Simple example app.js

App.js

const graphqlSettingsPerReq = async req => {
    const { user } = await getUser(req.header.authorization);
    
    return {
        graphiql: process.env.NODE_ENV !== 'production',
        schema,
        context: {
            user,
            req,
            dataloaders,
        },
        formatError: error => {
            console.log(error.message);
            console.log(error.locations);
            console.log(error.stack);

            return {
                message: error.message,
                locations: error.locations,
                stack: error.stack,
            };
        },
    }
}

// Iniciamos um no server GraphQL
const graphqlServer = GraphQLHTTP(graphqlSettingsPerReq)