Have `@page` understand malformed directives.

- The `@page` directive will now look for malformed directives and treat a view as a Razor page based on the existence of the malformed directive.
- Updated the `PageDirective` type to contain a reference to its responsible directive node.
- Added unit tests to validate malformed directives were picked up accordingly.
- Updated code generation test baselines to reflect the new malformed directive understanding.

#1448

src/Microsoft.AspNetCore.Mvc.Razor.Extensions/PageDirective.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;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language;
@@ -20,13 +21,16 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 builder.Usage = DirectiveUsage.FileScopedSinglyOccurring;
             });
 
-        private PageDirective(string routeTemplate)
+        private PageDirective(string routeTemplate, IntermediateNode directiveNode)
         {
             RouteTemplate = routeTemplate;
+            DirectiveNode = directiveNode;
         }
 
         public string RouteTemplate { get; }
 
+        public IntermediateNode DirectiveNode { get; }
+
         public static IRazorEngineBuilder Register(IRazorEngineBuilder builder)
         {
             builder.AddDirective(Directive);
@@ -41,25 +45,27 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
                 visitor.Visit(documentNode.Children[i]);
             }
 
-            if (visitor.DirectiveNode == null)
+            if (visitor.DirectiveTokens == null)
             {
                 pageDirective = null;
                 return false;
             }
 
-            var tokens = visitor.DirectiveNode.Tokens.ToList();
+            var tokens = visitor.DirectiveTokens.ToList();
             string routeTemplate = null;
             if (tokens.Count > 0)
             {
                 routeTemplate = TrimQuotes(tokens[0].Content);
             }
 
-            pageDirective = new PageDirective(routeTemplate);
+            pageDirective = new PageDirective(routeTemplate, visitor.DirectiveNode);
             return true;
         }
 
         private static string TrimQuotes(string content)
         {
+            // Tokens aren't captured if they're malformed. Therefore, this method will
+            // always be called with a valid token content.
             Debug.Assert(content.Length >= 2);
             Debug.Assert(content.StartsWith("\"", StringComparison.Ordinal));
             Debug.Assert(content.EndsWith("\"", StringComparison.Ordinal));
@@ -69,13 +75,25 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 
         private class Visitor : IntermediateNodeWalker
         {
-            public DirectiveIntermediateNode DirectiveNode { get; private set; }
+            public IntermediateNode DirectiveNode { get; private set; }
+
+            public IEnumerable<DirectiveTokenIntermediateNode> DirectiveTokens { get; private set; }
 
             public override void VisitDirective(DirectiveIntermediateNode node)
             {
                 if (node.Descriptor == Directive)
                 {
                     DirectiveNode = node;
+                    DirectiveTokens = node.Tokens;
+                }
+            }
+
+            public override void VisitMalformedDirective(MalformedDirectiveIntermediateNode node)
+            {
+                if (DirectiveTokens == null && node.Descriptor == Directive)
+                {
+                    DirectiveNode = node;
+                    DirectiveTokens = node.Tokens;
                 }
             }
         }

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

@@ -1,7 +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.Diagnostics;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.Intermediate;
 
@@ -15,7 +15,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 
         protected override bool IsMatch(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
-            return PageDirective.TryGetPageDirective(documentNode, out var directive);
+            return PageDirective.TryGetPageDirective(documentNode, out var pageDirective);
         }
 
         protected override void OnDocumentStructureCreated(
@@ -49,26 +49,14 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         private void EnsureValidPageDirective(RazorCodeDocument codeDocument)
         {
             var document = codeDocument.GetDocumentIntermediateNode();
-            var visitor = new Visitor();
+            PageDirective.TryGetPageDirective(document, out var pageDirective);
-            visitor.VisitDocument(document);
 
-            if (visitor.DirectiveNode.IsImported())
+            Debug.Assert(pageDirective != null);
+
+            if (pageDirective.DirectiveNode.IsImported())
             {
-                visitor.DirectiveNode.Diagnostics.Add(
+                pageDirective.DirectiveNode.Diagnostics.Add(
-                    RazorExtensionsDiagnosticFactory.CreatePageDirective_CannotBeImported(visitor.DirectiveNode.Source.Value));
+                    RazorExtensionsDiagnosticFactory.CreatePageDirective_CannotBeImported(pageDirective.DirectiveNode.Source.Value));
-            }
-        }
-
-        private class Visitor : IntermediateNodeWalker
-        {
-            public DirectiveIntermediateNode DirectiveNode { get; private set; }
-
-            public override void VisitDirective(DirectiveIntermediateNode node)
-            {
-                if (node.Descriptor == PageDirective.Directive)
-                {
-                    DirectiveNode = node;
-                }
             }
         }
     }

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

@@ -10,6 +10,25 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
 {
     public class PageDirectiveTest
     {
+        [Fact]
+        public void TryGetPageDirective_ReturnsTrue_IfPageIsMalformed()
+        {
+            // Arrange
+            var content = "@page \"some-route-template\" Invalid";
+            var sourceDocument = RazorSourceDocument.Create(content, "file");
+            var codeDocument = RazorCodeDocument.Create(sourceDocument);
+            var engine = CreateEngine();
+            var irDocument = CreateIRDocument(engine, codeDocument);
+
+            // Act
+            var result = PageDirective.TryGetPageDirective(irDocument, out var pageDirective);
+
+            // Assert
+            Assert.True(result);
+            Assert.Equal("some-route-template", pageDirective.RouteTemplate);
+            Assert.NotNull(pageDirective.DirectiveNode);
+        }
+
         [Fact]
         public void TryGetPageDirective_ReturnsTrue_IfPageIsImported()
         {
@@ -48,7 +67,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
         }
 
         [Fact]
-        public void TryGetPageDirective_ReturnsFalse_IfPageDoesStartWithDirective()
+        public void TryGetPageDirective_ReturnsTrue_IfPageDoesStartWithDirective()
         {
             // Arrange
             var content = "Hello @page";
@@ -61,8 +80,9 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             var result = PageDirective.TryGetPageDirective(irDocument, out var pageDirective);
 
             // Assert
-            Assert.False(result);
+            Assert.True(result);
-            Assert.Null(pageDirective);
+            Assert.Null(pageDirective.RouteTemplate);
+            Assert.NotNull(pageDirective.DirectiveNode);
         }
 
         [Fact]

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

@@ -1,6 +1,6 @@
 // <auto-generated/>
 #pragma warning disable 1591
-[assembly:global::Microsoft.AspNetCore.Mvc.Razor.Compilation.RazorViewAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml))]
+[assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml), null)]
 namespace AspNetCore
 {
     #line hidden
@@ -12,7 +12,7 @@ namespace AspNetCore
     using Microsoft.AspNetCore.Mvc;
     using Microsoft.AspNetCore.Mvc.Rendering;
     using Microsoft.AspNetCore.Mvc.ViewFeatures;
-    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml : global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<dynamic>
+    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml : global::Microsoft.AspNetCore.Mvc.RazorPages.Page
     {
         #pragma warning disable 219
         private void __RazorDirectiveTokenHelpers__() {
@@ -35,7 +35,9 @@ namespace AspNetCore
         [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<dynamic> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml>)PageContext?.ViewData;
+        public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml Model => ViewData.Model;
     }
 }
 #pragma warning restore 1591

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

@@ -1,6 +1,6 @@
 Document - 
     CSharpCode - 
-        IntermediateToken -  - CSharp - [assembly:global::Microsoft.AspNetCore.Mvc.Razor.Compilation.RazorViewAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml))]
+        IntermediateToken -  - CSharp - [assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml), null)]
     NamespaceDeclaration -  - AspNetCore
         UsingDirective -  - TModel = global::System.Object
         UsingDirective - (1:0,1 [12] ) - System
@@ -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_MalformedPageDirective_cshtml - global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<dynamic> - 
+        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml - 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
@@ -47,3 +47,7 @@ Document -
             Inject - 
             Inject - 
             Inject - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml>)PageContext?.ViewData;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml Model => ViewData.Model;

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

@@ -1,7 +1,7 @@
 #pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/MalformedPageDirective.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "5a9ff8440150c6746e4a8ba63bc633ea84930405"
 // <auto-generated/>
 #pragma warning disable 1591
-[assembly:global::Microsoft.AspNetCore.Mvc.Razor.Compilation.RazorViewAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml))]
+[assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml), null)]
 namespace AspNetCore
 {
     #line hidden
@@ -12,7 +12,7 @@ namespace AspNetCore
     using Microsoft.AspNetCore.Mvc;
     using Microsoft.AspNetCore.Mvc.Rendering;
     using Microsoft.AspNetCore.Mvc.ViewFeatures;
-    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml : global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<dynamic>
+    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml : global::Microsoft.AspNetCore.Mvc.RazorPages.Page
     {
         #pragma warning disable 1998
         public async override global::System.Threading.Tasks.Task ExecuteAsync()
@@ -31,7 +31,9 @@ namespace AspNetCore
         [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<dynamic> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> Html { get; private set; }
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml>)PageContext?.ViewData;
+        public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml Model => ViewData.Model;
     }
 }
 #pragma warning restore 1591

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

@@ -1,6 +1,6 @@
 Document - 
     CSharpCode - 
-        IntermediateToken -  - CSharp - [assembly:global::Microsoft.AspNetCore.Mvc.Razor.Compilation.RazorViewAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml))]
+        IntermediateToken -  - CSharp - [assembly:global::Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.RazorPageAttribute(null, typeof(AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml), null)]
     NamespaceDeclaration -  - AspNetCore
         UsingDirective - (1:0,1 [14] ) - System
         UsingDirective - (16:1,1 [34] ) - System.Collections.Generic
@@ -9,7 +9,7 @@ Document -
         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
-        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml - global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<dynamic> - 
+        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml - global::Microsoft.AspNetCore.Mvc.RazorPages.Page - 
             MethodDeclaration -  - public async override - global::System.Threading.Tasks.Task - ExecuteAsync
                 MalformedDirective - (0:0,0 [6] MalformedPageDirective.cshtml) - page
                 CSharpCode - 
@@ -30,3 +30,7 @@ Document -
             Inject - 
             Inject - 
             Inject - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml> ViewData => (global::Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary<TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml>)PageContext?.ViewData;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - public TestFiles_IntegrationTests_CodeGenerationIntegrationTest_MalformedPageDirective_cshtml Model => ViewData.Model;