graphql-yoga/esm/plugins/useUnhandledRoute.js

import landingPageBody from '../landing-page-html.js';
export function useUnhandledRoute(args) {
    return {
        onRequest({ request, fetchAPI, endResponse, url }) {
            const { pathname: requestPath } = url;
            if (requestPath !== args.graphqlEndpoint) {
                if (args.showLandingPage === true &&
                    request.method === 'GET' &&
                    !!request.headers?.get('accept')?.includes('text/html')) {
                    endResponse(new fetchAPI.Response(landingPageBody
                        .replace(/__GRAPHIQL_LINK__/g, args.graphqlEndpoint)
                        .replace(/__REQUEST_PATH__/g, requestPath), {
                        status: 404,
                        statusText: 'Not Found',
                        headers: {
                            'Content-Type': 'text/html',
                        },
                    }));
                    return;
                }
                endResponse(new fetchAPI.Response('', {
                    status: 404,
                    statusText: 'Not Found',
                }));
            }
        },
    };
}