Merge branch 'rel/vs15.7' into dev

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

@@ -60,7 +60,12 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             WriteTargetElementString(context.CodeWriter, node.TagHelper);
 
             // Initialize declaration.
-            using (context.CodeWriter.BuildClassDeclaration(PublicModifiers, node.ClassName, TagHelperTypeName, interfaces: null))
+            using (context.CodeWriter.BuildClassDeclaration(
+                PublicModifiers,
+                node.ClassName,
+                TagHelperTypeName,
+                interfaces: null,
+                typeParameters: null))
             {
                 // Add view component helper.
                 context.CodeWriter.WriteVariableDeclaration(

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

@@ -112,11 +112,13 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 var leadingDirectiveCodeDocument = RazorCodeDocument.Create(codeDocument.Source);
                 LeadingDirectiveParsingEngine.Engine.Process(leadingDirectiveCodeDocument);
 
-                var documentIRNode = leadingDirectiveCodeDocument.GetDocumentIntermediateNode();
+                var leadingDirectiveDocumentNode = leadingDirectiveCodeDocument.GetDocumentIntermediateNode();
-                if (!PageDirective.TryGetPageDirective(documentIRNode, out var _))
+                if (!PageDirective.TryGetPageDirective(leadingDirectiveDocumentNode, out var _))
                 {
                     // The page directive is not the leading directive. Add an error.
-                    pageDirective.DirectiveNode.Diagnostics.Add(
+                    // Note: Adding the error to the top-level document node because the directive node will be removed by a later optimization pass.
+                    var originalDocumentNode = codeDocument.GetDocumentIntermediateNode();
+                    originalDocumentNode.Diagnostics.Add(
                         RazorExtensionsDiagnosticFactory.CreatePageDirective_MustExistAtTheTopOfFile(pageDirective.DirectiveNode.Source.Value));
                 }
             }

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

@@ -60,7 +60,12 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             WriteTargetElementString(context.CodeWriter, node.TagHelper);
 
             // Initialize declaration.
-            using (context.CodeWriter.BuildClassDeclaration(PublicModifiers, node.ClassName, TagHelperTypeName, interfaces: null))
+            using (context.CodeWriter.BuildClassDeclaration(
+                PublicModifiers,
+                node.ClassName,
+                TagHelperTypeName,
+                interfaces: null,
+                typeParameters: null))
             {
                 // Add view component helper.
                 context.CodeWriter.WriteVariableDeclaration(

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

@@ -374,7 +374,8 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             IList<string> modifiers,
             string name,
             string baseType,
-            IEnumerable<string> interfaces)
+            IList<string> interfaces,
+            IList<string> typeParameters)
         {
             for (var i = 0; i < modifiers.Count; i++)
             {
@@ -385,8 +386,15 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
             writer.Write("class ");
             writer.Write(name);
 
+            if (typeParameters != null && typeParameters.Count > 0)
+            {
+                writer.Write("<");
+                writer.Write(string.Join(", ", typeParameters));
+                writer.Write(">");
+            }
+
             var hasBaseType = !string.IsNullOrEmpty(baseType);
-            var hasInterfaces = interfaces != null && interfaces.Count() > 0;
+            var hasInterfaces = interfaces != null && interfaces.Count > 0;
 
             if (hasBaseType || hasInterfaces)
             {

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

@@ -78,8 +78,8 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
                     {
                         algorithmId = "{8829d00f-11b8-4213-878b-770e8597ac16}";
                     }
-                    else if (string.Equals(algorithm, HashAlgorithmName.SHA1.Name, StringComparison.Ordinal) || 
+                    else if (string.Equals(algorithm, HashAlgorithmName.SHA1.Name, StringComparison.Ordinal) ||
-                        
+
                         // In 2.0, we didn't actually expose the name of the algorithm, so it's possible we could get null here.
                         // If that's the case, we just assume SHA1 since that's the only thing we supported in 2.0.
                         algorithm == null)
@@ -88,7 +88,7 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
                     }
                     else
                     {
-                        var supportedAlgorithms = string.Join(" ", new string[] 
+                        var supportedAlgorithms = string.Join(" ", new string[]
                         {
                             HashAlgorithmName.SHA1.Name,
                             HashAlgorithmName.SHA256.Name
@@ -143,7 +143,12 @@ namespace Microsoft.AspNetCore.Razor.Language.CodeGeneration
 
             public override void VisitClassDeclaration(ClassDeclarationIntermediateNode node)
             {
-                using (Context.CodeWriter.BuildClassDeclaration(node.Modifiers, node.ClassName, node.BaseType, node.Interfaces))
+                using (Context.CodeWriter.BuildClassDeclaration(
+                    node.Modifiers,
+                    node.ClassName,
+                    node.BaseType,
+                    node.Interfaces,
+                    node.TypeParameters.Select(p => p.ParameterName).ToArray()))
                 {
                     VisitDefault(node);
                 }

src/Microsoft.AspNetCore.Razor.Language/Intermediate/ClassDeclarationIntermediateNode.cs

@@ -16,7 +16,9 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
 
         public string BaseType { get; set; }
 
-        public IList<string> Interfaces { get; set; }
+        public IList<string> Interfaces { get; set; } = new List<string>();
+
+        public IList<TypeParameter> TypeParameters { get; set; } = new List<TypeParameter>();
 
         public override void Accept(IntermediateNodeVisitor visitor)
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/TypeParameter.cs

@@ -0,0 +1,10 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNetCore.Razor.Language.Intermediate
+{
+    public sealed class TypeParameter
+    {
+        public string ParameterName { get; set; }
+    }
+}

src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlMarkupParser.cs

@@ -931,7 +931,9 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         {
             // First, determine if this is a 'data-' attribute (since those can't use conditional attributes)
             var name = string.Concat(nameSymbols.Select(s => s.Content));
-            var attributeCanBeConditional = !name.StartsWith("data-", StringComparison.OrdinalIgnoreCase);
+            var attributeCanBeConditional = 
+                Context.FeatureFlags.EXPERIMENTAL_AllowConditionalDataDashAttributes ||
+                !name.StartsWith("data-", StringComparison.OrdinalIgnoreCase);
 
             // Accept the whitespace and name
             Accept(whitespace);

src/Microsoft.AspNetCore.Razor.Language/Legacy/ParserContext.cs

@@ -23,6 +23,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
             Source = new SeekableTextReader(chars, source.FilePath);
             DesignTimeMode = options.DesignTime;
+            FeatureFlags = options.FeatureFlags;
             ParseLeadingDirectives = options.ParseLeadingDirectives;
             Builder = new SyntaxTreeBuilder();
             ErrorSink = new ErrorSink();
@@ -33,6 +34,8 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         public ErrorSink ErrorSink { get; set; }
 
+        public RazorParserFeatureFlags FeatureFlags { get; }
+
         public HashSet<string> SeenDirectives { get; }
 
         public ITextDocument Source { get; }

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

@@ -9,6 +9,7 @@ namespace Microsoft.AspNetCore.Razor.Language
         {
             var allowMinimizedBooleanTagHelperAttributes = false;
             var allowHtmlCommentsInTagHelpers = false;
+            var experimental_AllowConditionalDataDashAttributes = false;
 
             if (version.CompareTo(RazorLanguageVersion.Version_2_1) >= 0)
             {
@@ -17,24 +18,40 @@ namespace Microsoft.AspNetCore.Razor.Language
                 allowHtmlCommentsInTagHelpers = true;
             }
 
-            return new DefaultRazorParserFeatureFlags(allowMinimizedBooleanTagHelperAttributes, allowHtmlCommentsInTagHelpers);
+            if (version.CompareTo(RazorLanguageVersion.Experimental) >= 0)
+            {
+                experimental_AllowConditionalDataDashAttributes = true;
+            }
+
+            return new DefaultRazorParserFeatureFlags(
+                allowMinimizedBooleanTagHelperAttributes,
+                allowHtmlCommentsInTagHelpers,
+                experimental_AllowConditionalDataDashAttributes);
         }
 
         public abstract bool AllowMinimizedBooleanTagHelperAttributes { get; }
 
         public abstract bool AllowHtmlCommentsInTagHelpers { get; }
 
+        public abstract bool EXPERIMENTAL_AllowConditionalDataDashAttributes { get; }
+
         private class DefaultRazorParserFeatureFlags : RazorParserFeatureFlags
         {
-            public DefaultRazorParserFeatureFlags(bool allowMinimizedBooleanTagHelperAttributes, bool allowHtmlCommentsInTagHelpers)
+            public DefaultRazorParserFeatureFlags(
+                bool allowMinimizedBooleanTagHelperAttributes,
+                bool allowHtmlCommentsInTagHelpers,
+                bool experimental_AllowConditionalDataDashAttributes)
             {
                 AllowMinimizedBooleanTagHelperAttributes = allowMinimizedBooleanTagHelperAttributes;
                 AllowHtmlCommentsInTagHelpers = allowHtmlCommentsInTagHelpers;
+                EXPERIMENTAL_AllowConditionalDataDashAttributes = experimental_AllowConditionalDataDashAttributes;
             }
 
             public override bool AllowMinimizedBooleanTagHelperAttributes { get; }
 
             public override bool AllowHtmlCommentsInTagHelpers { get; }
+
+            public override bool EXPERIMENTAL_AllowConditionalDataDashAttributes { get; }
         }
     }
 }

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

@@ -290,6 +290,14 @@ public class AllTagHelper : {typeof(TagHelper).FullName}
             
             RunRuntimeTest(compilation);
         }
+
+        [Fact]
+        public void RazorPageWithNoLeadingPageDirective_Runtime()
+        {
+            var compilation = BaseCompilation;
+
+            RunRuntimeTest(compilation);
+        }
         #endregion
 
         #region DesignTime
@@ -577,6 +585,14 @@ public class AllTagHelper : {typeof(TagHelper).FullName}
             
             RunDesignTimeTest(compilation);
         }
+
+        [Fact]
+        public void RazorPageWithNoLeadingPageDirective_DesignTime()
+        {
+            var compilation = BaseCompilation;
+
+            RunDesignTimeTest(compilation);
+        }
         #endregion
 
         private void RunRuntimeTest(

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

@@ -68,9 +68,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             visitor.Visit(irDocument);
 
             // Assert
-            var pageDirectives = irDocument.FindDirectiveReferences(PageDirective.Directive);
+            var documentNode = codeDocument.GetDocumentIntermediateNode();
-            var directive = Assert.Single(pageDirectives);
+            var diagnostic = Assert.Single(documentNode.Diagnostics);
-            var diagnostic = Assert.Single(directive.Node.Diagnostics);
             Assert.Equal(expectedDiagnostic, diagnostic);
         }
 
@@ -98,9 +97,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             visitor.Visit(irDocument);
 
             // Assert
-            var pageDirectives = irDocument.FindDirectiveReferences(PageDirective.Directive);
+            var documentNode = codeDocument.GetDocumentIntermediateNode();
-            var directive = Assert.Single(pageDirectives);
+            Assert.Empty(documentNode.Diagnostics);
-            Assert.Empty(directive.Node.Diagnostics);
         }
 
         [Fact]

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml

@@ -0,0 +1,2 @@
+<div>Some text here.</div>
+@page

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

@@ -0,0 +1,42 @@
+// <auto-generated/>
+#pragma warning disable 1591
+namespace AspNetCore
+{
+    #line hidden
+    using TModel = global::System.Object;
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Threading.Tasks;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.AspNetCore.Mvc.Rendering;
+    using Microsoft.AspNetCore.Mvc.ViewFeatures;
+    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective : global::Microsoft.AspNetCore.Mvc.RazorPages.Page
+    {
+        #pragma warning disable 219
+        private void __RazorDirectiveTokenHelpers__() {
+        }
+        #pragma warning restore 219
+        #pragma warning disable 0414
+        private static System.Object __o = null;
+        #pragma warning restore 0414
+        #pragma warning disable 1998
+        public async override global::System.Threading.Tasks.Task ExecuteAsync()
+        {
+        }
+        #pragma warning restore 1998
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.IModelExpressionProvider ModelExpressionProvider { get; private set; }
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IUrlHelper Url { get; private set; }
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IViewComponentHelper Component { get; private set; }
+        [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<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective>)PageContext?.ViewData;
+        public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective Model => ViewData.Model;
+    }
+}
+#pragma warning restore 1591

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

@@ -0,0 +1 @@
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml(2,1): Error RZ3906: The '@page' directive must precede all other elements defined in a Razor file.

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

@@ -0,0 +1,46 @@
+Document - 
+    NamespaceDeclaration -  - AspNetCore
+        UsingDirective -  - TModel = global::System.Object
+        UsingDirective - (1:0,1 [12] ) - System
+        UsingDirective - (16:1,1 [32] ) - System.Collections.Generic
+        UsingDirective - (51:2,1 [17] ) - System.Linq
+        UsingDirective - (71:3,1 [28] ) - System.Threading.Tasks
+        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_RazorPageWithNoLeadingPageDirective - global::Microsoft.AspNetCore.Mvc.RazorPages.Page - 
+            DesignTimeDirective - 
+                DirectiveToken - (231:7,8 [62] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TModel>
+                DirectiveToken - (294:7,71 [4] ) - Html
+                DirectiveToken - (308:8,8 [54] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IJsonHelper
+                DirectiveToken - (363:8,63 [4] ) - Json
+                DirectiveToken - (377:9,8 [53] ) - global::Microsoft.AspNetCore.Mvc.IViewComponentHelper
+                DirectiveToken - (431:9,62 [9] ) - Component
+                DirectiveToken - (450:10,8 [43] ) - global::Microsoft.AspNetCore.Mvc.IUrlHelper
+                DirectiveToken - (494:10,52 [3] ) - Url
+                DirectiveToken - (507:11,8 [70] ) - global::Microsoft.AspNetCore.Mvc.ViewFeatures.IModelExpressionProvider
+                DirectiveToken - (578:11,79 [23] ) - ModelExpressionProvider
+                DirectiveToken - (617:12,14 [96] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.UrlResolutionTagHelper, Microsoft.AspNetCore.Mvc.Razor
+                DirectiveToken - (729:13,14 [87] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.HeadTagHelper, Microsoft.AspNetCore.Mvc.Razor
+                DirectiveToken - (832:14,14 [87] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.BodyTagHelper, Microsoft.AspNetCore.Mvc.Razor
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning disable 0414
+            CSharpCode - 
+                IntermediateToken -  - CSharp - private static System.Object __o = null;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning restore 0414
+            MethodDeclaration -  - public async override - global::System.Threading.Tasks.Task - ExecuteAsync
+                HtmlContent - (0:0,0 [28] RazorPageWithNoLeadingPageDirective.cshtml)
+                    IntermediateToken - (0:0,0 [5] RazorPageWithNoLeadingPageDirective.cshtml) - Html - <div>
+                    IntermediateToken - (5:0,5 [15] RazorPageWithNoLeadingPageDirective.cshtml) - Html - Some text here.
+                    IntermediateToken - (20:0,20 [6] RazorPageWithNoLeadingPageDirective.cshtml) - Html - </div>
+                    IntermediateToken - (26:0,26 [2] RazorPageWithNoLeadingPageDirective.cshtml) - Html - \n
+            Inject - 
+            Inject - 
+            Inject - 
+            Inject - 
+            Inject - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective>)PageContext?.ViewData;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective Model => ViewData.Model;

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

@@ -0,0 +1,41 @@
+#pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "1d35b023a80ffd4cbf92549aae24d6c47f4af7e5"
+// <auto-generated/>
+#pragma warning disable 1591
+[assembly: global::Microsoft.AspNetCore.Razor.Hosting.RazorCompiledItemAttribute(typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective), @"mvc.1.0.razor-page", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml")]
+[assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(@"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml", typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective), null)]
+namespace AspNetCore
+{
+    #line hidden
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Threading.Tasks;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.AspNetCore.Mvc.Rendering;
+    using Microsoft.AspNetCore.Mvc.ViewFeatures;
+    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"1d35b023a80ffd4cbf92549aae24d6c47f4af7e5", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml")]
+    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective : global::Microsoft.AspNetCore.Mvc.RazorPages.Page
+    {
+        #pragma warning disable 1998
+        public async override global::System.Threading.Tasks.Task ExecuteAsync()
+        {
+            BeginContext(0, 28, true);
+            WriteLiteral("<div>Some text here.</div>\r\n");
+            EndContext();
+        }
+        #pragma warning restore 1998
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.IModelExpressionProvider ModelExpressionProvider { get; private set; }
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IUrlHelper Url { get; private set; }
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IViewComponentHelper Component { get; private set; }
+        [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<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective>)PageContext?.ViewData;
+        public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective Model => ViewData.Model;
+    }
+}
+#pragma warning restore 1591

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

@@ -0,0 +1 @@
+TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml(2,1): Error RZ3906: The '@page' directive must precede all other elements defined in a Razor file.

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

@@ -0,0 +1,33 @@
+Document - 
+    RazorCompiledItemAttribute - 
+    CSharpCode - 
+        IntermediateToken -  - CSharp - [assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(@"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/RazorPageWithNoLeadingPageDirective.cshtml", typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective), null)]
+    NamespaceDeclaration -  - AspNetCore
+        UsingDirective - (1:0,1 [14] ) - System
+        UsingDirective - (16:1,1 [34] ) - System.Collections.Generic
+        UsingDirective - (51:2,1 [19] ) - System.Linq
+        UsingDirective - (71:3,1 [30] ) - System.Threading.Tasks
+        UsingDirective - (102:4,1 [32] ) - Microsoft.AspNetCore.Mvc
+        UsingDirective - (135:5,1 [42] ) - Microsoft.AspNetCore.Mvc.Rendering
+        UsingDirective - (178:6,1 [45] ) - Microsoft.AspNetCore.Mvc.ViewFeatures
+        RazorSourceChecksumAttribute - 
+        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective - global::Microsoft.AspNetCore.Mvc.RazorPages.Page - 
+            MethodDeclaration -  - public async override - global::System.Threading.Tasks.Task - ExecuteAsync
+                CSharpCode - 
+                    IntermediateToken -  - CSharp - BeginContext(0, 28, true);
+                HtmlContent - (0:0,0 [28] RazorPageWithNoLeadingPageDirective.cshtml)
+                    IntermediateToken - (0:0,0 [5] RazorPageWithNoLeadingPageDirective.cshtml) - Html - <div>
+                    IntermediateToken - (5:0,5 [15] RazorPageWithNoLeadingPageDirective.cshtml) - Html - Some text here.
+                    IntermediateToken - (20:0,20 [6] RazorPageWithNoLeadingPageDirective.cshtml) - Html - </div>
+                    IntermediateToken - (26:0,26 [2] RazorPageWithNoLeadingPageDirective.cshtml) - Html - \n
+                CSharpCode - 
+                    IntermediateToken -  - CSharp - EndContext();
+            Inject - 
+            Inject - 
+            Inject - 
+            Inject - 
+            Inject - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective>)PageContext?.ViewData;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPageWithNoLeadingPageDirective Model => ViewData.Model;

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

@@ -218,6 +218,11 @@ namespace TestNamespace
                 },
                 BaseType = "TestBase",
                 Interfaces = new List<string> { "IFoo", "IBar", },
+                TypeParameters = new List<TypeParameter>
+                {
+                    new TypeParameter() { ParameterName = "TKey", },
+                    new TypeParameter() { ParameterName = "TValue", },
+                },
                 ClassName = "TestClass",
             });
 
@@ -236,7 +241,7 @@ namespace TestNamespace
 @"#pragma checksum ""test.cshtml"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""da39a3ee5e6b4b0d3255bfef95601890afd80709""
 // <auto-generated/>
 #pragma warning disable 1591
-internal class TestClass : TestBase, IFoo, IBar
+internal class TestClass<TKey, TValue> : TestBase, IFoo, IBar
 {
 }
 #pragma warning restore 1591

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/RazorTemplateEngineIntegrationTest.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.IO;
+using Microsoft.AspNetCore.Razor.Language.Intermediate;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
@@ -66,6 +67,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 
                 engine.ConfigureClass((document, @class) =>
                 {
+                    @class.TypeParameters = new[] { new TypeParameter() { ParameterName = "TValue", }, };
                     @class.Interfaces = new[] { "global::System.IDisposable" };
                     @class.BaseType = "CustomBaseType";
                 });

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

@@ -1957,7 +1957,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             Block expected,
             params RazorDiagnostic[] expectedErrors)
         {
-            var result = ParseCodeBlock(document, descriptors, designTime: false);
+            var result = ParseCodeBlock(RazorLanguageVersion.Latest, document, descriptors, designTime: false);
 
             EvaluateResults(result, expected, expectedErrors);
         }

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

@@ -9,9 +9,13 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
     {
         internal abstract ISet<string> KeywordSet { get; }
 
-        internal override RazorSyntaxTree ParseBlock(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime)
+        internal override RazorSyntaxTree ParseBlock(
+            RazorLanguageVersion version, 
+            string document, 
+            IEnumerable<DirectiveDescriptor> directives, 
+            bool designTime)
         {
-            return ParseCodeBlock(document, directives, designTime);
+            return ParseCodeBlock(version, document, directives, designTime);
         }
 
         internal void ImplicitExpressionTest(string input, params RazorDiagnostic[] errors)

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

@@ -559,6 +559,30 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             Assert.Equal(rewritten.Children.Count(), results.Root.Children.Count());
         }
 
+        [Fact]
+        public void ConditionalAttributesAreEnabledForDataAttributesWithExperimentalFlag()
+        {
+            ParseBlockTest(
+                RazorLanguageVersion.Experimental,
+                "<span data-foo='@foo'></span>",
+                new MarkupBlock(
+                    new MarkupTagBlock(
+                        Factory.Markup("<span"),
+                        new MarkupBlock(
+                            new AttributeBlockChunkGenerator("data-foo", new LocationTagged<string>(" data-foo='", 5, 0, 5), new LocationTagged<string>("'", 20, 0, 20)),
+                            Factory.Markup(" data-foo='").With(SpanChunkGenerator.Null),
+                            new MarkupBlock(new DynamicAttributeBlockChunkGenerator(new LocationTagged<string>(string.Empty, 16, 0, 16), 16, 0, 16),
+                                new ExpressionBlock(
+                                    Factory.CodeTransition(),
+                                    Factory.Code("foo")
+                                           .AsImplicitExpression(CSharpCodeParser.DefaultKeywords)
+                                           .Accepts(AcceptedCharactersInternal.NonWhiteSpace))),
+                            Factory.Markup("'").With(SpanChunkGenerator.Null)),
+                        Factory.Markup(">").Accepts(AcceptedCharactersInternal.None)),
+                    new MarkupTagBlock(
+                        Factory.Markup("</span>").Accepts(AcceptedCharactersInternal.None))));
+        }
+
         [Fact]
         public void ConditionalAttributesAreDisabledForDataAttributesInBlock()
         {

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

@@ -1,16 +1,19 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-
 using System.Collections.Generic;
 
 namespace Microsoft.AspNetCore.Razor.Language.Legacy
 {
     public abstract class MarkupParserTestBase : CodeParserTestBase
     {
-        internal override RazorSyntaxTree ParseBlock(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime)
+        internal override RazorSyntaxTree ParseBlock(
+            RazorLanguageVersion version,
+            string document,
+            IEnumerable<DirectiveDescriptor> directives,
+            bool designTime)
         {
-            return ParseHtmlBlock(document, directives, designTime);
+            return ParseHtmlBlock(version, document, directives, designTime);
         }
 
         internal virtual void SingleSpanDocumentTest(string document, BlockKindInternal blockKind, SpanKindInternal spanType)

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

@@ -3962,7 +3962,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                     .Build(),
             };
 
-            var featureFlags = new TestRazorParserFeatureFlags(allowMinimizedBooleanTagHelperAttributes: false, allowHtmlCommentsInTagHelper: false);
+            var featureFlags = new TestRazorParserFeatureFlags();
 
             var expectedOutput = new MarkupBlock(
                 new MarkupTagHelperBlock(
@@ -3994,15 +3994,21 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         private class TestRazorParserFeatureFlags : RazorParserFeatureFlags
         {
-            public TestRazorParserFeatureFlags(bool allowMinimizedBooleanTagHelperAttributes, bool allowHtmlCommentsInTagHelper)
+            public TestRazorParserFeatureFlags(
+                bool allowMinimizedBooleanTagHelperAttributes = false,
+                bool allowHtmlCommentsInTagHelper = false,
+                bool experimental_AllowConditionalDataDashAttributes = false)
             {
                 AllowMinimizedBooleanTagHelperAttributes = allowMinimizedBooleanTagHelperAttributes;
                 AllowHtmlCommentsInTagHelpers = allowHtmlCommentsInTagHelper;
+                EXPERIMENTAL_AllowConditionalDataDashAttributes = experimental_AllowConditionalDataDashAttributes;
             }
 
             public override bool AllowMinimizedBooleanTagHelperAttributes { get; }
 
             public override bool AllowHtmlCommentsInTagHelpers { get; }
+
+            public override bool EXPERIMENTAL_AllowConditionalDataDashAttributes { get; }
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/RazorTemplateEngineIntegrationTest/GenerateCodeWithConfigureClass.codegen.cs

@@ -5,7 +5,7 @@ namespace Razor
 {
     #line hidden
     [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"38aa8e26c5d2a85c61d8e93fe69dd326fe82671b", @"/TestFiles/IntegrationTests/RazorTemplateEngineIntegrationTest/GenerateCodeWithConfigureClass.cshtml")]
-    protected internal class MyClass : CustomBaseType, global::System.IDisposable
+    protected internal class MyClass<TValue> : CustomBaseType, global::System.IDisposable
     {
         #pragma warning disable 1998
         public async override global::System.Threading.Tasks.Task ExecuteAsync()

test/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/IntermediateNodeWriter.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -12,7 +13,7 @@ using Microsoft.AspNetCore.Razor.Language.Intermediate;
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 {
     // Serializes single IR nodes (shallow).
-    public class IntermediateNodeWriter : 
+    public class IntermediateNodeWriter :
         IntermediateNodeVisitor,
         IExtensionIntermediateNodeVisitor<SectionIntermediateNode>
     {
@@ -32,7 +33,21 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 
         public override void VisitClassDeclaration(ClassDeclarationIntermediateNode node)
         {
-            WriteContentNode(node, string.Join(" ", node.Modifiers), node.ClassName, node.BaseType, string.Join(", ", node.Interfaces ?? new List<string>()));
+            var entries = new List<string>()
+            {
+                string.Join(" ", node.Modifiers),
+                node.ClassName,
+                node.BaseType,
+                string.Join(", ", node.Interfaces ?? Array.Empty<string>())
+            };
+
+            // Avoid adding the type parameters to the baseline if they aren't present.
+            if (node.TypeParameters != null && node.TypeParameters.Count > 0)
+            {
+                entries.Add(string.Join(", ", node.TypeParameters));
+            }
+
+            WriteContentNode(node, entries.ToArray());
         }
 
         public override void VisitCSharpExpressionAttributeValue(CSharpExpressionAttributeValueIntermediateNode node)

test/Microsoft.AspNetCore.Razor.Test.Common/Language/Legacy/ParserTestBase.cs

@@ -32,23 +32,43 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         internal RazorSyntaxTree ParseBlock(string document, bool designTime)
         {
-            return ParseBlock(document, null, designTime);
+            return ParseBlock(RazorLanguageVersion.Latest, document, designTime);
         }
 
-        internal abstract RazorSyntaxTree ParseBlock(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime);
+        internal RazorSyntaxTree ParseBlock(RazorLanguageVersion version, string document, bool designTime)
-
-        internal virtual RazorSyntaxTree ParseDocument(string document, bool designTime = false)
         {
-            return ParseDocument(document, null, designTime);
+            return ParseBlock(version, document, null, designTime);
         }
 
-        internal virtual RazorSyntaxTree ParseDocument(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime = false)
+        internal RazorSyntaxTree ParseBlock(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime)
+        {
+            return ParseBlock(RazorLanguageVersion.Latest, document, directives, designTime);
+        }
+
+        internal abstract RazorSyntaxTree ParseBlock(RazorLanguageVersion version, string document, IEnumerable<DirectiveDescriptor> directives, bool designTime);
+
+        internal RazorSyntaxTree ParseDocument(string document, bool designTime = false)
+        {
+            return ParseDocument(RazorLanguageVersion.Latest, document, designTime);
+        }
+
+        internal RazorSyntaxTree ParseDocument(RazorLanguageVersion version, string document, bool designTime = false)
+        {
+            return ParseDocument(version, document, null, designTime);
+        }
+
+        internal RazorSyntaxTree ParseDocument(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime = false)
+        {
+            return ParseDocument(RazorLanguageVersion.Latest, document, directives, designTime);
+        }
+
+        internal virtual RazorSyntaxTree ParseDocument(RazorLanguageVersion version, string document, IEnumerable<DirectiveDescriptor> directives, bool designTime = false)
         {
             directives = directives ?? Array.Empty<DirectiveDescriptor>();
 
             var source = TestRazorSourceDocument.Create(document, filePath: null);
 
-            var options = CreateParserOptions(directives, designTime);
+            var options = CreateParserOptions(version, directives, designTime);
             var context = new ParserContext(source, options);
 
             var codeParser = new CSharpCodeParser(directives, context);
@@ -73,12 +93,12 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return syntaxTree;
         }
 
-        internal virtual RazorSyntaxTree ParseHtmlBlock(string document, IEnumerable<DirectiveDescriptor> directives, bool designTime = false)
+        internal virtual RazorSyntaxTree ParseHtmlBlock(RazorLanguageVersion version, string document, IEnumerable<DirectiveDescriptor> directives, bool designTime = false)
         {
             directives = directives ?? Array.Empty<DirectiveDescriptor>();
 
             var source = TestRazorSourceDocument.Create(document, filePath: null);
-            var options = CreateParserOptions(directives, designTime);
+            var options = CreateParserOptions(version, directives, designTime);
             var context = new ParserContext(source, options);
 
             var parser = new HtmlMarkupParser(context);
@@ -95,12 +115,13 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return RazorSyntaxTree.Create(root, source, diagnostics, options);
         }
 
-        internal virtual RazorSyntaxTree ParseCodeBlock(string document, bool designTime = false)
+        internal RazorSyntaxTree ParseCodeBlock(string document, bool designTime = false)
         {
-            return ParseCodeBlock(document, Enumerable.Empty<DirectiveDescriptor>(), designTime);
+            return ParseCodeBlock(RazorLanguageVersion.Latest, document, Enumerable.Empty<DirectiveDescriptor>(), designTime);
         }
 
         internal virtual RazorSyntaxTree ParseCodeBlock(
+            RazorLanguageVersion version,
             string document,
             IEnumerable<DirectiveDescriptor> directives,
             bool designTime)
@@ -108,7 +129,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             directives = directives ?? Array.Empty<DirectiveDescriptor>();
 
             var source = TestRazorSourceDocument.Create(document, filePath: null);
-            var options = CreateParserOptions(directives, designTime);
+            var options = CreateParserOptions(version, directives, designTime);
             var context = new ParserContext(source, options);
 
             var parser = new CSharpCodeParser(directives, context);
@@ -152,6 +173,11 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             ParseBlockTest(document, null, designTime, expectedErrors);
         }
 
+        internal virtual void ParseBlockTest(RazorLanguageVersion version, string document, Block expectedRoot)
+        {
+            ParseBlockTest(version, document, expectedRoot, false, null);
+        }
+
         internal virtual void ParseBlockTest(string document, Block expectedRoot)
         {
             ParseBlockTest(document, expectedRoot, false, null);
@@ -182,9 +208,19 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             ParseBlockTest(document, null, expected, designTime, expectedErrors);
         }
 
+        internal virtual void ParseBlockTest(RazorLanguageVersion version, string document, Block expected, bool designTime, params RazorDiagnostic[] expectedErrors)
+        {
+            ParseBlockTest(version, document, null, expected, designTime, expectedErrors);
+        }
+
         internal virtual void ParseBlockTest(string document, IEnumerable<DirectiveDescriptor> directives, Block expected, bool designTime, params RazorDiagnostic[] expectedErrors)
         {
-            var result = ParseBlock(document, directives, designTime);
+            ParseBlockTest(RazorLanguageVersion.Latest, document, directives, expected, designTime, expectedErrors);
+        }
+
+        internal virtual void ParseBlockTest(RazorLanguageVersion version, string document, IEnumerable<DirectiveDescriptor> directives, Block expected, bool designTime, params RazorDiagnostic[] expectedErrors)
+        {
+            var result = ParseBlock(version, document, directives, designTime);
 
             if (FixupSpans)
             {
@@ -604,24 +640,16 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return block.Build();
         }
 
-        private static RazorParserOptions CreateParserOptions(IEnumerable<DirectiveDescriptor> directives, bool designTime)
+        private static RazorParserOptions CreateParserOptions(
+            RazorLanguageVersion version, 
+            IEnumerable<DirectiveDescriptor> directives, 
+            bool designTime)
         {
-            if (designTime)
+            return new DefaultRazorParserOptions(
-            {
+                directives.ToArray(),
-                return RazorParserOptions.CreateDesignTime(ConfigureOptions);
+                designTime,
-            }
+                parseLeadingDirectives: false,
-            else
+                version: version);
-            {
-                return RazorParserOptions.Create(ConfigureOptions);
-            }
-
-            void ConfigureOptions(RazorParserOptionsBuilder builder)
-            {
-                foreach (var directive in directives)
-                {
-                    builder.Directives.Add(directive);
-                }
-            }
         }
 
         private class IgnoreOutputBlock : Block