How would look like a prisma-mapper.base.ts ?

[balibou]

Thanks a lot for this repo !

I would like to know how it would be possible to use a mapper with Prisma (like orm-mapper.base.ts).
As far as I understand, it sounds that it's not meant for creating model inside a class, but only inside a schema.prisma file

Thanks for any help !

[Sairyss]

Prisma generates typescript types/interfaces for you: https://www.prisma.io/docs/concepts/components/prisma-client/advanced-type-safety
In a mapper you will just need to map your domain entity to match that type so you can save it into a db

[balibou]

Ah great ! thanks for your explanation and the link provided !

[balibou]

@Sairyss is there any chance you can provide an example of repository for using prisma typescript types/interfaces with mapper ? (for both methods toDomainEntity and toOrmEntity)

I'm totally stuck on the implementation of the classes

[Sairyss]

I don't use Prisma, but according to their docs it generates TS types based on your schemas and exports them from @prisma/client/index.d.ts https://www.prisma.io/docs/concepts/components/prisma-schema/data-model#type-definitions.

The mapper would look something like this:

// user type exported from prisma, not sure if the "from" is correct but it should be somewhere in your project
import { User as PrismaUser } from "@prisma/client"; 

export class UserOrmMapper extends OrmMapper<UserEntity, PrismaUser> {
  protected toOrmProps(entity: UserEntity): PrismaUser {
    const props = entity.getPropsCopy();

    const prismaUser: PrismaUser = {
      email: props.email.value,
      role: props.role,
    };
    return prismaUser;
  }

  protected toDomainProps(prismaUser: PrismaUser): EntityProps<UserProps> {
    const id = new UUID(prismaUser.id);
    const props: UserProps = {
      email: new Email(prismaUser.email),
      role: prismaUser.role,
    };
    return { id, props };
  }
}

Repository can look something like this:

export class UserRepository {
  protected constructor(
    protected readonly mapper: OrmMapper<UserEntity, PrismaUser>,
  ) {}

   private readonly prisma = new PrismaClient();

    async save(entity: UserEntity): Promise<UserEntity> {
        entity.validate(); // Protecting invariant before saving
        const ormEntity = this.mapper.toOrmEntity(entity);
        const user = await this.prisma.user.create({ data: ormEntity })

        return this.mapper.toDomainEntity(user);
  }
}

You might need to modify base classes slightly to support prisma instead of typeorm, but the general principles are the same

[balibou]

Thanks @Sairyss I'm gonna try this :)

[balibou]

Everything working like a charm, thanks @Sairyss !