Update built-in directives to use DirectiveUsage.

- Updated integration code gen and IR bits to reflect new directive usage.
- Updated existing unit tests that happened to test directives in code blocks to now test what happens when they exist at the document level. Being inside of a code block is now invalid and we have separate tests for that scenario.

#1376

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

@@ -14,7 +14,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public static readonly DirectiveDescriptor Directive = DirectiveDescriptor.CreateDirective(
             "model",
             DirectiveKind.SingleLine,
-            builder => builder.AddTypeToken());
+            builder =>
+            {
+                builder.AddTypeToken();
+                builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
+            });
 
         public static IRazorEngineBuilder Register(IRazorEngineBuilder builder)
         {
@@ -55,7 +59,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             }
             else
             {
-                return  "dynamic";
+                return "dynamic";
             }
         }
 

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

@@ -17,7 +17,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public static readonly DirectiveDescriptor Directive = DirectiveDescriptor.CreateDirective(
             "namespace",
             DirectiveKind.SingleLine,
-            builder => builder.AddNamespaceToken());
+            builder =>
+            {
+                builder.AddNamespaceToken();
+                builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
+            });
 
         public static void Register(IRazorEngineBuilder builder)
         {
@@ -58,7 +62,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                     // No namespace node. Skip.
                     return;
                 }
-                
+
                 if (TryComputeNamespace(codeDocument.Source.FilePath, directive, out var computedNamespace))
                 {
                     // Beautify the class name since we're using a hierarchy for namespaces.

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

@@ -14,7 +14,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         public static readonly DirectiveDescriptor Directive = DirectiveDescriptor.CreateDirective(
             "page",
             DirectiveKind.SingleLine,
-            builder => builder.AddOptionalStringToken());
+            builder =>
+            {
+                builder.AddOptionalStringToken();
+                builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
+            });
 
         private PageDirective(string routeTemplate)
         {

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

@@ -10,7 +10,11 @@ namespace Microsoft.AspNetCore.Razor.Language.Extensions
         public static readonly DirectiveDescriptor Directive = DirectiveDescriptor.CreateDirective(
             SyntaxConstants.CSharp.InheritsKeyword,
             DirectiveKind.SingleLine,
-            builder => builder.AddTypeToken());
+            builder =>
+            {
+                builder.AddTypeToken();
+                builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
+            });
 
         public static void Register(IRazorEngineBuilder builder)
         {

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

@@ -14,7 +14,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
     public class ModelDirectiveTest
     {
         [Fact]
-        public void ModelDirective_GetModelType_GetsTypeFromLastWellFormedDirective()
+        public void ModelDirective_GetModelType_GetsTypeFromFirstWellFormedDirective()
         {
             // Arrange
             var codeDocument = CreateDocument(@"
@@ -31,7 +31,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var result = ModelDirective.GetModelType(irDocument);
 
             // Assert
-            Assert.Equal("Type2", result);
+            Assert.Equal("Type1", result);
         }
 
         [Fact]
@@ -101,7 +101,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             // Assert
             var @class = FindClassNode(irDocument);
             Assert.NotNull(@class);
-            Assert.Equal("BaseType<Type2>", @class.BaseType);
+            Assert.Equal("BaseType<Type1>", @class.BaseType);
         }
 
         [Fact]

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_DesignTime.diagnostics.txt

@@ -1,8 +1,14 @@
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(4,1): Error RZ9999: The 'page' directive may only occur once per document.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(5,1): Error RZ9999: The 'page' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(5,7): Error RZ9999: The 'page' directive expects a string surrounded by double quotes.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(7,1): Error RZ9999: The 'model' directive must exist prior to markup or code.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(7,7): Error RZ9999: The 'model' directive expects a type name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(8,1): Error RZ9999: The 'model' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(8,8): Error RZ9999: The 'model' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(10,8): Error RZ9999: The 'inject' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(11,9): Error RZ9999: The 'inject' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(12,26): Error RZ9999: The 'inject' directive expects an identifier.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(14,1): Error RZ9999: The 'namespace' directive must exist prior to markup or code.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(14,11): Error RZ9999: The 'namespace' directive expects a namespace name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,1): Error RZ9999: The 'namespace' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,12): Error RZ9999: The 'namespace' directive expects a namespace name.

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_DesignTime.ir.txt

@@ -31,6 +31,7 @@ Document -
             MethodDeclaration -  - public async override - global::System.Threading.Tasks.Task - ExecuteAsync
                 HtmlContent - (83:0,83 [4] IncompleteDirectives.cshtml)
                     IntermediateToken - (83:0,83 [4] IncompleteDirectives.cshtml) - Html - \n\n
+                MalformedDirective - (94:3,0 [8] IncompleteDirectives.cshtml)
                 MalformedDirective - (102:4,0 [6] IncompleteDirectives.cshtml)
                 HtmlContent - (108:4,6 [5] IncompleteDirectives.cshtml)
                     IntermediateToken - (108:4,6 [5] IncompleteDirectives.cshtml) - Html - "\n\n

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_Runtime.diagnostics.txt

@@ -1,8 +1,14 @@
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(4,1): Error RZ9999: The 'page' directive may only occur once per document.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(5,1): Error RZ9999: The 'page' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(5,7): Error RZ9999: The 'page' directive expects a string surrounded by double quotes.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(7,1): Error RZ9999: The 'model' directive must exist prior to markup or code.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(7,7): Error RZ9999: The 'model' directive expects a type name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(8,1): Error RZ9999: The 'model' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(8,8): Error RZ9999: The 'model' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(10,8): Error RZ9999: The 'inject' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(11,9): Error RZ9999: The 'inject' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(12,26): Error RZ9999: The 'inject' directive expects an identifier.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(14,1): Error RZ9999: The 'namespace' directive must exist prior to markup or code.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(14,11): Error RZ9999: The 'namespace' directive expects a namespace name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,1): Error RZ9999: The 'namespace' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,12): Error RZ9999: The 'namespace' directive expects a namespace name.

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_Runtime.ir.txt

@@ -17,6 +17,7 @@ Document -
                     IntermediateToken - (83:0,83 [4] IncompleteDirectives.cshtml) - Html - \n\n
                 CSharpCode - 
                     IntermediateToken -  - CSharp - EndContext();
+                MalformedDirective - (94:3,0 [8] IncompleteDirectives.cshtml)
                 MalformedDirective - (102:4,0 [6] IncompleteDirectives.cshtml)
                 CSharpCode - 
                     IntermediateToken -  - CSharp - BeginContext(108, 5, true);

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels_DesignTime.codegen.cs

@@ -10,7 +10,7 @@ namespace AspNetCore
     using Microsoft.AspNetCore.Mvc;
     using Microsoft.AspNetCore.Mvc.Rendering;
     using Microsoft.AspNetCore.Mvc.ViewFeatures;
-    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MultipleModels_cshtml : global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<System.Collections.IEnumerable>
+    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MultipleModels_cshtml : global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<ThisShouldBeGenerated>
     {
         #pragma warning disable 219
         private void __RazorDirectiveTokenHelpers__() {
@@ -39,6 +39,6 @@ System.Collections.IEnumerable __typeHelper = default(System.Collections.IEnumer
         [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
         public global::Microsoft.AspNetCore.Mvc.Rendering.IJsonHelper Json { get; private set; }
         [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
-        public global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<System.Collections.IEnumerable> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<ThisShouldBeGenerated> Html { get; private set; }
     }
 }

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels_DesignTime.diagnostics.txt

@@ -0,0 +1 @@
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels.cshtml(2,1): Error RZ9999: The 'model' directive may only occur once per document.

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels_DesignTime.ir.txt

@@ -10,7 +10,7 @@ Document -
         UsingDirective - (102:4,1 [30] ) - Microsoft.AspNetCore.Mvc
         UsingDirective - (135:5,1 [40] ) - Microsoft.AspNetCore.Mvc.Rendering
         UsingDirective - (178:6,1 [43] ) - Microsoft.AspNetCore.Mvc.ViewFeatures
-        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MultipleModels_cshtml - global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<System.Collections.IEnumerable> - 
+        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MultipleModels_cshtml - global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<ThisShouldBeGenerated> - 
             DesignTimeDirective - 
                 DirectiveToken - (231:7,8 [62] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TModel>
                 DirectiveToken - (294:7,71 [4] ) - Html
@@ -30,6 +30,8 @@ Document -
             CSharpCode - 
                 IntermediateToken -  - CSharp - private static System.Object __o = null;
             MethodDeclaration -  - public async override - global::System.Threading.Tasks.Task - ExecuteAsync
+                MalformedDirective - (30:1,0 [39] MultipleModels.cshtml)
+                    DirectiveToken - (37:1,7 [30] MultipleModels.cshtml) - System.Collections.IEnumerable
             Inject - 
             Inject - 
             Inject - 

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels_DesignTime.mappings.txt

@@ -1,10 +1,10 @@
 Source Location: (7:0,7 [21] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels.cshtml)
 |ThisShouldBeGenerated|
-Generated Location: (839:17,0 [21] )
+Generated Location: (830:17,0 [21] )
 |ThisShouldBeGenerated|
 
 Source Location: (37:1,7 [30] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MultipleModels.cshtml)
 |System.Collections.IEnumerable|
-Generated Location: (969:21,0 [30] )
+Generated Location: (960:21,0 [30] )
 |System.Collections.IEnumerable|
 

test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/CSharpDirectivesTest.cs

@@ -12,7 +12,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
     public class CSharpDirectivesTest : CsHtmlCodeParserTestBase
     {
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_ErrorsIfNestedInCode()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_ErrorsIfNestedInCode()
         {
             // Arrange
             var descriptor = DirectiveDescriptor.CreateDirective(
@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var chunkGenerator = new DirectiveChunkGenerator(descriptor);
@@ -52,7 +52,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         }
 
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_ErrorsIfNestedInHtml()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_ErrorsIfNestedInHtml()
         {
             // Arrange
             var descriptor = DirectiveDescriptor.CreateDirective(
@@ -60,7 +60,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var chunkGenerator = new DirectiveChunkGenerator(descriptor);
@@ -89,7 +89,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         }
 
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_ErrorsIfDuplicate()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_ErrorsIfDuplicate()
         {
             // Arrange
             var descriptor = DirectiveDescriptor.CreateDirective(
@@ -97,7 +97,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var chunkGenerator = new DirectiveChunkGenerator(descriptor);
@@ -130,7 +130,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         }
 
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_CanBeBeneathOtherDirectives()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_CanBeBeneathOtherDirectives()
         {
             // Arrange
             var customDescriptor = DirectiveDescriptor.CreateDirective(
@@ -138,7 +138,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var somethingDescriptor = DirectiveDescriptor.CreateDirective(
@@ -146,7 +146,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddMemberToken();
                 });
 
@@ -173,7 +173,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         }
 
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_CanBeBeneathOtherWhiteSpaceCommentsAndDirectives()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_CanBeBeneathOtherWhiteSpaceCommentsAndDirectives()
         {
             // Arrange
             var customDescriptor = DirectiveDescriptor.CreateDirective(
@@ -181,7 +181,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var somethingDescriptor = DirectiveDescriptor.CreateDirective(
@@ -189,7 +189,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddMemberToken();
                 });
 
@@ -231,7 +231,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         }
 
         [Fact]
-        public void DirectiveDescriptor_SinglePreContent_MixedContentErrors()
+        public void DirectiveDescriptor_FileScopedSinglyOccurring_MixedContentErrors()
         {
             // Arrange
             var customDescriptor = DirectiveDescriptor.CreateDirective(
@@ -239,7 +239,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddTypeToken();
                 });
             var somethingDescriptor = DirectiveDescriptor.CreateDirective(
@@ -247,7 +247,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 DirectiveKind.SingleLine,
                 builder =>
                 {
-                    builder.Usage = DirectiveUsage.SinglePreContent;
+                    builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
                     builder.AddMemberToken();
                 });
             var chunkGenerator = new DirectiveChunkGenerator(somethingDescriptor);
@@ -1350,58 +1350,54 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                         .Accepts(AcceptedCharactersInternal.AnyExceptNewline)));
         }
 
-        [Fact]
-        public void ParseBlock_InheritsDirective()
-        {
-            ParseCodeBlockTest(
-                "@inherits System.Web.WebPages.WebPage",
-                new[] { InheritsDirective.Directive, },
-                new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
-                    Factory.CodeTransition(),
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                    Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
-                    Factory.Span(SpanKindInternal.Code, "System.Web.WebPages.WebPage", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens.First())));
-        }
-
         [Fact]
         public void InheritsDirectiveSupportsArrays()
         {
-            ParseCodeBlockTest(
+            ParseDocumentTest(
                 "@inherits string[[]][]",
                 new[] { InheritsDirective.Directive, },
-                new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
+                new MarkupBlock(
+                    Factory.EmptyHtml(),
+                    new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
                     Factory.CodeTransition(),
                     Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
                     Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
-                    Factory.Span(SpanKindInternal.Code, "string[[]][]", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens.First())));
+                    Factory.Span(SpanKindInternal.Code, "string[[]][]", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens.First())),
+                    Factory.EmptyHtml()));
         }
 
         [Fact]
         public void InheritsDirectiveSupportsNestedGenerics()
         {
-            ParseCodeBlockTest(
+            ParseDocumentTest(
                 "@inherits System.Web.Mvc.WebViewPage<IEnumerable<MvcApplication2.Models.RegisterModel>>",
                 new[] { InheritsDirective.Directive, },
-                new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
+                new MarkupBlock(
-                    Factory.CodeTransition(),
+                    Factory.EmptyHtml(),
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                    new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
-                    Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                        Factory.CodeTransition(),
-                    Factory.Span(SpanKindInternal.Code, "System.Web.Mvc.WebViewPage<IEnumerable<MvcApplication2.Models.RegisterModel>>", markup: false)
+                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                        .AsDirectiveToken(InheritsDirective.Directive.Tokens.First())));
+                        Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                        Factory.Span(SpanKindInternal.Code, "System.Web.Mvc.WebViewPage<IEnumerable<MvcApplication2.Models.RegisterModel>>", markup: false)
+                            .AsDirectiveToken(InheritsDirective.Directive.Tokens.First())),
+                    Factory.EmptyHtml()));
         }
 
         [Fact]
         public void InheritsDirectiveSupportsTypeKeywords()
         {
-            ParseCodeBlockTest(
+            ParseDocumentTest(
                 "@inherits string",
                 new[] { InheritsDirective.Directive, },
-                new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
+                new MarkupBlock(
-                    Factory.CodeTransition(),
+                    Factory.EmptyHtml(),
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                    new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
-                    Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                        Factory.CodeTransition(),
-                    Factory.Span(SpanKindInternal.Code, "string", markup: false)
+                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                        .AsDirectiveToken(InheritsDirective.Directive.Tokens.First())));
+                        Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                        Factory.Span(SpanKindInternal.Code, "string", markup: false)
+                            .AsDirectiveToken(InheritsDirective.Directive.Tokens.First())),
+                    Factory.EmptyHtml()));
         }
 
         [Fact]

test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/CSharpSpecialBlockTest.cs

@@ -19,26 +19,34 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 RazorDiagnostic.Create(
                     new RazorError(
                         LegacyResources.FormatUnexpectedEOFAfterDirective(InheritsDirective.Directive.Directive, "type"),
-                        new SourceLocation(8, 0, 8), 1)));
+                        new SourceLocation(9, 0, 9), 1)));
 
             // Act & Assert
-            ParseBlockTest(
+            ParseDocumentTest(
-                "inherits",
+                "@inherits",
                 new[] { InheritsDirective.Directive },
-                new DirectiveBlock(chunkGenerator,
+                new MarkupBlock(
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None)));
+                    Factory.EmptyHtml(),
+                    new DirectiveBlock(chunkGenerator,
+                        Factory.CodeTransition(),
+                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None)),
+                    Factory.EmptyHtml()));
         }
 
         [Fact]
         public void InheritsBlockAcceptsMultipleGenericArguments()
         {
-            ParseBlockTest(
+            ParseDocumentTest(
-                "inherits Foo.Bar<Biz<Qux>, string, int>.Baz",
+                "@inherits Foo.Bar<Biz<Qux>, string, int>.Baz",
                 new[] { InheritsDirective.Directive },
-                new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
+                new MarkupBlock(
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                    Factory.EmptyHtml(),
-                    Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                    new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
-                    Factory.Span(SpanKindInternal.Code, "Foo.Bar<Biz<Qux>, string, int>.Baz", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens[0])));
+                        Factory.CodeTransition(),
+                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                        Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
+                        Factory.Span(SpanKindInternal.Code, "Foo.Bar<Biz<Qux>, string, int>.Baz", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens[0])),
+                    Factory.EmptyHtml()));
         }
 
         [Fact]
@@ -50,15 +58,19 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 RazorDiagnostic.Create(
                     new RazorError(
                         LegacyResources.FormatDirectiveExpectsTypeName(InheritsDirective.Directive.Directive),
-                        24, 0, 24, Environment.NewLine.Length)));
+                        25, 0, 25, Environment.NewLine.Length)));
 
             // Act & Assert
-            ParseBlockTest(
+            ParseDocumentTest(
-                "inherits                " + Environment.NewLine + "foo",
+                "@inherits                " + Environment.NewLine + "foo",
                 new[] { InheritsDirective.Directive },
-                new DirectiveBlock(chunkGenerator,
+                new MarkupBlock(
-                    Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                    Factory.EmptyHtml(),
-                    Factory.Span(SpanKindInternal.Code, "                ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace)));
+                    new DirectiveBlock(chunkGenerator,
+                        Factory.CodeTransition(),
+                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
+                        Factory.Span(SpanKindInternal.Code, "                ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace)),
+                    Factory.Markup(Environment.NewLine + "foo")));
         }
 
         [Fact]

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_DesignTime.codegen.cs

@@ -1,12 +1,12 @@
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
 {
     #line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
+#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
 using System.Globalization;
 
 #line default
 #line hidden
-#line 4 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
+#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
 using System.ComponentModel;
 
 #line default

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_DesignTime.ir.txt

@@ -1,11 +1,11 @@
 Document - 
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-        UsingDirective - (31:1,1 [26] BasicImports_Imports0.cshtml) - System.Globalization
+        UsingDirective - (1:0,1 [26] BasicImports_Imports0.cshtml) - System.Globalization
-        UsingDirective - (80:3,1 [27] BasicImports_Imports0.cshtml) - System.ComponentModel
+        UsingDirective - (30:1,1 [27] BasicImports_Imports0.cshtml) - System.ComponentModel
         UsingDirective - (23:1,1 [18] BasicImports_Imports1.cshtml) - System.Text
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_DesignTime - Hello - 
             DesignTimeDirective - 
-                DirectiveToken - (119:4,10 [5] BasicImports_Imports0.cshtml) - Hello
+                DirectiveToken - (69:2,10 [5] BasicImports_Imports0.cshtml) - Hello
             CSharpCode - 
                 IntermediateToken -  - CSharp - private static System.Object __o = null;
             MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml

@@ -1,5 +1,5 @@
-<p>This will get ignored</p>
+@using System.Globalization
-@using System.Globalization
-@("And also this")
 @using System.ComponentModel
 @inherits Hello
+@("And also this")
+<p>This will get ignored</p>

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Runtime.codegen.cs

@@ -2,12 +2,12 @@
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
 {
     #line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
+#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
 using System.Globalization;
 
 #line default
 #line hidden
-#line 4 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
+#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
 using System.ComponentModel;
 
 #line default

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Runtime.ir.txt

@@ -1,7 +1,7 @@
 Document - 
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-        UsingDirective - (31:1,1 [28] BasicImports_Imports0.cshtml) - System.Globalization
+        UsingDirective - (1:0,1 [28] BasicImports_Imports0.cshtml) - System.Globalization
-        UsingDirective - (80:3,1 [29] BasicImports_Imports0.cshtml) - System.ComponentModel
+        UsingDirective - (30:1,1 [29] BasicImports_Imports0.cshtml) - System.ComponentModel
         UsingDirective - (23:1,1 [20] BasicImports_Imports1.cshtml) - System.Text
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_Runtime - Hello - 
             MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_DesignTime.diagnostics.txt

@@ -8,6 +8,7 @@ TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cs
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(12,2): Error RZ9999: Directive 'tagHelperPrefix' must have a value.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(13,18): Error RZ9999: Unterminated string literal.  Strings that start with a quotation mark (") must be terminated before the end of the line.  However, strings that start with @ and a quotation mark (@") can span multiple lines.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,10): Error RZ9999: The 'inherits' directive expects a type name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(16,1): Error RZ9999: The 'inherits' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(16,11): Error RZ9999: The 'inherits' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(19,1): Error RZ9999: Unexpected literal following the 'functions' directive. Expected '{'.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(21,1): Error RZ9999: Unexpected literal following the 'functions' directive. Expected '{'.

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives_Runtime.diagnostics.txt

@@ -8,6 +8,7 @@ TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cs
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(12,2): Error RZ9999: Directive 'tagHelperPrefix' must have a value.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(13,18): Error RZ9999: Unterminated string literal.  Strings that start with a quotation mark (") must be terminated before the end of the line.  However, strings that start with @ and a quotation mark (@") can span multiple lines.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(15,10): Error RZ9999: The 'inherits' directive expects a type name.
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(16,1): Error RZ9999: The 'inherits' directive may only occur once per document.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(16,11): Error RZ9999: The 'inherits' directive expects a type name.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(19,1): Error RZ9999: Unexpected literal following the 'functions' directive. Expected '{'.
 TestFiles/IntegrationTests/CodeGenerationIntegrationTest/IncompleteDirectives.cshtml(21,1): Error RZ9999: Unexpected literal following the 'functions' directive. Expected '{'.

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml

@@ -1,3 +1,3 @@
-@foo()
+@inherits foo.bar<baz<biz>>.boz
 
-@inherits foo.bar<baz<biz>>.boz
+@foo()

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits_DesignTime.codegen.cs

@@ -15,7 +15,7 @@ foo.bar<baz<biz>>.boz __typeHelper = default(foo.bar<baz<biz>>.boz);
         #pragma warning disable 1998
         public async System.Threading.Tasks.Task ExecuteAsync()
         {
-#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml"
+#line 3 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml"
 __o = foo();
 
 #line default

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits_DesignTime.ir.txt

@@ -2,11 +2,11 @@ Document -
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_Inherits_DesignTime - foo.bar<baz<biz>>.boz - 
             DesignTimeDirective - 
-                DirectiveToken - (20:2,10 [21] Inherits.cshtml) - foo.bar<baz<biz>>.boz
+                DirectiveToken - (10:0,10 [21] Inherits.cshtml) - foo.bar<baz<biz>>.boz
             CSharpCode - 
                 IntermediateToken -  - CSharp - private static System.Object __o = null;
             MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync
-                CSharpExpression - (1:0,1 [5] Inherits.cshtml)
+                HtmlContent - (33:1,0 [2] Inherits.cshtml)
-                    IntermediateToken - (1:0,1 [5] Inherits.cshtml) - CSharp - foo()
+                    IntermediateToken - (33:1,0 [2] Inherits.cshtml) - Html - \n
-                HtmlContent - (6:0,6 [4] Inherits.cshtml)
+                CSharpExpression - (36:2,1 [5] Inherits.cshtml)
-                    IntermediateToken - (6:0,6 [4] Inherits.cshtml) - Html - \n\n
+                    IntermediateToken - (36:2,1 [5] Inherits.cshtml) - CSharp - foo()

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits_DesignTime.mappings.txt

@@ -1,9 +1,9 @@
-Source Location: (20:2,10 [21] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml)
+Source Location: (10:0,10 [21] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml)
 |foo.bar<baz<biz>>.boz|
 Generated Location: (349:8,0 [21] )
 |foo.bar<baz<biz>>.boz|
 
-Source Location: (1:0,1 [5] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml)
+Source Location: (36:2,1 [5] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml)
 |foo()|
 Generated Location: (747:18,6 [5] )
 |foo()|

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits_Runtime.codegen.cs

@@ -1,4 +1,4 @@
-#pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "081d0c0715ffeacf3f97a2f3a8443e1e47346419"
+#pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "d5c565b0bb468550fca15010c0addc84e79c5297"
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
 {
     #line hidden
@@ -7,12 +7,12 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
         #pragma warning disable 1998
         public async System.Threading.Tasks.Task ExecuteAsync()
         {
-#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml"
+            WriteLiteral("\r\n");
+#line 3 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits.cshtml"
 Write(foo());
 
 #line default
 #line hidden
-            WriteLiteral("\r\n\r\n");
         }
         #pragma warning restore 1998
     }

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Inherits_Runtime.ir.txt

@@ -2,7 +2,7 @@ Document -
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_Inherits_Runtime - foo.bar<baz<biz>>.boz - 
             MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync
-                CSharpExpression - (1:0,1 [5] Inherits.cshtml)
+                HtmlContent - (33:1,0 [2] Inherits.cshtml)
-                    IntermediateToken - (1:0,1 [5] Inherits.cshtml) - CSharp - foo()
+                    IntermediateToken - (33:1,0 [2] Inherits.cshtml) - Html - \n
-                HtmlContent - (6:0,6 [4] Inherits.cshtml)
+                CSharpExpression - (36:2,1 [5] Inherits.cshtml)
-                    IntermediateToken - (6:0,6 [4] Inherits.cshtml) - Html - \n\n
+                    IntermediateToken - (36:2,1 [5] Inherits.cshtml) - CSharp - foo()