title: NestJs - ParseUUIDPipe - Validation failed (uuid vundefined is expected)
body: <p>I have a basic controller setup:</p>
  
  <pre><code>@Controller('')
  export class AController {
   @Get(':id')
    async getThing(@Param('id', ParseUUIDPipe) id: string): Promise&lt;RegisterRead[] | IntervalRead[]&gt; {
        return id
    }
  }
  </code></pre>
  
  <p>And I get the following error:</p>
  
  <pre><code>{
      "statusCode": 400,
      "error": "Bad Request",
      "message": "Validation failed (uuid vundefined is expected)"
  }
  </code></pre>
  
  <p>Also see: <a href="https://github.com/nestjs/nest/issues/2960" rel="nofollow noreferrer">https://github.com/nestjs/nest/issues/2960</a></p>