IsUUID Decorator problem.

[karenfnet]

@IsUUID works for Body() in Nest.js but doesn't work for Param() with its DTO, and I have global validation pipe, so everything must be validated to pass to controller, is there any solution?

[sunnypatell]

@karenfnet @Param() receives raw strings from the URL, so class-validator decorators on a DTO may not work the same way as @Body(). for UUID validation on route params, use NestJS's built-in ParseUUIDPipe directly:

@Get(':id')
findOne(@Param('id', new ParseUUIDPipe({ version: '4' })) id: string) {
  return this.service.findOne(id);
}

this validates the param before it reaches the controller and returns a 422 if the UUID is invalid.

if you still want to use a DTO approach for params, make sure your ValidationPipe has transform: true and transformOptions: { enableImplicitConversion: true } so the DTO is properly instantiated from the param string.

but for single-param validation, ParseUUIDPipe is the recommended pattern.

ref: NestJS ParseUUIDPipe docs