@Singleton

One shared instance per decorated class.

Kind	Runtime
Backends	legacy, stage3
Requires generate	No

When to use

• Application-wide services (caches, config holders, stateless facades)
• NestJS services that should not be re-instantiated per injection site when used without Nest's default scope

When not to use

• Request-scoped or per-user state — use prototype scope or Nest request scope
• Types that must be mockable with fresh instances in every unit test (prefer manual DI in tests)

Example

import { Singleton } from 'lombok-typescript/legacy';

@Singleton
export class AppConfig {
  load() {
    return { env: 'production' };
  }
}

const a = new AppConfig();
const b = new AppConfig();
console.assert(a === b);

Works alongside @Injectable() in examples/nestjs.

v0.1 limitations

• Process-wide singleton (not cluster-safe distributed singleton).
• No destroy/teardown hook.