Ambiguity in Roslyn's CompilationUnitSyntax.ReplaceNode

c#, roslyn

Solution

There are two overloads of `ReplaceNode()` (both are extension methods):

public static TRoot ReplaceNode<TRoot, TNode>(
    this TRoot root, TNode oldNode, TNode newNode)
    where TRoot : CommonSyntaxNode where TNode : CommonSyntaxNode;

in `Roslyn.Compilers.CommonSyntaxNodeExtensions`.

public static TRoot ReplaceNode<TRoot>(
    this TRoot root, SyntaxNode node, SyntaxRemoveOptions options, 
    Func<SyntaxNode, SyntaxTriviaList> keepLeadingTrivia = null,
    Func<SyntaxNode, SyntaxTriviaList> keepTrailingTrivia = null)
    where TRoot : SyntaxNode

in `Roslyn.Compilers.CSharp.SyntaxExtensions`.

You want the first one, but the error message talks about the second one, which indicates that you're missing `using Roslyn.Compilers;`.

Problem

I'm trying to replace CompilationUnitSyntax of a class using Roslyn. However, ReplaceNode that I'm using has a different signature than ReplaceNode in Roslyn FAQ and any StackOverflow question that I've looked at. Can anyone point out why is that, and how can I use ReplaceNode that takes old ClassDeclarationSyntax and new ClassDeclarationSyntax as parameters? I'm looking at September CTP FAQ¹, method: ``` [FAQ(26)] public void AddMethodToClass() ``` particularly the following line: ``` CompilationUnitSyntax newCompilationUnit = compilationUnit.ReplaceNode(classDeclaration, newClassDeclaration); ``` When I'm attempting to build this code, I'm getting an error because ReplaceNode expects different arguments: ``` 'Roslyn.Compilers.CSharp.CompilationUnitSyntax' does not contain a definition for 'ReplaceNode' and the best extension method overload 'Roslyn.Compilers.CSharp.SyntaxExtensions.ReplaceNode<TRoot>(TRoot, Roslyn.Compilers.CSharp.SyntaxNode, Roslyn.Compilers.SyntaxRemoveOptions, System.Func<Roslyn.Compilers.CSharp.SyntaxNode,Roslyn.Compilers.CSharp.SyntaxTriviaList>, System.Func<Roslyn.Compilers.CSharp.SyntaxNode,Roslyn.Compilers.CSharp.SyntaxTriviaList>)' ``` ¹ I'm fairly sure I'm using the September CTP: I'm using the FAQ from %userprofile%\Documents\Microsoft Roslyn CTP - September 2012\CSharp\APISampleUnitTestsCS\FAQ.cs NuGet says that my Roslyn package has version 1.2.20906.2

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