sdk/Sdk.Generators/FunctionMethodSyntaxReceiver.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.

using System.Collections.Generic;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;

namespace Microsoft.Azure.Functions.Worker.Sdk.Generators
{
    public partial class FunctionMetadataProviderGenerator
    {
        /// <summary>
        /// Created on demand before each generation pass
        /// </summary>
        internal class FunctionMethodSyntaxReceiver : ISyntaxReceiver
        {
            public List<MethodDeclarationSyntax> CandidateMethods { get; } = new();

            /// <summary>
            /// Called for every syntax node in the compilation, we can inspect the nodes and save any information useful for generation
            /// </summary>
            public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
            {
                if (syntaxNode is MethodDeclarationSyntax {AttributeLists.Count: > 0} methodSyntax)
                {
                    // collect all methods with attributes - we will verify they are functions when we have access to symbols to get the full name
                    CandidateMethods.Add(methodSyntax);
                }
            }
        }
    }
}