Is there a way to have Nest use the ExceptionsHandler error message as the API response message when an exception is thrown? - exception

Question

When an error is thrown within my Nest API, often times the error that is thrown is not an HttpException, and therefore the standard Nest API response that I see from the client's side is:
{
"statusCode": 500,
"message": "Internal server error"
}
But when I look at the console log, there is a much more descriptive error message, for example:
[Nest] 18476 - 06/23/2022, 2:28:07 PM ERROR [ExceptionsHandler] Cannot perform update query
because update values are not defined.
UpdateValuesMissingError: Cannot perform update query because update values are not defined.
Is there a way I can route this message to be the in the response body of the response given back to the API client?

Answer 1

You can use Global Filter in NestJs to catch error and then throw a good error.
For exemple, you can create a Exception Filter
// UpdateValuesMissingError.exception-filter.ts
import { ArgumentsHost, Catch, ExceptionFilter } from '#nestjs/common';
import { Request, Response } from 'express';
#Catch(UpdateValuesMissingError)
export class UpdateValuesMissingErrorFilter implements ExceptionFilter {
catch(exception: UpdateValuesMissingError, host: ArgumentsHost) {
const ctx = host.switchToHttp();
const response = ctx.getResponse<Response>();
const request = ctx.getRequest<Request>();
console.log(exception);
response.status(400).json({
statusCode: 400,
timestamp: new Date().toISOString(),
path: request.url,
});
}
}
and in your main.ts add this
app.useGlobalFilters(new HttpExceptionFilter());
And now in response.status(400).json({}) you can add everything you want in your body. Like the error message of Axios.