@nl-framework/config

Configuration utilities for the NL Framework. This package wraps the core ConfigLoader and ConfigService with a module-first API so you can expose configuration values through dependency injection.

Installation

bun add @nl-framework/config

Quick start

Register the module at the root of your application. By default it loads YAML files from the config directory (default.yaml, <env>.yaml, then env.yaml):

import { Module } from '@nl-framework/core';
import { ConfigModule, ConfigService } from '@nl-framework/config';

@Module({
  imports: [
    ConfigModule.forRoot({
      dir: 'config',
      path: 'env.yaml',
      overrides: {
        app: { port: 4000 },
      },
    }),
  ],
})
export class AppModule {
  constructor(private readonly config: ConfigService) {}
}

Resolve values anywhere in your DI graph:

@Injectable()
export class AppService {
  constructor(private readonly config: ConfigService) {}

  getPort(): number {
    return this.config.get<number>('app.port', 3000);
  }
}

Async options

Use forRootAsync when configuration comes from other providers:

@Module({
  imports: [
    ConfigModule.forRootAsync({
      useFactory: async () => ({
        dir: 'config',
        overrides: {
          feature: {
            cache: process.env.ENABLE_CACHE === 'true',
          },
        },
      }),
    }),
  ],
})
export class AppModule {}

You can also provide a class that implements ConfigModuleOptionsFactory.

Feature slices

Expose nested configuration once and inject it elsewhere using forFeature:

import { Inject } from '@nl-framework/core';
import { ConfigModule, getConfigFeatureToken } from '@nl-framework/config';

const databaseConfigToken = getConfigFeatureToken('database');

@Module({
  imports: [
    ConfigModule.forRoot(),
    ConfigModule.forFeature('database'),
  ],
})
export class DatabaseModule {
  constructor(@Inject(databaseConfigToken) private readonly config: Record<string, unknown>) {}
}

The token is stable (Symbol.for('nl:config:feature:<path>')) so you can reuse it without storing a reference.

API

• ConfigModule.forRoot(options?: ConfigModuleOptions) — Load YAML configuration using explicit options.
• ConfigModule.forRootAsync(options: ConfigModuleAsyncOptions) — Resolve options via DI (useFactory, useClass, or useExisting).
• ConfigModule.forFeature(pathOrOptions) — Provide a specific config slice (with optional transform) as an injectable token.
• ConfigService — Re-exported from @nl-framework/core for convenience.
• ConfigLoader — Re-exported loader utility for manual use.

Testing

This package ships with Bun tests. Run them with:

bun run packages/config/package.json test