create type at runtime in a service

[light rivet]

this issue started of as a TS issue but it seems nest made it tougher to solve so gues this can count as a nestjs issue now?
i have this prisma issue have been stuck on for weeks now where i have my prisma/database service (call it what ever you want)
where i extend prisma with a custom findbyId method docs here
but that caused typescript to not regonize this custom method, prisma has a solution for this found here and that is to create a typing at run type (hate it) but then the issue with nest
i cant really create this typing at run time because i cant define it in the class but outside is not going to work either
so when i got another service that uses this databaseService i should be using this extended version but if i cant define it in the class our outside
let alone use it in the constructor of another service what am i supposed to do?

ps: I left out the onModuleInit and enableShutdownHooks out to keep things relative

@Injectable()
export class DatabaseService extends PrismaClient implements OnModuleInit {
  private readonly logger = new Logger(DatabaseService.name)

  constructor() {
    super()
    this.$extends({
      model: {
        $allModels: {
          async findById<T, A>(
            this: T,
            id: Prisma.Exact<A, Prisma.Args<T, 'findUniqueOrThrow'>['where']>,
          ): Promise<Prisma.Result<T, A, 'findUniqueOrThrow'>> {
            const context = Prisma.getExtensionContext(this)
            const result = await (context as any).findUniqueOrThrow({ where: { id } })
            return result
          },
        },
      },
    })
  }
}

so not only am i stuck with a TS issue i also got the nestjs problem where i can not create the typing because i'm working in a class here

[sinful summit]

Don't know how many times I have to give you some of the possible solutions... Also again, I would not recommend this, if you want active record, use an ORM that actually supports it properly.

• Define an interface and use that instead when injecting your prisma client.
  • Use declaration merging. Downside is that if you inject the raw prisma client that you get types for something that doesnt exist.
• Return the extended prisma client from the class and let it infer the type and use it like _service.getClient()

also you could probably do something like this to hack the system:

export class PrismaService extends PrismaClient {
  public constructor() {
    super();
    this.setup();
  }

  public setup() {
    return this.$extends({
      model: {
        user: {
          test() {
            return 0;
          },
        },
      },
    });
  }
}

type ExtendedPrismaClient = ReturnType<PrismaService['setup']>;

const a: ExtendedPrismaClient = new PrismaService();

a.user.test();

[light rivet]

somehow i knew you would reply first
sorry offending you for not seemingly listening to your advice
i tried to ask follow up question and giving extra context you also mentioned you where done with it
as far as i remember?
after giving you a week in time to reply you didn't
and the #1056608823219081266 channel more dead then the flys i killed in my life (that needs to be looked at btw)

and being stuck with this longer then i like to admit i moved my issue to here with the extra context included because i have been stuck not able to do anything else, you could call me desperate at this point

• although i can understand your reasoning switching ORM would bring more issues with it then it would be worth
  besides what else is there other then Prisma and typeOrm?
• i tried decloration merging already and learned those issues my self 😅
• i'm going to need to look at this these 2, at this point my head hurts trying to make sense
  so i'm going to take a little break before i continue on those 2 suggestions

still appreciate the responses you just gave me

[sinful summit]

you could also ditch the extends idea and just pass it some kind of specification

[light rivet]

Fair point

[light rivet]

i have been thinking about a solution like this one
but could't fully wrap my head around it
i was there but not fully yet

i have to thank you for this

either way if i'm going to proceed with the custom method or just dont use it at all
the problem will be solved with either those 2 solutions

gues this answers it then