Get rid of RazorConfiguration.DesignTime

This change makes it so that we no longer create 'design time' engines.
The choice of design time or runtime is made when we initiate a code
generation operation.

Options instances are now created as part of the CodeDocument
initialization. Our existing code can still be created using a
RazorEngine so our passes that initialize the options still support the
old code path.

src/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X/ModelDirective.cs

@@ -29,7 +29,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             }
 
             builder.AddDirective(Directive);
-            builder.Features.Add(new Pass(builder.Configuration.DesignTime));
+            builder.Features.Add(new Pass());
             return builder;
         }
 
@@ -64,13 +64,6 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 
         internal class Pass : IntermediateNodePassBase, IRazorDirectiveClassifierPass
         {
-            private readonly bool _designTime;
-
-            public Pass(bool designTime)
-            {
-                _designTime = designTime;
-            }
-
             // Runs after the @inherits directive
             public override int Order => 5;
 
@@ -79,7 +72,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
                 var visitor = new Visitor();
                 var modelType = GetModelType(documentNode, visitor);
 
-                if (_designTime)
+                if (documentNode.Options.DesignTime)
                 {
                     // Alias the TModel token to a known type.
                     // This allows design time compilation to succeed for Razor files where the token isn't replaced.
@@ -143,7 +136,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             }
 
             builder.AddDirective(Directive);
-            builder.Features.Add(new Pass(builder.DesignTime));
+            builder.Features.Add(new Pass());
             return builder;
         }
         #endregion

src/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X/MvcImportProjectFeature.cs

@@ -10,7 +10,7 @@ using Microsoft.AspNetCore.Razor.Language;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 {
-    internal class DefaultMvcImportFeature : RazorProjectEngineFeatureBase, IRazorImportFeature
+    internal class MvcImportProjectFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
     {
         private const string ImportsFileName = "_ViewImports.cshtml";
 

src/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X/RazorExtensions.cs

@@ -16,8 +16,6 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
                 throw new ArgumentNullException(nameof(builder));
             }
 
-            EnsureDesignTime(builder);
-
             InjectDirective.Register(builder);
             ModelDirective.Register(builder);
 
@@ -37,7 +35,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             builder.Features.Add(new ModelExpressionPass());
             builder.Features.Add(new MvcViewDocumentClassifierPass());
 
-            builder.SetImportFeature(new DefaultMvcImportFeature());
+            builder.SetImportFeature(new MvcImportProjectFeature());
         }
 
         public static void RegisterViewComponentTagHelpers(RazorProjectEngineBuilder builder)
@@ -47,22 +45,10 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
                 throw new ArgumentNullException(nameof(builder));
             }
 
-            EnsureDesignTime(builder);
-
             builder.Features.Add(new ViewComponentTagHelperPass());
             builder.AddTargetExtension(new ViewComponentTagHelperTargetExtension());
         }
 
-        private static void EnsureDesignTime(RazorProjectEngineBuilder builder)
-        {
-            if (builder.Configuration.DesignTime)
-            {
-                return;
-            }
-
-            throw new NotSupportedException(Resources.RuntimeCodeGenerationNotSupported);
-        }
-
         #region Obsolete
         public static void Register(IRazorEngineBuilder builder)
         {

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/AssemblyAttributeInjectionPass.cs

@@ -14,6 +14,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 
         protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
+            if (documentNode.Options.DesignTime)
+            {
+                return;
+            }
+
             var @namespace = documentNode.FindPrimaryNamespace();
             if (@namespace == null || string.IsNullOrEmpty(@namespace.Content))
             {

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/InstrumentationPass.cs

@@ -15,6 +15,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 
         protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
+            if (documentNode.Options.DesignTime)
+            {
+                return;
+            }
+
             var walker = new Visitor();
             walker.VisitDocument(documentNode);
 

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/ModelDirective.cs

@@ -29,7 +29,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             }
 
             builder.AddDirective(Directive);
-            builder.Features.Add(new Pass(builder.Configuration.DesignTime));
+            builder.Features.Add(new Pass());
             return builder;
         }
 
@@ -71,13 +71,6 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 
         internal class Pass : IntermediateNodePassBase, IRazorDirectiveClassifierPass
         {
-            private readonly bool _designTime;
-
-            public Pass(bool designTime)
-            {
-                _designTime = designTime;
-            }
-
             // Runs after the @inherits directive
             public override int Order => 5;
 
@@ -86,7 +79,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 var visitor = new Visitor();
                 var modelType = GetModelType(documentNode, visitor);
 
-                if (_designTime)
+                if (documentNode.Options.DesignTime)
                 {
                     // Alias the TModel token to a known type.
                     // This allows design time compilation to succeed for Razor files where the token isn't replaced.
@@ -150,7 +143,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             }
 
             builder.AddDirective(Directive);
-            builder.Features.Add(new Pass(builder.DesignTime));
+            builder.Features.Add(new Pass());
             return builder;
         }
         #endregion

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/MvcImportProjectFeature.cs

@@ -10,7 +10,7 @@ using Microsoft.AspNetCore.Razor.Language;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 {
-    internal class DefaultMvcImportFeature : RazorProjectEngineFeatureBase, IRazorImportFeature
+    internal class MvcImportProjectFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
     {
         private const string ImportsFileName = "_ViewImports.cshtml";
 

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/RazorExtensions.cs

@@ -36,14 +36,10 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             builder.Features.Add(new ViewComponentTagHelperPass());
             builder.Features.Add(new RazorPageDocumentClassifierPass());
             builder.Features.Add(new MvcViewDocumentClassifierPass());
+            builder.Features.Add(new AssemblyAttributeInjectionPass());
+            builder.Features.Add(new InstrumentationPass());
 
-            if (!builder.Configuration.DesignTime)
-            {
-                builder.Features.Add(new AssemblyAttributeInjectionPass());
-                builder.Features.Add(new InstrumentationPass());
-            }
-
-            builder.SetImportFeature(new DefaultMvcImportFeature());
+            builder.SetImportFeature(new MvcImportProjectFeature());
         }
 
         #region Obsolete

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

@@ -6,7 +6,7 @@ using System.Collections.Generic;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
-    internal class DefaultRazorImportFeature : RazorProjectEngineFeatureBase, IRazorImportFeature
+    internal class DefaultImportProjectFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
     {
         public IReadOnlyList<RazorSourceDocument> GetImports(RazorProjectItem projectItem) => Array.Empty<RazorSourceDocument>();
     }

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

@@ -1,16 +1,30 @@
 // 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.AspNetCore.Razor.Language
 {
     internal class DefaultRazorCodeGenerationOptionsBuilder : RazorCodeGenerationOptionsBuilder
     {
-        public DefaultRazorCodeGenerationOptionsBuilder(bool designTime)
+        private bool _designTime;
+
+        public DefaultRazorCodeGenerationOptionsBuilder(RazorConfiguration configuration)
         {
-            DesignTime = designTime;
+            if (configuration == null)
+            {
+                throw new ArgumentNullException(nameof(configuration));
+            }
         }
 
-        public override bool DesignTime { get; }
+        public DefaultRazorCodeGenerationOptionsBuilder(bool designTime)
+        {
+            _designTime = designTime;
+        }
+
+        public override RazorConfiguration Configuration { get; }
+
+        public override bool DesignTime => _designTime;
 
         public override int IndentSize { get; set; } = 4;
 
@@ -22,5 +36,10 @@ namespace Microsoft.AspNetCore.Razor.Language
         {
             return new DefaultRazorCodeGenerationOptions(IndentWithTabs, IndentSize, DesignTime, SuppressChecksum, SuppressMetadataAttributes);
         }
+
+        public override void SetDesignTime(bool designTime)
+        {
+            _designTime = designTime;
+        }
     }
 }

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

@@ -0,0 +1,32 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Linq;
+
+namespace Microsoft.AspNetCore.Razor.Language
+{
+    internal class DefaultRazorCodeGenerationOptionsFactoryProjectFeature : RazorProjectEngineFeatureBase, IRazorCodeGenerationOptionsFactoryProjectFeature
+    {
+        private IConfigureRazorCodeGenerationOptionsFeature[] _configureOptions;
+
+        protected override void OnInitialized()
+        {
+            _configureOptions = ProjectEngine.EngineFeatures.OfType<IConfigureRazorCodeGenerationOptionsFeature>().ToArray();
+        }
+
+        public RazorCodeGenerationOptions Create(Action<RazorCodeGenerationOptionsBuilder> configure)
+        {
+            var builder = new DefaultRazorCodeGenerationOptionsBuilder(ProjectEngine.Configuration);
+            configure?.Invoke(builder);
+
+            for (var i = 0; i < _configureOptions.Length; i++)
+            {
+                _configureOptions[i].Configure(builder);
+            }
+
+            var options = builder.Build();
+            return options;
+        }
+    }
+}

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

@@ -5,7 +5,9 @@ using System.Linq;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
+#pragma warning disable CS0618 // Type or member is obsolete
     internal class DefaultRazorCodeGenerationOptionsFeature : RazorEngineFeatureBase, IRazorCodeGenerationOptionsFeature
+#pragma warning restore CS0618 // Type or member is obsolete
     {
         private readonly bool _designTime;
         private IConfigureRazorCodeGenerationOptionsFeature[] _configureOptions;

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

@@ -11,6 +11,7 @@ using Microsoft.AspNetCore.Razor.Language.Legacy;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
+#pragma warning disable CS0618 // Type or member is obsolete
     internal class DefaultRazorIntermediateNodeLoweringPhase : RazorEnginePhaseBase, IRazorIntermediateNodeLoweringPhase
     {
         private IRazorCodeGenerationOptionsFeature _optionsFeature;
@@ -31,7 +32,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             var document = new DocumentIntermediateNode();
             var builder = IntermediateNodeBuilder.Create(document);
 
-            document.Options = _optionsFeature.GetOptions();
+            document.Options = codeDocument.GetCodeGenerationOptions() ?? _optionsFeature.GetOptions();
 
             var namespaces = new Dictionary<string, SourceSpan?>(StringComparer.Ordinal);
 
@@ -785,4 +786,5 @@ namespace Microsoft.AspNetCore.Razor.Language
         private static bool IsMalformed(List<RazorDiagnostic> diagnostics)
             => diagnostics.Count > 0 && diagnostics.Any(diagnostic => diagnostic.Severity == RazorDiagnosticSeverity.Error);
     }
+#pragma warning restore CS0618 // Type or member is obsolete
 }

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

@@ -9,23 +9,43 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     internal class DefaultRazorParserOptionsBuilder : RazorParserOptionsBuilder
     {
-        public DefaultRazorParserOptionsBuilder(bool designTime, RazorLanguageVersion version)
+        private bool _designTime;
+
+        public DefaultRazorParserOptionsBuilder(RazorConfiguration configuration)
         {
-            DesignTime = designTime;
-            Version = version;
+            if (configuration == null)
+            {
+                throw new ArgumentNullException(nameof(configuration));
+            }
+
+            Configuration = configuration;
+            LanguageVersion = configuration.LanguageVersion;
         }
 
-        public override bool DesignTime { get; }
+        public DefaultRazorParserOptionsBuilder(bool designTime, RazorLanguageVersion version)
+        {
+            _designTime = designTime;
+            LanguageVersion = version;
+        }
+
+        public override RazorConfiguration Configuration { get; }
+
+        public override bool DesignTime => _designTime;
 
         public override ICollection<DirectiveDescriptor> Directives { get; } = new List<DirectiveDescriptor>();
 
         public override bool ParseLeadingDirectives { get; set; }
 
-        public override RazorLanguageVersion Version { get; }
+        public override RazorLanguageVersion LanguageVersion { get; }
 
         public override RazorParserOptions Build()
         {
-            return new DefaultRazorParserOptions(Directives.ToArray(), DesignTime, ParseLeadingDirectives, Version);
+            return new DefaultRazorParserOptions(Directives.ToArray(), DesignTime, ParseLeadingDirectives, LanguageVersion);
+        }
+
+        public override void SetDesignTime(bool designTime)
+        {
+            _designTime = designTime;
         }
     }
 }

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

@@ -0,0 +1,32 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Linq;
+
+namespace Microsoft.AspNetCore.Razor.Language
+{
+    internal class DefaultRazorParserOptionsFactoryProjectFeature : RazorProjectEngineFeatureBase, IRazorParserOptionsFactoryProjectFeature
+    {
+        private IConfigureRazorParserOptionsFeature[] _configureOptions;
+
+        protected override void OnInitialized()
+        {
+            _configureOptions = ProjectEngine.EngineFeatures.OfType<IConfigureRazorParserOptionsFeature>().ToArray();
+        }
+
+        public RazorParserOptions Create(Action<RazorParserOptionsBuilder> configure)
+        {
+            var builder = new DefaultRazorParserOptionsBuilder(ProjectEngine.Configuration);
+            configure?.Invoke(builder);
+
+            for (var i = 0; i < _configureOptions.Length; i++)
+            {
+                _configureOptions[i].Configure(builder);
+            }
+            
+            var options = builder.Build();
+            return options;
+        }
+    }
+}

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

@@ -5,7 +5,9 @@ using System.Linq;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
+#pragma warning disable CS0618 // Type or member is obsolete
     internal class DefaultRazorParserOptionsFeature : RazorEngineFeatureBase, IRazorParserOptionsFeature
+#pragma warning restore CS0618 // Type or member is obsolete
     {
         private readonly bool _designTime;
         private readonly RazorLanguageVersion _version;

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

@@ -3,6 +3,7 @@
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
+#pragma warning disable CS0618 // Type or member is obsolete
     internal class DefaultRazorParsingPhase : RazorEnginePhaseBase, IRazorParsingPhase
     {
         private IRazorParserOptionsFeature _optionsFeature;
@@ -14,7 +15,7 @@ namespace Microsoft.AspNetCore.Razor.Language
 
         protected override void ExecuteCore(RazorCodeDocument codeDocument)
         {
-            var options = _optionsFeature.GetOptions();
+            var options = codeDocument.GetParserOptions() ??_optionsFeature.GetOptions();
             var syntaxTree = RazorSyntaxTree.Parse(codeDocument.Source, options);
             codeDocument.SetSyntaxTree(syntaxTree);
 
@@ -26,4 +27,5 @@ namespace Microsoft.AspNetCore.Razor.Language
             codeDocument.SetImportSyntaxTrees(importSyntaxTrees);
         }
     }
+#pragma warning restore CS0618 // Type or member is obsolete
 }

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

@@ -10,10 +10,16 @@ namespace Microsoft.AspNetCore.Razor.Language
     internal class DefaultRazorProjectEngine : RazorProjectEngine
     {
         public DefaultRazorProjectEngine(
+            RazorConfiguration configuration,
             RazorEngine engine,
             RazorProjectFileSystem fileSystem,
-            IReadOnlyList<IRazorProjectEngineFeature> features)
+            IReadOnlyList<IRazorProjectEngineFeature> projectFeatures)
         {
+            if (configuration == null)
+            {
+                throw new ArgumentNullException(nameof(configuration));
+            }
+
             if (engine == null)
             {
                 throw new ArgumentNullException(nameof(engine));
@@ -24,39 +30,87 @@ namespace Microsoft.AspNetCore.Razor.Language
                 throw new ArgumentNullException(nameof(fileSystem));
             }
 
-            if (features == null)
+            if (projectFeatures == null)
             {
-                throw new ArgumentNullException(nameof(features));
+                throw new ArgumentNullException(nameof(projectFeatures));
             }
 
+            Configuration = configuration;
             Engine = engine;
             FileSystem = fileSystem;
-            Features = features;
+            ProjectFeatures = projectFeatures;
 
-            for (var i = 0; i < features.Count; i++)
+            for (var i = 0; i < projectFeatures.Count; i++)
             {
-                features[i].ProjectEngine = this;
+                projectFeatures[i].ProjectEngine = this;
             }
         }
 
+        public override RazorConfiguration Configuration { get; }
+
         public override RazorProjectFileSystem FileSystem { get; }
 
         public override RazorEngine Engine { get; }
 
-        public override IReadOnlyList<IRazorProjectEngineFeature> Features { get; }
+        public override IReadOnlyList<IRazorProjectEngineFeature> ProjectFeatures { get; }
 
-        public override RazorCodeDocument Process(RazorProjectItem projectItem)
+        protected override void ConfigureParserOptions(RazorParserOptionsBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+        }
+
+        protected override void ConfigureDesignTimeParserOptions(RazorParserOptionsBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.SetDesignTime(true);
+        }
+
+        protected override void ConfigureCodeGenerationOptions(RazorCodeGenerationOptionsBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+        }
+
+        protected override void ConfigureDesignTimeCodeGenerationOptions(RazorCodeGenerationOptionsBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.SetDesignTime(true);
+            builder.SuppressChecksum = true;
+            builder.SuppressMetadataAttributes = true;
+        }
+
+        protected override RazorCodeDocument ProcessCore(
+            RazorProjectItem projectItem,
+            Action<RazorParserOptionsBuilder> configureParser,
+            Action<RazorCodeGenerationOptionsBuilder> configureCodeGeneration)
         {
             if (projectItem == null)
             {
                 throw new ArgumentNullException(nameof(projectItem));
             }
 
-            var importFeature = GetRequiredFeature<IRazorImportFeature>();
-            var imports = importFeature.GetImports(projectItem);
             var sourceDocument = RazorSourceDocument.ReadFrom(projectItem);
 
-            var codeDocument = RazorCodeDocument.Create(sourceDocument, imports);
+            var importFeature = GetRequiredFeature<IImportProjectFeature>();
+            var imports = importFeature.GetImports(projectItem);
+
+            var parserOptions = GetRequiredFeature<IRazorParserOptionsFactoryProjectFeature>().Create(configureParser);
+            var codeGenerationOptions = GetRequiredFeature<IRazorCodeGenerationOptionsFactoryProjectFeature>().Create(configureCodeGeneration);
+
+            var codeDocument = RazorCodeDocument.Create(sourceDocument, imports, parserOptions, codeGenerationOptions);
 
             Engine.Process(codeDocument);
 
@@ -65,7 +119,7 @@ namespace Microsoft.AspNetCore.Razor.Language
 
         private TFeature GetRequiredFeature<TFeature>() where TFeature : IRazorProjectEngineFeature
         {
-            var feature = Features.OfType<TFeature>().FirstOrDefault();
+            var feature = ProjectFeatures.OfType<TFeature>().FirstOrDefault();
             if (feature == null)
             {
                 throw new InvalidOperationException(

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

@@ -22,29 +22,19 @@ namespace Microsoft.AspNetCore.Razor.Language
             Phases = new List<IRazorEnginePhase>();
         }
 
+        public override RazorConfiguration Configuration { get; }
+
         public override RazorProjectFileSystem FileSystem { get; }
 
         public override ICollection<IRazorFeature> Features { get; }
 
         public override IList<IRazorEnginePhase> Phases { get; }
-
-        public override RazorConfiguration Configuration { get; }
-
+        
         public override RazorProjectEngine Build()
         {
-            RazorEngine engine = null;
-
-            if (Configuration.DesignTime)
-            {
-                engine = RazorEngine.CreateDesignTimeEmpty(ConfigureRazorEngine);
-            }
-            else
-            {
-                engine = RazorEngine.CreateEmpty(ConfigureRazorEngine);
-            }
-
-            var projectEngineFeatures = Features.OfType<IRazorProjectEngineFeature>().ToArray();
-            var projectEngine = new DefaultRazorProjectEngine(engine, FileSystem, projectEngineFeatures);
+            var engine = RazorEngine.CreateEmpty(ConfigureRazorEngine);
+            var projectFeatures = Features.OfType<IRazorProjectEngineFeature>().ToArray();
+            var projectEngine = new DefaultRazorProjectEngine(Configuration, engine, FileSystem, projectFeatures);
 
             return projectEngine;
         }

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

@@ -16,8 +16,6 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
     {
         private static readonly string[] PrivateModifiers = new string[] { "private" };
 
-        public bool DesignTime { get; set; }
-
         public string RunnerVariableName { get; set; } = "__tagHelperRunner";
 
         public string StringValueBufferVariableName { get; set; } = "__tagHelperStringValueBuffer";
@@ -82,7 +80,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 throw new InvalidOperationException(message);
             }
 
-            if (DesignTime)
+            if (context.Options.DesignTime)
             {
                 context.RenderChildren(node);
             }
@@ -136,7 +134,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 .Write(CreateTagHelperMethodName)
                 .WriteLine("<global::" + node.TypeName + ">();");
 
-            if (!DesignTime)
+            if (!context.Options.DesignTime)
             {
                 context.CodeWriter.WriteInstanceMethodInvocation(
                     ExecutionContextVariableName,
@@ -153,7 +151,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 throw new InvalidOperationException(message);
             }
 
-            if (!DesignTime)
+            if (!context.Options.DesignTime)
             {
                 context.CodeWriter
                     .Write("await ")
@@ -200,7 +198,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 throw new InvalidOperationException(message);
             }
 
-            if (DesignTime)
+            if (context.Options.DesignTime)
             {
                 context.RenderChildren(node);
             }
@@ -284,7 +282,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 throw new InvalidOperationException(message);
             }
 
-            if (!DesignTime)
+            if (!context.Options.DesignTime)
             {
                 // Ensure that the property we're trying to set has initialized its dictionary bound properties.
                 if (node.IsIndexerNameMatch &&
@@ -338,7 +336,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             // If we get there, this is the first time seeing this property so we need to evaluate the expression.
             if (node.BoundAttribute.ExpectsStringValue(node.AttributeName))
             {
-                if (DesignTime)
+                if (context.Options.DesignTime)
                 {
                     context.RenderChildren(node);
 
@@ -370,7 +368,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             }
             else
             {
-                if (DesignTime)
+                if (context.Options.DesignTime)
                 {
                     var firstMappedChild = node.Children.FirstOrDefault(child => child.Source != null) as IntermediateNode;
                     var valueStart = firstMappedChild?.Source;
@@ -456,7 +454,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
                 }
             }
 
-            if (!DesignTime)
+            if (!context.Options.DesignTime)
             {
                 // We need to inform the context of the attribute value.
                 context.CodeWriter
@@ -474,7 +472,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
 
         public void WriteTagHelperRuntime(CodeRenderingContext context, DefaultTagHelperRuntimeIntermediateNode node)
         {
-            if (!DesignTime)
+            if (!context.Options.DesignTime)
             {
                 context.CodeWriter.WriteLine("#line hidden");
 
@@ -566,7 +564,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
             }
             else if (node is IntermediateToken token)
             {
-                if (DesignTime && node.Source != null)
+                if (context.Options.DesignTime && node.Source != null)
                 {
                     context.AddSourceMappingFor(node);
                 }

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

@@ -15,6 +15,13 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
 
         protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
+            // Only supports design time. This pass rewrites directives so they will have the right design time
+            // behavior and would break things if it ran for runtime.
+            if (!documentNode.Options.DesignTime)
+            {
+                return;
+            }
+
             var walker = new DesignTimeHelperWalker();
             walker.VisitDocument(documentNode);
         }

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

@@ -15,6 +15,12 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
 
         protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
+            // There's no value in executing this pass at design time, it just prevents some allocations.
+            if (documentNode.Options.DesignTime)
+            {
+                return;
+            }
+            
             var walker = new PreallocatedTagHelperWalker();
             walker.VisitDocument(documentNode);
         }

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

@@ -5,7 +5,7 @@ using System.Collections.Generic;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
-    public interface IRazorImportFeature : IRazorProjectEngineFeature
+    public interface IImportProjectFeature : IRazorProjectEngineFeature
     {
         IReadOnlyList<RazorSourceDocument> GetImports(RazorProjectItem projectItem);
     }

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

@@ -0,0 +1,12 @@
+// 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.AspNetCore.Razor.Language
+{
+    internal interface IRazorCodeGenerationOptionsFactoryProjectFeature : IRazorProjectEngineFeature
+    {
+        RazorCodeGenerationOptions Create(Action<RazorCodeGenerationOptionsBuilder> configure);
+    }
+}

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

@@ -1,8 +1,11 @@
 // 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.AspNetCore.Razor.Language
 {
+    [Obsolete("In Razor 2.1 and newer, use RazorCodeDocument.GetCodeGenerationOptions().")]
     public interface IRazorCodeGenerationOptionsFeature : IRazorEngineFeature
     {
         RazorCodeGenerationOptions GetOptions();

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

@@ -0,0 +1,12 @@
+// 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.AspNetCore.Razor.Language
+{
+    internal interface IRazorParserOptionsFactoryProjectFeature : IRazorProjectEngineFeature
+    {
+        RazorParserOptions Create(Action<RazorParserOptionsBuilder> configure);
+    }
+}

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

@@ -1,8 +1,11 @@
 // 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.AspNetCore.Razor.Language
 {
+    [Obsolete("In Razor 2.1 and newer, use RazorCodeDocument.GetParserOptions().")]
     public interface IRazorParserOptionsFeature : IRazorEngineFeature
     {
         RazorParserOptions GetOptions();

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

@@ -30,6 +30,23 @@ namespace Microsoft.AspNetCore.Razor.Language
             return new DefaultRazorCodeDocument(source, imports);
         }
 
+        public static RazorCodeDocument Create(
+            RazorSourceDocument source, 
+            IEnumerable<RazorSourceDocument> imports,
+            RazorParserOptions parserOptions,
+            RazorCodeGenerationOptions codeGenerationOptions)
+        {
+            if (source == null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
+            var codeDocument = new DefaultRazorCodeDocument(source, imports);
+            codeDocument.SetParserOptions(parserOptions);
+            codeDocument.SetCodeGenerationOptions(codeGenerationOptions);
+            return codeDocument;
+        }
+
         public abstract IReadOnlyList<RazorSourceDocument> Imports { get; }
 
         public abstract ItemCollection Items { get; }

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

@@ -109,6 +109,46 @@ namespace Microsoft.AspNetCore.Razor.Language
             document.Items[typeof(RazorCSharpDocument)] = csharp;
         }
 
+        public static RazorParserOptions GetParserOptions(this RazorCodeDocument document)
+        {
+            if (document == null)
+            {
+                throw new ArgumentNullException(nameof(document));
+            }
+
+            return (RazorParserOptions)document.Items[typeof(RazorParserOptions)];
+        }
+
+        public static void SetParserOptions(this RazorCodeDocument document, RazorParserOptions parserOptions)
+        {
+            if (document == null)
+            {
+                throw new ArgumentNullException(nameof(document));
+            }
+
+            document.Items[typeof(RazorParserOptions)] = parserOptions;
+        }
+
+        public static RazorCodeGenerationOptions GetCodeGenerationOptions(this RazorCodeDocument document)
+        {
+            if (document == null)
+            {
+                throw new ArgumentNullException(nameof(document));
+            }
+
+            return (RazorCodeGenerationOptions)document.Items[typeof(RazorCodeGenerationOptions)];
+        }
+
+        public static void SetCodeGenerationOptions(this RazorCodeDocument document, RazorCodeGenerationOptions codeGenerationOptions)
+        {
+            if (document == null)
+            {
+                throw new ArgumentNullException(nameof(document));
+            }
+
+            document.Items[typeof(RazorCodeGenerationOptions)] = codeGenerationOptions;
+        }
+
         private class ImportSyntaxTreesHolder
         {
             public ImportSyntaxTreesHolder(IReadOnlyList<RazorSyntaxTree> syntaxTrees)

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

@@ -5,6 +5,8 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     public abstract class RazorCodeGenerationOptionsBuilder
     {
+        public virtual RazorConfiguration Configuration => null;
+
         public abstract bool DesignTime { get; }
 
         public abstract int IndentSize { get; set; }
@@ -41,5 +43,9 @@ namespace Microsoft.AspNetCore.Razor.Language
         public virtual bool SuppressMetadataAttributes { get; set; }
 
         public abstract RazorCodeGenerationOptions Build();
+
+        public virtual void SetDesignTime(bool designTime)
+        {
+        }
     }
 }

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

@@ -12,22 +12,12 @@ namespace Microsoft.AspNetCore.Razor.Language
         public static readonly RazorConfiguration Default = new RazorConfiguration(
             RazorLanguageVersion.Latest, 
             "unnamed",
-            Array.Empty<RazorExtension>(),
-            designTime: false);
-
-        // This is used only in some back-compat scenarios. We don't expose it because there's no
-        // use case for anyone else to use it.
-        internal static readonly RazorConfiguration DefaultDesignTime = new RazorConfiguration(
-            RazorLanguageVersion.Latest,
-            "unnamed",
-            Array.Empty<RazorExtension>(),
-            designTime: true);
+            Array.Empty<RazorExtension>());
 
         public RazorConfiguration(
             RazorLanguageVersion languageVersion, 
             string configurationName,
-            IEnumerable<RazorExtension> extensions,
-            bool designTime)
+            IEnumerable<RazorExtension> extensions)
         {
             if (languageVersion == null)
             {
@@ -47,7 +37,6 @@ namespace Microsoft.AspNetCore.Razor.Language
             LanguageVersion = languageVersion;
             ConfigurationName = configurationName;
             Extensions = extensions.ToArray();
-            DesignTime = designTime;
         }
 
         public string ConfigurationName { get; }
@@ -55,7 +44,5 @@ namespace Microsoft.AspNetCore.Razor.Language
         public IReadOnlyList<RazorExtension> Extensions { get; }
 
         public RazorLanguageVersion LanguageVersion { get; }
-
-        public bool DesignTime { get; }
     }
 }

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

@@ -17,27 +17,27 @@ namespace Microsoft.AspNetCore.Razor.Language
             return Create(configure: null);
         }
 
-        public static RazorEngine Create(Action<IRazorEngineBuilder> configure) => CreateCore(RazorConfiguration.Default, configure);
+        public static RazorEngine Create(Action<IRazorEngineBuilder> configure) => CreateCore(RazorConfiguration.Default, false, configure);
 
         public static RazorEngine CreateDesignTime()
         {
             return CreateDesignTime(configure: null);
         }
 
-        public static RazorEngine CreateDesignTime(Action<IRazorEngineBuilder> configure) => CreateCore(RazorConfiguration.DefaultDesignTime, configure);
+        public static RazorEngine CreateDesignTime(Action<IRazorEngineBuilder> configure) => CreateCore(RazorConfiguration.Default, true, configure);
 
         // Internal since RazorEngine APIs are going to be obsolete.
-        internal static RazorEngine CreateCore(RazorConfiguration configuration, Action<IRazorEngineBuilder> configure)
+        internal static RazorEngine CreateCore(RazorConfiguration configuration, bool designTime, Action<IRazorEngineBuilder> configure)
         {
             if (configuration == null)
             {
                 throw new ArgumentNullException(nameof(configuration));
             }
 
-            var builder = new DefaultRazorEngineBuilder(configuration.DesignTime);
+            var builder = new DefaultRazorEngineBuilder(designTime);
             AddDefaults(builder);
 
-            if (configuration.DesignTime)
+            if (designTime)
             {
                 AddDefaultDesignTimeFeatures(configuration, builder.Features);
             }
@@ -152,7 +152,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             var targetExtension = features.OfType<IRazorTargetExtensionFeature>().FirstOrDefault();
             Debug.Assert(targetExtension != null);
 
-            targetExtension.TargetExtensions.Add(new DefaultTagHelperTargetExtension() { DesignTime = false });
+            targetExtension.TargetExtensions.Add(new DefaultTagHelperTargetExtension());
             targetExtension.TargetExtensions.Add(new PreallocatedAttributeTargetExtension());
         }
 
@@ -170,7 +170,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             var targetExtension = features.OfType<IRazorTargetExtensionFeature>().FirstOrDefault();
             Debug.Assert(targetExtension != null);
 
-            targetExtension.TargetExtensions.Add(new DefaultTagHelperTargetExtension() { DesignTime = true });
+            targetExtension.TargetExtensions.Add(new DefaultTagHelperTargetExtension());
             targetExtension.TargetExtensions.Add(new DesignTimeDirectiveTargetExtension());
         }
 

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

@@ -1,21 +1,26 @@
 // 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;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
     public abstract class RazorParserOptionsBuilder
     {
+        public virtual RazorConfiguration Configuration => null;
+
         public abstract bool DesignTime { get; }
 
         public abstract ICollection<DirectiveDescriptor> Directives { get; }
 
         public abstract bool ParseLeadingDirectives { get; set; }
 
-        public virtual RazorLanguageVersion Version { get; }
+        public virtual RazorLanguageVersion LanguageVersion { get; }
 
         public abstract RazorParserOptions Build();
+
+        public virtual void SetDesignTime(bool designTime)
+        {
+        }
     }
 }

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

@@ -3,26 +3,63 @@
 
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.Language.Extensions;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
     public abstract class RazorProjectEngine
     {
+        public abstract RazorConfiguration Configuration { get; }
+
         public abstract RazorProjectFileSystem FileSystem { get; }
 
         public abstract RazorEngine Engine { get; }
 
-        public abstract IReadOnlyList<IRazorProjectEngineFeature> Features { get; }
+        public IReadOnlyList<IRazorEngineFeature> EngineFeatures => Engine.Features;
 
-        public abstract RazorCodeDocument Process(RazorProjectItem projectItem);
+        public IReadOnlyList<IRazorEnginePhase> Phases => Engine.Phases;
 
-        public static RazorProjectEngine Create(RazorProjectFileSystem fileSystem) => Create(fileSystem, configure: null);
+        public abstract IReadOnlyList<IRazorProjectEngineFeature> ProjectFeatures { get; }
 
-        public static RazorProjectEngine Create(RazorProjectFileSystem fileSystem, Action<RazorProjectEngineBuilder> configure) => Create(fileSystem, RazorConfiguration.Default, configure);
+        protected abstract void ConfigureParserOptions(RazorParserOptionsBuilder builder);
+
+        protected abstract void ConfigureDesignTimeParserOptions(RazorParserOptionsBuilder builder);
+
+        protected abstract void ConfigureCodeGenerationOptions(RazorCodeGenerationOptionsBuilder builder);
+
+        protected abstract void ConfigureDesignTimeCodeGenerationOptions(RazorCodeGenerationOptionsBuilder builder);
+
+        public virtual RazorCodeDocument Process(RazorProjectItem projectItem)
+        {
+            if (projectItem == null)
+            {
+                throw new ArgumentNullException(nameof(projectItem));
+            }
+
+            return ProcessCore(projectItem, ConfigureParserOptions, ConfigureCodeGenerationOptions);
+        }
+
+        public virtual RazorCodeDocument ProcessDesignTime(RazorProjectItem projectItem)
+        {
+            if (projectItem == null)
+            {
+                throw new ArgumentNullException(nameof(projectItem));
+            }
+
+            return ProcessCore(projectItem, ConfigureDesignTimeParserOptions, ConfigureDesignTimeCodeGenerationOptions);
+        }
+
+        protected abstract RazorCodeDocument ProcessCore(
+            RazorProjectItem projectItem,
+            Action<RazorParserOptionsBuilder> configureParser,
+            Action<RazorCodeGenerationOptionsBuilder> configureCodeGeneration);
+
+        public static RazorProjectEngine Create(RazorConfiguration configuration, RazorProjectFileSystem fileSystem) => Create(configuration, fileSystem, configure: null);
 
         public static RazorProjectEngine Create(
-            RazorProjectFileSystem fileSystem,
             RazorConfiguration configuration,
+            RazorProjectFileSystem fileSystem,
             Action<RazorProjectEngineBuilder> configure)
         {
             if (fileSystem == null)
@@ -37,54 +74,90 @@ namespace Microsoft.AspNetCore.Razor.Language
 
             var builder = new DefaultRazorProjectEngineBuilder(configuration, fileSystem);
 
-            AddDefaults(builder);
-
-            if (configuration.DesignTime)
-            {
-                AddDesignTimeDefaults(builder);
-            }
-            else
-            {
-                AddRuntimeDefaults(builder);
-            }
+            RazorEngine.AddDefaultPhases(builder.Phases);
+            AddDefaultsFeatures(builder.Features);
 
             configure?.Invoke(builder);
 
             return builder.Build();
         }
-
-        private static void AddDefaults(RazorProjectEngineBuilder builder)
+        
+        private static void AddDefaultsFeatures(ICollection<IRazorFeature> features)
         {
-            builder.Features.Add(new DefaultRazorImportFeature());
-        }
+            features.Add(new DefaultImportProjectFeature());
 
-        private static void AddDesignTimeDefaults(RazorProjectEngineBuilder builder)
-        {
-            var engineFeatures = new List<IRazorEngineFeature>();
-            RazorEngine.AddDefaultFeatures(engineFeatures);
-            RazorEngine.AddDefaultDesignTimeFeatures(builder.Configuration, engineFeatures);
+            // General extensibility
+            features.Add(new DefaultRazorDirectiveFeature());
+            features.Add(new DefaultMetadataIdentifierFeature());
 
-            AddEngineFeaturesAndPhases(builder, engineFeatures);
-        }
+            // Options features
+            features.Add(new DefaultRazorParserOptionsFactoryProjectFeature());
+            features.Add(new DefaultRazorCodeGenerationOptionsFactoryProjectFeature());
 
-        private static void AddRuntimeDefaults(RazorProjectEngineBuilder builder)
-        {
-            var engineFeatures = new List<IRazorEngineFeature>();
-            RazorEngine.AddDefaultFeatures(engineFeatures);
-            RazorEngine.AddDefaultRuntimeFeatures(builder.Configuration, engineFeatures);
+            // Legacy options features
+            //
+            // These features are obsolete as of 2.1. Our code will resolve this but not invoke them.
+            features.Add(new DefaultRazorParserOptionsFeature(designTime: false, version: RazorLanguageVersion.Version_2_0));
+            features.Add(new DefaultRazorCodeGenerationOptionsFeature(designTime: false));
 
-            AddEngineFeaturesAndPhases(builder, engineFeatures);
-        }
+            // Syntax Tree passes
+            features.Add(new DefaultDirectiveSyntaxTreePass());
+            features.Add(new HtmlNodeOptimizationPass());
+            features.Add(new PreallocatedTagHelperAttributeOptimizationPass());
 
-        private static void AddEngineFeaturesAndPhases(RazorProjectEngineBuilder builder, IReadOnlyList<IRazorEngineFeature> engineFeatures)
-        {
-            for (var i = 0; i < engineFeatures.Count; i++)
+            // Intermediate Node Passes
+            features.Add(new DefaultDocumentClassifierPass());
+            features.Add(new MetadataAttributePass());
+            features.Add(new DesignTimeDirectivePass());
+            features.Add(new DirectiveRemovalOptimizationPass());
+            features.Add(new DefaultTagHelperOptimizationPass());
+
+            // Default Code Target Extensions
+            var targetExtensionFeature = new DefaultRazorTargetExtensionFeature();
+            features.Add(targetExtensionFeature);
+            targetExtensionFeature.TargetExtensions.Add(new MetadataAttributeTargetExtension());
+            targetExtensionFeature.TargetExtensions.Add(new DefaultTagHelperTargetExtension());
+            targetExtensionFeature.TargetExtensions.Add(new PreallocatedAttributeTargetExtension());
+            targetExtensionFeature.TargetExtensions.Add(new DesignTimeDirectiveTargetExtension());
+
+            // Default configuration
+            var configurationFeature = new DefaultDocumentClassifierPassFeature();
+            features.Add(configurationFeature);
+            configurationFeature.ConfigureClass.Add((document, @class) =>
             {
-                var engineFeature = engineFeatures[i];
-                builder.Features.Add(engineFeature);
-            }
+                @class.ClassName = "Template";
+                @class.Modifiers.Add("public");
+            });
 
-            RazorEngine.AddDefaultPhases(builder.Phases);
+            configurationFeature.ConfigureNamespace.Add((document, @namespace) =>
+            {
+                @namespace.Content = "Razor";
+            });
+
+            configurationFeature.ConfigureMethod.Add((document, method) =>
+            {
+                method.MethodName = "ExecuteAsync";
+                method.ReturnType = $"global::{typeof(Task).FullName}";
+
+                method.Modifiers.Add("public");
+                method.Modifiers.Add("async");
+                method.Modifiers.Add("override");
+            });
+        }
+
+        internal static void AddDefaultRuntimeFeatures(RazorConfiguration configuration, ICollection<IRazorEngineFeature> features)
+        {
+            // Configure options
+            features.Add(new DefaultRazorParserOptionsFeature(designTime: false, version: configuration.LanguageVersion));
+            features.Add(new DefaultRazorCodeGenerationOptionsFeature(designTime: false));
+        }
+
+        internal static void AddDefaultDesignTimeFeatures(RazorConfiguration configuration, ICollection<IRazorEngineFeature> features)
+        {
+            // Configure options
+            features.Add(new DefaultRazorParserOptionsFeature(designTime: true, version: configuration.LanguageVersion));
+            features.Add(new DefaultRazorCodeGenerationOptionsFeature(designTime: true));
+            features.Add(new SuppressChecksumOptionsFeature());
         }
     }
 }

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

@@ -7,14 +7,14 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     public abstract class RazorProjectEngineBuilder
     {
+        public abstract RazorConfiguration Configuration { get; }
+
         public abstract RazorProjectFileSystem FileSystem { get; }
 
         public abstract ICollection<IRazorFeature> Features { get; }
 
         public abstract IList<IRazorEnginePhase> Phases { get; }
 
-        public abstract RazorConfiguration Configuration { get; }
-
         public abstract RazorProjectEngine Build();
     }
 }

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

@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     public static class RazorProjectEngineBuilderExtensions
     {
-        public static void SetImportFeature(this RazorProjectEngineBuilder builder, IRazorImportFeature feature)
+        public static void SetImportFeature(this RazorProjectEngineBuilder builder, IImportProjectFeature feature)
         {
             if (builder == null)
             {
@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             }
 
             // Remove any existing import features in favor of the new one we're given.
-            var existingFeatures = builder.Features.OfType<IRazorImportFeature>().ToArray();
+            var existingFeatures = builder.Features.OfType<IImportProjectFeature>().ToArray();
             foreach (var existingFeature in existingFeatures)
             {
                 builder.Features.Remove(existingFeature);

src/Microsoft.VisualStudio.Editor.Razor/DefaultTemplateEngineFactoryService.cs

@@ -43,12 +43,12 @@ namespace Microsoft.VisualStudio.Editor.Razor
             var project = FindProject(projectPath);
             var configuration = (project?.Configuration as MvcExtensibilityConfiguration) ?? DefaultConfiguration;
             var razorLanguageVersion = configuration.LanguageVersion;
-            var razorConfiguration = new RazorConfiguration(razorLanguageVersion, "unnamed", Array.Empty<RazorExtension>(), designTime: true);
+            var razorConfiguration = new RazorConfiguration(razorLanguageVersion, "unnamed", Array.Empty<RazorExtension>());
 
             RazorEngine engine;
             if (razorLanguageVersion.Major == 1)
             {
-                engine = RazorEngine.CreateCore(razorConfiguration, b =>
+                engine = RazorEngine.CreateCore(razorConfiguration, true, b =>
                 {
                     configure?.Invoke(b);
 
@@ -66,7 +66,7 @@ namespace Microsoft.VisualStudio.Editor.Razor
             }
             else
             {
-                engine = RazorEngine.CreateCore(razorConfiguration, b =>
+                engine = RazorEngine.CreateCore(razorConfiguration, true, b =>
                 {
                     configure?.Invoke(b);
 

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

@@ -13,7 +13,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void Execute_NoOps_IfNamespaceNodeIsMissing()
         {
             // Arrange
-            var irDocument = new DocumentIntermediateNode();
+            var irDocument = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var pass = new AssemblyAttributeInjectionPass
             {
                 Engine = RazorEngine.Create(),
@@ -30,7 +34,10 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void Execute_NoOps_IfNamespaceNodeHasEmptyContent()
         {
             // Arrange
-            var irDocument = new DocumentIntermediateNode();
+            var irDocument = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode() { Content = string.Empty };
             @namespace.Annotations[CommonAnnotations.PrimaryNamespace] = CommonAnnotations.PrimaryNamespace;
@@ -53,7 +60,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void Execute_NoOps_IfClassNameNodeIsMissing()
         {
             // Arrange
-            var irDocument = new DocumentIntermediateNode();
+            var irDocument = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode() { Content = "SomeNamespace" };
             builder.Push(@namespace);
@@ -67,7 +78,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             pass.Execute(TestRazorCodeDocument.CreateEmpty(), irDocument);
 
             // Assert
-            Assert.Collection(irDocument.Children,
+            Assert.Collection(
+                irDocument.Children,
                 node => Assert.Same(@namespace, node));
         }
 
@@ -75,7 +87,10 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void Execute_NoOps_IfClassNameIsEmpty()
         {
             // Arrange
-            var irDocument = new DocumentIntermediateNode();
+            var irDocument = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode
             {
@@ -115,6 +130,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var irDocument = new DocumentIntermediateNode
             {
                 DocumentKind = "Default",
+                Options = RazorCodeGenerationOptions.CreateDefault(),
             };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode() { Content = "SomeNamespace" };
@@ -138,7 +154,54 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             pass.Execute(TestRazorCodeDocument.CreateEmpty(), irDocument);
 
             // Assert
-            Assert.Collection(irDocument.Children,
+            Assert.Collection(
+                irDocument.Children,
+                node => Assert.Same(@namespace, node));
+        }
+
+        [Fact]
+        public void Execute_NoOps_ForDesignTime()
+        {
+            // Arrange
+            var irDocument = new DocumentIntermediateNode
+            {
+                DocumentKind = MvcViewDocumentClassifierPass.MvcViewDocumentKind,
+                Options = RazorCodeGenerationOptions.CreateDesignTimeDefault(),
+            };
+            var builder = IntermediateNodeBuilder.Create(irDocument);
+            var @namespace = new NamespaceDeclarationIntermediateNode
+            {
+                Content = "SomeNamespace",
+                Annotations =
+                {
+                    [CommonAnnotations.PrimaryNamespace] = CommonAnnotations.PrimaryNamespace
+                },
+            };
+            builder.Push(@namespace);
+            var @class = new ClassDeclarationIntermediateNode
+            {
+                ClassName = "SomeName",
+                Annotations =
+                {
+                    [CommonAnnotations.PrimaryClass] = CommonAnnotations.PrimaryClass,
+                },
+            };
+            builder.Add(@class);
+
+            var pass = new AssemblyAttributeInjectionPass
+            {
+                Engine = RazorEngine.Create(),
+            };
+
+            var source = TestRazorSourceDocument.Create("test", new RazorSourceDocumentProperties(filePath: null, relativePath: "/Views/Index.cshtml"));
+            var document = RazorCodeDocument.Create(source);
+
+            // Act
+            pass.Execute(document, irDocument);
+
+            // Assert
+            Assert.Collection(
+                irDocument.Children,
                 node => Assert.Same(@namespace, node));
         }
 
@@ -150,6 +213,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var irDocument = new DocumentIntermediateNode
             {
                 DocumentKind = MvcViewDocumentClassifierPass.MvcViewDocumentKind,
+                Options = RazorCodeGenerationOptions.CreateDefault(),
             };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode
@@ -202,6 +266,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var irDocument = new DocumentIntermediateNode
             {
                 DocumentKind = MvcViewDocumentClassifierPass.MvcViewDocumentKind,
+                Options = RazorCodeGenerationOptions.CreateDefault(),
             };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode
@@ -254,6 +319,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var irDocument = new DocumentIntermediateNode
             {
                 DocumentKind = RazorPageDocumentClassifierPass.RazorPageDocumentKind,
+                Options = RazorCodeGenerationOptions.CreateDefault(),
             };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var pageDirective = new DirectiveIntermediateNode
@@ -313,6 +379,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var irDocument = new DocumentIntermediateNode
             {
                 DocumentKind = MvcViewDocumentClassifierPass.MvcViewDocumentKind,
+                Options = RazorCodeGenerationOptions.CreateDefault(),
             };
             var builder = IntermediateNodeBuilder.Create(irDocument);
             var @namespace = new NamespaceDeclarationIntermediateNode

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

@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var imports = new List<RazorSourceDocument>();
 
             // Act
-            DefaultMvcImportFeature.AddDefaultDirectivesImport(imports);
+            MvcImportProjectFeature.AddDefaultDirectivesImport(imports);
 
             // Assert
             var import = Assert.Single(imports);
@@ -37,7 +37,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 new TestRazorProjectItem("/Contact/_ViewImports.cshtml"),
                 projectItem,
             });
-            var mvcImportFeature = new DefaultMvcImportFeature()
+            var mvcImportFeature = new MvcImportProjectFeature()
             {
                 ProjectEngine = Mock.Of<RazorProjectEngine>(projectEngine => projectEngine.FileSystem == testFileSystem)
             };
@@ -58,7 +58,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var imports = new List<RazorSourceDocument>();
             var projectItem = new TestRazorProjectItem("/Pages/Contact/Index.cshtml");
             var testFileSystem = new TestRazorProjectFileSystem(new[] { projectItem });
-            var mvcImportFeature = new DefaultMvcImportFeature()
+            var mvcImportFeature = new MvcImportProjectFeature()
             {
                 ProjectEngine = Mock.Of<RazorProjectEngine>(projectEngine => projectEngine.FileSystem == testFileSystem)
             };

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

@@ -10,11 +10,47 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 {
     public class InstrumentationPassTest
     {
+        [Fact]
+        public void InstrumentationPass_NoOps_ForDesignTime()
+        {
+            // Arrange
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDesignTimeDefault(),
+            };
+
+            var builder = IntermediateNodeBuilder.Create(document);
+            builder.Push(new HtmlContentIntermediateNode());
+            builder.Add(new IntermediateToken()
+            {
+                Content = "Hi",
+                Kind = TokenKind.Html,
+            });
+            builder.Pop();
+
+            var pass = new InstrumentationPass()
+            {
+                Engine = RazorEngine.CreateEmpty(b => { }),
+            };
+
+            // Act
+            pass.Execute(TestRazorCodeDocument.CreateEmpty(), document);
+
+            // Assert
+            Children(
+                document,
+                n => IntermediateNodeAssert.Html("Hi", n));
+        }
+
         [Fact]
         public void InstrumentationPass_InstrumentsHtml()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
 
             builder.Push(new HtmlContentIntermediateNode()
@@ -49,7 +85,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_SkipsHtml_WithoutLocation()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new HtmlContentIntermediateNode());
             builder.Add(new IntermediateToken()
@@ -77,7 +117,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_InstrumentsCSharpExpression()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new CSharpExpressionIntermediateNode()
             {
@@ -109,7 +153,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_SkipsCSharpExpression_WithoutLocation()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new CSharpExpressionIntermediateNode());
             builder.Add(new IntermediateToken()
@@ -136,7 +184,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_SkipsCSharpExpression_InsideTagHelperAttribute()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new TagHelperIntermediateNode());
 
@@ -183,7 +235,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_SkipsCSharpExpression_InsideTagHelperProperty()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new TagHelperIntermediateNode());
 
@@ -230,7 +286,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_InstrumentsTagHelper()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Add(new TagHelperIntermediateNode()
             {
@@ -257,7 +317,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public void InstrumentationPass_SkipsTagHelper_WithoutLocation()
         {
             // Arrange
-            var document = new DocumentIntermediateNode();
+            var document = new DocumentIntermediateNode()
+            {
+                Options = RazorCodeGenerationOptions.CreateDefault(),
+            };
+
             var builder = IntermediateNodeBuilder.Create(document);
             builder.Push(new TagHelperIntermediateNode());
 

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

@@ -61,7 +61,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -88,7 +88,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -114,7 +114,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -139,7 +139,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -163,8 +163,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 @inherits BaseType<TModel>
 ");
 
-            var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: true)
+            var engine = CreateDesignTimeEngine();
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -193,8 +193,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 @model SomeType
 ");
 
-            var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: true)
+            var engine = CreateDesignTimeEngine();
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -246,6 +246,18 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             });
         }
 
+        private RazorEngine CreateDesignTimeEngine()
+        {
+            return RazorEngine.CreateDesignTime(b =>
+            {
+                // Notice we're not registering the ModelDirective.Pass here so we can run it on demand.
+                b.AddDirective(ModelDirective.Directive);
+
+                // There's some special interaction with the inherits directive
+                InheritsDirective.Register(b);
+            });
+        }
+
         private DocumentIntermediateNode CreateIRDocument(RazorEngine engine, RazorCodeDocument codeDocument)
         {
             for (var i = 0; i < engine.Phases.Count; i++)

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.Test/DefaultMvcImportFeatureTest.cs

@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             var imports = new List<RazorSourceDocument>();
 
             // Act
-            DefaultMvcImportFeature.AddDefaultDirectivesImport(imports);
+            MvcImportProjectFeature.AddDefaultDirectivesImport(imports);
 
             // Assert
             var import = Assert.Single(imports);
@@ -37,7 +37,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
                 new TestRazorProjectItem("/Contact/_ViewImports.cshtml"),
                 projectItem,
             });
-            var mvcImportFeature = new DefaultMvcImportFeature()
+            var mvcImportFeature = new MvcImportProjectFeature()
             {
                 ProjectEngine = Mock.Of<RazorProjectEngine>(projectEngine => projectEngine.FileSystem == testFileSystem)
             };
@@ -58,7 +58,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             var imports = new List<RazorSourceDocument>();
             var projectItem = new TestRazorProjectItem("/Pages/Contact/Index.cshtml");
             var testFileSystem = new TestRazorProjectFileSystem(new[] { projectItem });
-            var mvcImportFeature = new DefaultMvcImportFeature()
+            var mvcImportFeature = new MvcImportProjectFeature()
             {
                 ProjectEngine = Mock.Of<RazorProjectEngine>(projectEngine => projectEngine.FileSystem == testFileSystem)
             };

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.Test/ModelDirectiveTest.cs

@@ -61,7 +61,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -88,7 +88,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -114,7 +114,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -139,7 +139,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 ");
 
             var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: false)
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -163,8 +163,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 @inherits BaseType<TModel>
 ");
 
-            var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: true)
+            var engine = CreateDesignTimeEngine();
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -193,8 +193,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
 @model SomeType
 ");
 
-            var engine = CreateEngine();
-            var pass = new ModelDirective.Pass(designTime: true)
+            var engine = CreateDesignTimeEngine();
+            var pass = new ModelDirective.Pass()
             {
                 Engine = engine,
             };
@@ -246,6 +246,18 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             });
         }
 
+        private RazorEngine CreateDesignTimeEngine()
+        {
+            return RazorEngine.CreateDesignTime(b =>
+            {
+                // Notice we're not registering the ModelDirective.Pass here so we can run it on demand.
+                b.AddDirective(ModelDirective.Directive);
+
+                // There's some special interaction with the inherits directive
+                InheritsDirective.Register(b);
+            });
+        }
+
         private DocumentIntermediateNode CreateIRDocument(RazorEngine engine, RazorCodeDocument codeDocument)
         {
             for (var i = 0; i < engine.Phases.Count; i++)

test/Microsoft.AspNetCore.Razor.Language.Test/DefaultRazorProjectEngineIntegrationTest.cs

@@ -8,16 +8,61 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     public class DefaultRazorProjectEngineIntegrationTest
     {
+        [Fact]
+        public void Process_SetsOptions_Runtime()
+        {
+            // Arrange
+            var projectItem = new TestRazorProjectItem("Index.cshtml");
+
+            var projectEngine = RazorProjectEngine.Create(RazorConfiguration.Default, TestRazorProjectFileSystem.Empty);
+
+            // Act
+            var codeDocument = projectEngine.Process(projectItem);
+
+            // Assert
+            var parserOptions = codeDocument.GetParserOptions();
+            Assert.False(parserOptions.DesignTime);
+
+            var codeGenerationOptions = codeDocument.GetCodeGenerationOptions();
+            Assert.False(codeGenerationOptions.DesignTime);
+            Assert.False(codeGenerationOptions.SuppressChecksum);
+            Assert.False(codeGenerationOptions.SuppressMetadataAttributes);
+        }
+
+        [Fact]
+        public void ProcessDesignTime_SetsOptions_DesignTime()
+        {
+            // Arrange
+            var projectItem = new TestRazorProjectItem("Index.cshtml");
+
+            var projectEngine = RazorProjectEngine.Create(RazorConfiguration.Default, TestRazorProjectFileSystem.Empty);
+
+            // Act
+            var codeDocument = projectEngine.ProcessDesignTime(projectItem);
+
+            // Assert
+            var parserOptions = codeDocument.GetParserOptions();
+            Assert.True(parserOptions.DesignTime);
+
+            var codeGenerationOptions = codeDocument.GetCodeGenerationOptions();
+            Assert.True(codeGenerationOptions.DesignTime);
+            Assert.True(codeGenerationOptions.SuppressChecksum);
+            Assert.True(codeGenerationOptions.SuppressMetadataAttributes);
+        }
+
         [Fact]
         public void Process_GetsImportsFromFeature()
         {
             // Arrange
             var projectItem = new TestRazorProjectItem("Index.cshtml");
+
             var testImport = TestRazorSourceDocument.Create();
-            var importFeature = new Mock<IRazorImportFeature>();
-            importFeature.Setup(feature => feature.GetImports(It.IsAny<RazorProjectItem>()))
+            var importFeature = new Mock<IImportProjectFeature>();
+            importFeature
+                .Setup(feature => feature.GetImports(It.IsAny<RazorProjectItem>()))
                 .Returns(new[] { testImport });
-            var projectEngine = RazorProjectEngine.Create(TestRazorProjectFileSystem.Empty, builder =>
+
+            var projectEngine = RazorProjectEngine.Create(RazorConfiguration.Default, TestRazorProjectFileSystem.Empty, builder =>
             {
                 builder.SetImportFeature(importFeature.Object);
             });
@@ -35,7 +80,7 @@ namespace Microsoft.AspNetCore.Razor.Language
         {
             // Arrange
             var projectItem = new TestRazorProjectItem("Index.cshtml");
-            var projectEngine = RazorProjectEngine.Create(TestRazorProjectFileSystem.Empty);
+            var projectEngine = RazorProjectEngine.Create(RazorConfiguration.Default, TestRazorProjectFileSystem.Empty);
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);

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

@@ -68,7 +68,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         public void WriteTagHelperBody_DesignTime_WritesChildren()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -133,7 +133,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         public void WriteTagHelperCreate_DesignTime_RendersCorrectly_UsesSpecifiedTagHelperType()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -190,7 +190,7 @@ __tagHelperExecutionContext.Add(__TestNamespace_MyTagHelper);
         public void WriteTagHelperExecute_DesignTime_WritesNothing()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -243,7 +243,7 @@ __tagHelperExecutionContext = __tagHelperScopeManager.End();
         public void WriteTagHelperHtmlAttribute_DesignTime_WritesNothing()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -431,7 +431,7 @@ EndAddHtmlAttributeValues(__tagHelperExecutionContext);
         public void WriteTagHelperProperty_DesignTime_StringProperty_HtmlContent_RendersCorrectly()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -472,7 +472,7 @@ __InputTagHelper.StringProp = ""value"";
         public void WriteTagHelperProperty_DesignTime_StringProperty_NonHtmlContent_RendersCorrectly()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -513,7 +513,7 @@ __InputTagHelper.StringProp = string.Empty;
         public void WriteTagHelperProperty_DesignTime_NonStringProperty_RendersCorrectly()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -560,7 +560,7 @@ __InputTagHelper.IntProp = 32;
         public void WriteTagHelperProperty_DesignTime_NonStringProperty_SecondUseOfAttribute()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -602,7 +602,7 @@ __InputTagHelper.IntProp = 32;
         public void WriteTagHelperProperty_DesignTime_NonStringProperty_RendersCorrectly_WithoutLocation()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -642,7 +642,7 @@ __InputTagHelper.IntProp = 32;
         public void WriteTagHelperProperty_DesignTime_NonStringIndexer_RendersCorrectly()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -687,7 +687,7 @@ __InputTagHelper.IntIndexer[""bound""] = 32;
         public void WriteTagHelperProperty_DesignTime_NonStringIndexer_RendersCorrectly_WithoutLocation()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
 
             var tagHelperNode = new TagHelperIntermediateNode();
@@ -1064,7 +1064,7 @@ __tagHelperExecutionContext.AddTagHelperAttribute(""foo-bound"", __InputTagHelpe
         public void WriteTagHelperRuntime_DesignTime_WritesNothing()
         {
             // Arrange
-            var extension = new DefaultTagHelperTargetExtension() { DesignTime = true };
+            var extension = new DefaultTagHelperTargetExtension();
             var context = TestCodeRenderingContext.CreateDesignTime();
             
             var node = new DefaultTagHelperRuntimeIntermediateNode();

test/Microsoft.AspNetCore.Razor.Language.Test/RazorCodeDocumentExtensionsTest.cs

@@ -148,5 +148,67 @@ namespace Microsoft.AspNetCore.Razor.Language
             // Assert
             Assert.Same(expected, codeDocument.Items[typeof(TagHelperDocumentContext)]);
         }
+
+        [Fact]
+        public void GetParserOptions_ReturnsSyntaxTree()
+        {
+            // Arrange
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+
+            var expected = RazorParserOptions.CreateDefault();
+            codeDocument.Items[typeof(RazorParserOptions)] = expected;
+
+            // Act
+            var actual = codeDocument.GetParserOptions();
+
+            // Assert
+            Assert.Same(expected, actual);
+        }
+
+        [Fact]
+        public void SetParserOptions_SetsSyntaxTree()
+        {
+            // Arrange
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+
+            var expected = RazorParserOptions.CreateDefault();
+
+            // Act
+            codeDocument.SetParserOptions(expected);
+
+            // Assert
+            Assert.Same(expected, codeDocument.Items[typeof(RazorParserOptions)]);
+        }
+
+        [Fact]
+        public void GetCodeGenerationOptions_ReturnsSyntaxTree()
+        {
+            // Arrange
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+
+            var expected = RazorCodeGenerationOptions.CreateDefault();
+            codeDocument.Items[typeof(RazorCodeGenerationOptions)] = expected;
+
+            // Act
+            var actual = codeDocument.GetCodeGenerationOptions();
+
+            // Assert
+            Assert.Same(expected, actual);
+        }
+
+        [Fact]
+        public void SetCodeGenerationOptions_SetsSyntaxTree()
+        {
+            // Arrange
+            var codeDocument = TestRazorCodeDocument.CreateEmpty();
+
+            var expected = RazorCodeGenerationOptions.CreateDefault();
+
+            // Act
+            codeDocument.SetCodeGenerationOptions(expected);
+
+            // Assert
+            Assert.Same(expected, codeDocument.Items[typeof(RazorCodeGenerationOptions)]);
+        }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/RazorEngineTest.cs

@@ -145,7 +145,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             Assert.Collection(
                 feature.TargetExtensions,
                 extension => Assert.IsType<MetadataAttributeTargetExtension>(extension),
-                extension => Assert.False(Assert.IsType<DefaultTagHelperTargetExtension>(extension).DesignTime),
+                extension => Assert.IsType<DefaultTagHelperTargetExtension>(extension),
                 extension => Assert.IsType<PreallocatedAttributeTargetExtension>(extension));
         }
 
@@ -190,7 +190,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             Assert.Collection(
                 feature.TargetExtensions,
                 extension => Assert.IsType<MetadataAttributeTargetExtension>(extension),
-                extension => Assert.True(Assert.IsType<DefaultTagHelperTargetExtension>(extension).DesignTime),
+                extension => Assert.IsType<DefaultTagHelperTargetExtension>(extension),
                 extension => Assert.IsType<DesignTimeDirectiveTargetExtension>(extension));
         }
 

test/Microsoft.AspNetCore.Razor.Language.Test/RazorProjectEngineBuilderExtensionsTest.cs

@@ -14,11 +14,11 @@ namespace Microsoft.AspNetCore.Razor.Language
         {
             // Arrange
             var builder = new DefaultRazorProjectEngineBuilder(RazorConfiguration.Default, Mock.Of<RazorProjectFileSystem>());
-            var testFeature1 = Mock.Of<IRazorImportFeature>();
-            var testFeature2 = Mock.Of<IRazorImportFeature>();
+            var testFeature1 = Mock.Of<IImportProjectFeature>();
+            var testFeature2 = Mock.Of<IImportProjectFeature>();
             builder.Features.Add(testFeature1);
             builder.Features.Add(testFeature2);
-            var newFeature = Mock.Of<IRazorImportFeature>();
+            var newFeature = Mock.Of<IImportProjectFeature>();
 
             // Act
             builder.SetImportFeature(newFeature);

test/Microsoft.AspNetCore.Razor.Language.Test/RazorProjectEngineTest.cs

@@ -0,0 +1,85 @@
+// 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;
+using System.Linq;
+using Microsoft.AspNetCore.Razor.Language.Extensions;
+using Moq;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Razor.Language.Test
+{
+    public class RazorProjectEngineTest
+    {
+        [Fact]
+        public void CreateDesignTime_Lambda_AddsFeaturesAndPhases()
+        {
+            // Arrange
+
+            // Act
+            var engine = RazorProjectEngine.Create(RazorConfiguration.Default, Mock.Of<RazorProjectFileSystem>());
+
+            // Assert
+            AssertDefaultPhases(engine);
+            AssertDefaultFeatures(engine);
+            AssertDefaultDirectives(engine);
+            AssertDefaultTargetExtensions(engine);
+        }
+
+        private static void AssertDefaultPhases(RazorProjectEngine engine)
+        {
+            Assert.Collection(
+                engine.Phases,
+                phase => Assert.IsType<DefaultRazorParsingPhase>(phase),
+                phase => Assert.IsType<DefaultRazorSyntaxTreePhase>(phase),
+                phase => Assert.IsType<DefaultRazorTagHelperBinderPhase>(phase),
+                phase => Assert.IsType<DefaultRazorIntermediateNodeLoweringPhase>(phase),
+                phase => Assert.IsType<DefaultRazorDocumentClassifierPhase>(phase),
+                phase => Assert.IsType<DefaultRazorDirectiveClassifierPhase>(phase),
+                phase => Assert.IsType<DefaultRazorOptimizationPhase>(phase),
+                phase => Assert.IsType<DefaultRazorCSharpLoweringPhase>(phase));
+        }
+
+        private static void AssertDefaultFeatures(RazorProjectEngine engine)
+        {
+            var features = engine.EngineFeatures.OrderBy(f => f.GetType().Name).ToArray();
+            Assert.Collection(
+                features,
+                feature => Assert.IsType<DefaultDirectiveSyntaxTreePass>(feature),
+                feature => Assert.IsType<DefaultDocumentClassifierPass>(feature),
+                feature => Assert.IsType<DefaultDocumentClassifierPassFeature>(feature),
+                feature => Assert.IsType<DefaultMetadataIdentifierFeature>(feature),
+                feature => Assert.IsType<DefaultRazorCodeGenerationOptionsFeature>(feature),
+                feature => Assert.IsType<DefaultRazorDirectiveFeature>(feature),
+                feature => Assert.IsType<DefaultRazorParserOptionsFeature>(feature),
+                feature => Assert.IsType<DefaultRazorTargetExtensionFeature>(feature),
+                feature => Assert.IsType<DefaultTagHelperOptimizationPass>(feature),
+                feature => Assert.IsType<DesignTimeDirectivePass>(feature),
+                feature => Assert.IsType<DirectiveRemovalOptimizationPass>(feature),
+                feature => Assert.IsType<HtmlNodeOptimizationPass>(feature),
+                feature => Assert.IsType<MetadataAttributePass>(feature),
+                feature => Assert.IsType<PreallocatedTagHelperAttributeOptimizationPass>(feature));
+        }
+
+        private static void AssertDefaultDirectives(RazorProjectEngine engine)
+        {
+            var feature = engine.EngineFeatures.OfType<IRazorDirectiveFeature>().FirstOrDefault();
+            Assert.NotNull(feature);
+            Assert.Empty(feature.Directives);
+        }
+
+        private static void AssertDefaultTargetExtensions(RazorProjectEngine engine)
+        {
+            var feature = engine.EngineFeatures.OfType<IRazorTargetExtensionFeature>().FirstOrDefault();
+            Assert.NotNull(feature);
+
+            var extensions = feature.TargetExtensions.OrderBy(f => f.GetType().Name).ToArray();
+            Assert.Collection(
+                extensions,
+                extension => Assert.IsType<DefaultTagHelperTargetExtension>(extension),
+                extension => Assert.IsType<DesignTimeDirectiveTargetExtension>(extension),
+                extension => Assert.IsType<MetadataAttributeTargetExtension>(extension),
+                extension => Assert.IsType<PreallocatedAttributeTargetExtension>(extension));
+        }
+    }
+}