Database

TypeORM configuration with PostgreSQL via DatabaseModule and DataSource factory.

The database infrastructure uses TypeORM with PostgreSQL. The connection is managed by a singleton DataSource injected via a custom token.

DatabaseModule

typescript 
@Module({
  providers: [
    EnvService,
    {
      provide: DATA_SOURCE_PROVIDER_TOKEN,
      useFactory: dataSourceFactory,
      inject: [EnvService],
    },
  ],
  exports: [EnvService, DATA_SOURCE_PROVIDER_TOKEN],
})
export class DatabaseModule {}

DataSource factory

typescript 
import { DbContext } from '@/core/database/db-context';
import path from 'node:path';

export const DATA_SOURCE_PROVIDER_TOKEN = 'DATA_SOURCE';

export async function dataSourceFactory(env: EnvService) {
  const dataSource = new DataSource({
    type: 'postgres',
    url: env.get('DATABASE_URL'),
    schema: env.get('DATABASE_SCHEMA'),
    entities: Array.from(DbContext.entities.values()),
    migrations: [path.join(__dirname, 'migrations', '[0-9]*.{ts,js}')],
    migrationsTableName: 'migrations',
    migrationsTransactionMode: 'all',
    invalidWhereValuesBehavior: {
      undefined: 'ignore',
    },
  });

  await dataSource.initialize();
  await dataSource.runMigrations();

  return dataSource;
}

Pending migrations are applied automatically when the API starts. The migration:run / migration:revert scripts remain available for CI and manual operations.

Injection token

Repositories receive the DataSource via token, not the class directly:

typescript 
constructor(@Inject(DATA_SOURCE_PROVIDER_TOKEN) dataSource: DataSource) {
  super(dataSource, Person);
}

Environment variable

The connection URL comes from DATABASE_URL, validated in the Zod schema (format from .env.example):

env 
DATABASE_URL=postgresql://postgres:root@localhost:5432/koala_nest

Adding new entities

  1. Create the entity in src/domain/entities/ with @Entity from @/core/database/entity.
  2. Generate the migration and restart the API (or use migration:run).

The @Entity decorator registers the class in DbContext.entities. At runtime, Nest imports entities via repositories; in the CLI, load-all-entities.ts loads files under src/domain/entities/ to populate the same DbContext used by migration-datasource.ts — no manual entity list is required.

InfraModule

InfraModule aggregates repositories and exports RepositoryModule:

typescript 
@Module({
  imports: [RepositoryModule],
  exports: [RepositoryModule],
})
export class InfraModule {}