Modelling Layers in Effect Veterans: Challenges and Patterns

declare const make: (config: DatabaseConfig) => Effect.Effect<Scope, never, Database>

// returns: Layer.Layer<never, ConfigError, Database>
export const makeLayer = (config: Config.Config.Wrap<DatabaseConfig>) =>
  Layer.scoped(
    Database,
    Effect.flatMap(Effect.config(Config.unwrap(config)), make),
  )

declare const make: Effect.Effect<Database, never, OrderRepo>

// type: Layer.Layer<Database, never, OrderRepo>
export const layer = Layer.effect(OrderRepo, make)

declare const make: (config: FulfillmentServiceConfig) => Effect.Effect<OrderRepo | ProductRepo | CustomerRepo, never, FulfillmentService>

// returns: Layer.Layer<OrderRepo | ProductRepo | CustomerRepo, ConfigError, FulfillmentService>
export const makeLayer = (config: Config.Config.Wrap<FulfillmentServiceConfig>) =>
  Layer.effect(
    FulfillmentService,
    Effect.flatMap(Effect.config(Config.unwrap(config)), make),
  )