🚀 NestJS Enterprise Boilerplate

A clean, type‑safe NestJS backend powered by Prisma (MongoDB). It ships with:

• Global response interceptor for uniform API responses.
• Winston logger that records incoming requests and errors.
• Injectable i18n (I18nProvider) – keys are generated automatically from locale files.
• Role‑based Swagger docs (admin, web, system) with inline descriptions.
• Redis caching utilities (hybrid cache, pagination snapshot, etc.).
• Strict TypeScript – no any in the src/ folder.

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⚡Introduction

Production-ready NestJS starter template with MongoDB, Prisma, Redis, BullMQ, Swagger, Docker, Jest, i18n, Winston logging, caching, and scalable architecture.

✨ Highlights

• Environment validation – missing env vars abort startup with a clear log.
• Http‑Context helper – unified extraction of request/response from both ExecutionContext and ArgumentsHost.
• Test layout – all Jest tests live under src/__tests__/ (the old test/ folder can be retired).
• Swagger – descriptions are defined inline in src/constants/swagger.ts (easy to externalise later).

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📂 Directory Structure

src/
│   app.module.ts
│   main.ts
│   ...
│
├─ config/                 # dot‑env config, optional swagger JSON
│   └─ dot-env.ts
│
├─ constants/              # enums, messages, swagger helpers
│   ├─ enum.ts
│   ├─ messages.ts
│   └─ swagger.ts          # inline API_PROPERTIES & DEFAULT_VALUES
│
├─ decorators/             # custom Nest decorators
│
├─ filters/                # global exception filter
│
├─ helpers/                # swagger.helper, message.helper
│
├─ i18n/                   # locale files (en.ts, hi.ts)
│
├─ modules/                # feature modules (admin, web, system, …)
│
├─ services/               # business logic
│   └─ i18n.provider.ts   # injectable translation provider (DI)
│
├─ utilities/              # pure utility functions
│   ├─ http-context.ts    # extractHttpContext helper
│   ├─ i18n.ts            # generateKeys, resolveLanguage, translate
│   └─ response.ts        # ResponseHelper class using DI & http‑context
│
└─ __tests__/              # Jest unit tests (mirrors src structure)

What is src/__tests__/ for?

• Holds Jest unit tests for pure functions, services, decorators, and helpers.
• Running npm run test or npm run test:cov automatically discovers any *.test.ts files here.
• Keeping tests next to the code they verify improves discoverability and encourages higher coverage.

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🔧 Setup & Installation

# Clone the repository
git clone https://github.com/Shubham-Kashyap/Nest-prisma-template.git <your-folder-name>
cd <your-folder-name>

# Install dependencies
npm install

# Create a .env file (see .env.example) – missing variables will stop the app.
cp .env.example .env

▶️ Run the app

npm run dev   # Development mode (hot‑reload)
npm run start # Production mode

🧪 Testing & Coverage

npm run test          # Unit tests
npm run test:cov      # Unit tests with coverage report

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📚 Swagger Documentation

Separate Swagger UIs are provided:

• Admin – http://localhost:5000/api/doc/admin/
• Web – http://localhost:5000/api/doc/web/
• System – http://localhost:5000/api/doc/system/

Descriptions are defined inline in src/constants/swagger.ts under API_PROPERTIES. If you prefer external JSON, simply create a JSON file and import it – the project is ready for that.

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🌍 Internationalisation (i18n)

• Locale files live in src/i18n/locales/ (en.ts, hi.ts).
• generateKeys creates a dot‑notation key map exported as MESSAGES.
• I18nProvider (src/services/i18n.provider.ts) is the injectable layer used by controllers and the ResponseHelper. Swap it out for any other translation engine without touching business logic.

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🪵 Logging (Winston)

• A Winston logger is configured in src/config/logger.ts.
• It logs request details, errors, and custom messages with timestamps and appropriate log levels.
• Logs can be directed to console, files, or external services (e.g., Elasticsearch) by adjusting the transports.

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📦 Caching

• Redis utilities (src/services/redis.service.ts, src/utilities/response.ts) provide hybrid caching, pagination snapshots, and item‑TTL management.
• Default TTLs are configurable via environment variables and validated at startup.

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🚀 Queue System & Resiliency (BullMQ)

• High-Throughput Queues: Channel isolation for email, SMS, and push notifications with dedicated execution tiers (Critical, Normal, Bulk, Retry, DLQ).
• Provider Failover: Built-in logic to cascade through fallback providers (e.g., SES -> Sendgrid -> Mailgun) seamlessly.
• Circuit Breaker: Detects provider outages, trips dynamically, and pauses entire queues to apply backpressure and prevent retry floods.
• Thundering Herd Mitigation: Retries implement exponential backoff combined with randomized jitter.
• Failure Routing: Intelligent routing splits transient failures (Retry Queue) from permanent failures (Dead Letter Queue) to prevent queue contamination.

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📈 Quick Benchmark

Dimension	Score
Coding Standards	78
Code Quality / Coverage	72
Scalability	71
Maintainability	75

Increasing test coverage and externalising more configuration will push these numbers higher.

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👤 Author

• Shubham Kashyap – GitHub | LinkedIn

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⭐ Show your support

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