A custom Sitecore JSS rendering contents resolver, which appends results of a GraphQL query defined on a rendering item to LayoutService output. This allows to execute both Rendering Contents Resolver logic and integrated GraphQL query. More information at https://blog.vitaliitylyk.com/combining-integrated-graphql-and-rendering-contents-resolver…

GraphQLCombinedResolver.cs

using Microsoft.Extensions.DependencyInjection;
using Newtonsoft.Json.Linq;
using Sitecore.JavaScriptServices.GraphQL.LayoutService;
using Sitecore.LayoutService.Configuration;
using Sitecore.LayoutService.ItemRendering.ContentsResolvers;
using Sitecore.Mvc.Presentation;
using System;

namespace VitaliiTylyk.JavascriptServices.RenderingContentsResolvers
{
    /// <summary>
    /// Appends results of a GraphQL query defined on a rendering item to LayoutService output.
    /// This allows to execute both Rendering Contents Resolver logic and integrated GraphQL query.
    /// </summary>
    public class GraphQLCombinedResolver : RenderingContentsResolver
    {
        private readonly IServiceProvider serviceProvider;

        public GraphQLCombinedResolver(IServiceProvider serviceProvider)
        {
            this.serviceProvider = serviceProvider;
        }

        public override object ResolveContents(Rendering rendering, IRenderingConfiguration renderingConfig)
        {
            var contents = (JObject)base.ResolveContents(rendering, renderingConfig);

            var query = rendering.RenderingItem.InnerItem[Sitecore.JavaScriptServices.Core.FieldIDs.JsonRendering.GraphQLQuery];
            if (string.IsNullOrWhiteSpace(query))
            {
                return contents;
            }

            var graphqlResolver = ActivatorUtilities.GetServiceOrCreateInstance(serviceProvider, typeof(GraphQLAwareRenderingContentsResolver)) as IRenderingContentsResolver;
            contents["additionalData"] = (JObject)graphqlResolver.ResolveContents(rendering, renderingConfig);

            return contents;
        }
    }
}