javascript - NestJS a Express spôsobujú občasné UnhandledPromiseRejectionWarning

Nemôžem za nič na svete na to prísť. Stáva sa to raz za čas, nespôsobuje to žiadne problémy samotnej aplikácii, ale nemám tušenie, čo to spôsobuje. Robím súbežné volania na API z prehliadača, ak to má s tým niečo spoločné.

[Nest] 16608   - 11/7/2018, 1:23:08 PM   [NestApplication] Nest application successfully started
[Nest] 16608   - 11/7/2018, 1:23:23 PM   [LoggerMiddleware] Request /api/observation-statement/pending-count +14943ms
[Nest] 16608   - 11/7/2018, 1:23:23 PM   [LoggerMiddleware] Request /api/observation-statement/revision-count +16ms


(node:14968) UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at ServerResponse.setHeader (_http_outgoing.js:469:11)
at ServerResponse.header (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\express\lib\response.js:767:10)
at ServerResponse.send (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\express\lib\response.js:170:12)
at ServerResponse.json (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\express\lib\response.js:267:15)
at ExpressAdapter.reply (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\@nestjs\core\adapters\express-adapter.js:44:52)
at ExceptionsHandler.catch (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\@nestjs\core\exceptions\base-exception-filter.js:16:33)
at ExceptionsHandler.next (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\@nestjs\core\exceptions\exceptions-handler.js:15:20)
at C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\@nestjs\core\router\router-proxy.js:23:35
at Layer.handle_error (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\express\lib\router\layer.js:71:5)
at trim_prefix (C:\Users\Ricardo Saracino\IdeaProjects\sor-api\node_modules\express\lib\router\index.js:315:13)
(node:14968) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:14968) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Znížil som volania na celkom jednoduchú funkciu a uistil som sa, že volanie vracia jedinečnú hodnotu (myslel som si, že by to mohol byť problém 304)

@Get('revision-count')
async countRevisions(@User() user, @Param() params) {

    user.count ++;

    return {
        status: 'success',
        data: {
            rand: user.count,
        }
    };
}

Toto sa dialo pred middleware.