Merge pull request #12976 from CyrusNajmabadi/xmlParamTweaks

Tiny cleanup tweaks to 'remove doc comment node'.

src/Features/Core/Portable/DocumentationComments/CodeFixes/AbstractRemoveDocCommentNodeCodeFixProvider.cs

 // Copyright (c) Microsoft.  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.Collections.Immutable;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
-using System.Collections.Generic;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.DiagnosticComments.CodeFixes
 {
-    internal abstract class AbstractRemoveDocCommentNodeCodeFixProvider<TXMLElement> : CodeFixProvider
+    internal abstract class AbstractRemoveDocCommentNodeCodeFixProvider<TXmlElementSyntax> : CodeFixProvider
+        where TXmlElementSyntax : SyntaxNode
     {
         public override FixAllProvider GetFixAllProvider() => WellKnownFixAllProviders.BatchFixer;
 
         public abstract override ImmutableArray<string> FixableDiagnosticIds { get; }
+
         protected abstract string DocCommentSignifierToken { get; }
 
         protected abstract SyntaxTriviaList GetRevisedDocCommentTrivia(string docCommentText);
@@ -29,31 +31,25 @@ public async sealed override Task RegisterCodeFixesAsync(CodeFixContext context)
             {
                 context.RegisterCodeFix(
                     new MyCodeAction(
-                        c => RemoveDuplicateParamTag(context.Document, context.Span, c)),
+                        c => RemoveDuplicateParamTagAsync(context.Document, context.Span, c)),
                     context.Diagnostics);
             }
-
-            return;
         }
 
-        private SyntaxNode GetParamNode(SyntaxNode root, TextSpan span, CancellationToken cancellationToken = default(CancellationToken))
+        private TXmlElementSyntax GetParamNode(SyntaxNode root, TextSpan span, CancellationToken cancellationToken = default(CancellationToken))
         {
             // First, we get the node the diagnostic fired on
             // Then, we climb the tree to the first parent that is of the type XMLElement
             // This is to correctly handle XML nodes that are nested in other XML nodes, so we only
             // remove the node the diagnostic fired on and its children, but no parent nodes
             var paramNode = root.FindNode(span, findInsideTrivia: true);
-            while (paramNode != null && !(paramNode is TXMLElement))
-            {
-                paramNode = paramNode.Parent;
-            }
-
-            return paramNode is TXMLElement ? paramNode : null;
+            return paramNode.FirstAncestorOrSelf<TXmlElementSyntax>();
         }
 
-        private async Task<Document> RemoveDuplicateParamTag(Document document, TextSpan span, CancellationToken cancellationToken)
+        private async Task<Document> RemoveDuplicateParamTagAsync(
+            Document document, TextSpan span, CancellationToken cancellationToken)
         {
-            var root = await document.GetSyntaxRootAsync().ConfigureAwait(false);
+            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
             var paramNode = GetParamNode(root, span, cancellationToken);
 
             var removedNodes = new List<SyntaxNode> { paramNode };
@@ -80,8 +76,8 @@ private async Task<Document> RemoveDuplicateParamTag(Document document, TextSpan
 
         private class MyCodeAction : CodeAction.DocumentChangeAction
         {
-            public MyCodeAction(Func<CancellationToken, Task<Document>> createChangedDocument) :
-                base(FeaturesResources.Remove_tag, createChangedDocument)
+            public MyCodeAction(Func<CancellationToken, Task<Document>> createChangedDocument)
+                : base(FeaturesResources.Remove_tag, createChangedDocument)
             {
             }
         }