Redesign RazorViewEngine caching

Fixes #3337

src/Microsoft.AspNet.Mvc.Razor/Compilation/CompilationResult.cs

@@ -10,83 +10,63 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
     /// <summary>
     /// Represents the result of compilation.
     /// </summary>
-    public class CompilationResult
+    public struct CompilationResult
     {
         /// <summary>
-        /// Creates a new instance of <see cref="CompilationResult"/>.
+        /// Initializes a new instance of <see cref="CompilationResult"/> for a successful compilation.
-        /// </summary>
-        protected CompilationResult()
-        {
-        }
-
-        /// <summary>
-        /// Gets (or sets in derived types) the type produced as a result of compilation.
-        /// </summary>
-        /// <remarks>This property is <c>null</c> when compilation failed.</remarks>
-        public Type CompiledType { get; protected set; }
-
-        /// <summary>
-        /// Gets (or sets in derived types) the generated C# content that was compiled.
-        /// </summary>
-        public string CompiledContent { get; protected set; }
-
-        /// <summary>
-        /// Gets the <see cref="CompilationFailure"/>s produced from parsing or compiling the Razor file.
-        /// </summary>
-        /// <remarks>This property is <c>null</c> when compilation succeeded. An empty sequence
-        /// indicates a failed compilation.</remarks>
-        public IEnumerable<CompilationFailure> CompilationFailures { get; private set; }
-
-        /// <summary>
-        /// Gets the <see cref="CompilationResult"/>.
-        /// </summary>
-        /// <returns>The current <see cref="CompilationResult"/> instance.</returns>
-        /// <exception cref="CompilationFailedException">Thrown if compilation failed.</exception>
-        public CompilationResult EnsureSuccessful()
-        {
-            if (CompilationFailures != null)
-            {
-                throw new CompilationFailedException(CompilationFailures);
-            }
-
-            return this;
-        }
-
-        /// <summary>
-        /// Creates a <see cref="CompilationResult"/> for a failed compilation.
-        /// </summary>
-        /// <param name="compilationFailures"><see cref="CompilationFailure"/>s produced from parsing or
-        /// compiling the Razor file.</param>
-        /// <returns>A <see cref="CompilationResult"/> instance for a failed compilation.</returns>
-        public static CompilationResult Failed(IEnumerable<CompilationFailure> compilationFailures)
-        {
-            if (compilationFailures == null)
-            {
-                throw new ArgumentNullException(nameof(compilationFailures));
-            }
-
-            return new CompilationResult
-            {
-                CompilationFailures = compilationFailures
-            };
-        }
-
-        /// <summary>
-        /// Creates a <see cref="CompilationResult"/> for a successful compilation.
         /// </summary>
         /// <param name="type">The compiled type.</param>
-        /// <returns>A <see cref="CompilationResult"/> instance for a successful compilation.</returns>
+        public CompilationResult(Type type)
-        public static CompilationResult Successful(Type type)
         {
             if (type == null)
             {
                 throw new ArgumentNullException(nameof(type));
             }
 
-            return new CompilationResult
+            CompiledType = type;
+            CompilationFailures = null;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="CompilationResult"/> for a failed compilation.
+        /// </summary>
+        /// <param name="compilationFailures"><see cref="CompilationFailure"/>s produced from parsing or
+        /// compiling the Razor file.</param>
+        public CompilationResult(IEnumerable<CompilationFailure> compilationFailures)
+        {
+            if (compilationFailures == null)
             {
-                CompiledType = type
+                throw new ArgumentNullException(nameof(compilationFailures));
-            };
+            }
+
+            CompiledType = null;
+            CompilationFailures = compilationFailures;
+        }
+
+        /// <summary>
+        /// Gets the type produced as a result of compilation.
+        /// </summary>
+        /// <remarks>This property is <c>null</c> when compilation failed.</remarks>
+        public Type CompiledType { get; }
+
+        /// <summary>
+        /// Gets the <see cref="CompilationFailure"/>s produced from parsing or compiling the Razor file.
+        /// </summary>
+        /// <remarks>This property is <c>null</c> when compilation succeeded. An empty sequence
+        /// indicates a failed compilation.</remarks>
+        public IEnumerable<CompilationFailure> CompilationFailures { get; }
+
+        /// <summary>
+        /// Gets the <see cref="CompilationResult"/>.
+        /// </summary>
+        /// <returns>The current <see cref="CompilationResult"/> instance.</returns>
+        /// <exception cref="CompilationFailedException">Thrown if compilation failed.</exception>
+        public void EnsureSuccessful()
+        {
+            if (CompilationFailures != null)
+            {
+                throw new CompilationFailedException(CompilationFailures);
+            }
         }
     }
 }

src/Microsoft.AspNet.Mvc.Razor/Compilation/CompilerCache.cs

@@ -8,6 +8,7 @@ using System.Diagnostics;
 using System.Text;
 using Microsoft.AspNet.FileProviders;
 using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNet.Mvc.Razor.Compilation
 {
@@ -56,7 +57,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
 
             foreach (var item in precompiledViews)
             {
-                var cacheEntry = new CompilerCacheResult(CompilationResult.Successful(item.Value));
+                var cacheEntry = new CompilerCacheResult(new CompilationResult(item.Value));
                 _cache.Set(GetNormalizedPath(item.Key), cacheEntry);
             }
         }
@@ -95,33 +96,29 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             string normalizedPath,
             Func<RelativeFileInfo, CompilationResult> compile)
         {
-            CompilerCacheResult cacheResult;
             var fileInfo = _fileProvider.GetFileInfo(normalizedPath);
             MemoryCacheEntryOptions cacheEntryOptions;
-            CompilerCacheResult cacheResultToCache;
+            CompilerCacheResult cacheResult;
             if (!fileInfo.Exists)
             {
-                cacheResultToCache = CompilerCacheResult.FileNotFound;
+                var expirationToken = _fileProvider.Watch(normalizedPath);
-                cacheResult = CompilerCacheResult.FileNotFound;
+                cacheResult = new CompilerCacheResult(new[] { expirationToken });
 
                 cacheEntryOptions = new MemoryCacheEntryOptions();
-                cacheEntryOptions.AddExpirationToken(_fileProvider.Watch(normalizedPath));
+                cacheEntryOptions.AddExpirationToken(expirationToken);
             }
             else
             {
                 var relativeFileInfo = new RelativeFileInfo(fileInfo, normalizedPath);
-                var compilationResult = compile(relativeFileInfo).EnsureSuccessful();
+                var compilationResult = compile(relativeFileInfo);
+                compilationResult.EnsureSuccessful();
                 cacheEntryOptions = GetMemoryCacheEntryOptions(normalizedPath);
-
+                cacheResult = new CompilerCacheResult(
-                // By default the CompilationResult returned by IRoslynCompiler is an instance of
+                    compilationResult,
-                // UncachedCompilationResult. This type has the generated code as a string property and do not want
+                    cacheEntryOptions.ExpirationTokens);
-                // to cache it. We'll instead cache the unwrapped result.
-                cacheResultToCache = new CompilerCacheResult(
-                    CompilationResult.Successful(compilationResult.CompiledType));
-                cacheResult = new CompilerCacheResult(compilationResult);
             }
 
-            _cache.Set(normalizedPath, cacheResultToCache, cacheEntryOptions);
+            _cache.Set(normalizedPath, cacheResult, cacheEntryOptions);
             return cacheResult;
         }
 

src/Microsoft.AspNet.Mvc.Razor/Compilation/CompilerCacheResult.cs

@@ -2,46 +2,77 @@
 // 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.Extensions.Primitives;
 
 namespace Microsoft.AspNet.Mvc.Razor.Compilation
 {
     /// <summary>
     /// Result of <see cref="ICompilerCache"/>.
     /// </summary>
-    public class CompilerCacheResult
+    public struct CompilerCacheResult
     {
-        /// <summary>
-        /// Result of <see cref="ICompilerCache"/> when the specified file does not exist in the
-        /// file system.
-        /// </summary>
-        public static CompilerCacheResult FileNotFound { get; } = new CompilerCacheResult();
-
         /// <summary>
         /// Initializes a new instance of <see cref="CompilerCacheResult"/> with the specified
-        /// <see cref="CompilationResult"/>.
+        /// <see cref="Compilation.CompilationResult"/>.
         /// </summary>
-        /// <param name="compilationResult">The <see cref="Compilation.CompilationResult"/> </param>
+        /// <param name="compilationResult">The <see cref="Compilation.CompilationResult"/>.</param>
         public CompilerCacheResult(CompilationResult compilationResult)
+            : this(compilationResult, new IChangeToken[0])
         {
-            if (compilationResult == null)
-            {
-                throw new ArgumentNullException(nameof(compilationResult));
-            }
-
-            CompilationResult = compilationResult;
         }
 
         /// <summary>
-        /// Initializes a new instance of <see cref="CompilerCacheResult"/> for a failed file lookup.
+        /// Initializes a new instance of <see cref="CompilerCacheResult"/> with the specified
+        /// <see cref="Compilation.CompilationResult"/>.
         /// </summary>
-        protected CompilerCacheResult()
+        /// <param name="compilationResult">The <see cref="Compilation.CompilationResult"/>.</param>
+        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances that indicate when
+        /// this result has expired.</param>
+        public CompilerCacheResult(CompilationResult compilationResult, IList<IChangeToken> expirationTokens)
         {
+            if (expirationTokens == null)
+            {
+                throw new ArgumentNullException(nameof(expirationTokens));
+            }
+
+            CompilationResult = compilationResult;
+            Success = true;
+            ExpirationTokens = expirationTokens;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="CompilerCacheResult"/> for a file that could not be
+        /// found in the file system.
+        /// </summary>
+        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances that indicate when
+        /// this result has expired.</param>
+        public CompilerCacheResult(IList<IChangeToken> expirationTokens)
+        {
+            if (expirationTokens == null)
+            {
+                throw new ArgumentNullException(nameof(expirationTokens));
+            }
+
+            CompilationResult = default(CompilationResult);
+            Success = false;
+            ExpirationTokens = expirationTokens;
         }
 
         /// <summary>
         /// The <see cref="Compilation.CompilationResult"/>.
         /// </summary>
-        /// <remarks>This property is null when file lookup failed.</remarks>
+        /// <remarks>This property is not available when <see cref="Success"/> is <c>false</c>.</remarks>
         public CompilationResult CompilationResult { get; }
+
+        /// <summary>
+        /// <see cref="IChangeToken"/> instances that indicate when this result has expired.
+        /// </summary>
+        public IList<IChangeToken> ExpirationTokens { get; }
+
+        /// <summary>
+        /// Gets a value that determines if the view was successfully found and compiled.
+        /// </summary>
+        public bool Success { get; }
     }
 }

src/Microsoft.AspNet.Mvc.Razor/Compilation/RazorCompilationService.cs

@@ -100,7 +100,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
                 failures.Add(compilationFailure);
             }
 
-            return CompilationResult.Failed(failures);
+            return new CompilationResult(failures);
         }
 
         private DiagnosticMessage CreateDiagnosticMessage(RazorError error, string filePath)

src/Microsoft.AspNet.Mvc.Razor/Compilation/RoslynCompilationService.cs

@@ -149,7 +149,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
                     var type = assembly.GetExportedTypes()
                                        .First(t => t.Name.StartsWith(_classPrefix, StringComparison.Ordinal));
 
-                    return UncachedCompilationResult.Successful(type, compilationContent);
+                    return new CompilationResult(type);
                 }
             }
         }
@@ -214,7 +214,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
                 failures.Add(compilationFailure);
             }
 
-            return CompilationResult.Failed(failures);
+            return new CompilationResult(failures);
         }
 
         private static string GetFilePath(string relativePath, Diagnostic diagnostic)

src/Microsoft.AspNet.Mvc.Razor/Compilation/UncachedCompilationResult.cs

@@ -1,47 +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;
-
-namespace Microsoft.AspNet.Mvc.Razor.Compilation
-{
-    /// <summary>
-    /// Represents the result of compilation that does not come from the <see cref="ICompilerCache" />.
-    /// </summary>
-    public class UncachedCompilationResult : CompilationResult
-    {
-        private UncachedCompilationResult()
-        {
-        }
-
-        public string RazorFileContent { get; private set; }
-
-        /// <summary>
-        /// Creates a <see cref="UncachedCompilationResult"/> that represents a success in compilation.
-        /// </summary>
-        /// <param name="type">The compiled type.</param>
-        /// <param name="compiledContent">The generated C# content that was compiled.</param>
-        /// <returns>An <see cref="UncachedCompilationResult"/> instance that indicates a successful
-        /// compilation.</returns>
-        public static UncachedCompilationResult Successful(
-            Type type,
-            string compiledContent)
-        {
-            if (type == null)
-            {
-                throw new ArgumentNullException(nameof(type));
-            }
-
-            if (compiledContent == null)
-            {
-                throw new ArgumentNullException(nameof(compiledContent));
-            }
-
-            return new UncachedCompilationResult
-            {
-                CompiledType = type,
-                CompiledContent = compiledContent,
-            };
-        }
-    }
-}

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

@@ -7,10 +7,10 @@ using Microsoft.AspNet.Mvc.Razor.Compilation;
 namespace Microsoft.AspNet.Mvc.Razor
 {
     /// <summary>
-    /// Represents a <see cref="IRazorPageFactory"/> that creates <see cref="RazorPage"/> instances
+    /// Represents a <see cref="IRazorPageFactoryProvider"/> that creates <see cref="RazorPage"/> instances
     /// from razor files in the file system.
     /// </summary>
-    public class VirtualPathRazorPageFactory : IRazorPageFactory
+    public class DefaultRazorPageFactoryProvider : IRazorPageFactoryProvider
     {
         /// <remarks>
         /// This delegate holds on to an instance of <see cref="IRazorCompilationService"/>.
@@ -20,11 +20,11 @@ namespace Microsoft.AspNet.Mvc.Razor
         private ICompilerCache _compilerCache;
 
         /// <summary>
-        /// Initializes a new instance of <see cref="VirtualPathRazorPageFactory"/>.
+        /// Initializes a new instance of <see cref="DefaultRazorPageFactoryProvider"/>.
         /// </summary>
         /// <param name="razorCompilationService">The <see cref="IRazorCompilationService"/>.</param>
         /// <param name="compilerCacheProvider">The <see cref="ICompilerCacheProvider"/>.</param>
-        public VirtualPathRazorPageFactory(
+        public DefaultRazorPageFactoryProvider(
             IRazorCompilationService razorCompilationService,
             ICompilerCacheProvider compilerCacheProvider)
         {
@@ -46,7 +46,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         }
 
         /// <inheritdoc />
-        public IRazorPage CreateInstance(string relativePath)
+        public RazorPageFactoryResult CreateFactory(string relativePath)
         {
             if (relativePath == null)
             {
@@ -58,18 +58,33 @@ namespace Microsoft.AspNet.Mvc.Razor
                 // For tilde slash paths, drop the leading ~ to make it work with the underlying IFileProvider.
                 relativePath = relativePath.Substring(1);
             }
-
             var result = CompilerCache.GetOrAdd(relativePath, _compileDelegate);
-
+            if (result.Success)
-            if (result == CompilerCacheResult.FileNotFound)
             {
-                return null;
+                var pageFactory = GetPageFactory(result.CompilationResult.CompiledType, relativePath);
+                return new RazorPageFactoryResult(pageFactory, result.ExpirationTokens);
             }
+            else
+            {
+                return new RazorPageFactoryResult(result.ExpirationTokens);
+            }
+        }
 
-            var page = (IRazorPage)Activator.CreateInstance(result.CompilationResult.CompiledType);
+        /// <summary>
-            page.Path = relativePath;
+        /// Creates a factory for <see cref="IRazorPage"/>.
-
+        /// </summary>
-            return page;
+        /// <param name="compiledType">The <see cref="Type"/> to produce an instance of <see cref="IRazorPage"/>
+        /// from.</param>
+        /// <param name="relativePath">The application relative path of the page.</param>
+        /// <returns>A factory for <paramref name="compiledType"/>.</returns>
+        protected virtual Func<IRazorPage> GetPageFactory(Type compiledType, string relativePath)
+        {
+            return () =>
+            {
+                var page = (IRazorPage)Activator.CreateInstance(compiledType);
+                page.Path = relativePath;
+                return page;
+            };
         }
     }
 }

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

@@ -1,176 +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.Concurrent;
-using System.Collections.Generic;
-using Microsoft.Extensions.Internal;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Default implementation of <see cref="IViewLocationCache"/>.
-    /// </summary>
-    public class DefaultViewLocationCache : IViewLocationCache
-    {
-        // A mapping of keys generated from ViewLocationExpanderContext to view locations.
-        private readonly ConcurrentDictionary<ViewLocationCacheKey, ViewLocationCacheResult> _cache;
-
-        /// <summary>
-        /// Initializes a new instance of <see cref="DefaultViewLocationCache"/>.
-        /// </summary>
-        public DefaultViewLocationCache()
-        {
-            _cache = new ConcurrentDictionary<ViewLocationCacheKey, ViewLocationCacheResult>(
-                ViewLocationCacheKeyComparer.Instance);
-        }
-
-        /// <inheritdoc />
-        public ViewLocationCacheResult Get(ViewLocationExpanderContext context)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            var cacheKey = GenerateKey(context, copyViewExpanderValues: false);
-            ViewLocationCacheResult result;
-            if (_cache.TryGetValue(cacheKey, out result))
-            {
-                return result;
-            }
-
-            return ViewLocationCacheResult.None;
-        }
-
-        /// <inheritdoc />
-        public void Set(
-            ViewLocationExpanderContext context,
-            ViewLocationCacheResult value)
-        {
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            var cacheKey = GenerateKey(context, copyViewExpanderValues: true);
-            _cache.TryAdd(cacheKey, value);
-        }
-
-        // Internal for unit testing
-        internal static ViewLocationCacheKey GenerateKey(
-            ViewLocationExpanderContext context,
-            bool copyViewExpanderValues)
-        {
-            var controller = RazorViewEngine.GetNormalizedRouteValue(
-                context.ActionContext,
-                RazorViewEngine.ControllerKey);
-
-            var area = RazorViewEngine.GetNormalizedRouteValue(
-                context.ActionContext,
-                RazorViewEngine.AreaKey);
-
-
-            var values = context.Values;
-            if (values != null && copyViewExpanderValues)
-            {
-                // When performing a Get, avoid creating a copy of the values dictionary
-                values = new Dictionary<string, string>(values, StringComparer.Ordinal);
-            }
-
-            return new ViewLocationCacheKey(
-                context.ViewName,
-                controller,
-                area,
-                context.IsPartial,
-                values);
-        }
-
-        // Internal for unit testing
-        internal class ViewLocationCacheKeyComparer : IEqualityComparer<ViewLocationCacheKey>
-        {
-            public static readonly ViewLocationCacheKeyComparer Instance = new ViewLocationCacheKeyComparer();
-
-            public bool Equals(ViewLocationCacheKey x, ViewLocationCacheKey y)
-            {
-                if (x.IsPartial != y.IsPartial ||
-                    !string.Equals(x.ViewName, y.ViewName, StringComparison.Ordinal) ||
-                    !string.Equals(x.ControllerName, y.ControllerName, StringComparison.Ordinal) ||
-                    !string.Equals(x.AreaName, y.AreaName, StringComparison.Ordinal))
-                {
-                    return false;
-                }
-
-                if (ReferenceEquals(x.Values, y.Values))
-                {
-                    return true;
-                }
-
-                if (x.Values == null || y.Values == null || (x.Values.Count != y.Values.Count))
-                {
-                    return false;
-                }
-
-                foreach (var item in x.Values)
-                {
-                    string yValue;
-                    if (!y.Values.TryGetValue(item.Key, out yValue) ||
-                        !string.Equals(item.Value, yValue, StringComparison.Ordinal))
-                    {
-                        return false;
-                    }
-                }
-
-                return true;
-            }
-
-            public int GetHashCode(ViewLocationCacheKey key)
-            {
-                var hashCodeCombiner = HashCodeCombiner.Start();
-                hashCodeCombiner.Add(key.IsPartial ? 1 : 0);
-                hashCodeCombiner.Add(key.ViewName, StringComparer.Ordinal);
-                hashCodeCombiner.Add(key.ControllerName, StringComparer.Ordinal);
-                hashCodeCombiner.Add(key.AreaName, StringComparer.Ordinal);
-
-                if (key.Values != null)
-                {
-                    foreach (var item in key.Values)
-                    {
-                        hashCodeCombiner.Add(item.Key, StringComparer.Ordinal);
-                        hashCodeCombiner.Add(item.Value, StringComparer.Ordinal);
-                    }
-                }
-
-                return hashCodeCombiner;
-            }
-        }
-
-        // Internal for unit testing
-        internal struct ViewLocationCacheKey
-        {
-            public ViewLocationCacheKey(
-                string viewName,
-                string controllerName,
-                string areaName,
-                bool isPartial,
-                IDictionary<string, string> values)
-            {
-                ViewName = viewName;
-                ControllerName = controllerName;
-                AreaName = areaName;
-                IsPartial = isPartial;
-                Values = values;
-            }
-
-            public string ViewName { get; }
-
-            public string ControllerName { get; }
-
-            public string AreaName { get; }
-
-            public bool IsPartial { get; }
-
-            public IDictionary<string, string> Values { get; }
-        }
-    }
-}

src/Microsoft.AspNet.Mvc.Razor/DependencyInjection/MvcRazorMvcCoreBuilderExtensions.cs

@@ -131,8 +131,6 @@ namespace Microsoft.Extensions.DependencyInjection
 
             services.TryAddSingleton<IRazorViewEngine, RazorViewEngine>();
 
-            // Caches view locations that are valid for the lifetime of the application.
-            services.TryAddSingleton<IViewLocationCache, DefaultViewLocationCache>();
             services.TryAdd(ServiceDescriptor.Singleton<IChunkTreeCache>(serviceProvider =>
             {
                 var cachedFileProvider = serviceProvider.GetRequiredService<IOptions<RazorViewEngineOptions>>();
@@ -147,10 +145,8 @@ namespace Microsoft.Extensions.DependencyInjection
 
             // In the default scenario the following services are singleton by virtue of being initialized as part of
             // creating the singleton RazorViewEngine instance.
-            services.TryAddTransient<IRazorViewFactory, RazorViewFactory>();
+            services.TryAddTransient<IRazorPageFactoryProvider, DefaultRazorPageFactoryProvider>();
-            services.TryAddTransient<IRazorPageFactory, VirtualPathRazorPageFactory>();
             services.TryAddTransient<IRazorCompilationService, RazorCompilationService>();
-            services.TryAddTransient<IViewStartProvider, ViewStartProvider>();
             services.TryAddTransient<IMvcRazorHost, MvcRazorHost>();
 
             // This caches Razor page activation details that are valid for the lifetime of the application.

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

@@ -6,13 +6,13 @@ namespace Microsoft.AspNet.Mvc.Razor
     /// <summary>
     /// Defines methods that are used for creating <see cref="IRazorPage"/> instances at a given path.
     /// </summary>
-    public interface IRazorPageFactory
+    public interface IRazorPageFactoryProvider
     {
         /// <summary>
-        /// Creates a <see cref="IRazorPage"/> for the specified path.
+        /// Creates a <see cref="IRazorPage"/> factory for the specified path.
         /// </summary>
         /// <param name="relativePath">The path to locate the page.</param>
-        /// <returns>The IRazorPage instance if it exists, null otherwise.</returns>
+        /// <returns>The <see cref="RazorPageFactoryResult"/> instance.</returns>
-        IRazorPage CreateInstance(string relativePath);
+        RazorPageFactoryResult CreateFactory(string relativePath);
     }
 }

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

@@ -1,23 +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.AspNet.Mvc.ViewEngines;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Defines methods to create <see cref="RazorView"/> instances with a given <see cref="IRazorPage"/>.
-    /// </summary>
-    public interface IRazorViewFactory
-    {
-        /// <summary>
-        /// Creates a <see cref="RazorView"/> providing it with the <see cref="IRazorPage"/> to execute.
-        /// </summary>
-        /// <param name="viewEngine">The <see cref="IRazorViewEngine"/> that was used to locate Layout pages
-        /// that will be part of <paramref name="page"/>'s execution.</param>
-        /// <param name="page">The <see cref="IRazorPage"/> instance to execute.</param>
-        /// <param name="isPartial">Determines if the view is to be executed as a partial.</param>
-        /// <returns>A <see cref="IView"/> instance that renders the contents of the <paramref name="page"/></returns>
-        IView GetView(IRazorViewEngine viewEngine, IRazorPage page, bool isPartial);
-    }
-}

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

@@ -1,27 +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.
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Specifies the contracts for caching view locations generated by <see cref="IViewLocationExpander"/>.
-    /// </summary>
-    public interface IViewLocationCache
-    {
-        /// <summary>
-        /// Gets a cached view location based on the specified <paramref name="context"/>.
-        /// </summary>
-        /// <param name="context">The <see cref="ViewLocationExpanderContext"/> for the current view location
-        /// expansion.</param>
-        /// <returns>The cached location, if available, <c>null</c> otherwise.</returns>
-        ViewLocationCacheResult Get(ViewLocationExpanderContext context);
-
-        /// <summary>
-        /// Adds a cache entry for values specified by <paramref name="context"/>.
-        /// </summary>
-        /// <param name="context">The <see cref="ViewLocationExpanderContext"/> for the current view location
-        /// expansion.</param>
-        /// <param name="value">The view location that is to be cached.</param>
-        void Set(ViewLocationExpanderContext context, ViewLocationCacheResult value);
-    }
-}

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

@@ -1,21 +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.Collections.Generic;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Defines methods for locating ViewStart pages that are applicable to a page.
-    /// </summary>
-    public interface IViewStartProvider
-    {
-        /// <summary>
-        /// Given a view path, returns a sequence of ViewStart instances
-        /// that are applicable to the specified view.
-        /// </summary>
-        /// <param name="path">The path of the page to locate ViewStart files for.</param>
-        /// <returns>A sequence of <see cref="IRazorPage"/> that represent ViewStart.</returns>
-        IEnumerable<IRazorPage> GetViewStartPages(string path);
-    }
-}

src/Microsoft.AspNet.Mvc.Razor/Precompilation/RazorPreCompiler.cs

@@ -146,8 +146,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Precompilation
                 return null;
             }
 
-            return GeneratePrecompiledAssembly(syntaxTrees.Where(tree => tree != null),
+            return GeneratePrecompiledAssembly(
-                                               razorFiles.Where(file => file != null));
+                syntaxTrees.Where(tree => tree != null),
+                razorFiles.Where(file => file != null));
         }
 
         protected virtual RazorFileInfoCollection GeneratePrecompiledAssembly(
@@ -174,13 +175,15 @@ namespace Microsoft.AspNet.Mvc.Razor.Precompilation
             var references = CompileContext.Compilation.References
                                                              .Concat(new[] { applicationReference });
 
-            var preCompilationOptions = CompilationSettings.CompilationOptions
+            var preCompilationOptions = CompilationSettings
-                                                           .WithOutputKind(OutputKind.DynamicallyLinkedLibrary);
+                .CompilationOptions
+                .WithOutputKind(OutputKind.DynamicallyLinkedLibrary);
 
-            var compilation = CSharpCompilation.Create(assemblyResourceName,
+            var compilation = CSharpCompilation.Create(
-                                                       options: preCompilationOptions,
+                assemblyResourceName,
-                                                       syntaxTrees: syntaxTrees,
+                options: preCompilationOptions,
-                                                       references: references);
+                syntaxTrees: syntaxTrees,
+                references: references);
 
             var generateSymbols = GenerateSymbols && SymbolsUtility.SupportsSymbolsGeneration();
             // These streams are returned to the runtime and consequently cannot be disposed.
@@ -279,9 +282,10 @@ namespace Microsoft.AspNet.Mvc.Razor.Precompilation
 
                 if (results.Success)
                 {
-                    var syntaxTree = SyntaxTreeGenerator.Generate(results.GeneratedCode,
+                    var syntaxTree = SyntaxTreeGenerator.Generate(
-                                                                  fileInfo.FileInfo.PhysicalPath,
+                        results.GeneratedCode,
-                                                                  CompilationSettings);
+                        fileInfo.FileInfo.PhysicalPath,
+                        CompilationSettings);
                     var fullTypeName = results.GetMainClassName(host, syntaxTree);
 
                     if (fullTypeName != null)
@@ -297,9 +301,10 @@ namespace Microsoft.AspNet.Mvc.Razor.Precompilation
                 }
                 else
                 {
-                    var diagnostics = results.ParserErrors
+                    var diagnostics = results
-                                             .Select(error => error.ToDiagnostics(fileInfo.FileInfo.PhysicalPath))
+                        .ParserErrors
-                                             .ToList();
+                        .Select(error => error.ToDiagnostics(fileInfo.FileInfo.PhysicalPath))
+                        .ToList();
 
                     return new PrecompilationCacheEntry(diagnostics);
                 }

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

@@ -0,0 +1,72 @@
+// 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.Extensions.Primitives;
+
+namespace Microsoft.AspNet.Mvc.Razor
+{
+    /// <summary>
+    /// Result of <see cref="IRazorPageFactoryProvider.CreateFactory(string)"/>.
+    /// </summary>
+    public struct RazorPageFactoryResult
+    {
+        /// <summary>
+        /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
+        /// specified <paramref name="expirationTokens"/>.
+        /// </summary>
+        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances.</param>
+        public RazorPageFactoryResult(IList<IChangeToken> expirationTokens)
+        {
+            if (expirationTokens == null)
+            {
+                throw new ArgumentNullException(nameof(expirationTokens));
+            }
+
+            ExpirationTokens = expirationTokens;
+            RazorPageFactory = null;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
+        /// specified <see cref="IRazorPage"/> factory.
+        /// </summary>
+        /// <param name="razorPageFactory">The <see cref="IRazorPage"/> factory.</param>
+        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances.</param>
+        public RazorPageFactoryResult(
+            Func<IRazorPage> razorPageFactory,
+            IList<IChangeToken> expirationTokens)
+        {
+            if (razorPageFactory == null)
+            {
+                throw new ArgumentNullException(nameof(razorPageFactory));
+            }
+
+            if (expirationTokens == null)
+            {
+                throw new ArgumentNullException(nameof(expirationTokens));
+            }
+
+            RazorPageFactory = razorPageFactory;
+            ExpirationTokens = expirationTokens;
+        }
+
+        /// <summary>
+        /// The <see cref="IRazorPage"/> factory.
+        /// </summary>
+        /// <remarks>This property is <c>null</c> when <see cref="Success"/> is <c>false</c>.</remarks>
+        public Func<IRazorPage> RazorPageFactory { get; }
+
+        /// <summary>
+        /// One or more <see cref="IChangeToken"/>s associated with this instance of
+        /// <see cref="RazorPageFactoryResult"/>.
+        /// </summary>
+        public IList<IChangeToken> ExpirationTokens { get; }
+
+        /// <summary>
+        /// Gets a value that determines if the page was successfully located.
+        /// </summary>
+        public bool Success => RazorPageFactory != null;
+    }
+}

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

@@ -7,9 +7,9 @@ using System.Collections.Generic;
 namespace Microsoft.AspNet.Mvc.Razor
 {
     /// <summary>
-    /// Represents the results of locating a <see cref="IRazorPage"/>.
+    /// Result of locating a <see cref="IRazorPage"/>.
     /// </summary>
-    public class RazorPageResult
+    public struct RazorPageResult
     {
         /// <summary>
         /// Initializes a new instance of <see cref="RazorPageResult"/> for a successful discovery.
@@ -30,6 +30,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             Name = name;
             Page = page;
+            SearchedLocations = null;
         }
 
         /// <summary>
@@ -50,6 +51,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
 
             Name = name;
+            Page = null;
             SearchedLocations = searchedLocations;
         }
 

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

@@ -22,7 +22,6 @@ namespace Microsoft.AspNet.Mvc.Razor
     {
         private readonly IRazorViewEngine _viewEngine;
         private readonly IRazorPageActivator _pageActivator;
-        private readonly IViewStartProvider _viewStartProvider;
         private readonly HtmlEncoder _htmlEncoder;
         private IPageExecutionListenerFeature _pageExecutionFeature;
 
@@ -31,22 +30,22 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// </summary>
         /// <param name="viewEngine">The <see cref="IRazorViewEngine"/> used to locate Layout pages.</param>
         /// <param name="pageActivator">The <see cref="IRazorPageActivator"/> used to activate pages.</param>
-        /// <param name="viewStartProvider">The <see cref="IViewStartProvider"/> used for discovery of _ViewStart
+        /// <param name="viewStartPages">The sequence of <see cref="IRazorPage" /> instances executed as _ViewStarts.
+        /// </param>
         /// <param name="razorPage">The <see cref="IRazorPage"/> instance to execute.</param>
         /// <param name="htmlEncoder">The HTML encoder.</param>
         /// <param name="isPartial">Determines if the view is to be executed as a partial.</param>
-        /// pages</param>
         public RazorView(
             IRazorViewEngine viewEngine,
             IRazorPageActivator pageActivator,
-            IViewStartProvider viewStartProvider,
+            IReadOnlyList<IRazorPage> viewStartPages,
             IRazorPage razorPage,
             HtmlEncoder htmlEncoder,
             bool isPartial)
         {
             _viewEngine = viewEngine;
             _pageActivator = pageActivator;
-            _viewStartProvider = viewStartProvider;
+            ViewStartPages = viewStartPages;
             RazorPage = razorPage;
             _htmlEncoder = htmlEncoder;
             IsPartial = isPartial;
@@ -68,6 +67,12 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// </summary>
         public bool IsPartial { get; }
 
+        /// <summary>
+        /// Gets the sequence of _ViewStart <see cref="IRazorPage"/> instances
+        /// that are executed by this view if <see cref="IsPartial"/> is <c>false</c>.
+        /// </summary>
+        public IReadOnlyList<IRazorPage> ViewStartPages { get; }
+
         private bool EnableInstrumentation
         {
             get { return _pageExecutionFeature != null; }
@@ -153,14 +158,13 @@ namespace Microsoft.AspNet.Mvc.Razor
 
         private async Task RenderViewStartAsync(ViewContext context)
         {
-            var viewStarts = _viewStartProvider.GetViewStartPages(RazorPage.Path);
-
             string layout = null;
             var oldFilePath = context.ExecutingFilePath;
             try
             {
-                foreach (var viewStart in viewStarts)
+                for (var i = 0; i < ViewStartPages.Count; i++)
                 {
+                    var viewStart = ViewStartPages[i];
                     context.ExecutingFilePath = viewStart.Path;
                     // Copy the layout value from the previous view start (if any) to the current.
                     viewStart.Layout = layout;

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

@@ -5,10 +5,12 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
-using System.Linq;
+using System.Text.Encodings.Web;
 using Microsoft.AspNet.Mvc.Routing;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.OptionsModel;
+using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNet.Mvc.Razor
 {
@@ -22,41 +24,34 @@ namespace Microsoft.AspNet.Mvc.Razor
     public class RazorViewEngine : IRazorViewEngine
     {
         private const string ViewExtension = ".cshtml";
-        internal const string ControllerKey = "controller";
+        private const string ControllerKey = "controller";
-        internal const string AreaKey = "area";
+        private const string AreaKey = "area";
+        private static readonly ViewLocationCacheItem[] EmptyViewStartLocationCacheItems =
+            new ViewLocationCacheItem[0];
+        private static readonly TimeSpan _cacheExpirationDuration = TimeSpan.FromMinutes(20);
 
-        private static readonly IEnumerable<string> _viewLocationFormats = new[]
+        private readonly IRazorPageFactoryProvider _pageFactory;
-        {
-            "/Views/{1}/{0}" + ViewExtension,
-            "/Views/Shared/{0}" + ViewExtension,
-        };
-
-        private static readonly IEnumerable<string> _areaViewLocationFormats = new[]
-        {
-            "/Areas/{2}/Views/{1}/{0}" + ViewExtension,
-            "/Areas/{2}/Views/Shared/{0}" + ViewExtension,
-            "/Views/Shared/{0}" + ViewExtension,
-        };
-
-        private readonly IRazorPageFactory _pageFactory;
-        private readonly IRazorViewFactory _viewFactory;
         private readonly IList<IViewLocationExpander> _viewLocationExpanders;
-        private readonly IViewLocationCache _viewLocationCache;
+        private readonly IRazorPageActivator _pageActivator;
+        private readonly HtmlEncoder _htmlEncoder;
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="RazorViewEngine" /> class.
+        /// Initializes a new instance of the <see cref="RazorViewEngine" />.
         /// </summary>
-        /// <param name="pageFactory">The page factory used for creating <see cref="IRazorPage"/> instances.</param>
         public RazorViewEngine(
-            IRazorPageFactory pageFactory,
+            IRazorPageFactoryProvider pageFactory,
-            IRazorViewFactory viewFactory,
+            IRazorPageActivator pageActivator,
-            IOptions<RazorViewEngineOptions> optionsAccessor,
+            HtmlEncoder htmlEncoder,
-            IViewLocationCache viewLocationCache)
+            IOptions<RazorViewEngineOptions> optionsAccessor)
         {
             _pageFactory = pageFactory;
-            _viewFactory = viewFactory;
+            _pageActivator = pageActivator;
             _viewLocationExpanders = optionsAccessor.Value.ViewLocationExpanders;
-            _viewLocationCache = viewLocationCache;
+            _htmlEncoder = htmlEncoder;
+            ViewLookupCache = new MemoryCache(new MemoryCacheOptions
+            {
+                CompactOnMemoryPressure = false
+            });
         }
 
         /// <summary>
@@ -72,10 +67,11 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// For example, the view for the <c>Test</c> action of <c>HomeController</c> should be located at
         /// <c>/Views/Home/Test.cshtml</c>. Locations such as <c>/views/home/test.cshtml</c> would not be discovered
         /// </remarks>
-        public virtual IEnumerable<string> ViewLocationFormats
+        public virtual IEnumerable<string> ViewLocationFormats { get; } = new[]
         {
-            get { return _viewLocationFormats; }
+            "/Views/{1}/{0}" + ViewExtension,
-        }
+            "/Views/Shared/{0}" + ViewExtension,
+        };
 
         /// <summary>
         /// Gets the locations where this instance of <see cref="RazorViewEngine"/> will search for views within an
@@ -92,15 +88,20 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// For example, the view for the <c>Test</c> action of <c>HomeController</c> should be located at
         /// <c>/Views/Home/Test.cshtml</c>. Locations such as <c>/views/home/test.cshtml</c> would not be discovered
         /// </remarks>
-        public virtual IEnumerable<string> AreaViewLocationFormats
+        public virtual IEnumerable<string> AreaViewLocationFormats { get; } = new[]
         {
-            get { return _areaViewLocationFormats; }
+            "/Areas/{2}/Views/{1}/{0}" + ViewExtension,
-        }
+            "/Areas/{2}/Views/Shared/{0}" + ViewExtension,
+            "/Views/Shared/{0}" + ViewExtension,
+        };
+
+        /// <summary>
+        /// A cache for results of view lookups.
+        /// </summary>
+        protected IMemoryCache ViewLookupCache { get; }
 
         /// <inheritdoc />
-        public ViewEngineResult FindView(
+        public ViewEngineResult FindView(ActionContext context, string viewName)
-            ActionContext context,
-            string viewName)
         {
             if (context == null)
             {
@@ -112,14 +113,12 @@ namespace Microsoft.AspNet.Mvc.Razor
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(viewName));
             }
 
-            var pageResult = GetRazorPageResult(context, viewName, isPartial: false);
+            var pageResult = GetViewLocationCacheResult(context, viewName, isPartial: false);
-            return CreateViewEngineResult(pageResult, _viewFactory, isPartial: false);
+            return CreateViewEngineResult(pageResult, viewName, isPartial: false);
         }
 
         /// <inheritdoc />
-        public ViewEngineResult FindPartialView(
+        public ViewEngineResult FindPartialView(ActionContext context, string partialViewName)
-            ActionContext context,
-            string partialViewName)
         {
             if (context == null)
             {
@@ -131,14 +130,12 @@ namespace Microsoft.AspNet.Mvc.Razor
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(partialViewName));
             }
 
-            var pageResult = GetRazorPageResult(context, partialViewName, isPartial: true);
+            var pageResult = GetViewLocationCacheResult(context, partialViewName, isPartial: true);
-            return CreateViewEngineResult(pageResult, _viewFactory, isPartial: true);
+            return CreateViewEngineResult(pageResult, partialViewName, isPartial: true);
         }
 
         /// <inheritdoc />
-        public RazorPageResult FindPage(
+        public RazorPageResult FindPage(ActionContext context, string pageName)
-            ActionContext context,
-            string pageName)
         {
             if (context == null)
             {
@@ -150,7 +147,16 @@ namespace Microsoft.AspNet.Mvc.Razor
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(pageName));
             }
 
-            return GetRazorPageResult(context, pageName, isPartial: true);
+            var cacheResult = GetViewLocationCacheResult(context, pageName, isPartial: true);
+            if (cacheResult.Success)
+            {
+                var razorPage = cacheResult.ViewEntry.PageFactory();
+                return new RazorPageResult(pageName, razorPage);
+            }
+            else
+            {
+                return new RazorPageResult(pageName, cacheResult.SearchedLocations);
+            }
         }
 
         /// <summary>
@@ -166,9 +172,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// <see cref="Abstractions.ActionDescriptor.RouteConstraints"/> for traditional routes to get route values
         /// produces consistently cased results.
         /// </remarks>
-        public static string GetNormalizedRouteValue(
+        public static string GetNormalizedRouteValue(ActionContext context, string key)
-            ActionContext context,
-            string key)
         {
             if (context == null)
             {
@@ -228,26 +232,14 @@ namespace Microsoft.AspNet.Mvc.Razor
             return stringRouteValue;
         }
 
-        private RazorPageResult GetRazorPageResult(
+        private ViewLocationCacheResult GetViewLocationCacheResult(
             ActionContext context,
             string pageName,
             bool isPartial)
         {
             if (IsApplicationRelativePath(pageName))
             {
-                var applicationRelativePath = pageName;
+                return LocatePageFromPath(pageName, isPartial);
-                if (!pageName.EndsWith(ViewExtension, StringComparison.OrdinalIgnoreCase))
-                {
-                    applicationRelativePath += ViewExtension;
-                }
-
-                var page = _pageFactory.CreateInstance(applicationRelativePath);
-                if (page != null)
-                {
-                    return new RazorPageResult(pageName, page);
-                }
-
-                return new RazorPageResult(pageName, new[] { pageName });
             }
             else
             {
@@ -255,105 +247,221 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
         }
 
-        private RazorPageResult LocatePageFromViewLocations(
+        private ViewLocationCacheResult LocatePageFromPath(string pageName, bool isPartial)
-            ActionContext context,
+        {
+            var applicationRelativePath = pageName;
+            if (!pageName.EndsWith(ViewExtension, StringComparison.OrdinalIgnoreCase))
+            {
+                applicationRelativePath += ViewExtension;
+            }
+
+            var cacheKey = new ViewLocationCacheKey(applicationRelativePath, isPartial);
+            ViewLocationCacheResult cacheResult;
+            if (!ViewLookupCache.TryGetValue(cacheKey, out cacheResult))
+            {
+                var expirationTokens = new HashSet<IChangeToken>();
+                cacheResult = CreateCacheResult(cacheKey, expirationTokens, applicationRelativePath, isPartial);
+
+                var cacheEntryOptions = new MemoryCacheEntryOptions();
+                cacheEntryOptions.SetSlidingExpiration(_cacheExpirationDuration);
+                foreach (var expirationToken in expirationTokens)
+                {
+                    cacheEntryOptions.AddExpirationToken(expirationToken);
+                }
+
+                // No views were found at the specified location. Create a not found result.
+                if (cacheResult == null)
+                {
+                    cacheResult = new ViewLocationCacheResult(new[] { pageName });
+                }
+
+                cacheResult = ViewLookupCache.Set<ViewLocationCacheResult>(
+                    cacheKey,
+                    cacheResult,
+                    cacheEntryOptions);
+            }
+
+            return cacheResult;
+        }
+
+        private ViewLocationCacheResult LocatePageFromViewLocations(
+            ActionContext actionContext,
             string pageName,
             bool isPartial)
         {
-            // Initialize the dictionary for the typical case of having controller and action tokens.
+            var controllerName = GetNormalizedRouteValue(actionContext, ControllerKey);
-            var areaName = GetNormalizedRouteValue(context, AreaKey);
+            var areaName = GetNormalizedRouteValue(actionContext, AreaKey);
+            var expanderContext = new ViewLocationExpanderContext(
+                actionContext,
+                pageName,
+                controllerName,
+                areaName,
+                isPartial);
+            Dictionary<string, string> expanderValues = null;
 
-            // Only use the area view location formats if we have an area token.
-            var viewLocations = !string.IsNullOrEmpty(areaName) ? AreaViewLocationFormats :
-                                                                  ViewLocationFormats;
-
-            var expanderContext = new ViewLocationExpanderContext(context, pageName, isPartial);
             if (_viewLocationExpanders.Count > 0)
             {
-                expanderContext.Values = new Dictionary<string, string>(StringComparer.Ordinal);
+                expanderValues = new Dictionary<string, string>(StringComparer.Ordinal);
+                expanderContext.Values = expanderValues;
 
-                // 1. Populate values from viewLocationExpanders.
                 // Perf: Avoid allocations
-                for( var i = 0; i < _viewLocationExpanders.Count; i++)
+                for (var i = 0; i < _viewLocationExpanders.Count; i++)
                 {
                     _viewLocationExpanders[i].PopulateValues(expanderContext);
                 }
             }
 
-            // 2. With the values that we've accumumlated so far, check if we have a cached result.
+            var cacheKey = new ViewLocationCacheKey(
-            IEnumerable<string> locationsToSearch = null;
+                expanderContext.ViewName,
-            var cachedResult = _viewLocationCache.Get(expanderContext);
+                expanderContext.ControllerName,
-            if (!cachedResult.Equals(ViewLocationCacheResult.None))
+                expanderContext.ViewName,
-            {
+                expanderContext.IsPartial,
-                if (cachedResult.IsFoundResult)
+                expanderValues);
-                {
-                    var page = _pageFactory.CreateInstance(cachedResult.ViewLocation);
 
-                    if (page != null)
+            ViewLocationCacheResult cacheResult;
-                    {
+            if (!ViewLookupCache.TryGetValue(cacheKey, out cacheResult))
-                        // 2a We have a cache entry where a view was previously found.
+            {
-                        return new RazorPageResult(pageName, page);
+                cacheResult = OnCacheMiss(expanderContext, cacheKey);
-                    }
-                }
-                else
-                {
-                    locationsToSearch = cachedResult.SearchedLocations;
-                }
             }
 
-            if (locationsToSearch == null)
+            return cacheResult;
+        }
+
+        private ViewLocationCacheResult OnCacheMiss(
+            ViewLocationExpanderContext expanderContext,
+            ViewLocationCacheKey cacheKey)
+        {
+            // Only use the area view location formats if we have an area token.
+            var viewLocations = !string.IsNullOrEmpty(expanderContext.AreaName) ?
+                AreaViewLocationFormats :
+                ViewLocationFormats;
+
+            for (var i = 0; i < _viewLocationExpanders.Count; i++)
             {
-                // 2b. We did not find a cached location or did not find a IRazorPage at the cached location.
+                viewLocations = _viewLocationExpanders[i].ExpandViewLocations(expanderContext, viewLocations);
-                // The cached value has expired and we need to look up the page.
-                foreach (var expander in _viewLocationExpanders)
-                {
-                    viewLocations = expander.ExpandViewLocations(expanderContext, viewLocations);
-                }
-
-                var controllerName = GetNormalizedRouteValue(context, ControllerKey);
-
-                locationsToSearch = viewLocations.Select(
-                    location => string.Format(
-                        CultureInfo.InvariantCulture,
-                        location,
-                        pageName,
-                        controllerName,
-                        areaName
-                    ));
             }
 
-            // 3. Use the expanded locations to look up a page.
+            ViewLocationCacheResult cacheResult = null;
             var searchedLocations = new List<string>();
-            foreach (var path in locationsToSearch)
+            var expirationTokens = new HashSet<IChangeToken>();
+            foreach (var location in viewLocations)
             {
-                var page = _pageFactory.CreateInstance(path);
+                var path = string.Format(
-                if (page != null)
+                    CultureInfo.InvariantCulture,
+                    location,
+                    expanderContext.ViewName,
+                    expanderContext.ControllerName,
+                    expanderContext.AreaName);
+
+                cacheResult = CreateCacheResult(cacheKey, expirationTokens, path, expanderContext.IsPartial);
+                if (cacheResult != null)
                 {
-                    // 3a. We found a page. Cache the set of values that produced it and return a found result.
+                    break;
-                    _viewLocationCache.Set(expanderContext, new ViewLocationCacheResult(path, searchedLocations));
-                    return new RazorPageResult(pageName, page);
                 }
 
                 searchedLocations.Add(path);
             }
 
-            // 3b. We did not find a page for any of the paths.
+            // No views were found at the specified location. Create a not found result.
-            _viewLocationCache.Set(expanderContext, new ViewLocationCacheResult(searchedLocations));
+            if (cacheResult == null)
-            return new RazorPageResult(pageName, searchedLocations);
+            {
+                cacheResult = new ViewLocationCacheResult(searchedLocations);
+            }
+
+            var cacheEntryOptions = new MemoryCacheEntryOptions();
+            cacheEntryOptions.SetSlidingExpiration(_cacheExpirationDuration);
+            foreach (var expirationToken in expirationTokens)
+            {
+                cacheEntryOptions.AddExpirationToken(expirationToken);
+            }
+
+            return ViewLookupCache.Set<ViewLocationCacheResult>(cacheKey, cacheResult, cacheEntryOptions);
+        }
+
+        private ViewLocationCacheResult CreateCacheResult(
+            ViewLocationCacheKey cacheKey,
+            HashSet<IChangeToken> expirationTokens,
+            string relativePath,
+            bool isPartial)
+        {
+            var factoryResult = _pageFactory.CreateFactory(relativePath);
+            if (factoryResult.ExpirationTokens != null)
+            {
+                for (var i = 0; i < factoryResult.ExpirationTokens.Count; i++)
+                {
+                    expirationTokens.Add(factoryResult.ExpirationTokens[i]);
+                }
+            }
+
+            if (factoryResult.Success)
+            {
+                // Don't need to lookup _ViewStarts for partials.
+                var viewStartPages = isPartial ?
+                    EmptyViewStartLocationCacheItems :
+                    GetViewStartPages(relativePath, expirationTokens);
+
+                return new ViewLocationCacheResult(
+                    new ViewLocationCacheItem(factoryResult.RazorPageFactory, relativePath),
+                    viewStartPages);
+            }
+
+            return null;
+        }
+
+        private IReadOnlyList<ViewLocationCacheItem> GetViewStartPages(
+            string path,
+            HashSet<IChangeToken> expirationTokens)
+        {
+            var viewStartPages = new List<ViewLocationCacheItem>();
+            foreach (var viewStartPath in ViewHierarchyUtility.GetViewStartLocations(path))
+            {
+                var result = _pageFactory.CreateFactory(viewStartPath);
+                if (result.ExpirationTokens != null)
+                {
+                    for (var i = 0; i < result.ExpirationTokens.Count; i++)
+                    {
+                        expirationTokens.Add(result.ExpirationTokens[i]);
+                    }
+                }
+
+                if (result.Success)
+                {
+                    // Populate the viewStartPages list so that _ViewStarts appear in the order the need to be
+                    // executed (closest last, furthest first). This is the reverse order in which
+                    // ViewHierarchyUtility.GetViewStartLocations returns _ViewStarts.
+                    viewStartPages.Insert(0, new ViewLocationCacheItem(result.RazorPageFactory, viewStartPath));
+                }
+            }
+
+            return viewStartPages;
         }
 
         private ViewEngineResult CreateViewEngineResult(
-            RazorPageResult result,
+            ViewLocationCacheResult result,
-            IRazorViewFactory razorViewFactory,
+            string viewName,
             bool isPartial)
         {
-            if (result.SearchedLocations != null)
+            if (!result.Success)
             {
-                return ViewEngineResult.NotFound(result.Name, result.SearchedLocations);
+                return ViewEngineResult.NotFound(viewName, result.SearchedLocations);
             }
 
-            var view = razorViewFactory.GetView(this, result.Page, isPartial);
+            var page = result.ViewEntry.PageFactory();
-            return ViewEngineResult.Found(result.Name, view);
+            var viewStarts = new IRazorPage[result.ViewStartEntries.Count];
+            for (var i = 0; i < viewStarts.Length; i++)
+            {
+                var viewStartItem = result.ViewStartEntries[i];
+                viewStarts[i] = result.ViewStartEntries[i].PageFactory();
+            }
+
+            var view = new RazorView(
+                this,
+                _pageActivator,
+                viewStarts,
+                page,
+                _htmlEncoder,
+                isPartial);
+            return ViewEngineResult.Found(viewName, view);
         }
 
         private static bool IsApplicationRelativePath(string name)

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

@@ -1,62 +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.Text.Encodings.Web;
-using Microsoft.AspNet.Mvc.ViewEngines;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <summary>
-    /// Represents the default <see cref="IRazorViewFactory"/> implementation that creates
-    /// <see cref="RazorView"/> instances with a given <see cref="IRazorPage"/>.
-    /// </summary>
-    public class RazorViewFactory : IRazorViewFactory
-    {
-        private readonly HtmlEncoder _htmlEncoder;
-        private readonly IRazorPageActivator _pageActivator;
-        private readonly IViewStartProvider _viewStartProvider;
-
-        /// <summary>
-        /// Initializes a new instance of RazorViewFactory
-        /// </summary>
-        /// <param name="pageActivator">The <see cref="IRazorPageActivator"/> used to activate pages.</param>
-        /// <param name="viewStartProvider">The <see cref="IViewStartProvider"/> used for discovery of _ViewStart
-        /// pages</param>
-        public RazorViewFactory(
-            IRazorPageActivator pageActivator,
-            IViewStartProvider viewStartProvider,
-            HtmlEncoder htmlEncoder)
-        {
-            _pageActivator = pageActivator;
-            _viewStartProvider = viewStartProvider;
-            _htmlEncoder = htmlEncoder;
-        }
-
-        /// <inheritdoc />
-        public IView GetView(
-            IRazorViewEngine viewEngine,
-            IRazorPage page,
-            bool isPartial)
-        {
-            if (viewEngine == null)
-            {
-                throw new ArgumentNullException(nameof(viewEngine));
-            }
-
-            if (page == null)
-            {
-                throw new ArgumentNullException(nameof(page));
-            }
-
-            var razorView = new RazorView(
-                viewEngine,
-                _pageActivator,
-                _viewStartProvider,
-                page,
-                _htmlEncoder,
-                isPartial);
-            return razorView;
-        }
-    }
-}

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

@@ -0,0 +1,34 @@
+// 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;
+
+namespace Microsoft.AspNet.Mvc.Razor
+{
+    /// <summary>
+    /// An item in <see cref="ViewLocationCacheResult"/>.
+    /// </summary>
+    public struct ViewLocationCacheItem
+    {
+        /// <summary>
+        /// Initializes a new instance of <see cref="ViewLocationCacheItem"/>.
+        /// </summary>
+        /// <param name="razorPageFactory">The <see cref="IRazorPage"/> factory.</param>
+        /// <param name="location">The application relative path of the <see cref="IRazorPage"/>.</param>
+        public ViewLocationCacheItem(Func<IRazorPage> razorPageFactory, string location)
+        {
+            PageFactory = razorPageFactory;
+            Location = location;
+        }
+
+        /// <summary>
+        /// Gets the application relative path of the <see cref="IRazorPage"/>
+        /// </summary>
+        public string Location { get; }
+
+        /// <summary>
+        /// Gets the <see cref="IRazorPage"/> factory.
+        /// </summary>
+        public Func<IRazorPage> PageFactory { get; }
+    }
+}

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

@@ -0,0 +1,147 @@
+// 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.Extensions.Internal;
+
+namespace Microsoft.AspNet.Mvc.Razor
+{
+    /// <summary>
+    /// Key for entries in <see cref="RazorViewEngine.ViewLookupCache"/>.
+    /// </summary>
+    public struct ViewLocationCacheKey : IEquatable<ViewLocationCacheKey>
+    {
+        /// <summary>
+        /// Initializes a new instance of <see cref="ViewLocationCacheKey"/>.
+        /// </summary>
+        /// <param name="viewName">The view name or path.</param>
+        /// <param name="isPartial">Determines if the view is a partial.</param>
+        public ViewLocationCacheKey(
+            string viewName,
+            bool isPartial)
+            : this(
+                  viewName,
+                  controllerName: null,
+                  areaName: null,
+                  isPartial: isPartial,
+                  values: null)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="ViewLocationCacheKey"/>.
+        /// </summary>
+        /// <param name="viewName">The view name.</param>
+        /// <param name="controllerName">The controller name.</param>
+        /// <param name="areaName">The area name.</param>
+        /// <param name="isPartial">Determines if the view is a partial.</param>
+        /// <param name="values">Values from <see cref="IViewLocationExpander"/> instances.</param>
+        public ViewLocationCacheKey(
+            string viewName,
+            string controllerName,
+            string areaName,
+            bool isPartial,
+            IReadOnlyDictionary<string, string> values)
+        {
+            ViewName = viewName;
+            ControllerName = controllerName;
+            AreaName = areaName;
+            IsPartial = isPartial;
+            ViewLocationExpanderValues = values;
+        }
+
+        /// <summary>
+        /// Gets the view name.
+        /// </summary>
+        public string ViewName { get; }
+
+        /// <summary>
+        /// Gets the controller name.
+        /// </summary>
+        public string ControllerName { get; }
+
+        /// <summary>
+        /// Gets the area name.
+        /// </summary>
+        public string AreaName { get; }
+
+        /// <summary>
+        /// Determines if the view is a partial.
+        /// </summary>
+        public bool IsPartial { get; }
+
+        /// <summary>
+        /// Gets the values populated by <see cref="IViewLocationExpander"/> instances.
+        /// </summary>
+        public IReadOnlyDictionary<string, string> ViewLocationExpanderValues { get; }
+
+        /// <inheritdoc />
+        public bool Equals(ViewLocationCacheKey y)
+        {
+            if (IsPartial != y.IsPartial ||
+                !string.Equals(ViewName, y.ViewName, StringComparison.Ordinal) ||
+                !string.Equals(ControllerName, y.ControllerName, StringComparison.Ordinal) ||
+                !string.Equals(AreaName, y.AreaName, StringComparison.Ordinal))
+            {
+                return false;
+            }
+
+            if (ReferenceEquals(ViewLocationExpanderValues, y.ViewLocationExpanderValues))
+            {
+                return true;
+            }
+
+            if (ViewLocationExpanderValues == null ||
+                y.ViewLocationExpanderValues == null ||
+                (ViewLocationExpanderValues.Count != y.ViewLocationExpanderValues.Count))
+            {
+                return false;
+            }
+
+            foreach (var item in ViewLocationExpanderValues)
+            {
+                string yValue;
+                if (!y.ViewLocationExpanderValues.TryGetValue(item.Key, out yValue) ||
+                    !string.Equals(item.Value, yValue, StringComparison.Ordinal))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        /// <inheritdoc />
+        public override bool Equals(object obj)
+        {
+            if (obj is ViewLocationCacheKey)
+            {
+                return Equals((ViewLocationCacheKey)obj);
+            }
+
+            return false;
+        }
+
+        /// <inheritdoc />
+        public override int GetHashCode()
+        {
+            var hashCodeCombiner = HashCodeCombiner.Start();
+            hashCodeCombiner.Add(IsPartial ? 1 : 0);
+            hashCodeCombiner.Add(ViewName, StringComparer.Ordinal);
+            hashCodeCombiner.Add(ControllerName, StringComparer.Ordinal);
+            hashCodeCombiner.Add(AreaName, StringComparer.Ordinal);
+
+            if (ViewLocationExpanderValues != null)
+            {
+                foreach (var item in ViewLocationExpanderValues)
+                {
+                    hashCodeCombiner.Add(item.Key, StringComparer.Ordinal);
+                    hashCodeCombiner.Add(item.Value, StringComparer.Ordinal);
+                }
+            }
+
+            return hashCodeCombiner;
+        }
+    }
+}

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

@@ -3,36 +3,32 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNet.Mvc.Razor
 {
     /// <summary>
-    /// Result of <see cref="IViewLocationCache"/> lookups.
+    /// Result of view location cache lookup.
     /// </summary>
-    public struct ViewLocationCacheResult : IEquatable<ViewLocationCacheResult>
+    public class ViewLocationCacheResult
     {
         /// <summary>
         /// Initializes a new instance of <see cref="ViewLocationCacheResult"/>
         /// for a view that was successfully found at the specified location.
         /// </summary>
-        /// <param name="foundLocation">The view location.</param>
+        /// <param name="view">The <see cref="ViewLocationCacheItem"/> for the found view.</param>
-        /// <param name="searchedLocations">Locations that were searched
+        /// <param name="viewStarts"><see cref="ViewLocationCacheItem"/>s for applicable _ViewStarts.</param>
-        /// in addition to <paramref name="foundLocation"/>.</param>
         public ViewLocationCacheResult(
-            string foundLocation,
+            ViewLocationCacheItem view,
-            IEnumerable<string> searchedLocations)
+            IReadOnlyList<ViewLocationCacheItem> viewStarts)
-            : this(searchedLocations)
         {
-            if (foundLocation == null)
+            if (viewStarts == null)
             {
-                throw new ArgumentNullException(nameof(foundLocation));
+                throw new ArgumentNullException(nameof(viewStarts));
             }
 
-            ViewLocation = foundLocation;
+            ViewEntry = view;
-            SearchedLocations = searchedLocations;
+            ViewStartEntries = viewStarts;
-            IsFoundResult = true;
+            Success = true;
         }
 
         /// <summary>
@@ -48,27 +44,26 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
 
             SearchedLocations = searchedLocations;
-            ViewLocation = null;
-            IsFoundResult = false;
         }
 
         /// <summary>
-        /// A <see cref="ViewLocationCacheResult"/> that represents a cache miss.
+        /// <see cref="ViewLocationCacheItem"/> for the located view.
         /// </summary>
-        public static readonly ViewLocationCacheResult None = new ViewLocationCacheResult(Enumerable.Empty<string>());
+        /// <remarks><c>null</c> if <see cref="Success"/> is <c>false</c>.</remarks>
+        public ViewLocationCacheItem ViewEntry { get; }
 
         /// <summary>
-        /// The location the view was found.
+        /// <see cref="ViewLocationCacheItem"/>s for applicable _ViewStarts.
         /// </summary>
-        /// <remarks>This is available if <see cref="IsFoundResult"/> is <c>true</c>.</remarks>
+        /// <remarks><c>null</c> if <see cref="Success"/> is <c>false</c>.</remarks>
-        public string ViewLocation { get; }
+        public IReadOnlyList<ViewLocationCacheItem> ViewStartEntries { get; }
 
         /// <summary>
         /// The sequence of locations that were searched.
         /// </summary>
         /// <remarks>
-        /// When <see cref="IsFoundResult"/> is <c>true</c> this includes all paths that were search prior to finding
+        /// When <see cref="Success"/> is <c>true</c> this includes all paths that were search prior to finding
-        /// a view at <see cref="ViewLocation"/>. When <see cref="IsFoundResult"/> is <c>false</c>, this includes
+        /// a view at <see cref="ViewEntry"/>. When <see cref="Success"/> is <c>false</c>, this includes
         /// all search paths.
         /// </remarks>
         public IEnumerable<string> SearchedLocations { get; }
@@ -76,55 +71,6 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// <summary>
         /// Gets a value that indicates whether the view was successfully found.
         /// </summary>
-        public bool IsFoundResult { get; }
+        public bool Success { get; }
-
-        /// <inheritdoc />
-        public bool Equals(ViewLocationCacheResult other)
-        {
-            if (IsFoundResult != other.IsFoundResult)
-            {
-                return false;
-            }
-
-            if (IsFoundResult)
-            {
-                return string.Equals(ViewLocation, other.ViewLocation, StringComparison.Ordinal);
-            }
-            else
-            {
-                if (SearchedLocations == other.SearchedLocations)
-                {
-                    return true;
-                }
-
-                if (SearchedLocations == null || other.SearchedLocations == null)
-                {
-                    return false;
-                }
-
-                return Enumerable.SequenceEqual(SearchedLocations, other.SearchedLocations, StringComparer.Ordinal);
-            }
-        }
-
-        /// <inheritdoc />
-        public override int GetHashCode()
-        {
-            var hashCodeCombiner = HashCodeCombiner.Start();
-            hashCodeCombiner.Add(IsFoundResult);
-
-            if (IsFoundResult)
-            {
-                hashCodeCombiner.Add(ViewLocation, StringComparer.Ordinal);
-            }
-            else if (SearchedLocations != null)
-            {
-                foreach (var location in SearchedLocations)
-                {
-                    hashCodeCombiner.Add(location, StringComparer.Ordinal);
-                }
-            }
-
-            return hashCodeCombiner;
-        }
     }
 }

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

@@ -16,10 +16,14 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// </summary>
         /// <param name="actionContext">The <see cref="Mvc.ActionContext"/> for the current executing action.</param>
         /// <param name="viewName">The view name.</param>
+        /// <param name="controllerName">The controller name.</param>
+        /// <param name="areaName">The area name.</param>
         /// <param name="isPartial">Determines if the view being discovered is a partial.</param>
         public ViewLocationExpanderContext(
             ActionContext actionContext,
             string viewName,
+            string controllerName,
+            string areaName,
             bool isPartial)
         {
             if (actionContext == null)
@@ -34,6 +38,8 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             ActionContext = actionContext;
             ViewName = viewName;
+            ControllerName = controllerName;
+            AreaName = areaName;
             IsPartial = isPartial;
         }
 
@@ -47,6 +53,16 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// </summary>
         public string ViewName { get; }
 
+        /// <summary>
+        /// Gets the controller name.
+        /// </summary>
+        public string ControllerName { get; }
+
+        /// <summary>
+        /// Gets the area name.
+        /// </summary>
+        public string AreaName { get; }
+
         /// <summary>
         /// Gets a value that determines if a partial view is being discovered.
         /// </summary>

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

@@ -1,41 +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 System.Linq;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    /// <inheritdoc />
-    public class ViewStartProvider : IViewStartProvider
-    {
-        private readonly IRazorPageFactory _pageFactory;
-
-        public ViewStartProvider(IRazorPageFactory pageFactory)
-        {
-            _pageFactory = pageFactory;
-        }
-
-        /// <inheritdoc />
-        public IEnumerable<IRazorPage> GetViewStartPages(string path)
-        {
-            if (path == null)
-            {
-                throw new ArgumentNullException(nameof(path));
-            }
-
-            var viewStartLocations = ViewHierarchyUtility.GetViewStartLocations(path);
-            var viewStarts = viewStartLocations.Select(_pageFactory.CreateInstance)
-                                               .Where(p => p != null)
-                                               .ToArray();
-
-            // GetViewStartLocations return ViewStarts inside-out that is the _ViewStart closest to the page
-            // is the first: e.g. [ /Views/Home/_ViewStart, /Views/_ViewStart, /_ViewStart ]
-            // However they need to be executed outside in, so we'll reverse the sequence.
-            Array.Reverse(viewStarts);
-
-            return viewStarts;
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.Razor.Test/Compilation/CompilationResultTest.cs

@@ -15,7 +15,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             // Arrange
             var compilationFailure = new CompilationFailure("test", Enumerable.Empty<Microsoft.Extensions.PlatformAbstractions.DiagnosticMessage>());
             var failures = new[] { compilationFailure };
-            var result = CompilationResult.Failed(failures);
+            var result = new CompilationResult(failures);
 
             // Act and Assert
             Assert.Null(result.CompiledType);

test/Microsoft.AspNet.Mvc.Razor.Test/Compilation/CompilerCacheTest.cs

@@ -36,8 +36,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result = cache.GetOrAdd("/some/path", ThrowsIfCalled);
 
             // Assert
-            Assert.Same(CompilerCacheResult.FileNotFound, result);
+            Assert.False(result.Success);
-            Assert.Null(result.CompilationResult);
         }
 
         [Fact]
@@ -48,18 +47,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider);
             var type = typeof(TestView);
-            var expected = UncachedCompilationResult.Successful(type, "hello world");
+            var expected = new CompilationResult(type);
 
             // Act
             var result = cache.GetOrAdd(ViewPath, _ => expected);
 
             // Assert
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result);
+            Assert.True(result.Success);
-            var actual = Assert.IsType<UncachedCompilationResult>(result.CompilationResult);
+            Assert.Same(type, result.CompilationResult.CompiledType);
-            Assert.NotNull(actual);
-            Assert.Same(expected, actual);
-            Assert.Equal("hello world", actual.CompiledContent);
-            Assert.Same(type, actual.CompiledType);
         }
 
         [Theory]
@@ -75,15 +70,13 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             fileProvider.AddFile(viewPath, "some content");
             var cache = new CompilerCache(fileProvider);
             var type = typeof(TestView);
-            var expected = UncachedCompilationResult.Successful(type, "hello world");
+            var expected = new CompilationResult(type);
 
             // Act - 1
             var result1 = cache.GetOrAdd(@"Areas\Finances\Views\Home\Index.cshtml", _ => expected);
 
             // Assert - 1
-            var compilationResult = Assert.IsType<UncachedCompilationResult>(result1.CompilationResult);
+            Assert.Same(type, result1.CompilationResult.CompiledType);
-            Assert.Same(expected, compilationResult);
-            Assert.Same(type, compilationResult.CompiledType);
 
             // Act - 2
             var result2 = cache.GetOrAdd(relativePath, ThrowsIfCalled);
@@ -93,21 +86,21 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
         }
 
         [Fact]
-        public void GetOrAdd_ReturnsFileNotFoundIfFileWasDeleted()
+        public void GetOrAdd_ReturnsFailedCompilationResult_IfFileWasRemovedFromFileSystem()
         {
             // Arrange
             var fileProvider = new TestFileProvider();
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider);
             var type = typeof(TestView);
-            var expected = UncachedCompilationResult.Successful(type, "hello world");
+            var expected = new CompilationResult(type);
 
             // Act 1
             var result1 = cache.GetOrAdd(ViewPath, _ => expected);
 
             // Assert 1
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result1);
+            Assert.True(result1.Success);
-            Assert.Same(expected, result1.CompilationResult);
+            Assert.Same(expected.CompiledType, result1.CompilationResult.CompiledType);
 
             // Act 2
             // Delete the file from the file system and set it's expiration token.
@@ -116,8 +109,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result2 = cache.GetOrAdd(ViewPath, ThrowsIfCalled);
 
             // Assert 2
-            Assert.Same(CompilerCacheResult.FileNotFound, result2);
+            Assert.False(result2.Success);
-            Assert.Null(result2.CompilationResult);
         }
 
         [Fact]
@@ -127,22 +119,22 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var fileProvider = new TestFileProvider();
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider);
-            var expected1 = UncachedCompilationResult.Successful(typeof(TestView), "hello world");
+            var expected1 = new CompilationResult(typeof(TestView));
-            var expected2 = UncachedCompilationResult.Successful(typeof(DifferentView), "different content");
+            var expected2 = new CompilationResult(typeof(DifferentView));
 
             // Act 1
             var result1 = cache.GetOrAdd(ViewPath, _ => expected1);
 
             // Assert 1
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result1);
+            Assert.True(result1.Success);
-            Assert.Same(expected1, result1.CompilationResult);
+            Assert.Same(typeof(TestView), result1.CompilationResult.CompiledType);
 
             // Act 2
             // Verify we're getting cached results.
             var result2 = cache.GetOrAdd(ViewPath, ThrowsIfCalled);
 
             // Assert 2
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result2);
+            Assert.True(result2.Success);
             Assert.Same(expected1.CompiledType, result2.CompilationResult.CompiledType);
 
             // Act 3
@@ -150,8 +142,8 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result3 = cache.GetOrAdd(ViewPath, _ => expected2);
 
             // Assert 3
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result3);
+            Assert.True(result3.Success);
-            Assert.Same(expected2, result3.CompilationResult);
+            Assert.Same(expected2.CompiledType, result3.CompilationResult.CompiledType);
         }
 
         [Theory]
@@ -162,22 +154,22 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var fileProvider = new TestFileProvider();
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider);
-            var expected1 = UncachedCompilationResult.Successful(typeof(TestView), "hello world");
+            var expected1 = new CompilationResult(typeof(TestView));
-            var expected2 = UncachedCompilationResult.Successful(typeof(DifferentView), "different content");
+            var expected2 = new CompilationResult(typeof(DifferentView));
 
             // Act 1
             var result1 = cache.GetOrAdd(ViewPath, _ => expected1);
 
             // Assert 1
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result1);
+            Assert.True(result1.Success);
-            Assert.Same(expected1, result1.CompilationResult);
+            Assert.Same(expected1.CompiledType, result1.CompilationResult.CompiledType);
 
             // Act 2
             // Verify we're getting cached results.
             var result2 = cache.GetOrAdd(ViewPath, ThrowsIfCalled);
 
             // Assert 2
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result2);
+            Assert.True(result2.Success);
             Assert.Same(expected1.CompiledType, result2.CompilationResult.CompiledType);
 
             // Act 3
@@ -185,8 +177,8 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result3 = cache.GetOrAdd(ViewPath, _ => expected2);
 
             // Assert 2
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result3);
+            Assert.True(result3.Success);
-            Assert.Same(expected2, result3.CompilationResult);
+            Assert.Same(expected2.CompiledType, result3.CompilationResult.CompiledType);
         }
 
         [Fact]
@@ -198,21 +190,20 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider);
             var type = typeof(TestView);
-            var expected = UncachedCompilationResult.Successful(type, "hello world");
+            var expected = new CompilationResult(type);
 
             // Act 1
             var result1 = cache.GetOrAdd(ViewPath, _ => expected);
 
             // Assert 1
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result1);
+            Assert.True(result1.Success);
-            Assert.Same(expected, result1.CompilationResult);
+            Assert.Same(type, result1.CompilationResult.CompiledType);
 
             // Act 2
             var result2 = cache.GetOrAdd(ViewPath, ThrowsIfCalled);
 
             // Assert 2
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result2);
+            Assert.True(result2.Success);
-            Assert.IsType<CompilationResult>(result2.CompilationResult);
             Assert.Same(type, result2.CompilationResult.CompiledType);
             mockFileProvider.Verify(v => v.GetFileInfo(ViewPath), Times.Once());
         }
@@ -228,7 +219,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result = cache.GetOrAdd(PrecompiledViewsPath, ThrowsIfCalled);
 
             // Assert
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result);
+            Assert.True(result.Success);
             Assert.Same(typeof(PreCompile), result.CompilationResult.CompiledType);
         }
 
@@ -245,7 +236,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result = cache.GetOrAdd(PrecompiledViewsPath, ThrowsIfCalled);
 
             // Assert
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result);
+            Assert.True(result.Success);
             Assert.Same(typeof(PreCompile), result.CompilationResult.CompiledType);
         }
 
@@ -263,7 +254,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result = cache.GetOrAdd(PrecompiledViewsPath, ThrowsIfCalled);
 
             // Assert
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result);
+            Assert.True(result.Success);
             Assert.Same(typeof(PreCompile), result.CompilationResult.CompiledType);
         }
 
@@ -274,26 +265,26 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var fileProvider = new TestFileProvider();
             fileProvider.AddFile(ViewPath, "some content");
             var cache = new CompilerCache(fileProvider, _precompiledViews);
-            var expected = CompilationResult.Successful(typeof(TestView));
+            var expected = new CompilationResult(typeof(TestView));
 
             // Act 1
             var result1 = cache.GetOrAdd(ViewPath, _ => expected);
 
             // Assert 1
-            Assert.Same(expected, result1.CompilationResult);
+            Assert.Same(typeof(TestView), result1.CompilationResult.CompiledType);
 
             // Act 2
             var result2 = cache.GetOrAdd(ViewPath, ThrowsIfCalled);
 
             // Assert 2
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result2);
+            Assert.True(result2.Success);
             Assert.Same(typeof(TestView), result2.CompilationResult.CompiledType);
 
             // Act 3
             var result3 = cache.GetOrAdd(PrecompiledViewsPath, ThrowsIfCalled);
 
             // Assert 3
-            Assert.NotSame(CompilerCacheResult.FileNotFound, result2);
+            Assert.True(result2.Success);
             Assert.Same(typeof(PreCompile), result3.CompilationResult.CompiledType);
         }
 

test/Microsoft.AspNet.Mvc.Razor.Test/Compilation/RazorCompilationServiceTest.cs

@@ -36,7 +36,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
 
             var compiler = new Mock<ICompilationService>();
             compiler.Setup(c => c.Compile(relativeFileInfo, It.IsAny<string>()))
-                    .Returns(CompilationResult.Successful(typeof(RazorCompilationServiceTest)));
+                    .Returns(new CompilationResult(typeof(RazorCompilationServiceTest)));
 
             var razorService = new RazorCompilationService(compiler.Object, host.Object, GetOptions());
 
@@ -106,7 +106,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
                     .Returns(Stream.Null);
             var relativeFileInfo = new RelativeFileInfo(fileInfo.Object, @"Views\index\home.cshtml");
 
-            var compilationResult = CompilationResult.Successful(typeof(object));
+            var compilationResult = new CompilationResult(typeof(object));
             var compiler = new Mock<ICompilationService>();
             compiler.Setup(c => c.Compile(relativeFileInfo, code))
                     .Returns(compilationResult)
@@ -117,7 +117,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
             var result = razorService.Compile(relativeFileInfo);
 
             // Assert
-            Assert.Same(compilationResult, result);
+            Assert.Same(compilationResult.CompiledType, result.CompiledType);
             compiler.Verify();
         }
 

test/Microsoft.AspNet.Mvc.Razor.Test/Compilation/RoslynCompilationServiceTest.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Compilation
     public class RoslynCompilationServiceTest
     {
         [Fact]
-        public void Compile_ReturnsUncachedCompilationResultWithCompiledContent()
+        public void Compile_ReturnsCompilationResult()
         {
             // Arrange
             var content = @"
@@ -29,29 +29,31 @@ public class MyTestType  {}";
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions());
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions());
             var mvcRazorHost = new Mock<IMvcRazorHost>();
             mvcRazorHost.SetupGet(m => m.MainClassNamePrefix)
                         .Returns(string.Empty);
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost.Object,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions());
+                mvcRazorHost.Object,
-            var relativeFileInfo = new RelativeFileInfo(new TestFileInfo { PhysicalPath = "SomePath" },
+                GetOptions());
+            var relativeFileInfo = new RelativeFileInfo(
+                new TestFileInfo { PhysicalPath = "SomePath" },
                 "some-relative-path");
 
             // Act
             var result = compilationService.Compile(relativeFileInfo, content);
 
             // Assert
-            var uncachedResult = Assert.IsType<UncachedCompilationResult>(result);
             Assert.Equal("MyTestType", result.CompiledType.Name);
-            Assert.Equal(content, uncachedResult.CompiledContent);
         }
 
         [Fact]
@@ -67,19 +69,22 @@ this should fail";
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions());
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions());
             var mvcRazorHost = Mock.Of<IMvcRazorHost>();
             var fileProvider = new TestFileProvider();
             var fileInfo = fileProvider.AddFile(viewPath, fileContent);
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions(fileProvider));
+                mvcRazorHost,
+                GetOptions(fileProvider));
             var relativeFileInfo = new RelativeFileInfo(fileInfo, "some-relative-path");
 
             // Act
@@ -103,18 +108,22 @@ this should fail";
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions());
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions());
             var mvcRazorHost = Mock.Of<IMvcRazorHost>();
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions());
+                mvcRazorHost,
-            var relativeFileInfo = new RelativeFileInfo(new TestFileInfo { Content = fileContent },
+                GetOptions());
+            var relativeFileInfo = new RelativeFileInfo(
+                new TestFileInfo { Content = fileContent },
                 "some-relative-path");
 
             // Act
@@ -141,10 +150,12 @@ this should fail";
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions());
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions());
             var mvcRazorHost = Mock.Of<IMvcRazorHost>();
 
             var mockFileInfo = new Mock<IFileInfo>();
@@ -153,11 +164,12 @@ this should fail";
             var fileProvider = new TestFileProvider();
             fileProvider.AddFile(path, mockFileInfo.Object);
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions(fileProvider));
+                mvcRazorHost,
+                GetOptions(fileProvider));
 
             var relativeFileInfo = new RelativeFileInfo(mockFileInfo.Object, path);
 
@@ -187,20 +199,24 @@ public class MyNonCustomDefinedClass {}
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions { Defines = new[] { "MY_CUSTOM_DEFINE" } });
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions { Defines = new[] { "MY_CUSTOM_DEFINE" } });
             var mvcRazorHost = new Mock<IMvcRazorHost>();
             mvcRazorHost.SetupGet(m => m.MainClassNamePrefix)
                         .Returns("My");
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost.Object,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions());
+                mvcRazorHost.Object,
-            var relativeFileInfo = new RelativeFileInfo(new TestFileInfo { PhysicalPath = "SomePath" },
+                GetOptions());
+            var relativeFileInfo = new RelativeFileInfo(
+                new TestFileInfo { PhysicalPath = "SomePath" },
                 "some-relative-path");
 
             // Act
@@ -222,21 +238,25 @@ public class NotRazorPrefixType {}";
             var libraryExporter = GetLibraryExporter();
 
             var compilerOptionsProvider = new Mock<ICompilerOptionsProvider>();
-            compilerOptionsProvider.Setup(p => p.GetCompilerOptions(applicationEnvironment.ApplicationName,
+            compilerOptionsProvider
-                                                                    applicationEnvironment.RuntimeFramework,
+                .Setup(p => p.GetCompilerOptions(
-                                                                    applicationEnvironment.Configuration))
+                    applicationEnvironment.ApplicationName,
-                                   .Returns(new CompilerOptions());
+                    applicationEnvironment.RuntimeFramework,
+                    applicationEnvironment.Configuration))
+                .Returns(new CompilerOptions());
             var mvcRazorHost = new Mock<IMvcRazorHost>();
             mvcRazorHost.SetupGet(m => m.MainClassNamePrefix)
                         .Returns("RazorPrefix");
 
-            var compilationService = new RoslynCompilationService(applicationEnvironment,
+            var compilationService = new RoslynCompilationService(
-                                                                  libraryExporter,
+                applicationEnvironment,
-                                                                  compilerOptionsProvider.Object,
+                libraryExporter,
-                                                                  mvcRazorHost.Object,
+                compilerOptionsProvider.Object,
-                                                                  GetOptions());
+                mvcRazorHost.Object,
+                GetOptions());
 
-            var relativeFileInfo = new RelativeFileInfo(new TestFileInfo { PhysicalPath = "SomePath" },
+            var relativeFileInfo = new RelativeFileInfo(
+                new TestFileInfo { PhysicalPath = "SomePath" },
                 "some-relative-path");
 
             // Act
@@ -356,27 +376,33 @@ public class NotRazorPrefixType {}";
         private static ILibraryExporter GetLibraryExporter()
         {
             var fileReference = new Mock<IMetadataFileReference>();
-            fileReference.SetupGet(f => f.Path)
+            fileReference
-                         .Returns(typeof(string).Assembly.Location);
+                .SetupGet(f => f.Path)
+                .Returns(typeof(string).Assembly.Location);
             var libraryExport = new LibraryExport(fileReference.Object);
 
             var libraryExporter = new Mock<ILibraryExporter>();
-            libraryExporter.Setup(l => l.GetAllExports(It.IsAny<string>()))
+            libraryExporter
-                          .Returns(libraryExport);
+                .Setup(l => l.GetAllExports(It.IsAny<string>()))
+                .Returns(libraryExport);
             return libraryExporter.Object;
         }
 
         private IApplicationEnvironment GetApplicationEnvironment()
         {
             var applicationEnvironment = new Mock<IApplicationEnvironment>();
-            applicationEnvironment.SetupGet(a => a.ApplicationName)
+            applicationEnvironment
-                                  .Returns("MyApp");
+                .SetupGet(a => a.ApplicationName)
-            applicationEnvironment.SetupGet(a => a.RuntimeFramework)
+                .Returns("MyApp");
-                                  .Returns(new FrameworkName("ASPNET", new Version(5, 0)));
+            applicationEnvironment
-            applicationEnvironment.SetupGet(a => a.Configuration)
+                .SetupGet(a => a.RuntimeFramework)
-                                  .Returns("Debug");
+                .Returns(new FrameworkName("ASPNET", new Version(5, 0)));
-            applicationEnvironment.SetupGet(a => a.ApplicationBasePath)
+            applicationEnvironment
-                                  .Returns("MyBasePath");
+                .SetupGet(a => a.Configuration)
+                .Returns("Debug");
+            applicationEnvironment
+                .SetupGet(a => a.ApplicationBasePath)
+                .Returns("MyBasePath");
 
             return applicationEnvironment.Object;
         }
@@ -388,7 +414,8 @@ public class NotRazorPrefixType {}";
                 FileProvider = fileProvider ?? new TestFileProvider()
             };
             var options = new Mock<IOptions<RazorViewEngineOptions>>();
-            options.SetupGet(o => o.Value)
+            options
+                .SetupGet(o => o.Value)
                 .Returns(razorViewEngineOptions);
 
             return options.Object;

test/Microsoft.AspNet.Mvc.Razor.Test/DefaultRazorPageFactoryProviderTest.cs

@@ -0,0 +1,106 @@
+// 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.Threading.Tasks;
+using Microsoft.AspNet.Mvc.Razor.Compilation;
+using Microsoft.Extensions.Primitives;
+using Moq;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Razor.Test
+{
+    public class DefaultRazorPageFactoryProviderTest
+    {
+        [Fact]
+        public void CreateFactory_ReturnsExpirationTokensFromCompilerCache_ForUnsuccessfulResults()
+        {
+            // Arrange
+            var expirationTokens = new[]
+            {
+                Mock.Of<IChangeToken>(),
+                Mock.Of<IChangeToken>(),
+            };
+            var compilerCache = new Mock<ICompilerCache>();
+            compilerCache
+                .Setup(f => f.GetOrAdd(It.IsAny<string>(), It.IsAny<Func<RelativeFileInfo, CompilationResult>>()))
+                .Returns(new CompilerCacheResult(expirationTokens));
+            var compilerCacheProvider = new Mock<ICompilerCacheProvider>();
+            compilerCacheProvider
+                .SetupGet(c => c.Cache)
+                .Returns(compilerCache.Object);
+            var factoryProvider = new DefaultRazorPageFactoryProvider(
+                Mock.Of<IRazorCompilationService>(),
+                compilerCacheProvider.Object);
+
+            // Act
+            var result = factoryProvider.CreateFactory("/file-does-not-exist");
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Equal(expirationTokens, result.ExpirationTokens);
+        }
+
+        [Fact]
+        public void CreateFactory_ReturnsExpirationTokensFromCompilerCache_ForSuccessfulResults()
+        {
+            // Arrange
+            var expirationTokens = new[]
+            {
+                Mock.Of<IChangeToken>(),
+                Mock.Of<IChangeToken>(),
+            };
+            var compilerCache = new Mock<ICompilerCache>();
+            compilerCache
+                .Setup(f => f.GetOrAdd(It.IsAny<string>(), It.IsAny<Func<RelativeFileInfo, CompilationResult>>()))
+                .Returns(new CompilerCacheResult(new CompilationResult(typeof(object)), expirationTokens));
+            var compilerCacheProvider = new Mock<ICompilerCacheProvider>();
+            compilerCacheProvider
+                .SetupGet(c => c.Cache)
+                .Returns(compilerCache.Object);
+            var factoryProvider = new DefaultRazorPageFactoryProvider(
+                Mock.Of<IRazorCompilationService>(),
+                compilerCacheProvider.Object);
+
+            // Act
+            var result = factoryProvider.CreateFactory("/file-exists");
+
+            // Assert
+            Assert.True(result.Success);
+            Assert.Equal(expirationTokens, result.ExpirationTokens);
+        }
+
+        [Fact]
+        public void CreateFactory_ProducesDelegateThatSetsPagePath()
+        {
+            // Arrange
+            var compilerCache = new Mock<ICompilerCache>();
+            compilerCache
+                .Setup(f => f.GetOrAdd(It.IsAny<string>(), It.IsAny<Func<RelativeFileInfo, CompilationResult>>()))
+                .Returns(new CompilerCacheResult(new CompilationResult(typeof(TestRazorPage)), new IChangeToken[0]));
+            var compilerCacheProvider = new Mock<ICompilerCacheProvider>();
+            compilerCacheProvider
+                .SetupGet(c => c.Cache)
+                .Returns(compilerCache.Object);
+            var factoryProvider = new DefaultRazorPageFactoryProvider(
+                Mock.Of<IRazorCompilationService>(),
+                compilerCacheProvider.Object);
+
+            // Act
+            var result = factoryProvider.CreateFactory("/file-exists");
+
+            // Assert
+            Assert.True(result.Success);
+            var actual = result.RazorPageFactory();
+            Assert.Equal("/file-exists", actual.Path);
+        }
+
+        private class TestRazorPage : RazorPage
+        {
+            public override Task ExecuteAsync()
+            {
+                throw new NotImplementedException();
+            }
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.Razor.Test/DefaultViewLocationCacheTest.cs

@@ -1,522 +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.AspNet.Http.Internal;
-using Microsoft.AspNet.Mvc.Abstractions;
-using Microsoft.AspNet.Mvc.Routing;
-using Microsoft.AspNet.Routing;
-using Xunit;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    public class DefaultViewLocationCacheTest
-    {
-        public static IEnumerable<object[]> CacheEntryData
-        {
-            get
-            {
-                yield return new[] { new ViewLocationExpanderContext(GetActionContext(), "test", isPartial: false) };
-                yield return new[] { new ViewLocationExpanderContext(GetActionContext(), "test", isPartial: true) };
-
-                var areaActionContext = GetActionContext("controller2", "myarea");
-                yield return new[] { new ViewLocationExpanderContext(areaActionContext, "test2", isPartial: false) };
-                yield return new[] { new ViewLocationExpanderContext(areaActionContext, "test2", isPartial: true) };
-
-                var actionContext = GetActionContext("controller3", "area3");
-                var values = new Dictionary<string, string>(StringComparer.Ordinal)
-                {
-                    { "culture", "fr" },
-                    { "theme", "sleek" }
-                };
-                var expanderContext = new ViewLocationExpanderContext(actionContext, "test3", isPartial: false)
-                {
-                    Values = values
-                };
-                yield return new[] { expanderContext };
-
-                expanderContext = new ViewLocationExpanderContext(actionContext, "test3", isPartial: true)
-                {
-                    Values = values
-                };
-                yield return new[] { expanderContext };
-            }
-        }
-
-        private static DefaultViewLocationCache.ViewLocationCacheKeyComparer CacheKeyComparer =>
-            DefaultViewLocationCache.ViewLocationCacheKeyComparer.Instance;
-
-        [Theory]
-        [MemberData(nameof(CacheEntryData))]
-        public void Get_ReturnsNoneResultIfItemDoesNotExist(ViewLocationExpanderContext context)
-        {
-            // Arrange
-            var cache = new DefaultViewLocationCache();
-
-            // Act
-            var result = cache.Get(context);
-
-            // Assert
-            Assert.Equal(result, ViewLocationCacheResult.None);
-        }
-
-        [Theory]
-        [MemberData(nameof(CacheEntryData))]
-        public void InvokingGetAfterSet_ReturnsCachedItem(ViewLocationExpanderContext context)
-        {
-            // Arrange
-            var cache = new DefaultViewLocationCache();
-            var value = new ViewLocationCacheResult(
-                Guid.NewGuid().ToString(),
-                new[]
-                {
-                    Guid.NewGuid().ToString(),
-                    Guid.NewGuid().ToString()
-                });
-
-            // Act - 1
-            cache.Set(context, value);
-            var result = cache.Get(context);
-
-            // Assert - 1
-            Assert.Equal(value, result);
-
-            // Act - 2
-            result = cache.Get(context);
-
-            // Assert - 2
-            Assert.Equal(value, result);
-        }
-
-        [Theory]
-        [InlineData("View1", "View2")]
-        [InlineData("View1", "view1")]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfViewNamesAreDifferent(
-            string viewName1,
-            string viewName2)
-        {
-            // Arrange
-            var actionContext = GetActionContext();
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                actionContext,
-                viewName1,
-                isPartial: true);
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               actionContext,
-               viewName2,
-               isPartial: true);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Theory]
-        [InlineData(false, true)]
-        [InlineData(true, false)]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfIsPartialAreDifferent(
-            bool isPartial1,
-            bool isPartial2)
-        {
-            // Arrange
-            var actionContext = GetActionContext();
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                actionContext,
-                "View1",
-                isPartial1);
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               actionContext,
-               "View1",
-               isPartial2);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Theory]
-        [InlineData("Controller1", "Controller2")]
-        [InlineData("controller1", "Controller1")]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfIsControllerNamesAreDifferent(
-            string controller1,
-            string controller2)
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext(controller1),
-                "View1",
-                isPartial: false);
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext(controller2),
-               "View1",
-               isPartial: false);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Theory]
-        [InlineData("area1", null)]
-        [InlineData("Area1", "Area2")]
-        [InlineData("area1", "aRea1")]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfIsAreaNamesAreDifferent(
-            string area1,
-            string area2)
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", area1),
-                "View1",
-                isPartial: false);
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", area2),
-               "View1",
-               isPartial: false);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Fact]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsTrueIfControllerAreaAndViewNamesAreIdentical()
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.True(result);
-            Assert.Equal(hash1, hash2);
-        }
-
-        [Fact]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfViewLocationExpanderIsNullForEitherKey()
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            viewLocationExpanderContext1.Values = new Dictionary<string, string>
-            {
-                { "somekey", "somevalue" }
-            };
-
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Fact]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfExpanderValueCountIsDifferent()
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            viewLocationExpanderContext1.Values = new Dictionary<string, string>
-            {
-                { "somekey", "somevalue" }
-            };
-
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-            viewLocationExpanderContext2.Values = new Dictionary<string, string>
-            {
-                { "somekey", "somevalue" },
-                { "somekey2", "somevalue2" },
-            };
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Theory]
-        [InlineData("key1", "key2")]
-        [InlineData("Key1", "key1")]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfKeysAreDifferent(
-            string keyName1,
-            string keyName2)
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            viewLocationExpanderContext1.Values = new Dictionary<string, string>
-            {
-                { keyName1, "somevalue" }
-            };
-
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-            viewLocationExpanderContext2.Values = new Dictionary<string, string>
-            {
-                { keyName2, "somevalue" },
-            };
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        [Theory]
-        [InlineData("value1", null)]
-        [InlineData("value1", "value2")]
-        [InlineData("value1", "Value1")]
-        public void ViewLocationCacheKeyComparer_EqualsReturnsFalseIfValuesAreDifferent(
-            string value1,
-            string value2)
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            viewLocationExpanderContext1.Values = new Dictionary<string, string>
-            {
-                { "somekey", value1 }
-            };
-
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-            viewLocationExpanderContext2.Values = new Dictionary<string, string>
-            {
-                { "somekey", value2 },
-            };
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.False(result);
-            Assert.NotEqual(hash1, hash2);
-        }
-
-        public void ViewLocationCacheKeyComparer_EqualsReturnsTrueIfValuesAreSame()
-        {
-            // Arrange
-            var viewLocationExpanderContext1 = new ViewLocationExpanderContext(
-                GetActionContext("Controller1", "Area1"),
-                "View1",
-                isPartial: false);
-            viewLocationExpanderContext1.Values = new Dictionary<string, string>
-            {
-                { "somekey1", "value1" },
-                { "somekey2", "value2" },
-            };
-
-            var viewLocationExpanderContext2 = new ViewLocationExpanderContext(
-               GetActionContext("Controller1", "Area1"),
-               "View1",
-               isPartial: false);
-            viewLocationExpanderContext2.Values = new Dictionary<string, string>
-            {
-                { "somekey2", "value2" },
-                { "somekey1", "value1" },
-            };
-
-            // Act
-            var key1 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext1,
-                copyViewExpanderValues: false);
-
-            var key2 = DefaultViewLocationCache.GenerateKey(
-                viewLocationExpanderContext2,
-                copyViewExpanderValues: false);
-
-            var result = CacheKeyComparer.Equals(key1, key2);
-            var hash1 = CacheKeyComparer.GetHashCode(key1);
-            var hash2 = CacheKeyComparer.GetHashCode(key2);
-
-            // Assert
-            Assert.True(result);
-            Assert.Equal(hash1, hash2);
-        }
-
-        public static ActionContext GetActionContext(
-            string controller = "mycontroller",
-            string area = null)
-        {
-            var routeData = new RouteData();
-            routeData.Values["controller"] = controller;
-            if (area != null)
-            {
-                routeData.Values["area"] = area;
-            }
-
-            var actionDesciptor = new ActionDescriptor();
-            actionDesciptor.RouteConstraints = new List<RouteDataActionConstraint>();
-            return new ActionContext(new DefaultHttpContext(), routeData, actionDesciptor);
-        }
-
-        private static ActionContext GetActionContextWithActionDescriptor(
-            IDictionary<string, object> routeValues,
-            IDictionary<string, string> routesInActionDescriptor,
-            bool isAttributeRouted)
-        {
-            var httpContext = new DefaultHttpContext();
-            var routeData = new RouteData();
-            foreach (var kvp in routeValues)
-            {
-                routeData.Values.Add(kvp.Key, kvp.Value);
-            }
-
-            var actionDescriptor = new ActionDescriptor();
-            if (isAttributeRouted)
-            {
-                actionDescriptor.AttributeRouteInfo = new Routing.AttributeRouteInfo();
-                foreach (var kvp in routesInActionDescriptor)
-                {
-                    actionDescriptor.RouteValueDefaults.Add(kvp.Key, kvp.Value);
-                }
-            }
-            else
-            {
-                actionDescriptor.RouteConstraints = new List<RouteDataActionConstraint>();
-                foreach (var kvp in routesInActionDescriptor)
-                {
-                    actionDescriptor.RouteConstraints.Add(new RouteDataActionConstraint(kvp.Key, kvp.Value));
-                }
-            }
-
-            return new ActionContext(httpContext, routeData, actionDescriptor);
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.Razor.Test/LanguageViewLocationExpanderTest.cs

@@ -131,7 +131,12 @@ namespace Microsoft.AspNet.Mvc.Razor
             IEnumerable<string> expectedViewLocations)
         {
             // Arrange
-            var viewLocationExpanderContext = new ViewLocationExpanderContext(new ActionContext(),"testView", false);
+            var viewLocationExpanderContext = new ViewLocationExpanderContext(
+                new ActionContext(), 
+                "testView", 
+                "test-controller",
+                "",
+                false);
             var languageViewLocationExpander = new LanguageViewLocationExpander(format);
             viewLocationExpanderContext.Values = new Dictionary<string, string>();
             viewLocationExpanderContext.Values["language"] = "en-GB";
@@ -150,7 +155,12 @@ namespace Microsoft.AspNet.Mvc.Razor
         public void ExpandViewLocations_NullContextValue(IEnumerable<string> viewLocations)
         {
             // Arrange
-            var viewLocationExpanderContext = new ViewLocationExpanderContext(new ActionContext(), "testView", false);
+            var viewLocationExpanderContext = new ViewLocationExpanderContext(
+                new ActionContext(), 
+                "testView", 
+                "test-controller",
+                "test-area",
+                false);
             var languageViewLocationExpander = new LanguageViewLocationExpander();
             viewLocationExpanderContext.Values = new Dictionary<string, string>();
 
@@ -168,7 +178,12 @@ namespace Microsoft.AspNet.Mvc.Razor
         public void ExpandViewLocations_IncorrectLocaleContextValue(IEnumerable<string> viewLocations)
         {
             // Arrange
-            var viewLocationExpanderContext = new ViewLocationExpanderContext(new ActionContext(), "testView", false);
+            var viewLocationExpanderContext = new ViewLocationExpanderContext(
+                new ActionContext(), 
+                "testView", 
+                "test-controller",
+                "test-area",
+                false);
             var languageViewLocationExpander = new LanguageViewLocationExpander();
             viewLocationExpanderContext.Values = new Dictionary<string, string>();
             viewLocationExpanderContext.Values["language"] = "!-invalid-culture-!";

test/Microsoft.AspNet.Mvc.Razor.Test/RazorViewEngineTest.cs

@@ -1,16 +1,19 @@
 // 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 System.Linq;
+using System.Threading;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
-using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.Routing;
 using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Routing;
 using Microsoft.AspNet.Testing;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.OptionsModel;
+using Microsoft.Extensions.Primitives;
+using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
 using Xunit;
 
@@ -116,18 +119,24 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         public void FindPartialView_ReturnsRazorView_IfLookupWasSuccessful()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            var viewFactory = new Mock<IRazorViewFactory>();
             var page = Mock.Of<IRazorPage>();
-            var view = Mock.Of<IView>();
+            var viewStart1 = Mock.Of<IRazorPage>();
+            var viewStart2 = Mock.Of<IRazorPage>();
 
-            pageFactory.Setup(p => p.CreateInstance(It.IsAny<string>()))
+            pageFactory
-                       .Returns(Mock.Of<IRazorPage>());
+                .Setup(p => p.CreateFactory("/Views/bar/test-view.cshtml"))
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), true))
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]));
-                       .Returns(view)
-                       .Verifiable();
 
-            var viewEngine = CreateViewEngine(pageFactory.Object, viewFactory.Object);
+            pageFactory
+                .Setup(p => p.CreateFactory("/Views/_ViewStart.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => viewStart2, new IChangeToken[0]));
+
+            pageFactory
+                .Setup(p => p.CreateFactory("/_ViewStart.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => viewStart1, new IChangeToken[0]));
+
+            var viewEngine = CreateViewEngine(pageFactory.Object);
             var context = GetActionContext(_controllerTestContext);
 
             // Act
@@ -135,9 +144,52 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
 
             // Assert
             Assert.True(result.Success);
-            Assert.Same(view, result.View);
+            var view = Assert.IsType<RazorView>(result.View);
+            Assert.Same(page, view.RazorPage);
             Assert.Equal("test-view", result.ViewName);
-            viewFactory.Verify();
+            Assert.Empty(view.ViewStartPages);
+        }
+
+        [Fact]
+        public void FindPartialView_DoesNotExpireCachedResults_IfViewStartsExpire()
+        {
+            // Arrange
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
+            var page = Mock.Of<IRazorPage>();
+            var viewStart = Mock.Of<IRazorPage>();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var changeToken = new CancellationChangeToken(cancellationTokenSource.Token);
+
+            pageFactory
+                .Setup(p => p.CreateFactory("/Views/bar/test-view.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]));
+
+            pageFactory
+                .Setup(p => p.CreateFactory("/Views/_ViewStart.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => viewStart, new[] { changeToken }));
+
+            var viewEngine = CreateViewEngine(pageFactory.Object);
+            var context = GetActionContext(_controllerTestContext);
+
+            // Act - 1
+            var result1 = viewEngine.FindPartialView(context, "test-view");
+
+            // Assert - 1
+            Assert.True(result1.Success);
+            var view1 = Assert.IsType<RazorView>(result1.View);
+            Assert.Same(page, view1.RazorPage);
+            Assert.Equal("test-view", result1.ViewName);
+            Assert.Empty(view1.ViewStartPages);
+
+            // Act - 2
+            cancellationTokenSource.Cancel();
+            var result2 = viewEngine.FindPartialView(context, "test-view");
+
+            // Assert - 2
+            Assert.True(result2.Success);
+            var view2 = Assert.IsType<RazorView>(result2.View);
+            Assert.Same(page, view2.RazorPage);
+            pageFactory.Verify(p => p.CreateFactory("/Views/bar/test-view.cshtml"), Times.Once());
         }
 
         [Theory]
@@ -150,8 +202,9 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             var context = GetActionContext(_controllerTestContext);
 
             // Act & Assert
-            ExceptionAssert.ThrowsArgumentNullOrEmpty(() => viewEngine.FindPartialView(context, partialViewName),
+            ExceptionAssert.ThrowsArgumentNullOrEmpty(
-                                                      "partialViewName");
+                () => viewEngine.FindPartialView(context, partialViewName),
+                "partialViewName");
         }
 
         [Theory]
@@ -266,18 +319,24 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         public void FindView_ReturnsRazorView_IfLookupWasSuccessful()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            var viewFactory = new Mock<IRazorViewFactory>();
             var page = Mock.Of<IRazorPage>();
-            var view = Mock.Of<IView>();
+            var viewStart1 = Mock.Of<IRazorPage>();
+            var viewStart2 = Mock.Of<IRazorPage>();
 
-            pageFactory.Setup(p => p.CreateInstance(It.IsAny<string>()))
+            pageFactory
-                       .Returns(Mock.Of<IRazorPage>());
+                .Setup(p => p.CreateFactory("/Views/bar/test-view.cshtml"))
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), false))
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]));
-                       .Returns(view)
-                       .Verifiable();
 
-            var viewEngine = CreateViewEngine(pageFactory.Object, viewFactory.Object);
+            pageFactory
+                .Setup(p => p.CreateFactory("/Views/_ViewStart.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => viewStart2, new IChangeToken[0]));
+
+            pageFactory
+                .Setup(p => p.CreateFactory("/_ViewStart.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => viewStart1, new IChangeToken[0]));
+
+            var viewEngine = CreateViewEngine(pageFactory.Object);
             var context = GetActionContext(_controllerTestContext);
 
             // Act
@@ -285,63 +344,66 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
 
             // Assert
             Assert.True(result.Success);
-            Assert.Same(view, result.View);
+            var view = Assert.IsType<RazorView>(result.View);
             Assert.Equal("test-view", result.ViewName);
-            viewFactory.Verify();
+            Assert.Same(page, view.RazorPage);
+            Assert.False(view.IsPartial);
+            Assert.Equal(new[] { viewStart1, viewStart2 }, view.ViewStartPages);
         }
 
         [Fact]
         public void FindView_UsesViewLocationFormat_IfRouteDoesNotContainArea()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            var viewFactory = new Mock<IRazorViewFactory>();
+
             var page = Mock.Of<IRazorPage>();
             pageFactory
-                .Setup(p => p.CreateInstance("fake-path1/bar/test-view.rzr"))
+                .Setup(p => p.CreateFactory("fake-path1/bar/test-view.rzr"))
-                .Returns(page)
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]))
                 .Verifiable();
-            var viewEngine = new OverloadedLocationViewEngine(
+            var viewEngine = new TestableRazorViewEngine(
                 pageFactory.Object,
-                viewFactory.Object,
+                GetOptionsAccessor());
-                GetOptionsAccessor(),
+            viewEngine.SetLocationFormats(
-                GetViewLocationCache());
+                new[] { "fake-path1/{1}/{0}.rzr" },
+                new[] { "fake-area-path/{2}/{1}/{0}.rzr" });
             var context = GetActionContext(_controllerTestContext);
-            viewFactory.Setup(v => v.GetView(viewEngine, page, false))
-                .Returns(Mock.Of<IView>());
 
             // Act
             var result = viewEngine.FindView(context, "test-view");
 
             // Assert
             pageFactory.Verify();
+            var view = Assert.IsType<RazorView>(result.View);
+            Assert.Same(page, view.RazorPage);
         }
 
         [Fact]
         public void FindView_UsesAreaViewLocationFormat_IfRouteContainsArea()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            var viewFactory = new Mock<IRazorViewFactory>();
             var page = Mock.Of<IRazorPage>();
             pageFactory
-                .Setup(p => p.CreateInstance("fake-area-path/foo/bar/test-view2.rzr"))
+                .Setup(p => p.CreateFactory("fake-area-path/foo/bar/test-view2.rzr"))
-                .Returns(page)
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]))
                 .Verifiable();
-            var viewEngine = new OverloadedLocationViewEngine(
+            var viewEngine = new TestableRazorViewEngine(
                 pageFactory.Object,
-                viewFactory.Object,
+                GetOptionsAccessor());
-                GetOptionsAccessor(),
+            viewEngine.SetLocationFormats(
-                GetViewLocationCache());
+                new[] { "fake-path1/{1}/{0}.rzr" },
+                new[] { "fake-area-path/{2}/{1}/{0}.rzr" });
             var context = GetActionContext(_areaTestContext);
-            viewFactory.Setup(v => v.GetView(viewEngine, page, false))
-                .Returns(Mock.Of<IView>());
 
             // Act
             var result = viewEngine.FindView(context, "test-view2");
 
             // Assert
             pageFactory.Verify();
+            var view = Assert.IsType<RazorView>(result.View);
+            Assert.Same(page, view.RazorPage);
         }
 
         [Theory]
@@ -351,46 +413,49 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             IEnumerable<string> expectedSeeds)
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            pageFactory.Setup(p => p.CreateInstance("test-string/bar.cshtml"))
+            pageFactory
-                       .Returns(Mock.Of<IRazorPage>())
+                .Setup(p => p.CreateFactory("test-string/bar.cshtml"))
-                       .Verifiable();
+                .Returns(new RazorPageFactoryResult(() => Mock.Of<IRazorPage>(), new IChangeToken[0]))
-
+                .Verifiable();
-            var viewFactory = new Mock<IRazorViewFactory>();
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), It.IsAny<bool>()))
-                       .Returns(Mock.Of<IView>());
 
             var expander1Result = new[] { "some-seed" };
             var expander1 = new Mock<IViewLocationExpander>();
-            expander1.Setup(e => e.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
+            expander1
-                    .Callback((ViewLocationExpanderContext c) =>
+                .Setup(e => e.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
-                    {
+                .Callback((ViewLocationExpanderContext c) =>
-                        Assert.NotNull(c.ActionContext);
+                {
-                        c.Values["expander-key"] = expander1.ToString();
+                    Assert.NotNull(c.ActionContext);
-                    })
+                    c.Values["expander-key"] = expander1.ToString();
-                    .Verifiable();
+                })
-            expander1.Setup(e => e.ExpandViewLocations(It.IsAny<ViewLocationExpanderContext>(),
+                .Verifiable();
-                                                      It.IsAny<IEnumerable<string>>()))
+            expander1
-                    .Callback((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
+                .Setup(e => e.ExpandViewLocations(
-                    {
+                    It.IsAny<ViewLocationExpanderContext>(),
-                        Assert.NotNull(c.ActionContext);
+                    It.IsAny<IEnumerable<string>>()))
-                        Assert.Equal(expectedSeeds, seeds);
+                .Callback((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
-                    })
+                {
-                    .Returns(expander1Result)
+                    Assert.NotNull(c.ActionContext);
-                    .Verifiable();
+                    Assert.Equal(expectedSeeds, seeds);
+                })
+                .Returns(expander1Result)
+                .Verifiable();
 
             var expander2 = new Mock<IViewLocationExpander>();
-            expander2.Setup(e => e.ExpandViewLocations(It.IsAny<ViewLocationExpanderContext>(),
+            expander2
-                                                      It.IsAny<IEnumerable<string>>()))
+                .Setup(e => e.ExpandViewLocations(
-                     .Callback((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
+                    It.IsAny<ViewLocationExpanderContext>(),
-                     {
+                    It.IsAny<IEnumerable<string>>()))
-                         Assert.Equal(expander1Result, seeds);
+                .Callback((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
-                     })
+                {
-                     .Returns(new[] { "test-string/{1}.cshtml" })
+                    Assert.Equal(expander1Result, seeds);
-                     .Verifiable();
+                })
+                .Returns(new[] { "test-string/{1}.cshtml" })
+                .Verifiable();
 
-            var viewEngine = CreateViewEngine(pageFactory.Object, viewFactory.Object,
+            var viewEngine = CreateViewEngine(
-                                 new[] { expander1.Object, expander2.Object });
+                pageFactory.Object,
+                new[] { expander1.Object, expander2.Object });
             var context = GetActionContext(routeValues);
 
             // Act
@@ -408,130 +473,152 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         public void FindView_CachesValuesIfViewWasFound()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var page = Mock.Of<IRazorPage>();
-            pageFactory.Setup(p => p.CreateInstance("/Views/bar/baz.cshtml"))
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-                       .Verifiable();
+            pageFactory
-            pageFactory.Setup(p => p.CreateInstance("/Views/Shared/baz.cshtml"))
+                .Setup(p => p.CreateFactory("/Views/bar/baz.cshtml"))
-                       .Returns(Mock.Of<IRazorPage>())
+                .Returns(new RazorPageFactoryResult(new IChangeToken[0]))
-                       .Verifiable();
-
-            var viewFactory = new Mock<IRazorViewFactory>();
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), false))
-                       .Returns(Mock.Of<IView>());
-
-            var cache = GetViewLocationCache();
-            var cacheMock = Mock.Get(cache);
-            cacheMock.Setup(c => c.Set(It.IsAny<ViewLocationExpanderContext>(), It.IsAny<ViewLocationCacheResult>()))
-                .Callback((ViewLocationExpanderContext _, ViewLocationCacheResult cacheResult) =>
-                {
-                    Assert.Equal("/Views/Shared/baz.cshtml", cacheResult.ViewLocation);
-                    Assert.Equal(new[] { "/Views/bar/baz.cshtml" }, cacheResult.SearchedLocations);
-                })
                 .Verifiable();
+            pageFactory
+               .Setup(p => p.CreateFactory("/Views/Shared/baz.cshtml"))
+               .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]))
+               .Verifiable();
 
-            var viewEngine = CreateViewEngine(pageFactory.Object, viewFactory.Object, cache: cache);
+            var viewEngine = CreateViewEngine(pageFactory.Object);
             var context = GetActionContext(_controllerTestContext);
 
-            // Act
+            // Act 1
-            var result = viewEngine.FindView(context, "baz");
+            var result1 = viewEngine.FindView(context, "baz");
 
-            // Assert
+            // Assert 1
-            Assert.True(result.Success);
+            Assert.True(result1.Success);
+            var view1 = Assert.IsType<RazorView>(result1.View);
+            Assert.Same(page, view1.RazorPage);
+            pageFactory.Verify();
+
+            // Act 2
+            pageFactory
+               .Setup(p => p.CreateFactory(It.IsAny<string>()))
+               .Throws(new Exception("Shouldn't be called"));
+
+            var result2 = viewEngine.FindView(context, "baz");
+
+            // Assert 2
+            Assert.True(result2.Success);
+            var view2 = Assert.IsType<RazorView>(result2.View);
+            Assert.Same(page, view2.RazorPage);
             pageFactory.Verify();
-            cacheMock.Verify();
         }
 
         [Fact]
-        public void FindView_UsesCachedValueIfViewWasFound()
+        public void FindView_InvokesPageFactoryIfChangeTokenExpired()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>(MockBehavior.Strict);
+            var page1 = Mock.Of<IRazorPage>();
-            pageFactory.Setup(p => p.CreateInstance("some-view-location"))
+            var page2 = Mock.Of<IRazorPage>();
-                       .Returns(Mock.Of<IRazorPage>())
+            var sequence = new MockSequence();
-                       .Verifiable();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var changeToken = new CancellationChangeToken(cancellationTokenSource.Token);
 
-            var viewFactory = new Mock<IRazorViewFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), false))
+            pageFactory
-                       .Returns(Mock.Of<IView>());
+                .InSequence(sequence)
+                .Setup(p => p.CreateFactory("/Views/bar/baz.cshtml"))
+                .Returns(new RazorPageFactoryResult(new[] { changeToken }));
+            pageFactory
+               .InSequence(sequence)
+               .Setup(p => p.CreateFactory("/Views/Shared/baz.cshtml"))
+               .Returns(new RazorPageFactoryResult(() => page1, new IChangeToken[0]))
+               .Verifiable();
+            pageFactory
+                .InSequence(sequence)
+                .Setup(p => p.CreateFactory("/Views/bar/baz.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => page2, new IChangeToken[0]));
 
-            var expander = new Mock<IViewLocationExpander>(MockBehavior.Strict);
+            var viewEngine = CreateViewEngine(pageFactory.Object);
-            expander.Setup(v => v.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
-                    .Verifiable();
-            var cacheMock = new Mock<IViewLocationCache>();
-            cacheMock.Setup(c => c.Get(It.IsAny<ViewLocationExpanderContext>()))
-                .Returns(new ViewLocationCacheResult("some-view-location", Enumerable.Empty<string>()))
-                .Verifiable();
-
-            var viewEngine = CreateViewEngine(pageFactory.Object,
-                                              viewFactory.Object,
-                                              new[] { expander.Object },
-                                              cacheMock.Object);
             var context = GetActionContext(_controllerTestContext);
 
-            // Act
+            // Act 1
-            var result = viewEngine.FindView(context, "baz");
+            var result1 = viewEngine.FindView(context, "baz");
 
-            // Assert
+            // Assert 1
-            Assert.True(result.Success);
+            Assert.True(result1.Success);
+            var view1 = Assert.IsType<RazorView>(result1.View);
+            Assert.Same(page1, view1.RazorPage);
+
+            // Act 2
+            cancellationTokenSource.Cancel();
+            var result2 = viewEngine.FindView(context, "baz");
+
+            // Assert 2
+            Assert.True(result2.Success);
+            var view2 = Assert.IsType<RazorView>(result2.View);
+            Assert.Same(page2, view2.RazorPage);
             pageFactory.Verify();
-            cacheMock.Verify();
-            expander.Verify();
         }
 
         [Fact]
-        public void FindView_LooksForViewsIfCachedViewDoesNotExist()
+        public void FindView_InvokesPageFactoryIfViewStartExpirationTokensHaveExpired()
         {
             // Arrange
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var page1 = Mock.Of<IRazorPage>();
-            pageFactory.Setup(p => p.CreateInstance("expired-location"))
+            var page2 = Mock.Of<IRazorPage>();
-                       .Returns((IRazorPage)null)
+            var viewStart = Mock.Of<IRazorPage>();
-                       .Verifiable();
+            var sequence = new MockSequence();
-            pageFactory.Setup(p => p.CreateInstance("some-view-location"))
+            var cancellationTokenSource = new CancellationTokenSource();
-                       .Returns(Mock.Of<IRazorPage>())
+            var changeToken = new CancellationChangeToken(cancellationTokenSource.Token);
-                       .Verifiable();
 
-            var viewFactory = new Mock<IRazorViewFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            viewFactory.Setup(p => p.GetView(It.IsAny<IRazorViewEngine>(), It.IsAny<IRazorPage>(), false))
+            pageFactory
-                       .Returns(Mock.Of<IView>());
+                .InSequence(sequence)
+                .Setup(p => p.CreateFactory("/Views/bar/baz.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => page1, new IChangeToken[0]));
+            pageFactory
+                .InSequence(sequence)
+               .Setup(p => p.CreateFactory("/Views/_ViewStart.cshtml"))
+               .Returns(new RazorPageFactoryResult(new[] { changeToken }))
+               .Verifiable();
+            pageFactory
+                .InSequence(sequence)
+                .Setup(p => p.CreateFactory("/Views/bar/baz.cshtml"))
+                .Returns(new RazorPageFactoryResult(() => page2, new IChangeToken[0]));
+            pageFactory
+                .InSequence(sequence)
+               .Setup(p => p.CreateFactory("/Views/_ViewStart.cshtml"))
+               .Returns(new RazorPageFactoryResult(() => viewStart, new IChangeToken[0]));
 
-            var cacheMock = new Mock<IViewLocationCache>();
+            var viewEngine = CreateViewEngine(pageFactory.Object);
-            cacheMock.Setup(c => c.Get(It.IsAny<ViewLocationExpanderContext>()))
-                .Returns(new ViewLocationCacheResult("expired-location", Enumerable.Empty<string>()));
-
-            var expander = new Mock<IViewLocationExpander>();
-            expander.Setup(v => v.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
-                    .Verifiable();
-            var expanderResult = new[] { "some-view-location" };
-            expander.Setup(v => v.ExpandViewLocations(
-                        It.IsAny<ViewLocationExpanderContext>(), It.IsAny<IEnumerable<string>>()))
-                    .Returns((ViewLocationExpanderContext c, IEnumerable<string> seed) => expanderResult)
-                    .Verifiable();
-
-            var viewEngine = CreateViewEngine(pageFactory.Object,
-                                              viewFactory.Object,
-                                              expanders: new[] { expander.Object },
-                                              cache: cacheMock.Object);
             var context = GetActionContext(_controllerTestContext);
 
-            // Act
+            // Act 1
-            var result = viewEngine.FindView(context, "baz");
+            var result1 = viewEngine.FindView(context, "baz");
 
-            // Assert
+            // Assert 1
-            Assert.True(result.Success);
+            Assert.True(result1.Success);
+            var view1 = Assert.IsType<RazorView>(result1.View);
+            Assert.Same(page1, view1.RazorPage);
+            Assert.Empty(view1.ViewStartPages);
+
+            // Act 2
+            cancellationTokenSource.Cancel();
+            var result2 = viewEngine.FindView(context, "baz");
+
+            // Assert 2
+            Assert.True(result2.Success);
+            var view2 = Assert.IsType<RazorView>(result2.View);
+            Assert.Same(page2, view2.RazorPage);
+            var actualViewStart = Assert.Single(view2.ViewStartPages);
+            Assert.Equal(viewStart, actualViewStart);
             pageFactory.Verify();
-            cacheMock.Verify();
-            expander.Verify();
         }
 
         // This test validates an important perf scenario of RazorViewEngine not constructing
         // multiple strings for views that do not exist in the file system on a per-request basis.
         [Fact]
-        public void FindView_DoesNotInvokeExpandViewLocations_IfCacheEntryMatchesButViewIsNotFound()
+        public void FindView_DoesNotInvokeViewLocationExpanders_IfChangeTokenHasNotExpired()
         {
             // Arrange
-            var pageFactory = Mock.Of<IRazorPageFactory>();
+            var pageFactory = Mock.Of<IRazorPageFactoryProvider>();
-            var viewFactory = Mock.Of<IRazorViewFactory>();
-            var cache = new DefaultViewLocationCache();
             var expander = new Mock<IViewLocationExpander>();
             var expandedLocations = new[]
             {
@@ -548,16 +635,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                 .Verifiable();
             expander
                 .Setup(v => v.ExpandViewLocations(
-                    It.IsAny<ViewLocationExpanderContext>(), It.IsAny<IEnumerable<string>>()))
+                    It.IsAny<ViewLocationExpanderContext>(),
-                .Returns((ViewLocationExpanderContext c, IEnumerable<string> viewLocations) => expandedLocations)
+                    It.IsAny<IEnumerable<string>>()))
+                .Returns(expandedLocations)
                 .Verifiable();
 
-
             var viewEngine = CreateViewEngine(
                 pageFactory,
-                viewFactory,
+                expanders: new[] { expander.Object });
-                expanders: new[] { expander.Object },
-                cache: cache);
             var context = GetActionContext(_controllerTestContext);
 
             // Act - 1
@@ -582,6 +667,70 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
                 Times.Once());
         }
 
+        [Fact]
+        public void FindView_InvokesViewLocationExpanders_IfChangeTokenExpires()
+        {
+            // Arrange
+            var cancellationTokenSource = new CancellationTokenSource();
+            var changeToken = new CancellationChangeToken(cancellationTokenSource.Token);
+            var page = Mock.Of<IRazorPage>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
+            pageFactory
+                .Setup(p => p.CreateFactory("viewlocation3"))
+                .Returns(new RazorPageFactoryResult(new[] { changeToken }));
+            var expander = new Mock<IViewLocationExpander>();
+            var expandedLocations = new[]
+            {
+                "viewlocation1",
+                "viewlocation2",
+                "viewlocation3",
+            };
+            expander
+                .Setup(v => v.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
+                .Callback((ViewLocationExpanderContext expanderContext) =>
+                {
+                    expanderContext.Values["somekey"] = "somevalue";
+                })
+                .Verifiable();
+            expander
+                .Setup(v => v.ExpandViewLocations(
+                    It.IsAny<ViewLocationExpanderContext>(),
+                    It.IsAny<IEnumerable<string>>()))
+                .Returns(expandedLocations)
+                .Verifiable();
+
+            var viewEngine = CreateViewEngine(
+                pageFactory.Object,
+                expanders: new[] { expander.Object });
+            var context = GetActionContext(_controllerTestContext);
+
+            // Act - 1
+            var result = viewEngine.FindView(context, "MyView");
+
+            // Assert - 1
+            Assert.False(result.Success);
+            Assert.Equal(expandedLocations, result.SearchedLocations);
+            expander.Verify();
+
+            // Act - 2
+            pageFactory
+                .Setup(p => p.CreateFactory("viewlocation3"))
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]));
+            cancellationTokenSource.Cancel();
+            result = viewEngine.FindView(context, "MyView");
+
+            // Assert - 2
+            Assert.True(result.Success);
+            var view = Assert.IsType<RazorView>(result.View);
+            Assert.Same(page, view.RazorPage);
+            expander.Verify(
+                v => v.PopulateValues(It.IsAny<ViewLocationExpanderContext>()),
+                Times.Exactly(2));
+            expander.Verify(
+                v => v.ExpandViewLocations(It.IsAny<ViewLocationExpanderContext>(), It.IsAny<IEnumerable<string>>()),
+                Times.Exactly(2));
+        }
+
         [Theory]
         [InlineData(null)]
         [InlineData("")]
@@ -604,36 +753,39 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         {
             // Arrange
             var page = Mock.Of<IRazorPage>();
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            pageFactory.Setup(p => p.CreateInstance("expanded-path/bar-layout"))
+            pageFactory
-                       .Returns(page)
+                .Setup(p => p.CreateFactory("expanded-path/bar-layout"))
-                       .Verifiable();
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]))
-
+                .Verifiable();
-            var viewFactory = new Mock<IRazorViewFactory>(MockBehavior.Strict);
 
             var expander = new Mock<IViewLocationExpander>();
-            expander.Setup(e => e.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
+            expander
-                    .Callback((ViewLocationExpanderContext c) =>
+                .Setup(e => e.PopulateValues(It.IsAny<ViewLocationExpanderContext>()))
-                    {
+                .Callback((ViewLocationExpanderContext c) =>
-                        Assert.NotNull(c.ActionContext);
+                {
-                        c.Values["expander-key"] = expander.ToString();
+                    Assert.NotNull(c.ActionContext);
-                    })
+                    c.Values["expander-key"] = expander.ToString();
-                    .Verifiable();
+                })
-            expander.Setup(e => e.ExpandViewLocations(It.IsAny<ViewLocationExpanderContext>(),
+                .Verifiable();
-                                                      It.IsAny<IEnumerable<string>>()))
+            expander
-                    .Returns((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
+                .Setup(e => e.ExpandViewLocations(
-                    {
+                    It.IsAny<ViewLocationExpanderContext>(),
-                        Assert.NotNull(c.ActionContext);
+                    It.IsAny<IEnumerable<string>>()))
-                        Assert.Equal(expectedSeeds, seeds);
+                .Returns((ViewLocationExpanderContext c, IEnumerable<string> seeds) =>
+                {
+                    Assert.NotNull(c.ActionContext);
+                    Assert.Equal(expectedSeeds, seeds);
 
-                        Assert.Equal(expander.ToString(), c.Values["expander-key"]);
+                    Assert.Equal(expander.ToString(), c.Values["expander-key"]);
 
-                        return new[] { "expanded-path/bar-{0}" };
+                    return new[] { "expanded-path/bar-{0}" };
-                    })
+                })
-                    .Verifiable();
+                .Verifiable();
 
-            var viewEngine = CreateViewEngine(pageFactory.Object, viewFactory.Object,
+            var viewEngine = CreateViewEngine(
-                                 new[] { expander.Object });
+                pageFactory.Object,
+                new[] { expander.Object });
             var context = GetActionContext(routeValues);
 
             // Act
@@ -686,10 +838,11 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             };
 
             var page = new Mock<IRazorPage>(MockBehavior.Strict).Object;
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            pageFactory.Setup(p => p.CreateInstance("/Views/Foo/details.cshtml"))
+            pageFactory
-                       .Returns(page)
+                .Setup(p => p.CreateFactory("/Views/Foo/details.cshtml"))
-                       .Verifiable();
+                .Returns(new RazorPageFactoryResult(() => page, new IChangeToken[0]))
+                .Verifiable();
 
             var viewEngine = CreateViewEngine(pageFactory.Object);
             var routesInActionDescriptor = new Dictionary<string, string>()
@@ -1092,23 +1245,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             }
         }
 
-        private RazorViewEngine CreateViewEngine(
+        private TestableRazorViewEngine CreateViewEngine(
-            IRazorPageFactory pageFactory = null,
+            IRazorPageFactoryProvider pageFactory = null,
-            IRazorViewFactory viewFactory = null,
+            IEnumerable<IViewLocationExpander> expanders = null)
-            IEnumerable<IViewLocationExpander> expanders = null,
-            IViewLocationCache cache = null)
         {
-            pageFactory = pageFactory ?? Mock.Of<IRazorPageFactory>();
+            pageFactory = pageFactory ?? Mock.Of<IRazorPageFactoryProvider>();
-            viewFactory = viewFactory ?? Mock.Of<IRazorViewFactory>();
+            return new TestableRazorViewEngine(
-
+                pageFactory,
-            cache = cache ?? GetViewLocationCache();
+                GetOptionsAccessor(expanders));
-
-            var viewEngine = new RazorViewEngine(pageFactory,
-                                                 viewFactory,
-                                                 GetOptionsAccessor(expanders),
-                                                 cache);
-
-            return viewEngine;
         }
 
         private static IOptions<RazorViewEngineOptions> GetOptionsAccessor(
@@ -1129,15 +1273,6 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             return optionsAccessor.Object;
         }
 
-        private static IViewLocationCache GetViewLocationCache()
-        {
-            var cacheMock = new Mock<IViewLocationCache>();
-            cacheMock.Setup(c => c.Get(It.IsAny<ViewLocationExpanderContext>()))
-                     .Returns<string>(null);
-
-            return cacheMock.Object;
-        }
-
         private static ActionContext GetActionContext(IDictionary<string, object> routeValues)
         {
             var httpContext = new DefaultHttpContext();
@@ -1185,32 +1320,33 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             return new ActionContext(httpContext, routeData, actionDescriptor);
         }
 
-        private class OverloadedLocationViewEngine : RazorViewEngine
+        private class TestableRazorViewEngine : RazorViewEngine
         {
-            public OverloadedLocationViewEngine(
+            private IEnumerable<string> _viewLocationFormats;
-                IRazorPageFactory pageFactory,
+            private IEnumerable<string> _areaViewLocationFormats;
-                IRazorViewFactory viewFactory,
+
-                IOptions<RazorViewEngineOptions> optionsAccessor,
+            public TestableRazorViewEngine(
-                IViewLocationCache cache)
+                IRazorPageFactoryProvider pageFactory,
-                : base(pageFactory, viewFactory, optionsAccessor, cache)
+                IOptions<RazorViewEngineOptions> optionsAccessor)
+                : base(pageFactory, Mock.Of<IRazorPageActivator>(), new HtmlTestEncoder(), optionsAccessor)
             {
             }
 
-            public override IEnumerable<string> ViewLocationFormats
+            public void SetLocationFormats(
+                IEnumerable<string> viewLocationFormats,
+                IEnumerable<string> areaViewLocationFormats)
             {
-                get
+                _viewLocationFormats = viewLocationFormats;
-                {
+                _areaViewLocationFormats = areaViewLocationFormats;
-                    return new[] { "fake-path1/{1}/{0}.rzr" };
-                }
             }
 
-            public override IEnumerable<string> AreaViewLocationFormats
+            public override IEnumerable<string> ViewLocationFormats =>
-            {
+                _viewLocationFormats != null ? _viewLocationFormats : base.ViewLocationFormats;
-                get
+
-                {
+            public override IEnumerable<string> AreaViewLocationFormats =>
-                    return new[] { "fake-area-path/{2}/{1}/{0}.rzr" };
+                _areaViewLocationFormats != null ? _areaViewLocationFormats : base.AreaViewLocationFormats;
-                }
+
-            }
+            public IMemoryCache ViewLookupCachePublic => ViewLookupCache;
         }
     }
 }

test/Microsoft.AspNet.Mvc.Razor.Test/RazorViewFactoryTest.cs

@@ -1,55 +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.Extensions.WebEncoders.Testing;
-using Moq;
-using Xunit;
-
-namespace Microsoft.AspNet.Mvc.Razor
-{
-    public class RazorViewFactoryTest
-    {
-        [Theory]
-        [InlineData(false)]
-        [InlineData(true)]
-        public void GetView_SetsIsPartial(bool isPartial)
-        {
-            // Arrange
-            var factory = new RazorViewFactory(
-                Mock.Of<IRazorPageActivator>(),
-                Mock.Of<IViewStartProvider>(),
-                new HtmlTestEncoder());
-            var page = Mock.Of<IRazorPage>();
-            var viewEngine = Mock.Of<IRazorViewEngine>();
-
-            // Act
-            var view = factory.GetView(viewEngine, page, isPartial);
-
-            // Assert
-            var razorView = Assert.IsType<RazorView>(view);
-            Assert.Same(page, razorView.RazorPage);
-            Assert.Equal(razorView.IsPartial, isPartial);
-        }
-
-        [Fact]
-        public void GetView_SetsRazorPage()
-        {
-            // Arrange
-            var factory = new RazorViewFactory(
-                Mock.Of<IRazorPageActivator>(),
-                Mock.Of<IViewStartProvider>(),
-                new HtmlTestEncoder());
-
-            var page = Mock.Of<IRazorPage>();
-            var viewEngine = Mock.Of<IRazorViewEngine>();
-
-            // Act
-            var view = factory.GetView(viewEngine, page, isPartial: false);
-
-            // Assert
-            Assert.NotNull(view);
-            var razorView = Assert.IsType<RazorView>(view);
-            Assert.Same(razorView.RazorPage, page);
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.Razor.Test/RazorViewTest.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Features;
 using Microsoft.AspNet.Http.Internal;
@@ -14,6 +13,7 @@ using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures;
 using Microsoft.AspNet.PageExecutionInstrumentation;
 using Microsoft.AspNet.Routing;
+using Microsoft.Extensions.Primitives;
 using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
 using Xunit;
@@ -39,12 +39,13 @@ namespace Microsoft.AspNet.Mvc.Razor
                 v.HtmlEncoder = new HtmlTestEncoder();
                 v.Write("Hello world");
             });
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     Mock.Of<IRazorPageActivator>(),
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                Mock.Of<IRazorPageActivator>(),
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: true);
+                new HtmlTestEncoder(),
+                isPartial: true);
             var viewContext = CreateViewContext(view);
             var expected = viewContext.Writer;
 
@@ -68,12 +69,13 @@ namespace Microsoft.AspNet.Mvc.Razor
                 Assert.Same(viewData, v.ViewContext.ViewData);
             });
             var activator = new Mock<IRazorPageActivator>();
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     activator.Object,
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                activator.Object,
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: true);
+                new HtmlTestEncoder(),
+                isPartial: true);
 
             var viewContext = CreateViewContext(view);
             var expectedWriter = viewContext.Writer;
@@ -132,12 +134,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             var viewEngine = new Mock<IRazorViewEngine>();
             viewEngine.Setup(v => v.FindPage(It.IsAny<ActionContext>(), LayoutPath))
                       .Returns(new RazorPageResult(LayoutPath, layout));
-            var view = new RazorView(viewEngine.Object,
+            var view = new RazorView(
-                                     activator,
+                viewEngine.Object,
-                                     CreateViewStartProvider(viewStart),
+                activator,
-                                     page,
+                new[] { viewStart },
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
 
             var viewContext = CreateViewContext(view);
             var expectedWriter = viewContext.Writer;
@@ -157,12 +160,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             var activator = new Mock<IRazorPageActivator>();
             activator.Setup(a => a.Activate(page, It.IsAny<ViewContext>()))
                      .Verifiable();
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     activator.Object,
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                activator.Object,
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: true);
+                new HtmlTestEncoder(),
+                isPartial: true);
             var viewContext = CreateViewContext(view);
 
             // Act
@@ -193,29 +197,28 @@ namespace Microsoft.AspNet.Mvc.Razor
                 v.Write("layout-content" + Environment.NewLine);
                 v.RenderBodyPublic();
             });
-            var pageFactory = new Mock<IRazorPageFactory>();
+            var pageFactory = new Mock<IRazorPageFactoryProvider>();
-            pageFactory.Setup(p => p.CreateInstance(LayoutPath))
+            pageFactory
-                       .Returns(layout);
+                .Setup(p => p.CreateFactory(LayoutPath))
+                .Returns(new RazorPageFactoryResult(() => layout, new IChangeToken[0]));
 
             var viewEngine = new Mock<IRazorViewEngine>();
             viewEngine.Setup(v => v.FindPage(It.IsAny<ActionContext>(), LayoutPath))
                       .Returns(new RazorPageResult(LayoutPath, layout));
 
-            var viewStartProvider = CreateViewStartProvider();
+            var view = new RazorView(
-            var view = new RazorView(viewEngine.Object,
+                viewEngine.Object,
-                                     Mock.Of<IRazorPageActivator>(),
+                Mock.Of<IRazorPageActivator>(),
-                                     viewStartProvider,
+                new IRazorPage[0],
-                                     page,
+                page,
-                                     new HtmlTestEncoder(),
+                new HtmlTestEncoder(),
-                                     isPartial: true);
+                isPartial: true);
             var viewContext = CreateViewContext(view);
 
             // Act
             await view.RenderAsync(viewContext);
 
             // Assert
-            Mock.Get(viewStartProvider)
-                .Verify(v => v.GetViewStartPages(It.IsAny<string>()), Times.Never());
             Assert.Equal(expected, viewContext.Writer.ToString());
         }
 
@@ -228,12 +231,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             {
                 actual = v.Output;
             });
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     Mock.Of<IRazorPageActivator>(),
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                Mock.Of<IRazorPageActivator>(),
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
             var viewContext = CreateViewContext(view);
             var original = viewContext.Writer;
 
@@ -253,12 +257,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             {
                 v.WriteLiteral("Hello world");
             });
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     Mock.Of<IRazorPageActivator>(),
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                Mock.Of<IRazorPageActivator>(),
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
             var viewContext = CreateViewContext(view);
             var original = viewContext.Writer;
 
@@ -280,12 +285,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             var activator = new Mock<IRazorPageActivator>();
             activator.Setup(a => a.Activate(page, It.IsAny<ViewContext>()))
                      .Verifiable();
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     activator.Object,
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(),
+                activator.Object,
-                                     page,
+                new IRazorPage[0],
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
             var viewContext = CreateViewContext(view);
 
             // Act
@@ -323,12 +329,13 @@ namespace Microsoft.AspNet.Mvc.Razor
                      .Verifiable();
             activator.Setup(a => a.Activate(page, It.IsAny<ViewContext>()))
                      .Verifiable();
-            var view = new RazorView(Mock.Of<IRazorViewEngine>(),
+            var view = new RazorView(
-                                     activator.Object,
+                Mock.Of<IRazorViewEngine>(),
-                                     CreateViewStartProvider(viewStart1, viewStart2),
+                activator.Object,
-                                     page,
+                new[] { viewStart1, viewStart2 },
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
             var viewContext = CreateViewContext(view);
 
             // Act
@@ -358,7 +365,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             var activator = new Mock<IRazorPageActivator>();
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     Mock.Of<IViewStartProvider>(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -422,7 +429,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      activator.Object,
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -464,7 +471,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -527,7 +534,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -587,7 +594,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -647,7 +654,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -712,7 +719,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -744,7 +751,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -808,7 +815,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -844,7 +851,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -889,7 +896,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -956,7 +963,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1009,7 +1016,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1059,7 +1066,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1089,7 +1096,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(Mock.Of<IRazorViewEngine>(),
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1134,7 +1141,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1204,13 +1211,9 @@ namespace Microsoft.AspNet.Mvc.Razor
             var viewEngine = new Mock<IRazorViewEngine>();
             viewEngine.Setup(p => p.FindPage(It.IsAny<ActionContext>(), "Layout"))
                        .Returns(new RazorPageResult("Layout", layout));
-            var viewStartProvider = new Mock<IViewStartProvider>();
-            viewStartProvider.Setup(v => v.GetViewStartPages(It.IsAny<string>()))
-                             .Returns(Enumerable.Empty<IRazorPage>())
-                             .Verifiable();
             var view = new RazorView(viewEngine.Object,
                                      Mock.Of<IRazorPageActivator>(),
-                                     viewStartProvider.Object,
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1222,7 +1225,6 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             // Assert
             feature.Verify();
-            viewStartProvider.Verify();
             Assert.True(layoutExecuted);
         }
 
@@ -1256,7 +1258,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(Mock.Of<IRazorViewEngine>(),
                                      Mock.Of<IRazorPageActivator>(),
-                                     Mock.Of<IViewStartProvider>(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: true);
@@ -1288,7 +1290,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(Mock.Of<IRazorViewEngine>(),
                                      Mock.Of<IRazorPageActivator>(),
-                                     Mock.Of<IViewStartProvider>(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial);
@@ -1328,7 +1330,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             var view = new RazorView(viewEngine,
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(viewStart1, viewStart2),
+                                     new[] { viewStart1, viewStart2 },
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: false);
@@ -1364,12 +1366,13 @@ namespace Microsoft.AspNet.Mvc.Razor
             });
             var viewEngine = Mock.Of<IRazorViewEngine>();
 
-            var view = new RazorView(viewEngine,
+            var view = new RazorView(
-                                     Mock.Of<IRazorPageActivator>(),
+                viewEngine,
-                                     CreateViewStartProvider(viewStart1, viewStart2),
+                Mock.Of<IRazorPageActivator>(),
-                                     page,
+                new[] { viewStart1, viewStart2 },
-                                     new HtmlTestEncoder(),
+                page,
-                                     isPartial: false);
+                new HtmlTestEncoder(),
+                isPartial: false);
             var viewContext = CreateViewContext(view);
 
             // Act
@@ -1402,13 +1405,14 @@ namespace Microsoft.AspNet.Mvc.Razor
                 v.RenderBodyPublic();
             });
             var viewEngine = new Mock<IRazorViewEngine>();
-            viewEngine.Setup(p => p.FindPage(It.IsAny<ActionContext>(), "/Layout.cshtml"))
+            viewEngine
-                       .Returns(new RazorPageResult("Layout", layout));
+                .Setup(p => p.FindPage(It.IsAny<ActionContext>(), "/Layout.cshtml"))
+                .Returns(new RazorPageResult("Layout", layout));
 
             var view = new RazorView(
                 viewEngine.Object,
                 Mock.Of<IRazorPageActivator>(),
-                CreateViewStartProvider(viewStart),
+                new[] { viewStart },
                 page,
                 new HtmlTestEncoder(),
                 isPartial: false);
@@ -1434,7 +1438,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             });
             var view = new RazorView(Mock.Of<IRazorViewEngine>(),
                                      Mock.Of<IRazorPageActivator>(),
-                                     CreateViewStartProvider(),
+                                     new IRazorPage[0],
                                      page,
                                      new HtmlTestEncoder(),
                                      isPartial: true);
@@ -1447,6 +1451,48 @@ namespace Microsoft.AspNet.Mvc.Razor
             Assert.True(isPartialPage.Value);
         }
 
+        [Fact]
+        public async Task RenderAsync_RendersViewStartsInOrderInWhichTheyAreSpecified()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                new[]
+                {
+                    "ViewStart1",
+                    "ViewStart2",
+                    "Page",
+                });
+            var page = new TestableRazorPage(v =>
+            {
+                v.WriteLiteral("Page");
+            });
+            var viewStart1 = new TestableRazorPage(v =>
+            {
+                v.WriteLiteral("ViewStart1" + Environment.NewLine);
+            });
+            var viewStart2 = new TestableRazorPage(v =>
+            {
+                v.WriteLiteral("ViewStart2" + Environment.NewLine);
+            });
+            var viewEngine = Mock.Of<IRazorViewEngine>();
+
+            var view = new RazorView(
+                viewEngine,
+                Mock.Of<IRazorPageActivator>(),
+                new[] { viewStart1, viewStart2 },
+                page,
+                new HtmlTestEncoder(),
+                isPartial: false);
+            var viewContext = CreateViewContext(view);
+
+            // Act
+            await view.RenderAsync(viewContext);
+
+            // Assert
+            Assert.Equal(expected, viewContext.Writer.ToString());
+        }
+
         private static TextWriter CreateBufferedWriter()
         {
             var mockWriter = new Mock<TextWriter>();
@@ -1469,17 +1515,6 @@ namespace Microsoft.AspNet.Mvc.Razor
                 new HtmlHelperOptions());
         }
 
-        private static IViewStartProvider CreateViewStartProvider(params IRazorPage[] viewStartPages)
-        {
-            viewStartPages = viewStartPages ?? new IRazorPage[0];
-            var viewStartProvider = new Mock<IViewStartProvider>();
-            viewStartProvider
-                .Setup(v => v.GetViewStartPages(It.IsAny<string>()))
-                .Returns(viewStartPages);
-
-            return viewStartProvider.Object;
-        }
-
         private class TestableRazorPage : RazorPage
         {
             private readonly Action<TestableRazorPage> _executeAction;