NestJS integration for Unifig.

Utilizes Nest's DI system to manage configurations.

Table of Contents

• Installation
• Quick Start
  • Caveats
• Multiple Configurations
• Scoped Configurations
• License

Installation

npm i @unifig/core @unifig/nest
# or
yarn add @unifig/core @unifig/nest

Quick Start

// main.ts
import { NestFactory } from '@nestjs/core';
import { Config } from '@unifig/core';

async function bootstrap() {
  await Config.register({
    template: AppSettings,
    adapter: () => ({ port: 3000, helloMessage: 'hello world' }),
  });
  const { AppModule } = await import('./app.module');
  const app = await NestFactory.create(AppModule);
  await app.listen(3000);
}
bootstrap();

// app.module.ts
@Module({
  imports: [ConfigModule.forRoot({ default: AppSettings })],
  providers: [AppService],
})
export class AppModule {}

After above setup configs containers are available to be injected by using

// app.service.ts
@Injectable()
export class AppService {
  constructor(@InjectConfig() private config: IConfigContainer<AppSettings>) {}

  sayHello() {
    return this.config.values.helloMessage;
  }
}

Caveats

Configurations need to be loaded before AppModule import in case of using global Config manager instance to configure application outside of Nest's DI.

An example would be task scheduling. Decorator @Cron('45 * * * * *') is being called at the moment of containing file import and needs the config to be already loaded.

Multiple Configurations

// main.ts
...
await Config.register({
  templates: [AppSettings, AuthSettings, FilesStorageSettings],
  adapter: new PlainConfigAdapter({ ... }),
});
...

// app.module.ts
@Module({
  imports: [
    ConfigModule.forRoot({
      templates: [AuthSettings, FilesStorageSettings],
      default: AppSettings,
    }),
  ],
  providers: [AppService],
})
export class AppModule {}

// app.service.ts
@Injectable()
export class AppService {
  constructor(
    private appSettings: AppSettings, // <-- static values loaded only once on app bootstrap
    @InjectConfig() private appSettings: IConfigContainer<AppSettings>,
    @InjectConfig(AuthSettings) private authSettings: IConfigContainer<AnotherAppSettings>,
  ) {}
}

Scoped Configurations

In addition to globally-accessible, configs can be injected with module scope.

// cats.module.ts
@Module({
  imports: [ConfigModule.forFeature(CatsConfig, OtherConfig)],
  providers: [CatsService],
})
export class CatsModule {}

// cats.service.ts
@Injectable()
export class CatsService {
  constructor(@InjectConfig(CatsConfig) private catsConfig: IConfigContainer<CatsConfig>) {}
}

License

This project is licensed under the MIT License - see the LICENSE file for details.