dabydat/alpha-omega/nestjs-libs-pattern

NestJS Libs / Shared Libraries Pattern

Shared libraries reduce duplication across services. Each lib is a self-contained NestJS module with its own structure, providing consistent functionality to multiple microservices.

Why Shared Libraries

See references/why-libs.md for the ❌ BAD duplicated-code example and the ✅ GOOD single-library example.

Library Structure

See references/library-structure.md for the folder tree of a lib.

Module Definition Pattern

See references/module-definition.md for the public main module + internal core module.

Options Pattern (Configuration)

See references/options-pattern.md for OAuthOptions, OAuthOptionsFactory, OAuthAsyncOptions, and registerAsync.

Service Pattern

See references/service-pattern.md (OAuthService with configuration).

Guard Pattern

See references/guard-pattern.md (AuthGuard).

Exception Pattern

See references/exception-pattern.md (OAuthException hierarchy).

Barrel Export (Public API)

See references/barrel-export.md.

DI Token Pattern

See references/di-token.md.

Consumer Usage

See references/consumer-usage.md.

Anti-Patterns to Avoid

See references/anti-patterns.md for the four ❌ examples (circular deps, global everything, no interface, no versioning).

Summary: Library Responsibilities

Golden rule: Libraries are modules. Modules have single responsibility. Don't bundle everything into one lib — split by domain (oauth, storage, notifications, stp_core).