Discussion on: End-to-end Type Safety in Clean Architecture

Thanks Sven. In my solution the source of truth is the domain model and this is pure TypeScript (no TypeGraph there). For example:

export interface Order {
  id: string
  customerName: string
  deliveryAddress: string
  items: Cupcake[]
}

The TypeGraph interfaces are the ones that are derived from the domain modules (note implements):

@ObjectType()
export class Order implements DomainOrder {
  @Field(() => ID)
  id!: string

  @Field()
  customerName!: string

  @Field()
  deliveryAddress!: string

  @Field(() => [Cupcake])
  items!: DomainCupcake[]
}

For me, this makes more sense (i.e. to derive GraphQL types from the domain) because GraphQL is just an interface to the domain. In other words, I prefer "domain first" design :)