NestJS

Map of content for NestJS. Links marked planned are pending topics. They will get filled in over time.

Fundamentals

What you need to master before any advanced pattern.

• Modules: feature, shared, core (planned)
• DI container: providers, scopes, custom providers (planned)
• Lifecycle hooks: OnModuleInit, OnApplicationBootstrap (planned)
• Request lifecycle: middleware, guards, interceptors, pipes, filters

Recipes

Task-oriented how-tos. See all recipes.

• File uploads with Multer
• NestJS CLI monorepos
• throttler
• Response serialization with class-transformer
• Request trace ID propagation
• Request validation with class-validator

Patterns

Architecture patterns that NestJS enables but does not enforce.

• CQRS: commands, queries, events (planned)
• Repository pattern: when yes, when no (planned)
• Domain events: EventEmitter2 vs CQRS events (planned)
• Error handling: filters and exception hierarchy (planned)

Data

• Prisma: setup, transactions, soft delete (planned)
• TypeORM: integration, error handling, relations
• Caching: CacheModule + Redis (planned)

Auth

• JWT strategy with Passport
• Guards vs Middleware: when to use each (planned)
• RBAC and CBAC (planned)

Testing

• Unit tests with Test.createTestingModule (planned)
• E2E with Supertest + Testcontainers (planned)
• Mocking strategy (planned)

Observability

• Structured logging with Pino (planned)
• OpenTelemetry: traces and metrics (planned)
• Health checks with Terminus (planned)

Deployment

• Docker: multistage builds (planned)
• Graceful shutdown (planned)
• Config validation with Zod (planned)

Gotchas

Problems I already solved and do not want to google again.

• Circular dependencies: forwardRef and how to avoid it (planned)
• Request-scoped providers: the hidden cost (planned)
• Async providers: useFactory with dependencies (planned)