Merge pull request #21 from sharwell/fix-17

DocumentNullJsonValue analyzer

Author: sharwell

OpenStackNetAnalyzers/OpenStackNetAnalyzers/DocumentNullJsonValueAnalyzer.cs

@@ -0,0 +1,124 @@
+namespace OpenStackNetAnalyzers
+{
+    using System;
+    using System.Collections.Immutable;
+    using System.Linq;
+    using Microsoft.CodeAnalysis;
+    using Microsoft.CodeAnalysis.CSharp;
+    using Microsoft.CodeAnalysis.CSharp.Syntax;
+    using Microsoft.CodeAnalysis.Diagnostics;
+
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public class DocumentNullJsonValueAnalyzer : DiagnosticAnalyzer
+    {
+        public const string DiagnosticId = "DocumentNullJsonValue";
+        internal const string Title = "Document null JSON value";
+        internal const string MessageFormat = "The <value> documentation for JSON property with type '{0}' should include '<token>{1}</token>'";
+        internal const string Category = "OpenStack.Documentation";
+        internal const string Description = "The <value> documentation for JSON properties should include NullIfNotIncluded or DefaultArrayIfNotIncluded";
+
+        private static DiagnosticDescriptor Descriptor =
+            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, Category, DiagnosticSeverity.Warning, isEnabledByDefault: true, description: Description);
+
+        private static readonly ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics =
+            ImmutableArray.Create(Descriptor);
+
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
+        {
+            get
+            {
+                return _supportedDiagnostics;
+            }
+        }
+
+        public override void Initialize(AnalysisContext context)
+        {
+            context.RegisterSymbolAction(HandleNamedType, SymbolKind.NamedType);
+        }
+
+        private void HandleNamedType(SymbolAnalysisContext context)
+        {
+            INamedTypeSymbol symbol = (INamedTypeSymbol)context.Symbol;
+            if (symbol.TypeKind != TypeKind.Class)
+                return;
+
+            if (!symbol.IsExtensibleJsonObject())
+                return;
+
+            foreach (var propertySymbol in symbol.GetMembers().OfType<IPropertySymbol>())
+            {
+                if (propertySymbol.SetMethod != null)
+                    continue;
+
+                var locations = propertySymbol.Locations;
+                if (locations.IsDefaultOrEmpty)
+                    continue;
+
+                var tree = locations[0].SourceTree;
+                if (tree == null)
+                    continue;
+
+                var root = tree.GetRoot(context.CancellationToken);
+                var node = root.FindNode(locations[0].SourceSpan, getInnermostNodeForTie: true);
+                var propertySyntax = node.FirstAncestorOrSelf<PropertyDeclarationSyntax>();
+                var getter = propertySyntax.AccessorList?.Accessors.FirstOrDefault(i => i.Keyword.IsKind(SyntaxKind.GetKeyword));
+                if (!(getter?.Body?.Statements.Count == 1))
+                    continue;
+
+                ReturnStatementSyntax returnStatement = getter?.Body?.Statements.FirstOrDefault() as ReturnStatementSyntax;
+                ExpressionSyntax returnExpression = returnStatement.Expression;
+                if (returnExpression.IsKind(SyntaxKind.SimpleMemberAccessExpression))
+                {
+                    MemberAccessExpressionSyntax memberAccess = (MemberAccessExpressionSyntax)returnExpression;
+                    if (!memberAccess.Expression.IsKind(SyntaxKind.ThisExpression))
+                        continue;
+                }
+
+                SemanticModel semanticModel = context.Compilation.GetSemanticModel(tree);
+                SymbolInfo symbolInfo = semanticModel.GetSymbolInfo(returnExpression, context.CancellationToken);
+                IFieldSymbol fieldSymbol = symbolInfo.Symbol as IFieldSymbol;
+                if (fieldSymbol.ContainingType != propertySymbol.ContainingType)
+                    continue;
+
+                if (!fieldSymbol.GetAttributes().Any(i => string.Equals("global::Newtonsoft.Json.JsonPropertyAttribute", i.AttributeClass.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat), StringComparison.Ordinal)))
+                    continue;
+
+                DocumentationCommentTriviaSyntax documentationCommentSyntax = propertySyntax.GetDocumentationCommentTriviaSyntax();
+                if (documentationCommentSyntax == null)
+                    continue;
+
+                XmlNodeSyntax valueNode = documentationCommentSyntax.Content.GetFirstXmlElement("value");
+                if (valueNode == null)
+                    continue;
+
+                string defaultValueToken = "NullIfNotIncluded";
+                ITypeSymbol propertyType = propertySymbol.Type;
+                if (propertyType.IsImmutableArray())
+                    defaultValueToken = "DefaultArrayIfNotIncluded";
+
+                XmlElementSyntax valueElementSyntax = valueNode as XmlElementSyntax;
+                if (valueElementSyntax != null)
+                {
+                    bool foundToken = false;
+                    foreach (XmlElementSyntax valueElementChild in valueElementSyntax.Content.OfType<XmlElementSyntax>())
+                    {
+                        if (!string.Equals("token", valueElementChild.StartTag?.Name?.ToString(), StringComparison.Ordinal))
+                            continue;
+
+                        if (!string.Equals(defaultValueToken, valueElementChild.Content.ToFullString()))
+                            continue;
+
+                        foundToken = true;
+                        break;
+                    }
+
+                    if (foundToken)
+                        continue;
+                }
+
+                string propertyTypeName = propertyType.ToMinimalDisplayString(semanticModel, returnExpression.SpanStart, SymbolDisplayFormat.CSharpErrorMessageFormat);
+                context.ReportDiagnostic(Diagnostic.Create(Descriptor, valueNode.GetLocation(), propertyTypeName, defaultValueToken));
+            }
+        }
+    }
+}

OpenStackNetAnalyzers/OpenStackNetAnalyzers/OpenStackNetAnalyzers.csproj

@@ -37,6 +37,7 @@
     <Compile Include="DocumentationSyntaxExtensions.cs" />
     <Compile Include="DocumentDelegatingApiCallAnalyzer.cs" />
     <Compile Include="DocumentDelegatingApiCallCodeFix.cs" />
+    <Compile Include="DocumentNullJsonValueAnalyzer.cs" />
     <Compile Include="DocumentValueFromSummaryAnalyzer.cs" />
     <Compile Include="DocumentValueFromSummaryCodeFix.cs" />
     <Compile Include="ImplementBuilderPatternAnalyzer.cs" />