Why allow a request to make it past the route matching process and in to the validation middleware when you're using validation pipes in your request decorators?
Instead add pattern matching to the route itself! This will prevent the request from making it further down the stack and executing validation logic straight away.
Did you know that you can use regular expression in your request decorators such as @Get(<path>(<regex pattern>)? This is supported out of the box, no special middleware needed.
Examples
Match the route that is passing a v4 uuid as a parameter
http://matthewdavis.io/befbbc34-8bce-4b31-b0fb-927ff5b2b2a5@Get('/:cameraId([a-f0-9]{8}-?[a-f0-9]{4}-?4[a-f0-9]{3}-?[89ab][a-f0-9]{3}-?[a-f0-9]{12})')
public get(@Param('cameraId') cameraId: string): Promise<Camera> {
//
}