NestJS - UnhandledPromiseRejectionWarning - nestjs

Question

Short version:
I am looking for a way to way to run my NestJS application with the '--trace-warnings' flags that nodeJS offers. Is there some way to do this or does NestJS offer something similar?
Long version:
Hi! NestJS noob here. I am trying to run a dev version of the NestJS application I am working on. However, on starting the application I get the error below.
Clearly, it is missing a catcherror somewhere! However, the dev version has a LOT of updates and this error can be anywhere so I am hoping for a more efficient way of finding this bug than just checking every single new function! In the errormessage there are a few tips on flags to run while starting the application (node --trace-warnings ...). However, these are for node and not NestJS.
So therefore my question; is there some way to run NestJS with the --trace-warnings flag or some other efficient way to find where I am missing the catcherror?
Thanks in advance!
Error:
(node:72899) UnhandledPromiseRejectionWarning: Error: connect ECONNREFUSED 127.0.0.1:6379
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1146:16)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:72899) 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(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:72899) [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.
(node:72899) UnhandledPromiseRejectionWarning: Error: connect ECONNREFUSED 127.0.0.1:6379
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1146:16)
(node:72899) 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(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)

Answer 1

Well, 6379 is the Redis default port, it seems like Nest cannot connect to it :)
By the way, give a look at this paragraph:
https://docs.nestjs.com/exception-filters#catch-everything
In order to catch every unhandled exception (regardless of the
exception type), leave the #Catch() decorator's parameter list empty,
e.g., #Catch().
import {
ExceptionFilter,
Catch,
ArgumentsHost,
HttpException,
HttpStatus,
} from '#nestjs/common';
#Catch()
export class AllExceptionsFilter implements ExceptionFilter {
catch(exception: unknown, host: ArgumentsHost) {
const ctx = host.switchToHttp();
const response = ctx.getResponse();
const request = ctx.getRequest();
const status =
exception instanceof HttpException
? exception.getStatus()
: HttpStatus.INTERNAL_SERVER_ERROR;
response.status(status).json({
statusCode: status,
timestamp: new Date().toISOString(),
path: request.url,
});
}
}

Answer 2

To answer your specific question:
I am looking for a way to way to run my NestJS application with the '--trace-warnings' flags that nodeJS offers. Is there some way to do this or does NestJS offer something similar?
I've been trying to do the same thing, and there seems to be next-to-no documentation online on how to do this. Through some trial and error, I've found that this seems to work:
node --trace-warnings -r source-map-support/register --inspect dist/main
Note that this won't rebuild your application (neither when you first start it up, or by watching for changes), so you'll need to do that manually. The debugger is enabled via --inspect switch, remove that if you don't need to debug.

Answer 3

try to use a npm response / request logger like winston or moesif you will get a lot of help trust me.
here are the links for these library for nestjs
https://github.com/scalio/nest-couchdb