Fix handling of <include> on fields

Fixes #3150

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/DocumentationRules/SA1608UnitTests.cs

@@ -222,6 +222,35 @@ public class ClassName
             await VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
         }
 
+        [Fact]
+        [WorkItem(3150, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3150")]
+        public async Task TestFieldWithIncludedSummaryDocumentationAsync()
+        {
+            var testCode = @"
+public class ClassName
+{
+    /// <include file='FieldWithSummary.xml' path='/FieldName/*' />
+    public int FieldName;
+}";
+            await VerifyCSharpDiagnosticAsync(testCode, DiagnosticResult.EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+        }
+
+        [Fact]
+        [WorkItem(3150, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3150")]
+        public async Task TestFieldWithIncludedDefaultSummaryDocumentationAsync()
+        {
+            var testCode = @"
+public class ClassName
+{
+    /// <include file='FieldWithDefaultSummary.xml' path='/FieldName/*' />
+    public {|#0:int FieldName|};
+}";
+
+            DiagnosticResult expected = Diagnostic().WithLocation(0);
+
+            await VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
+        }
+
         private static Task VerifyCSharpDiagnosticAsync(string source, DiagnosticResult expected, CancellationToken cancellationToken)
             => VerifyCSharpDiagnosticAsync(source, new[] { expected }, cancellationToken);
 
@@ -244,6 +273,20 @@ private static Task VerifyCSharpDiagnosticAsync(string source, DiagnosticResult[
     Summary description for the ClassName class.
   </summary>
 </ClassName>
+";
+            string fieldContentWithSummary = @"<?xml version=""1.0"" encoding=""utf-8"" ?>
+<FieldName>
+  <summary>
+    Foo
+  </summary>
+</FieldName>
+";
+            string fieldContentWithDefaultSummary = @"<?xml version=""1.0"" encoding=""utf-8"" ?>
+<FieldName>
+  <summary>
+    Summary description for the ClassName class.
+  </summary>
+</FieldName>
 ";
 
             var test = new StyleCopDiagnosticVerifier<SA1608ElementDocumentationMustNotHaveDefaultSummary>.CSharpTest
@@ -254,6 +297,8 @@ private static Task VerifyCSharpDiagnosticAsync(string source, DiagnosticResult[
                     { "ClassWithoutSummary.xml", contentWithoutSummary },
                     { "ClassWithSummary.xml", contentWithSummary },
                     { "ClassWithDefaultSummary.xml", contentWithDefaultSummary },
+                    { "FieldWithSummary.xml", fieldContentWithSummary },
+                    { "FieldWithDefaultSummary.xml", fieldContentWithDefaultSummary },
                 },
             };
 

StyleCop.Analyzers/StyleCop.Analyzers/DocumentationRules/ElementDocumentationBase.cs

@@ -234,29 +234,37 @@ private void HandleDeclaration(SyntaxNodeAnalysisContext context, StyleCopSettin
 
             if (hasIncludedDocumentation)
             {
-                var declaration = context.SemanticModel.GetDeclaredSymbol(node, context.CancellationToken);
-                var rawDocumentation = declaration?.GetDocumentationCommentXml(expandIncludes: true, cancellationToken: context.CancellationToken);
-                var completeDocumentation = XElement.Parse(rawDocumentation, LoadOptions.None);
+                var declaration = node switch
+                {
+                    BaseFieldDeclarationSyntax baseFieldDeclaration => baseFieldDeclaration.Declaration.Variables.FirstOrDefault() ?? node,
+                    _ => node,
+                };
 
-                if (this.inheritDocSuppressesWarnings &&
-                    completeDocumentation.Nodes().OfType<XElement>().Any(element => element.Name == XmlCommentHelper.InheritdocXmlTag))
+                var declaredSymbol = context.SemanticModel.GetDeclaredSymbol(declaration, context.CancellationToken);
+                if (declaredSymbol is not null)
                 {
-                    // Ignore nodes with an <inheritdoc/> tag in the included XML.
+                    var rawDocumentation = declaredSymbol?.GetDocumentationCommentXml(expandIncludes: true, cancellationToken: context.CancellationToken);
+                    var completeDocumentation = XElement.Parse(rawDocumentation ?? "<doc></doc>", LoadOptions.None);
+
+                    if (this.inheritDocSuppressesWarnings &&
+                        completeDocumentation.Nodes().OfType<XElement>().Any(element => element.Name == XmlCommentHelper.InheritdocXmlTag))
+                    {
+                        // Ignore nodes with an <inheritdoc/> tag in the included XML.
+                        return;
+                    }
+
+                    this.HandleCompleteDocumentation(context, needsComment, completeDocumentation, locations);
                     return;
                 }
-
-                this.HandleCompleteDocumentation(context, needsComment, completeDocumentation, locations);
             }
-            else
-            {
-                IEnumerable<XmlNodeSyntax> matchingXmlElements = string.IsNullOrEmpty(this.matchElementName)
-                    ? documentation.Content
-                        .Where(x => x is XmlElementSyntax || x is XmlEmptyElementSyntax)
-                        .Where(x => !string.Equals(x.GetName()?.ToString(), XmlCommentHelper.IncludeXmlTag, StringComparison.Ordinal))
-                    : documentation.Content.GetXmlElements(this.matchElementName);
 
-                this.HandleXmlElement(context, settings, needsComment, matchingXmlElements, locations);
-            }
+            IEnumerable<XmlNodeSyntax> matchingXmlElements = string.IsNullOrEmpty(this.matchElementName)
+                ? documentation.Content
+                    .Where(x => x is XmlElementSyntax || x is XmlEmptyElementSyntax)
+                    .Where(x => !string.Equals(x.GetName()?.ToString(), XmlCommentHelper.IncludeXmlTag, StringComparison.Ordinal))
+                : documentation.Content.GetXmlElements(this.matchElementName);
+
+            this.HandleXmlElement(context, settings, needsComment, matchingXmlElements, locations);
         }
     }
 }