Invalid example for NestJS. Looks like response validation is broken.

[Piranit]

Describe the bug
Invalid example for NestJS https://github.com/cdimascio/express-openapi-validator/tree/master/examples/9-nestjs

To Reproduce

1. Clone repository.
2. Install dependencies 'npm ci'
3. Notice that response validation is turned on https://github.com/cdimascio/express-openapi-validator/blob/master/examples/9-nestjs/src/app.module.ts#L22
4. Go to https://github.com/cdimascio/express-openapi-validator/blob/master/examples/9-nestjs/src/modules/ping/ping.controller.ts#L15
5. Change the response to '{ pongInvalid: value }'
6. Start server 'npm run start'
7. Make a GET request to "localhost:3000/ping/123"

Actual behavior
The response "{"pongInvalid":"123"}" returned without error.

Expected behavior
An error with an invalid response structure should be triggered.

Additional info
Also tried on a brand new NestJS version, same result.

System
node -v -> v18.16.0
nest -v -> 10.1.17

[4alexvlasov]

I have faced the same issue
so waiting for resolution too...

[maximerichrd]

Adding a required prop (and optionally, like below, an additionalProperties prop) in the openapi spec :

get:
      operationId: ping
      responses:
        200:
          description: Returns value
          content:
            application/json:
              schema:
                type: object
                properties:
                  pong:
                    type: string
                required:
                  - pong
                additionalProperties: false

then you'll get it work :

$ curl -X GET localhost:3000/ping/a
{"name":"Internal Server Error","status":500,"path":"/ping/a","errors":[{"path":".response.pong","message":"should have required property 'pong'","errorCode":"required.openapi.validation"}]}⏎

So I would say it's not broken : as far as I know, it just follows the openapi standard 🥳

To make it more obvious, maybe the example spec should just be changed by adding these 2 props required and additionalProperties ?