graphql-yoga/esm/plugins/use-request-id.js

import { getRequestId } from '../utils/request-id.js';
export const defaultGenerateRequestId = () => globalThis.crypto.randomUUID();
export const defaultRequestIdHeader = 'x-request-id';
export function getRequestIdHeaderName(opts) {
    return opts?.headerName || defaultRequestIdHeader;
}
/**
 * Reads a request id the host integration already assigned to the native request object it
 * passes through the server context (e.g. Fastify's `request.id`, or an Express/Koa
 * request-id middleware that sets `req.id`), before Yoga ever saw the request.
 *
 * This lets Yoga's own id generation defer to a host's existing correlation id instead of
 * minting an unrelated one of its own, without the host needing to disable `useRequestId` and
 * reimplement the logger scoping it provides.
 */
function getHostRequestId(serverContext) {
    const req = serverContext?.req;
    return typeof req?.id === 'string' && req.id.length > 0 ? req.id : undefined;
}
/**
 * Correlates everything happening while handling a request under a single request id.
 *
 * A request id the host integration already set on the native request object (see
 * {@link getHostRequestId}) is preferred first, so Yoga's logs always agree with the host's own;
 * otherwise, if `trustHeader` is enabled (the default), the `x-request-id` header of the
 * incoming request is used if present and usable (see {@link getRequestId}); otherwise, one is
 * generated. It is then added to the server context's `log`ger as the `requestId` attribute, and
 * set on the outgoing response's headers.
 */
export function useRequestId(opts) {
    const requestIdByRequest = new WeakMap();
    const headerName = getRequestIdHeaderName(opts);
    const trustHeader = opts?.trustHeader ?? true;
    const generateRequestId = opts?.generateRequestId || defaultGenerateRequestId;
    return {
        onRequest({ request, fetchAPI, serverContext }) {
            const generate = () => generateRequestId({
                request,
                fetchAPI,
                context: serverContext,
            });
            let requestId = getHostRequestId(serverContext);
            requestId ??= trustHeader
                ? getRequestId(request.headers.get(headerName), generate)
                : generate();
            requestIdByRequest.set(request, requestId);
            // `useConfigInServerContext` runs before this plugin and puts the logger in the server
            // context. It can still be missing when this plugin is used on its own, in which case the
            // request id is only propagated through the headers.
            serverContext.log &&= serverContext.log.child({ requestId });
        },
        onResponse({ request, response }) {
            const requestId = requestIdByRequest.get(request);
            if (requestId) {
                response.headers.set(headerName, requestId);
            }
        },
    };
}