;
             _pageFactory = pageFactory;
         }
 
         /// <inheritdoc />
         public IEnumerable<IRazorPage> GetViewStartPages([NotNull] string path)
         {
-            var viewStartLocations = GetViewStartLocations(path);
+            var viewStartLocations = ViewStartUtility.GetViewStartLocations(_appRoot, path);
             var viewStarts = viewStartLocations.Select(_pageFactory.CreateInstance)
                                                 .Where(p => p != null)
                                                 .ToArray();
@@ -38,55 +36,5 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             return viewStarts;
         }
-
-        internal IEnumerable<string> GetViewStartLocations(string path)
-        {
-            if (string.IsNullOrEmpty(path))
-            {
-                return Enumerable.Empty<string>();
-            }
-
-            var viewStartLocations = new List<string>();
-            var currentDir = GetViewDirectory(_appRoot, path);
-            while (IsSubDirectory(_appRoot, currentDir))
-            {
-                viewStartLocations.Add(Path.Combine(currentDir, ViewStartFileName));
-                currentDir = Path.GetDirectoryName(currentDir);
-            }
-
-            return viewStartLocations;
-        }
-
-        private static bool IsSubDirectory(string appRoot, string currentDir)
-        {
-            return currentDir.StartsWith(appRoot, StringComparison.OrdinalIgnoreCase);
-        }
-
-        private static string GetViewDirectory(string appRoot, string viewPath)
-        {
-            if (viewPath.StartsWith("~/"))
-            {
-                viewPath = viewPath.Substring(2);
-            }
-            else if (viewPath[0] == Path.DirectorySeparatorChar || 
-                     viewPath[0] == Path.AltDirectorySeparatorChar)
-            {
-                viewPath = viewPath.Substring(1);
-            }
-
-            var viewDir = Path.GetDirectoryName(viewPath);
-            return Path.GetFullPath(Path.Combine(appRoot, viewDir));
-        }
-
-        private static string TrimTrailingSlash(string path)
-        {
-            if (path.Length > 0 &&
-                path[path.Length - 1] == Path.DirectorySeparatorChar)
-            {
-                return path.Substring(0, path.Length - 1);
-            }
-
-            return path;
-        }
     }
 }

src/Microsoft.AspNet.Mvc/MvcServices.cs

@@ -42,7 +42,8 @@ namespace Microsoft.AspNet.Mvc
             yield return describe.Transient<IControllerAssemblyProvider, DefaultControllerAssemblyProvider>();
             yield return describe.Transient<IActionDiscoveryConventions, DefaultActionDiscoveryConventions>();
 
-            yield return describe.Instance<IMvcRazorHost>(new MvcRazorHost(typeof(RazorPage).FullName));
+            // The host is designed to be discarded after consumption and is very inexpensive to initialize.
+            yield return describe.Transient<IMvcRazorHost, MvcRazorHost>();
 
             yield return describe.Singleton<ICompilationService, RoslynCompilationService>();
             yield return describe.Singleton<IRazorCompilationService, RazorCompilationService>();

test/Microsoft.AspNet.Mvc.FunctionalTests/DirectivesTest.cs

@@ -0,0 +1,50 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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.Diagnostics;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Builder;
+using Microsoft.AspNet.TestHost;
+using RazorWebSite;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.FunctionalTests
+{
+    public class DirectivesTest
+    {
+        private readonly IServiceProvider _provider = TestHelper.CreateServices("RazorWebSite");
+        private readonly Action<IBuilder> _app = new Startup().Configure;
+
+        [Fact]
+        public async Task ViewsInheritsUsingsAndInjectDirectivesFromViewStarts()
+        {
+            var expected = @"Hello Person1";
+            var server = TestServer.Create(_provider, _app);
+            var client = server.Handler;
+
+            // Act
+            var result = await client.GetAsync("http://localhost/Directives/ViewInheritsInjectAndUsingsFromViewStarts");
+
+            // Assert
+            var body = await result.HttpContext.Response.ReadBodyAsStringAsync();
+            Assert.Equal(expected, body.Trim());
+        }
+
+        [Fact]
+        public async Task ViewInheritsBasePageFromViewStarts()
+        {
+            var expected = @"WriteLiteral says:layout:Write says:Write says:Hello Person2";
+            var server = TestServer.Create(_provider, _app);
+            var client = server.Handler;
+
+            // Act
+            var result = await client.GetAsync("http://localhost/Directives/ViewInheritsBasePageFromViewStarts");
+
+            // Assert
+            var body = await result.HttpContext.Response.ReadBodyAsStringAsync();
+            Assert.Equal(expected, body.Trim());
+        }
+
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/Directives/ChunkInheritanceUtilityTest.cs

@@ -0,0 +1,153 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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.AspNet.Razor.Generator.Compiler;
+using Moq;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    public class ChunkInheritanceUtilityTest
+    {
+        [Fact]
+        public void GetInheritedChunks_ReadsChunksFromViewStartsInPath()
+        {
+            // Arrange
+            var appRoot = @"x:\myapproot";
+            var fileSystem = new TestFileSystem();
+            fileSystem.AddFile(@"x:\myapproot\views\accounts\_viewstart.cshtml", "@using AccountModels");
+            fileSystem.AddFile(@"x:\myapproot\views\Shared\_viewstart.cshtml", "@inject SharedHelper Shared");
+            fileSystem.AddFile(@"x:\myapproot\views\home\_viewstart.cshtml", "@using MyNamespace");
+            fileSystem.AddFile(@"x:\myapproot\views\_viewstart.cshtml",
+@"@inject MyHelper<TModel> Helper
+@inherits MyBaseType
+
+@{
+    Layout = ""test.cshtml"";
+}
+
+");
+            var host = new MvcRazorHost(appRoot, fileSystem);
+            var utility = new ChunkInheritanceUtility(new CodeTree(), new Chunk[0], "dynamic");
+
+            // Act
+            var chunks = utility.GetInheritedChunks(host,
+                                                    fileSystem,
+                                                    appRoot,
+                                                    @"x:\myapproot\views\home\Index.cshtml");
+
+            // Assert
+            Assert.Equal(3, chunks.Count);
+            var usingChunk = Assert.IsType<UsingChunk>(chunks[0]);
+            Assert.Equal("MyNamespace", usingChunk.Namespace);
+
+            var injectChunk = Assert.IsType<InjectChunk>(chunks[1]);
+            Assert.Equal("MyHelper<TModel>", injectChunk.TypeName);
+            Assert.Equal("Helper", injectChunk.MemberName);
+
+            var setBaseTypeChunk = Assert.IsType<SetBaseTypeChunk>(chunks[2]);
+            Assert.Equal("MyBaseType", setBaseTypeChunk.TypeName);
+        }
+
+        [Fact]
+        public void GetInheritedChunks_ReturnsEmptySequenceIfNoViewStartsArePresent()
+        {
+            // Arrange
+            var appRoot = @"x:\myapproot";
+            var fileSystem = new TestFileSystem();
+            fileSystem.AddFile(@"x:\myapproot\_viewstart.cs", string.Empty);
+            fileSystem.AddFile(@"x:\myapproot\views\_Layout.cshtml", string.Empty);
+            fileSystem.AddFile(@"x:\myapproot\views\home\_not-viewstart.cshtml", string.Empty);
+            var host = new MvcRazorHost(appRoot, fileSystem);
+            var utility = new ChunkInheritanceUtility(new CodeTree(), new Chunk[0], "dynamic");
+
+            // Act
+            var chunks = utility.GetInheritedChunks(host,
+                                                    fileSystem,
+                                                    appRoot,
+                                                    @"x:\myapproot\views\home\Index.cshtml");
+
+            // Assert
+            Assert.Empty(chunks);
+        }
+
+        [Fact]
+        public void GetInheritedChunks_ReturnsDefaultInheritedChunks()
+        {
+            // Arrange
+            var appRoot = @"x:\myapproot";
+            var fileSystem = new TestFileSystem();
+            fileSystem.AddFile(@"x:\myapproot\views\_viewstart.cshtml",
+@"@inject DifferentHelper<TModel> Html
+@using AppNamespace.Models
+@{
+    Layout = ""test.cshtml"";
+}
+
+");
+            var host = new MvcRazorHost(appRoot, fileSystem);
+            var defaultChunks = new Chunk[]
+            {
+                new InjectChunk("MyTestHtmlHelper", "Html"),
+                new UsingChunk { Namespace = "AppNamespace.Model" },
+            };
+            var utility = new ChunkInheritanceUtility(new CodeTree(), defaultChunks, "dynamic");
+
+            // Act
+            var chunks = utility.GetInheritedChunks(host,
+                                                    fileSystem,
+                                                    appRoot,
+                                                    @"x:\myapproot\views\home\Index.cshtml");
+
+            // Assert
+            Assert.Equal(4, chunks.Count);
+            var injectChunk = Assert.IsType<InjectChunk>(chunks[0]);
+            Assert.Equal("DifferentHelper<TModel>", injectChunk.TypeName);
+            Assert.Equal("Html", injectChunk.MemberName);
+
+            var usingChunk = Assert.IsType<UsingChunk>(chunks[1]);
+            Assert.Equal("AppNamespace.Models", usingChunk.Namespace);
+
+            injectChunk = Assert.IsType<InjectChunk>(chunks[2]);
+            Assert.Equal("MyTestHtmlHelper", injectChunk.TypeName);
+            Assert.Equal("Html", injectChunk.MemberName);
+
+            usingChunk = Assert.IsType<UsingChunk>(chunks[3]);
+            Assert.Equal("AppNamespace.Model", usingChunk.Namespace);
+        }
+
+        [Fact]
+        public void MergeChunks_VisitsChunksPriorToMerging()
+        {
+            // Arrange
+            var codeTree = new CodeTree();
+            codeTree.Chunks.Add(new LiteralChunk());
+            codeTree.Chunks.Add(new ExpressionBlockChunk());
+            codeTree.Chunks.Add(new ExpressionBlockChunk());
+            
+            var merger = new Mock<IChunkMerger>();
+            var mockSequence = new MockSequence();
+            merger.InSequence(mockSequence)
+                  .Setup(m => m.VisitChunk(It.IsAny<LiteralChunk>()))
+                  .Verifiable();
+            merger.InSequence(mockSequence)
+                   .Setup(m => m.Merge(codeTree, It.IsAny<LiteralChunk>()))
+                   .Verifiable();
+            var inheritedChunks = new List<Chunk>
+            {
+                new CodeAttributeChunk(),
+                new LiteralChunk()
+            };
+            var utility = new ChunkInheritanceUtility(codeTree, inheritedChunks, "dynamic");
+
+            // Act
+            utility.ChunkMergers[typeof(LiteralChunk)] = merger.Object;
+            utility.MergeInheritedChunks(inheritedChunks);
+
+            // Assert
+            merger.Verify();
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/Directives/InjectChunkMergerTest.cs

@@ -0,0 +1,160 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Testing;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    public class InjectChunkMergerTest
+    {
+        [Fact]
+        public void Visit_ThrowsIfThePassedInChunkIsNotAInjectChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of 'Microsoft.AspNet.Mvc.Razor.InjectChunk'.";
+            var merger = new InjectChunkMerger("dynamic");
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.VisitChunk(new LiteralChunk()), "chunk", expected);
+        }
+
+        [Theory]
+        [InlineData("MyApp.TestHelper<TModel>", "MyApp.TestHelper<Person>")]
+        [InlineData("TestBaseType", "TestBaseType")]
+        public void Visit_UpdatesTModelTokenToMatchModelType(string typeName, string expectedValue)
+        {
+            // Arrange
+            var chunk = new InjectChunk(typeName, "TestHelper");
+            var merger = new InjectChunkMerger("Person");
+
+            // Act
+            merger.VisitChunk(chunk);
+
+            // Assert
+            Assert.Equal(expectedValue, chunk.TypeName);
+            Assert.Equal("TestHelper", chunk.MemberName);
+        }
+
+        [Fact]
+        public void Merge_ThrowsIfThePassedInChunkIsNotAInjectChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of 'Microsoft.AspNet.Mvc.Razor.InjectChunk'.";
+            var merger = new InjectChunkMerger("dynamic");
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.Merge(new CodeTree(), new LiteralChunk()), "chunk", expected);
+        }
+
+        [Fact]
+        public void Merge_AddsChunkIfChunkWithMatchingPropertyNameWasNotVisitedInCodeTree()
+        {
+            // Arrange
+            var expectedType = "MyApp.MyHelperType";
+            var expectedProperty = "MyHelper";
+            var merger = new InjectChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new InjectChunk(expectedType, expectedProperty));
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var injectChunk = Assert.IsType<InjectChunk>(chunk);
+            Assert.Equal(expectedType, injectChunk.TypeName);
+            Assert.Equal(expectedProperty, injectChunk.MemberName);
+        }
+
+        [Fact]
+        public void Merge_IgnoresChunkIfChunkWithMatchingPropertyNameWasVisitedInCodeTree()
+        {
+            // Arrange
+            var merger = new InjectChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.VisitChunk(new InjectChunk("MyTypeA", "MyProperty"));
+            merger.Merge(codeTree, new InjectChunk("MyTypeB", "MyProperty"));
+
+            // Assert
+            Assert.Empty(codeTree.Chunks);
+        }
+
+        [Fact]
+        public void Merge_MatchesPropertyNameInCaseSensitiveManner()
+        {
+            // Arrange
+            var merger = new InjectChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.VisitChunk(new InjectChunk("MyType", "MyProperty"));
+            merger.Merge(codeTree, new InjectChunk("MyType", "myproperty"));
+            merger.Merge(codeTree, new InjectChunk("MyTypeB", "different-property"));
+
+            // Assert
+            Assert.Equal(2, codeTree.Chunks.Count);
+            var injectChunk = Assert.IsType<InjectChunk>(codeTree.Chunks[0]);
+            Assert.Equal("MyType", injectChunk.TypeName);
+            Assert.Equal("myproperty", injectChunk.MemberName);
+
+            injectChunk = Assert.IsType<InjectChunk>(codeTree.Chunks[1]);
+            Assert.Equal("MyTypeB", injectChunk.TypeName);
+            Assert.Equal("different-property", injectChunk.MemberName);
+        }
+
+        [Fact]
+        public void Merge_ResolvesModelNameInTypesWithTModelToken()
+        {
+            // Arrange
+            var merger = new InjectChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new InjectChunk("MyHelper<TModel>", "MyProperty"));
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var injectChunk = Assert.IsType<InjectChunk>(chunk);
+            Assert.Equal("MyHelper<dynamic>", injectChunk.TypeName);
+            Assert.Equal("MyProperty", injectChunk.MemberName);
+        }
+
+        [Fact]
+        public void Merge_ReplacesTModelTokensWithModel()
+        {
+            // Arrange
+            var merger = new InjectChunkMerger("MyTestModel2");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new InjectChunk("MyHelper<TModel>", "MyProperty"));
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var injectChunk = Assert.IsType<InjectChunk>(chunk);
+            Assert.Equal("MyHelper<MyTestModel2>", injectChunk.TypeName);
+            Assert.Equal("MyProperty", injectChunk.MemberName);
+        }
+
+        [Fact]
+        public void Merge_IgnoresChunkIfChunkWithMatchingPropertyNameWasPreviouslyMerged()
+        {
+            // Arrange
+            var merger = new InjectChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new InjectChunk("SomeType", "Property"));
+            merger.Merge(codeTree, new InjectChunk("SomeOtherType", "Property"));
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var injectChunk = Assert.IsType<InjectChunk>(chunk);
+            Assert.Equal("SomeType", injectChunk.TypeName);
+            Assert.Equal("Property", injectChunk.MemberName);
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/Directives/SetBaseTypeChunkMergerTest.cs

@@ -0,0 +1,104 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Testing;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    public class SetBaseTypeChunkMergerTest
+    {
+        [Fact]
+        public void Visit_ThrowsIfThePassedInChunkIsNotASetBaseTypeChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of "+
+                           "'Microsoft.AspNet.Razor.Generator.Compiler.SetBaseTypeChunk'.";
+            var merger = new SetBaseTypeChunkMerger("dynamic");
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.VisitChunk(new LiteralChunk()), "chunk", expected);
+        }
+
+        [Theory]
+        [InlineData("MyApp.BaseType<TModel>", "MyApp.BaseType<Person>")]
+        [InlineData("TestBaseType", "TestBaseType")]
+        public void Visit_UpdatesTModelTokenToMatchModelType(string typeName, string expectedValue)
+        {
+            // Arrange
+            var chunk = new SetBaseTypeChunk
+            {
+                TypeName = typeName,
+            };
+            var merger = new SetBaseTypeChunkMerger("Person");
+
+            // Act
+            merger.VisitChunk(chunk);
+
+            // Assert
+            Assert.Equal(expectedValue, chunk.TypeName);
+        }
+
+        [Fact]
+        public void Merge_ThrowsIfThePassedInChunkIsNotASetBaseTypeChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of " +
+                           "'Microsoft.AspNet.Razor.Generator.Compiler.SetBaseTypeChunk'.";
+            var merger = new SetBaseTypeChunkMerger("dynamic");
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.Merge(new CodeTree(), new LiteralChunk()), "chunk", expected);
+        }
+
+        [Fact]
+        public void Merge_SetsBaseTypeIfItHasNotBeenSetInCodeTree()
+        {
+            // Arrange
+            var expected = "MyApp.Razor.MyBaseType";
+            var merger = new SetBaseTypeChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new SetBaseTypeChunk { TypeName = expected });
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var setBaseTypeChunk = Assert.IsType<SetBaseTypeChunk>(chunk);
+            Assert.Equal(expected, setBaseTypeChunk.TypeName);
+        }
+
+        [Fact]
+        public void Merge_IgnoresSetBaseTypeChunksIfCodeTreeContainsOne()
+        {
+            // Arrange
+            var merger = new SetBaseTypeChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.VisitChunk(new SetBaseTypeChunk { TypeName = "MyBaseType1" });
+            merger.Merge(codeTree, new SetBaseTypeChunk { TypeName = "MyBaseType2" });
+
+            // Assert
+            Assert.Empty(codeTree.Chunks);
+        }
+
+        [Fact]
+        public void Merge_IgnoresSetBaseTypeChunksIfSetBaseTypeWasPreviouslyMerged()
+        {
+            // Arrange
+            var merger = new SetBaseTypeChunkMerger("dynamic");
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new SetBaseTypeChunk { TypeName = "MyBase1" });
+            merger.Merge(codeTree, new SetBaseTypeChunk { TypeName = "MyBase2" });
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var setBaseTypeChunk = Assert.IsType<SetBaseTypeChunk>(chunk);
+            Assert.Equal("MyBase1", setBaseTypeChunk.TypeName);
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/Directives/UsingChunkMergerTest.cs

@@ -0,0 +1,106 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Generator.Compiler;
+using Microsoft.AspNet.Testing;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Razor.Directives
+{
+    public class UsingChunkMergerTest
+    {
+        [Fact]
+        public void Visit_ThrowsIfThePassedInChunkIsNotAUsingChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of 'Microsoft.AspNet.Razor.Generator.Compiler.UsingChunk'.";
+            var merger = new UsingChunkMerger();
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.VisitChunk(new LiteralChunk()), "chunk", expected);
+        }
+
+        [Fact]
+        public void Merge_ThrowsIfThePassedInChunkIsNotAUsingChunk()
+        {
+            // Arrange
+            var expected = "Argument must be an instance of 'Microsoft.AspNet.Razor.Generator.Compiler.UsingChunk'.";
+            var merger = new UsingChunkMerger();
+
+            // Act and Assert
+            ExceptionAssert.ThrowsArgument(() => merger.Merge(new CodeTree(), new LiteralChunk()), "chunk", expected);
+        }
+
+        [Fact]
+        public void Merge_AddsNamespacesThatHaveNotBeenVisitedInCodeTree()
+        {
+            // Arrange
+            var expected = "MyApp.Models";
+            var merger = new UsingChunkMerger();
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.VisitChunk(new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+            merger.Merge(codeTree, new UsingChunk { Namespace = expected });
+
+            // Assert
+            var chunk = Assert.Single(codeTree.Chunks);
+            var usingChunk = Assert.IsType<UsingChunk>(chunk);
+            Assert.Equal(expected, usingChunk.Namespace);
+        }
+
+        [Fact]
+        public void Merge_IgnoresNamespacesThatHaveBeenVisitedInCodeTree()
+        {
+            // Arrange
+            var merger = new UsingChunkMerger();
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.VisitChunk(new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+
+            // Assert
+            Assert.Empty(codeTree.Chunks);
+        }
+
+        [Fact]
+        public void Merge_IgnoresNamespacesThatHaveBeenVisitedDuringMerge()
+        {
+            // Arrange
+            var merger = new UsingChunkMerger();
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.Mvc.Razor" });
+
+            // Assert
+            Assert.Equal(2, codeTree.Chunks.Count);
+            var chunk = Assert.IsType<UsingChunk>(codeTree.Chunks[0]);
+            Assert.Equal("Microsoft.AspNet.Mvc", chunk.Namespace);
+            chunk = Assert.IsType<UsingChunk>(codeTree.Chunks[1]);
+            Assert.Equal("Microsoft.AspNet.Mvc.Razor", chunk.Namespace);
+        }
+
+        [Fact]
+        public void Merge_MacthesNamespacesInCaseSensitiveManner()
+        {
+            // Arrange
+            var merger = new UsingChunkMerger();
+            var codeTree = new CodeTree();
+
+            // Act
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.Mvc" });
+            merger.Merge(codeTree, new UsingChunk { Namespace = "Microsoft.AspNet.mvc" });
+
+            // Assert
+            Assert.Equal(2, codeTree.Chunks.Count);
+            var chunk = Assert.IsType<UsingChunk>(codeTree.Chunks[0]);
+            Assert.Equal("Microsoft.AspNet.Mvc", chunk.Namespace);
+            chunk = Assert.IsType<UsingChunk>(codeTree.Chunks[1]);
+            Assert.Equal("Microsoft.AspNet.mvc", chunk.Namespace);
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/InjectChunkVisitorTest.cs

@@ -3,12 +3,14 @@
 
 using System.Collections.Generic;
 using System.IO;
+using Microsoft.AspNet.FileSystems;
 using Microsoft.AspNet.Razor;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
 using Microsoft.AspNet.Razor.Text;
+using Moq;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.Razor
@@ -114,7 +116,7 @@ MyType2 @MyPropertyName2
         public void InjectVisitor_GeneratesCorrectLineMappings()
         {
             // Arrange
-            var host = new MvcRazorHost("RazorView")
+            var host = new MvcRazorHost("appRoot", Mock.Of<IFileSystem>())
             {
                 DesignTimeMode = true
             };
@@ -124,8 +126,8 @@ MyType2 @MyPropertyName2
             var expectedCode = ReadResource("TestFiles/Output/Inject.cs");
             var expectedLineMappings = new List<LineMapping>
             {
-                BuildLineMapping(1, 0, 1, 32, 3, 0, 17),
-                BuildLineMapping(28, 1, 8, 573, 26, 8, 20)
+                BuildLineMapping(1, 0, 1, 30, 3, 0, 17),
+                BuildLineMapping(28, 1, 8, 598, 26, 8, 20)
             };
 
             // Act
@@ -146,7 +148,7 @@ MyType2 @MyPropertyName2
         public void InjectVisitorWithModel_GeneratesCorrectLineMappings()
         {
             // Arrange
-            var host = new MvcRazorHost("RazorView")
+            var host = new MvcRazorHost("appRoot", Mock.Of<IFileSystem>())
             {
                 DesignTimeMode = true
             };
@@ -156,9 +158,9 @@ MyType2 @MyPropertyName2
             var expectedCode = ReadResource("TestFiles/Output/InjectWithModel.cs");
             var expectedLineMappings = new List<LineMapping>
             {
-                BuildLineMapping(7, 0, 7, 126, 6, 7, 7),
-                BuildLineMapping(24, 1, 8, 562, 26, 8, 20),
-                BuildLineMapping(54, 2, 8, 732, 34, 8, 22)
+                BuildLineMapping(7, 0, 7, 151, 6, 7, 7),
+                BuildLineMapping(24, 1, 8, 587, 26, 8, 20),
+                BuildLineMapping(54, 2, 8, 757, 34, 8, 23)
             };
 
             // Act
@@ -188,7 +190,7 @@ MyType2 @MyPropertyName2
 
         private static CodeGeneratorContext CreateContext()
         {
-            return CodeGeneratorContext.Create(new MvcRazorHost("RazorView"),
+            return CodeGeneratorContext.Create(new MvcRazorHost("appRoot", Mock.Of<IFileSystem>()),
                                               "MyClass",
                                               "MyNamespace",
                                               string.Empty,
@@ -203,11 +205,11 @@ MyType2 @MyPropertyName2
                                                     int generatedCharacterIndex,
                                                     int contentLength)
         {
-            var documentLocation = new SourceLocation(documentAbsoluteIndex, 
-                                                      documentLineIndex, 
+            var documentLocation = new SourceLocation(documentAbsoluteIndex,
+                                                      documentLineIndex,
                                                       documentCharacterIndex);
-            var generatedLocation = new SourceLocation(generatedAbsoluteIndex, 
-                                                       generatedLineIndex, 
+            var generatedLocation = new SourceLocation(generatedAbsoluteIndex,
+                                                       generatedLineIndex,
                                                        generatedCharacterIndex);
 
             return new LineMapping(

test/Microsoft.AspNet.Mvc.Razor.Host.Test/ModelChunkVisitorTest.cs

@@ -4,12 +4,14 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using Microsoft.AspNet.FileSystems;
 using Microsoft.AspNet.Razor;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
 using Microsoft.AspNet.Razor.Text;
+using Moq;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.Razor
@@ -106,7 +108,7 @@ Environment.NewLine +
         public void ModelVisitor_GeneratesCorrectLineMappings()
         {
             // Arrange
-            var host = new MvcRazorHost("RazorView")
+            var host = new MvcRazorHost("appRoot", Mock.Of<IFileSystem>())
             {
                 DesignTimeMode = true
             };
@@ -116,7 +118,7 @@ Environment.NewLine +
             var expectedCode = ReadResource("TestFiles/Output/Model.cs");
             var expectedLineMappings = new List<LineMapping>
             {
-                BuildLineMapping(7, 0, 7, 126, 6, 7, 30),
+                BuildLineMapping(7, 0, 7, 151, 6, 7, 30),
             };
 
             // Act
@@ -146,7 +148,7 @@ Environment.NewLine +
 
         private static CodeGeneratorContext CreateContext()
         {
-            return CodeGeneratorContext.Create(new MvcRazorHost("RazorView"),
+            return CodeGeneratorContext.Create(new MvcRazorHost("appRoot", Mock.Of<IFileSystem>()),
                                               "MyClass",
                                               "MyNamespace",
                                               string.Empty,

test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileSystem.cs

@@ -0,0 +1,45 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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 System.IO;
+using System.Text;
+using Microsoft.AspNet.FileSystems;
+using Moq;
+
+namespace Microsoft.AspNet.Mvc.Razor
+{
+    public class TestFileSystem : IFileSystem
+    {
+        private readonly Dictionary<string, IFileInfo> _lookup =
+            new Dictionary<string, IFileInfo>(StringComparer.Ordinal);
+
+        public bool TryGetDirectoryContents(string subpath, out IEnumerable<IFileInfo> contents)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void AddFile(string path, string contents)
+        {
+            var fileInfo = new Mock<IFileInfo>();
+            fileInfo.Setup(f => f.CreateReadStream())
+                    .Returns(new MemoryStream(Encoding.UTF8.GetBytes(contents)));
+            fileInfo.SetupGet(f => f.PhysicalPath)
+                    .Returns(path);
+            fileInfo.SetupGet(f => f.Name)
+                    .Returns(Path.GetFileName(path));
+            AddFile(path, fileInfo.Object);
+        }
+
+        public void AddFile(string path, IFileInfo contents)
+        {
+            _lookup.Add(path, contents);
+        }
+
+        public bool TryGetFileInfo(string subpath, out IFileInfo fileInfo)
+        {
+            return _lookup.TryGetValue(subpath, out fileInfo);
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFiles/Output/Inject.cs

@@ -1,4 +1,4 @@
-namespace Razor
+namespace Asp
 {
 #line 1 ""
 using MyNamespace
@@ -8,7 +8,7 @@ using MyNamespace
     ;
     using System.Threading.Tasks;
 
-    public class __CompiledTemplate : RazorView<dynamic>
+    public class __CompiledTemplate : Microsoft.AspNet.Mvc.Razor.RazorPage<dynamic>
     {
         private static object @__o;
         private void @__RazorDesignTimeHelpers__()

test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFiles/Output/InjectWithModel.cs

@@ -1,8 +1,8 @@
-namespace Razor
+namespace Asp
 {
     using System.Threading.Tasks;
 
-    public class __CompiledTemplate : RazorView<
+    public class __CompiledTemplate : Microsoft.AspNet.Mvc.Razor.RazorPage<
 #line 1 ""
        MyModel
 
@@ -32,7 +32,7 @@
         [Microsoft.AspNet.Mvc.ActivateAttribute]
         public
 #line 3 ""
-        MyService<TModel> Html
+        MyService<MyModel> Html
 
 #line default
 #line hidden

test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFiles/Output/Model.cs

@@ -1,8 +1,8 @@
-namespace Razor
+namespace Asp
 {
     using System.Threading.Tasks;
 
-    public class __CompiledTemplate : RazorView<
+    public class __CompiledTemplate : Microsoft.AspNet.Mvc.Razor.RazorPage<
 #line 1 ""
        System.Collections.IEnumerable
 

test/Microsoft.AspNet.Mvc.Razor.Host.Test/ViewStartUtilityTest.cs

@@ -2,12 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
-using System.Diagnostics;
-using Microsoft.Framework.Runtime;
-using Moq;
 using Xunit;
 
-namespace Microsoft.AspNet.Mvc.Razor.Test
+namespace Microsoft.AspNet.Mvc.Razor
 {
     public class ViewStartProviderTest
     {
@@ -18,10 +15,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         {
             // Arrange
             var appPath = @"x:\test";
-            var provider = new ViewStartProvider(GetAppEnv(appPath), Mock.Of<IRazorPageFactory>());
 
             // Act
-            var result = provider.GetViewStartLocations(viewPath);
+            var result = ViewStartUtility.GetViewStartLocations(appPath, viewPath);
 
             // Assert
             Assert.Empty(result);
@@ -37,9 +33,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                     "/Views/Home/View.cshtml",
                     new[]
                     {
-                        @"x:\test\myapp\Views\Home\_ViewStart.cshtml",
-                        @"x:\test\myapp\Views\_ViewStart.cshtml",
-                        @"x:\test\myapp\_ViewStart.cshtml",
+                        @"x:\test\myapp\Views\Home\_viewstart.cshtml",
+                        @"x:\test\myapp\Views\_viewstart.cshtml",
+                        @"x:\test\myapp\_viewstart.cshtml",
                     }
                 };
 
@@ -49,9 +45,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                     "Views/Home/View.cshtml",
                     new[]
                     {
-                        @"x:\test\myapp\Views\Home\_ViewStart.cshtml",
-                        @"x:\test\myapp\Views\_ViewStart.cshtml",
-                        @"x:\test\myapp\_ViewStart.cshtml",
+                        @"x:\test\myapp\Views\Home\_viewstart.cshtml",
+                        @"x:\test\myapp\Views\_viewstart.cshtml",
+                        @"x:\test\myapp\_viewstart.cshtml",
                     }
                 };
 
@@ -61,9 +57,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                     "Views/Home/View.cshtml",
                     new[]
                     {
-                        @"x:\test\myapp\Views\Home\_ViewStart.cshtml",
-                        @"x:\test\myapp\Views\_ViewStart.cshtml",
-                        @"x:\test\myapp\_ViewStart.cshtml",
+                        @"x:\test\myapp\Views\Home\_viewstart.cshtml",
+                        @"x:\test\myapp\Views\_viewstart.cshtml",
+                        @"x:\test\myapp\_viewstart.cshtml",
                     }
                 };
             }
@@ -75,22 +71,11 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                                                                              string viewPath,
                                                                              IEnumerable<string> expected)
         {
-            // Arrange
-            var provider = new ViewStartProvider(GetAppEnv(appPath), Mock.Of<IRazorPageFactory>());
-
             // Act
-            var result = provider.GetViewStartLocations(viewPath);
+            var result = ViewStartUtility.GetViewStartLocations(appPath, viewPath);
 
             // Assert
             Assert.Equal(expected, result);
         }
-
-        private static IApplicationEnvironment GetAppEnv(string appPath)
-        {
-            var appEnv = new Mock<IApplicationEnvironment>();
-            appEnv.Setup(p => p.ApplicationBasePath)
-                  .Returns(appPath);
-            return appEnv.Object;
-        }
     }
 }

test/Microsoft.AspNet.Mvc.Razor.Host.Test/project.json

@@ -4,7 +4,8 @@
   },
   "resources": "TestFiles\\**",
   "dependencies": {
-    "Microsoft.AspNet.Mvc.Razor.Host" : "",
+    "Microsoft.AspNet.Mvc.Razor.Host": "",
+    "Microsoft.AspNet.Testing": "1.0.0-*",
     "Xunit.KRunner": "1.0.0-*"
   },
   "commands": {

test/WebSites/RazorWebSite/Controllers/DirectivesController.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Diagnostics;
+using Microsoft.AspNet.Mvc;
+
+namespace RazorWebSite
+{
+    public class DirectivesController : Controller
+    {
+        public ViewResult ViewInheritsInjectAndUsingsFromViewStarts()
+        {
+            return View(new Person { Name = "Person1" });
+        }
+
+        public ViewResult ViewInheritsBasePageFromViewStarts()
+        {
+            return View("/views/directives/scoped/ViewInheritsBasePageFromViewStarts.cshtml", 
+                        new Person { Name = "Person2" });
+        }
+    }
+}

test/WebSites/RazorWebSite/MyBasePage.cs

@@ -0,0 +1,23 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.IO;
+using Microsoft.AspNet.Mvc.Razor;
+
+namespace RazorWebSite
+{
+    public abstract class MyBasePage<TModel> : RazorPage<TModel>
+    {
+        public override void WriteLiteral(object value)
+        {
+            base.WriteLiteral("WriteLiteral says:");
+            base.WriteLiteral(value);
+        }
+
+        public override void Write(object value)
+        {
+            base.WriteLiteral("Write says:");
+            base.Write(value);
+        }
+    }
+}

test/WebSites/RazorWebSite/Services/InjectedHelper.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace RazorWebSite
+{
+    public class InjectedHelper
+    {
+        public string Greet(Person person)
+        {
+            return "Hello " + person.Name;
+        }
+    }
+}

test/WebSites/RazorWebSite/Startup.cs

@@ -14,6 +14,7 @@ namespace RazorWebSite
             {
                 // Add MVC services to the services container
                 services.AddMvc(configuration);
+                services.AddTransient<InjectedHelper>();
             });
 
             // Add MVC to the request pipeline

test/WebSites/RazorWebSite/Views/Directives/Scoped/ViewInheritsBasePageFromViewStarts.cshtml

@@ -0,0 +1 @@
+@MyHelper.Greet(Model)

test/WebSites/RazorWebSite/Views/Directives/Scoped/_Layout.cshtml

@@ -0,0 +1 @@
+layout:@RenderBody()

test/WebSites/RazorWebSite/Views/Directives/Scoped/_ViewStart.cshtml

@@ -0,0 +1,4 @@
+@inherits MyBasePage<TModel>
+@{ 
+    Layout = "/Views/Directives/Scoped/_Layout.cshtml";
+}

test/WebSites/RazorWebSite/Views/Directives/ViewInheritsInjectAndUsingsFromViewStarts.cshtml

@@ -0,0 +1,2 @@
+@model MyPerson
+@MyHelper.Greet(Model)

test/WebSites/RazorWebSite/Views/Directives/_ViewStart.cshtml

@@ -0,0 +1,2 @@
+@using MyPerson = RazorWebSite.Person
+@inject InjectedHelper MyHelper

test/WebSites/RazorWebSite/Views/Shared/_Partial.cshtml

@@ -1,2 +1,2 @@
-@model RazorWebSite.Address
+@model Address
 @ViewData.Model.ZipCode

test/WebSites/RazorWebSite/Views/_ViewStart.cshtml

@@ -0,0 +1 @@
+@using RazorWebSite