@Factory

Named factory registry — register implementations and resolve by string key.

Kind	Hybrid (runtime registry)
Backends	legacy, stage3
Requires generate	No (optional companions if class has other codegen decorators)

When to use

• Multiple implementations of a concept selected by name ('email', 'sms')
• Lightweight factory pattern without a full DI container

When not to use

• Complex dependency graphs — use NestJS or Inversify
• When TypeScript discriminated unions and a plain switch are clearer

Example

import { Factory, createFromFactory } from 'lombok-typescript/legacy';

@Factory('email')
export class EmailNotifier {
  channel = 'email';
}

@Factory('sms')
export class SmsNotifier {
  channel = 'sms';
}

const email = createFromFactory<{ channel: string }>('email');

Registry helpers: registerFactory, getFactoryRegistry (advanced).

NestJS

See examples/nestjs for @Injectable() + @Factory together.

v0.1 limitations

• String keys are not compile-time checked — typos fail at runtime.
• No lifecycle management (singleton scope per key is manual).