The naming convention behind _def and _ctx

[lukaszmakuch]

Hi! 👋

I have a question about the naming convention behind fields such as _def and _ctx.
When I first saw them, I thought they were meant to be private.
But I concluded that they are actually public after reading the documentation and seeing them being used in application code, such as here:

      queryClient.invalidateQueries({
        queryKey: queries.todos.list._def,
        refetchActive: false,
      });

and here

export function useUserLikes(userId: string) {
  return useQuery(users.detail(userId)._ctx.likes);
};

My question is: are _def and _ctx public fields that I can safely use in my code, or are they private fields I shouldn't touch?

Cheers!

[lukemorales]

Hi @lukaszmakuch everything exposed for you through the typesystem is supposed to be used. The only reason they start with _ is to differentiate that these are "internal" properties auto generated by the lib, and not something yourself has declared as an entry key (if you try to create a key starting with _ you will have a runtime error), and also to not create a deny list of common property names you can't use.
These properties serve to give you access to some features like the query definition _def e.g., the fundamental query key to a composable query key (the _def of ['users', { userId: 1 }] is ['users']), or to give you access to contextual queries like shown in the docs.