Improved type safety for the prisma adapter.

[nnad3N]

Hi,
I just found out about Lucia today and I've already fallen in love with it. I'm currently using the prisma adapter and found that the attributes type in the Auth.createUser() function has Lucia.DatabaseUserAttributes type which causes an issue. Because of that type I have to pass all of the attributes, even if they are not required to create the user in prisma.

Example:

  declare namespace Lucia {
    type Auth = TAuth;
    type DatabaseUserAttributes = Omit<User, "id">;
  }

Right now I'm using this workaround:

  declare namespace Lucia {
    type Auth = TAuth;
    type DatabaseUserAttributes = Pick<
      Prisma.UserCreateInput,
      keyof Omit<User, "id">
    >;
  }

It works fine with my usecase, but I don't know if the Lucia.DatabaseUserAttributes is used somewhere else where making some fields optional would break the type safety, defeating the point of this workaround.

The solution:

It is quite easy to get the correct types thanks to the autogenerated types from prisma:

type UpdateDatabaseUserAttributes = Pick<
  Prisma.UserCreateInput,
  keyof Lucia.DatabaseUserAttributes
>;

I don't know if it's possible to implement an optional generic type for the auth methods that would benefit from the improved type safety or to change the types to work automagically. I'd like to hear if this idea can be implemented and if not - why?

Like I said, I just started using lucia and maybe I just don't understand something obvious.

[pilcrowonpaper]

Lucia doesn't support default and database-generated values right now (compatibility issues stemming from adapters). So columns should be null, not optional, and you'll have to pass the value in runtime.

[yrik]

@pilcrowonpaper Thank you for the answer. Do you have an example what a proper solution would be? Also struggling with prisma and lucia.