Add support for Vue composables unused properties detection

[maiolica]

A Vue composable is a function usually structured this way:

const useUserRole = (user: User) => {
  const isAdmin = computed(() => user.role === UsersRole.ADMIN);
  const isRegularUser = computed(() => user.role === UsersRole.REGULAR);

  return {
    isAdmin,
    isRegularUser,
  };
};

If isRegularUser is never exported in another file, ex.

const { isAdmin } = useUserRole();

could Knip detect it?

[webpro]

Knip currently can't detect it. Not members of exported objects, let alone those in return values.

A kind of similar request was unused props in React components.

Such features may one day be offered through custom "visitors" that may allow to implement what you need here (either optionally enabled in core or through external add-ons), but it's all very premature.