Add a new analyzer + baseline for existing instances

src/Analyzers/Razor.Diagnostics.Analyzers/DiagnosticCategory.cs

@@ -6,4 +6,6 @@ namespace Razor.Diagnostics.Analyzers;
 internal static class DiagnosticCategory
 {
     public const string Reliability = nameof(Reliability);
+
+    public const string Usage = nameof(Usage);
 }

src/Analyzers/Razor.Diagnostics.Analyzers/DiagnosticIds.cs

@@ -8,4 +8,6 @@ internal static class DiagnosticIds
     public const string PooledArrayBuilderAsRef = "RZD001";
 
     public const string IRemoteJsonServiceParameter = "RZD002";
+
+    public const string RawIntermediateTokenCreation = "RZD003";
 }

src/Analyzers/Razor.Diagnostics.Analyzers/GlobalSuppressions.cs

@@ -10,3 +10,4 @@
 
 [assembly: SuppressMessage("MicrosoftCodeAnalysisReleaseTracking", "RS2008:Enable analyzer release tracking", Justification = "<Pending>", Scope = "member", Target = "~F:Razor.Diagnostics.Analyzers.PooledArrayBuilderAsRefAnalyzer.Rule")]
 [assembly: SuppressMessage("MicrosoftCodeAnalysisReleaseTracking", "RS2008:Enable analyzer release tracking", Justification = "<Pending>", Scope = "member", Target = "~F:Razor.Diagnostics.Analyzers.IRemoteJsonServiceParameterAnalyzer.Rule")]
+[assembly: SuppressMessage("MicrosoftCodeAnalysisReleaseTracking", "RS2008:Enable analyzer release tracking", Justification = "<Pending>", Scope = "member", Target = "~F:Razor.Diagnostics.Analyzers.IntermediateTokenAnalyzer.Rule")]

src/Analyzers/Razor.Diagnostics.Analyzers/IntermediateTokenAnalyzer.cs

@@ -0,0 +1,127 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+
+namespace Razor.Diagnostics.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public class IntermediateTokenAnalyzer : DiagnosticAnalyzer
+{
+    private const string Title = "IntermediateToken with Kind CSharp";
+    private const string MessageFormat = "Avoid directly creating an IntermediateToken with Kind 'CSharp'. Instead, lower to an appropriate intermediate node and emit the C# in the output writer.";
+    private const string BaselineFileName = "IntermediateTokenBaseline.txt";
+
+    internal static readonly DiagnosticDescriptor Rule = new(
+        DiagnosticIds.RawIntermediateTokenCreation,
+        Title,
+        MessageFormat,
+        DiagnosticCategory.Usage,
+        DiagnosticSeverity.Warning,
+        isEnabledByDefault: true,
+        helpLinkUri: "https://github.com/dotnet/razor/issues/11858");
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [Rule];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.EnableConcurrentExecution();
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);
+
+        context.RegisterOperationAction(AnalyzeObjectCreation, OperationKind.ObjectCreation);
+        context.RegisterOperationAction(AnalyzeMethodInvocation, OperationKind.Invocation);
+    }
+
+    private void AnalyzeObjectCreation(OperationAnalysisContext context)
+    {
+        var objectCreation = (IObjectCreationOperation)context.Operation;
+
+        // Check if the type is IntermediateToken
+        if (objectCreation.Type?.Name != "IntermediateToken")
+        {
+            return;
+        }
+
+        // Resolve the TokenKind.CSharp enum value
+        var tokenKindType = context.Compilation.GetTypeByMetadataName("Microsoft.AspNetCore.Razor.Language.Intermediate.TokenKind");
+        if (tokenKindType == null)
+        {
+            return; // TokenKind enum not found
+        }
+
+        var csharpEnumMember = tokenKindType.GetMembers("CSharp").FirstOrDefault() as IFieldSymbol;
+        if (csharpEnumMember == null)
+        {
+            return; // TokenKind.CSharp enum member not found
+        }
+
+        // Check if the Kind property is set to TokenKind.CSharp via an initializer
+        var kindInitializer = objectCreation.Initializer?.Initializers
+            .OfType<ISimpleAssignmentOperation>()
+            .FirstOrDefault(init =>
+                init.Target is IPropertyReferenceOperation property &&
+                property.Property.Name == "Kind" &&
+                init.Value.ConstantValue.HasValue &&
+                init.Value.ConstantValue.Value == csharpEnumMember.ConstantValue);
+
+        // If the initializer doesnt set Kind to TokenKind.CSharp, return
+        if (kindInitializer == null)
+        {
+            return;
+        }
+
+        // Report the diagnostic if not suppressed
+        ReportIfNotSuppressed(context, objectCreation.Syntax.GetLocation());
+    }
+
+    private void AnalyzeMethodInvocation(OperationAnalysisContext context)
+    {
+        var invocation = (IInvocationOperation)context.Operation;
+
+        // Check if the method is IntermediateToken.CreateCSharpToken
+        if (invocation.TargetMethod.Name != "CreateCSharpToken" ||
+            invocation.TargetMethod.ContainingType.Name != "IntermediateToken")
+        {
+            return;
+        }
+
+        ReportIfNotSuppressed(context, invocation.Syntax.GetLocation());
+    }
+
+    private void ReportIfNotSuppressed(OperationAnalysisContext context, Location location)
+    {
+        // If we're a test project, ignore.
+        if (context.Compilation.AssemblyName?.Contains(".Test") == true)
+        {
+            return;
+        }
+
+        // Check if the warning is suppressed in the baseline file
+        // Note: code for regenerating the baseline from scratch can be found here: https://gist.github.com/chsienki/d06b2a3ee583191cacf80da79f6fc540
+        var additionalFiles = context.Options.AdditionalFiles;
+        var baselineFile = additionalFiles.FirstOrDefault(file => Path.GetFileName(file.Path) == BaselineFileName);
+        if (baselineFile != null)
+        {
+            var baselineDirectory = Path.GetDirectoryName(baselineFile.Path);
+            var locationFilePath = location.SourceTree?.FilePath;
+
+            var relativePath = locationFilePath?.Substring(baselineDirectory?.Length + 1 ?? 0).Replace("\\", "/");
+            var linePosition = location.GetLineSpan().StartLinePosition;
+            var locationString = $"{relativePath}:{linePosition.Line + 1}:{linePosition.Character + 1}";
+
+            var baselineContent = baselineFile.GetText(context.CancellationToken)?.ToString();
+            if (baselineContent != null && baselineContent.Contains(locationString))
+            {
+                return;
+            }
+        }
+
+        // Report the diagnostic
+        context.ReportDiagnostic(Diagnostic.Create(Rule, location));
+    }
+}

src/Analyzers/Razor.Diagnostics.Analyzers/Properties/launchSettings.json

@@ -0,0 +1,11 @@
+{
+  "profiles": {
+    "Razor.Diagnostics.Analyzers": {
+      "commandName": "Project"
+    },
+    "Run on Razor.Compiler": {
+      "commandName": "DebugRoslynComponent",
+      "targetProject": "..\\..\\Compiler\\Microsoft.CodeAnalysis.Razor.Compiler\\src\\Microsoft.CodeAnalysis.Razor.Compiler.csproj"
+    }
+  }
+}

src/Analyzers/Razor.Diagnostics.Analyzers/Razor.Diagnostics.Analyzers.csproj

@@ -6,6 +6,7 @@
     <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
     <ExcludeFromSourceOnlyBuild>false</ExcludeFromSourceOnlyBuild>
     <IsShippingPackage>false</IsShippingPackage>
+    <IsRoslynComponent>true</IsRoslynComponent>
   </PropertyGroup>
 
   <ItemGroup>

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/IntermediateTokenBaseline.txt

@@ -0,0 +1,82 @@
+Mvc/PagesPropertyInjectionPass.cs:32:34
+Mvc/PagesPropertyInjectionPass.cs:40:36
+Language/Intermediate/IntermediateToken.cs:22:103
+Language/Components/ComponentBindLoweringPass.cs:404:22
+Language/Components/ComponentBindLoweringPass.cs:421:23
+Language/Components/ComponentBindLoweringPass.cs:591:57
+Language/Components/ComponentBindLoweringPass.cs:812:40
+Language/Components/ComponentBindLoweringPass.cs:835:40
+Language/Components/ComponentBindLoweringPass.cs:841:40
+Language/Components/ComponentBindLoweringPass.cs:850:40
+Language/Components/ComponentBindLoweringPass.cs:871:36
+Language/Components/ComponentBindLoweringPass.cs:880:40
+Language/Components/ComponentBindLoweringPass.cs:895:40
+Language/Components/ComponentBindLoweringPass.cs:901:40
+Language/Components/ComponentBindLoweringPass.cs:910:40
+Language/Components/ComponentBindLoweringPass.cs:916:40
+Language/Components/ComponentBindLoweringPass.cs:922:40
+Language/Components/ComponentBindLoweringPass.cs:929:36
+Language/Components/ComponentBindLoweringPass.cs:951:35
+Language/Components/ComponentBindLoweringPass.cs:960:39
+Language/Components/ComponentBindLoweringPass.cs:970:39
+Language/Components/ComponentBindLoweringPass.cs:978:35
+Language/Components/ComponentBindLoweringPass.cs:1001:36
+Language/Components/ComponentBindLoweringPass.cs:1010:40
+Language/Components/ComponentBindLoweringPass.cs:1019:40
+Language/Components/ComponentBindLoweringPass.cs:1025:40
+Language/Components/ComponentBindLoweringPass.cs:1034:40
+Language/Components/ComponentBindLoweringPass.cs:1040:40
+Language/Components/ComponentBindLoweringPass.cs:1049:40
+Language/Components/ComponentBindLoweringPass.cs:1055:40
+Language/Components/ComponentBindLoweringPass.cs:1061:40
+Language/Components/ComponentBindLoweringPass.cs:1068:36
+Language/Components/ComponentBindLoweringPass.cs:1074:36
+Language/Components/ComponentBindLoweringPass.cs:1082:40
+Language/Components/ComponentBindLoweringPass.cs:1091:40
+Language/Components/ComponentBindLoweringPass.cs:1098:36
+Language/Components/ComponentBindLoweringPass.cs:1113:20
+Language/Components/ComponentBindLoweringPass.cs:1121:20
+Language/Components/ComponentBindLoweringPass.cs:1143:20
+Mvc/ModelDirective.cs:61:24
+Mvc/ModelDirective.cs:67:20
+Mvc/ModelDirective.cs:71:20
+Language/Extensions/AttributeDirectivePass.cs:33:35
+Language/Components/ComponentLayoutDirectivePass.cs:37:13
+Language/Components/ComponentLayoutDirectivePass.cs:38:13
+Language/Components/ComponentLayoutDirectivePass.cs:39:13
+Language/Components/ComponentEventHandlerLoweringPass.cs:181:13
+Language/Components/ComponentEventHandlerLoweringPass.cs:193:13
+Language/Components/ComponentEventHandlerLoweringPass.cs:263:28
+Language/Components/ComponentEventHandlerLoweringPass.cs:273:28
+Language/Extensions/DesignTimeDirectivePass.cs:42:25
+Language/Extensions/DesignTimeDirectivePass.cs:53:25
+Language/Extensions/DesignTimeDirectivePass.cs:64:25
+Language/Components/ComponentRenderModeDirectivePass.cs:51:17
+Language/Components/ComponentRenderModeDirectivePass.cs:63:28
+Language/Components/ComponentRenderModeDirectivePass.cs:70:17
+Language/Components/ComponentRenderModeDirectivePass.cs:81:17
+Language/Components/ComponentRenderModeDirectivePass.cs:93:36
+Mvc/ModelExpressionPass.cs:43:41
+Mvc/ModelExpressionPass.cs:53:45
+Mvc/ModelExpressionPass.cs:81:41
+Language/Components/ComponentRuntimeNodeWriter.cs:1048:25
+Language/Components/ComponentRuntimeNodeWriter.cs:1066:17
+Language/Components/ComponentRuntimeNodeWriter.cs:1076:17
+Mvc.Version2_X/PagesPropertyInjectionPass.cs:28:34
+Mvc.Version2_X/PagesPropertyInjectionPass.cs:36:36
+Mvc.Version2_X/AssemblyAttributeInjectionPass.cs:70:36
+Language/Extensions/EliminateMethodBodyPass.cs:47:21
+Language/Extensions/EliminateMethodBodyPass.cs:54:21
+Language/Extensions/EliminateMethodBodyPass.cs:61:21
+Language/Intermediate/BaseTypeWithModel.cs:14:24
+Language/Intermediate/BaseTypeWithModel.cs:15:27
+Language/Intermediate/BaseTypeWithModel.cs:16:25
+Language/Intermediate/BaseTypeWithModel.cs:17:24
+Language/Intermediate/BaseTypeWithModel.cs:30:24
+Mvc.Version2_X/InstrumentationPass.cs:42:32
+Mvc.Version2_X/InstrumentationPass.cs:55:30
+Language/Extensions/ImplementsDirectivePass.cs:26:39
+Language/Components/ComponentDesignTimeNodeWriter.cs:1181:25
+Language/Components/ComponentDesignTimeNodeWriter.cs:1205:29
+Language/Components/ComponentDesignTimeNodeWriter.cs:1224:17
+Language/Components/ComponentDesignTimeNodeWriter.cs:1234:17

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Microsoft.CodeAnalysis.Razor.Compiler.csproj

@@ -15,6 +15,10 @@
     <NoWarn>$(NoWarn);RS2008;RS1036</NoWarn>
   </PropertyGroup>
 
+  <ItemGroup>
+    <AdditionalFiles Include="IntermediateTokenBaseline.txt" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="$(SharedSourceRoot)\Microsoft.AspNetCore.Razor.Utilities.Shared\Microsoft.AspNetCore.Razor.Utilities.Shared.csproj" />
   </ItemGroup>