35 lines
1.8 KiB
C#
35 lines
1.8 KiB
C#
// Licensed to the .NET Foundation under one or more agreements.
|
|
// The .NET Foundation licenses this file to you under the MIT license.
|
|
// See the LICENSE file in the project root for more information.
|
|
|
|
using Microsoft.CodeAnalysis;
|
|
|
|
namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
|
|
|
|
/// <summary>
|
|
/// Extension methods for the <see cref="SyntaxNode"/> type.
|
|
/// </summary>
|
|
internal static class SyntaxNodeExtensions
|
|
{
|
|
/// <summary>
|
|
/// Checks whether a given <see cref="SyntaxNode"/> represents the first (partial) declaration of a given symbol.
|
|
/// </summary>
|
|
/// <param name="syntaxNode">The input <see cref="SyntaxNode"/> instance.</param>
|
|
/// <param name="symbol">The target <see cref="ISymbol"/> instance to check the syntax declaration for.</param>
|
|
/// <returns>Whether <paramref name="syntaxNode"/> is the first (partial) declaration for <paramref name="symbol"/>.</returns>
|
|
/// <remarks>
|
|
/// This extension can be used to avoid accidentally generating repeated members for types that have multiple partial declarations.
|
|
/// In order to keep this check efficient and without the need to collect all items and build some sort of hashset from them to
|
|
/// remove duplicates, each syntax node is symply compared against the available declaring syntax references for the target symbol.
|
|
/// If the syntax node matches the first syntax reference for the symbol, it is kept, otherwise it is considered a duplicate.
|
|
/// </remarks>
|
|
public static bool IsFirstSyntaxDeclarationForSymbol(this SyntaxNode syntaxNode, ISymbol symbol)
|
|
{
|
|
return
|
|
symbol.DeclaringSyntaxReferences.Length > 0 &&
|
|
symbol.DeclaringSyntaxReferences[0] is SyntaxReference syntaxReference &&
|
|
syntaxReference.SyntaxTree == syntaxNode.SyntaxTree &&
|
|
syntaxReference.Span == syntaxNode.Span;
|
|
}
|
|
}
|