aidd-service

Service authoring

Asynchronous data services. Live in the services/ layer per structure. Adhere to namespace for type and function organization.

Data = readonly JSON values or Blobs.

---

Front-end vs back-end services

FrontEndService {
  allowed: ["Observe<Data>", "other services (sub-Services)", "void-returning action functions"]
  notAllowed: ["Promise or AsyncGenerator return"]
}

BackEndService {
  typicallyReturns: "Promise<Data> | AsyncGenerator<Data>"
  notCalledFrom: "UI"
  calledBy: "front-end services"
}

Constraints {
  UI components: unidirectional path — data down via void actions, data up via Observe
}

Back-end services — usually stateless. Functions typically return Promise<Data> or AsyncGenerator<Data>. Not called directly from UI; front-end services call them.

---

Front-end service constraints

ServiceInterfaceForUI {
  mayContain: [
    "Observe<Data> — observable properties or factories",
    "Sub-Services — nested service interfaces",
    "Action functions — zero or more Data arguments, return void only",
    "Factory functions — create observables or sub-Services"
  ]
  observablesMayObserve: ["Data", "Service interfaces only"]
  compileTimeCheck: "Assert<AsyncDataService.IsValid<ServiceInterface>>"
}

Benefits

• Unidirectional flow — data down via actions, data up via Observe
• Async isolation — view and service decoupled
• Inspectability — action/observable data serializable
• Portability — implementation swappable across process boundaries
• Lazy Loading - can use AsyncDataService.createLazy to wrap with lazy load on first actual usage.

---

Folder structure

ServicePaths {
  "services/<name>-service/<name>-service.ts" = "Service interface only"
  "services/<name>-service/<function-name>.ts" = "One file per function; re-export from public"
  "services/<name>-service/<implementation>-<name>-service.ts" = "Implementation factory"
  "services/<name>-service/<implementation>-<name>-service/" = "Implementation folder if multi-file"
}

Constraints {
  Each function lives in its own file — not a single -service-functions.ts
  Interface file: types and optionally JSON schemas only; no implementation-specific code
  Implementation: factory function or static plain object only; no classes
  Namespace: export * as ServiceName from public.js or from functions/index.js
}