Simplify ancestor checks (#79513)

Author: CyrusNajmabadi

src/Analyzers/Core/CodeFixes/AddExplicitCast/AbstractAddExplicitCastCodeFixProvider.cs

@@ -73,8 +73,7 @@ public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
         var root = await document.GetRequiredSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
         var semanticModel = await document.GetRequiredSemanticModelAsync(cancellationToken).ConfigureAwait(false);
 
-        var spanNode = root.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true)
-            .GetAncestorsOrThis<TExpressionSyntax>().FirstOrDefault();
+        var spanNode = root.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true).GetAncestorOrThis<TExpressionSyntax>();
         if (spanNode == null)
             return;
 

src/Analyzers/VisualBasic/CodeFixes/AddExplicitCast/VisualBasicAddExplicitCastCodeFixProvider.vb

@@ -64,7 +64,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddExplicitCast
 
             Select Case diagnosticId
                 Case BC30512, BC42016
-                    Dim argument = spanNode.GetAncestors(Of ArgumentSyntax).FirstOrDefault()
+                    Dim argument = spanNode.GetAncestor(Of ArgumentSyntax)
                     If argument IsNot Nothing AndAlso argument.GetExpression.Equals(spanNode) Then
                         ' spanNode is an argument expression
                         Dim argumentList = DirectCast(argument.Parent, ArgumentListSyntax)

src/Workspaces/CSharp/Portable/Rename/CSharpRenameRewriterLanguageService.cs

@@ -1117,59 +1117,40 @@ public override void TryAddPossibleNameConflicts(ISymbol symbol, string replacem
     private static SyntaxNode? GetExpansionTarget(SyntaxToken token)
     {
         // get the directly enclosing statement
-        var enclosingStatement = token.GetAncestors(n => n is StatementSyntax).FirstOrDefault();
+        var enclosingStatement = token.GetAncestor<StatementSyntax>();
 
         // System.Func<int, int> myFunc = arg => X;
         var possibleLambdaExpression = enclosingStatement == null
-            ? token.GetAncestors(n => n is SimpleLambdaExpressionSyntax or ParenthesizedLambdaExpressionSyntax).FirstOrDefault()
+            ? token.GetAncestor<LambdaExpressionSyntax>()
             : null;
-        if (possibleLambdaExpression != null)
-        {
-            var lambdaExpression = ((LambdaExpressionSyntax)possibleLambdaExpression);
-            if (lambdaExpression.Body is ExpressionSyntax)
-            {
-                return lambdaExpression.Body;
-            }
-        }
+        if (possibleLambdaExpression?.ExpressionBody is not null)
+            return possibleLambdaExpression.ExpressionBody;
 
         // int M() => X;
         var possibleArrowExpressionClause = enclosingStatement == null
-            ? token.GetAncestors<ArrowExpressionClauseSyntax>().FirstOrDefault()
+            ? token.GetAncestor<ArrowExpressionClauseSyntax>()
             : null;
         if (possibleArrowExpressionClause != null)
-        {
             return possibleArrowExpressionClause.Expression;
-        }
 
         var enclosingNameMemberCrefOrnull = token.GetAncestors(n => n is NameMemberCrefSyntax).LastOrDefault();
-        if (enclosingNameMemberCrefOrnull != null)
-        {
-            if (token.Parent is TypeSyntax && token.Parent.Parent is TypeSyntax)
-            {
-                enclosingNameMemberCrefOrnull = null;
-            }
-        }
+        if (enclosingNameMemberCrefOrnull != null && token.Parent is TypeSyntax && token.Parent.Parent is TypeSyntax)
+            enclosingNameMemberCrefOrnull = null;
 
-        var enclosingXmlNameAttr = token.GetAncestors(n => n is XmlNameAttributeSyntax).FirstOrDefault();
+        var enclosingXmlNameAttr = token.GetAncestor<XmlNameAttributeSyntax>();
         if (enclosingXmlNameAttr != null)
-        {
             return null;
-        }
 
-        var enclosingInitializer = token.GetAncestors<EqualsValueClauseSyntax>().FirstOrDefault();
+        var enclosingInitializer = token.GetAncestor<EqualsValueClauseSyntax>();
         if (enclosingStatement == null && enclosingInitializer != null && enclosingInitializer.Parent is VariableDeclaratorSyntax)
-        {
             return enclosingInitializer.Value;
-        }
 
         var attributeSyntax = token.GetAncestor<AttributeSyntax>();
         if (attributeSyntax != null)
-        {
             return attributeSyntax;
-        }
 
         // there seems to be no statement above this one. Let's see if we can at least get an SimpleNameSyntax
-        return enclosingStatement ?? enclosingNameMemberCrefOrnull ?? token.GetAncestors(n => n is SimpleNameSyntax).FirstOrDefault();
+        return enclosingStatement ?? enclosingNameMemberCrefOrnull ?? token.GetAncestor<SimpleNameSyntax>();
     }
 
     #region "Helper Methods"

src/Workspaces/CSharp/Portable/Simplification/Reducers/CSharpEscapingReducer.cs

@@ -37,7 +37,7 @@ private static SyntaxToken SimplifyIdentifierToken(
     {
         var unescapedIdentifier = token.ValueText;
 
-        var enclosingXmlNameAttr = token.GetAncestors(n => n is XmlNameAttributeSyntax).FirstOrDefault();
+        var enclosingXmlNameAttr = token.GetAncestor<XmlNameAttributeSyntax>();
 
         // always escape keywords
         if (SyntaxFacts.GetKeywordKind(unescapedIdentifier) != SyntaxKind.None && enclosingXmlNameAttr == null)
@@ -52,32 +52,13 @@ private static SyntaxToken SimplifyIdentifierToken(
 
         if (SyntaxFacts.GetContextualKeywordKind(unescapedIdentifier) == SyntaxKind.AwaitKeyword)
         {
-            var enclosingLambdaExpression = parent.GetAncestorsOrThis(n => (n is SimpleLambdaExpressionSyntax or ParenthesizedLambdaExpressionSyntax)).FirstOrDefault();
-            if (enclosingLambdaExpression != null)
-            {
-                if (enclosingLambdaExpression is SimpleLambdaExpressionSyntax simpleLambda)
-                {
-                    if (simpleLambda.AsyncKeyword.Kind() == SyntaxKind.AsyncKeyword)
-                    {
-                        return token;
-                    }
-                }
-
-                if (enclosingLambdaExpression is ParenthesizedLambdaExpressionSyntax parenLamdba)
-                {
-                    if (parenLamdba.AsyncKeyword.Kind() == SyntaxKind.AsyncKeyword)
-                    {
-                        return token;
-                    }
-                }
-            }
-
-            var enclosingMethodBlock = parent.GetAncestorsOrThis(n => n is MethodDeclarationSyntax).FirstOrDefault();
+            var enclosingLambdaExpression = parent.GetAncestorOrThis<LambdaExpressionSyntax>();
+            if (enclosingLambdaExpression != null && enclosingLambdaExpression.AsyncKeyword != default)
+                return token;
 
-            if (enclosingMethodBlock != null && ((MethodDeclarationSyntax)enclosingMethodBlock).Modifiers.Any(SyntaxKind.AsyncKeyword))
-            {
+            var enclosingMethodBlock = parent.GetAncestorOrThis<MethodDeclarationSyntax>();
+            if (enclosingMethodBlock != null && enclosingMethodBlock.Modifiers.Any(SyntaxKind.AsyncKeyword))
                 return token;
-            }
         }
 
         // within a query all contextual query keywords need to be escaped, even if they appear in a non query context.

src/Workspaces/SharedUtilitiesAndExtensions/Workspace/CSharp/CodeGeneration/CSharpCodeGenerationService.cs

@@ -537,7 +537,7 @@ private static TDeclarationNode AddStatementsWorker<TDeclarationNode>(
 
         var token = location.FindToken(cancellationToken);
 
-        var block = token.Parent.GetAncestorsOrThis<BlockSyntax>().FirstOrDefault();
+        var block = token.Parent.GetAncestorOrThis<BlockSyntax>();
         if (block != null)
         {
             var blockStatements = block.Statements.ToSet();

src/Workspaces/VisualBasic/Portable/Simplification/Reducers/VisualBasicEscapingReducer.vb

@@ -123,7 +123,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Simplification
             ' escape contextual query keywords if they are the first token after a query expression 
             ' and on the following line
             Dim previousToken = identifier.GetPreviousToken(False, False, True, True)
-            Dim queryAncestorOfPrevious = previousToken.GetAncestors(Of QueryExpressionSyntax).FirstOrDefault()
+            Dim queryAncestorOfPrevious = previousToken.GetAncestor(Of QueryExpressionSyntax)
             If queryAncestorOfPrevious IsNot Nothing AndAlso queryAncestorOfPrevious.GetLastToken() = previousToken Then
                 lastTokenOfQuery = previousToken
 
@@ -162,7 +162,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Simplification
                     ' if this token is part of a XmlDocument, all trailing whitespace is part of the XmlDocument
                     ' so all line breaks actually will not help.
                     ' see VB spec #11.23.3
-                    If previousToken.GetAncestors(Of XmlDocumentSyntax).FirstOrDefault() IsNot Nothing Then
+                    If previousToken.GetAncestor(Of XmlDocumentSyntax) IsNot Nothing Then
                         Return identifier
                     End If