@dltech/nestjs-core

Shared NestJS utilities used across all Cubix backend services.

pnpm add @dltech/nestjs-core

Modules

• EnvModule / BaseEnvService
• LoggerModule
• Decorators
• TypeORM — Seeder

Env

Type-safe environment configuration backed by @nestjs/config.

// env.service.ts
@Injectable()
export class EnvService extends BaseEnvService<IEnvConfig> {}

// app.module.ts
EnvModule.forRoot({ envService: EnvService, validationSchema: envConfigValidation })

BaseEnvService<T> wraps ConfigService so that envService.get('KEY') is fully typed against your IEnvConfig interface with no casting required.

Logger

Drop-in structured logger module.

// app.module.ts
import { LoggerModule } from '@dltech/nestjs-core';

@Module({ imports: [LoggerModule] })
export class AppModule {}

Decorators

@CreateModule

Convenience decorator that applies common module-level defaults.

@CreateModule({ imports: [...] })
export class AppModule {}

@SseGenerator

Helper decorator for Server-Sent Events endpoints.

TypeORM — Seeder

A file-based, idempotent seeding system for local development. Mirrors the TypeORM migrations pattern: numbered files, sorted alphabetically, each run in order.

Setup (per project)

1. Add the db:seed script to package.json:

"db:seed": "cross-env NODE_ENV=development pnpm env:inject -- pnpm db:ts-node cli/seed-runner.ts",
"db:recreate": "pnpm db:schema:drop && pnpm db:migrate && pnpm db:seed"

2. Create cli/seed-runner.ts — the entry point:

import { resolve } from 'path';
import { runSeeds } from '@dltech/nestjs-core';
import { AppDataSource } from './data-source';

async function main(): Promise<void> {
  if (process.env.NODE_ENV !== 'development') {
    console.log('seed: NODE_ENV is not "development" — exiting safely');
    process.exit(0);
  }

  await AppDataSource.initialize();
  try {
    await runSeeds(AppDataSource, resolve(__dirname, '../seeds'));
    console.log('seed: all seeds complete');
  } finally {
    await AppDataSource.destroy();
  }
}

void main();

3. Create numbered seed files in seeds/:

// seeds/001-dev-user.ts
import type { Seeder } from '@dltech/nestjs-core';

export default (async (ds) => {
  const repo = ds.getRepository(User);
  if (await repo.findOne({ where: { email: '[email protected]' } })) return;
  await repo.save(repo.create({ email: '[email protected]', ... }));
}) satisfies Seeder;

How it works

| Concern | Detail | |---|---| | Ordering | Files sorted alphabetically — use 001-, 002-, … prefixes | | Idempotency | Each seed must guard against duplicate data (findOne → skip) | | Safety | seed-runner.ts exits with code 0 if NODE_ENV !== 'development' | | DataSource | Caller initializes and destroys — runSeeds only runs the files |

API

// Type for a seed file's default export
type Seeder = (ds: DataSource) => Promise<void>;

// Discovers and runs all .ts / .js files in seedsDir, sorted alphabetically
function runSeeds(ds: DataSource, seedsDir: string): Promise<void>;