Next.js pages/api/ graphql endpoint

graphql.js

import logger from '../../lib/logger'
import {getSession} from "next-auth/client";
import dynamic from "next/dynamic";


function isTrueStr(str) {
    return str === true ||
        (str != null &&
        str.toString().toLowerCase() === 'true')
}

/**
 * typeof window == 'undefined' doesn't work here, so client HttpLink was enriched by a header boolean field 'ssr'
 * @param req
 * @returns {Promise<{"content-type": string, "infra-token": *}>}
 */

async function prepareHeaders(req) {
    let infraToken = ""
    const ssr = isTrueStr(req.headers['ssr'])
    if (ssr == true) {
        //in SSR, we rely on client.query({context:{headers:{'infra-token':token}}})
        infraToken = req.headers['infra-token']
    } else {
        //in client rendering, we rely on the user that made the request
        const session = await getSession({req})
        infraToken = session?.infraToken
    }
    // logger.debug("api/graphql: {ssr: ", ssr, " Request token:", infraToken)
    let headers = {
        'content-type': 'application/json',
        'infra-token': infraToken,
        ssr
    }
    //On server-side, we must wrap our headers in a node-fetch Header class instance
    if (ssr) {
        const Headers = (await import('node-fetch')).Headers
        headers = new Headers(headers)
    }
    return headers;
}

export default async (_req, _res) => {
    let headers = await prepareHeaders(_req);

    const query = {
        method: 'POST', // *GET, POST, PUT, DELETE, etc.
        mode: 'cors', // no-cors, *cors, same-origin
        cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
        headers,
        redirect: 'follow', // manual, *follow, error
        body: JSON.stringify({
            operationName: _req.body.operationName,
            variables: _req.body.variables,
            query: _req.body.query
        }) // body data type must match "Content-Type" header
    };
    const graphqlBaseUrl = process.env.NEXT_PUBLIC_BACK_END_URL
    const res = await fetch(graphqlBaseUrl + '/api/graphql', query)
    const json = await res.json()
    _res.statusCode = 200;
    _res.setHeader('content-type', 'application/json');
    _res.setHeader('cache-control', 'no-store, max-age=0');
    _res.json(json)
    _res.end()
};