decorator-patterns

What problem does it solve?

NestJS projects often suffer from unclear decorator usage and tangled metadata when composing guards, interceptors, routes, and custom decorators. This skill clarifies which built-in decorators to use, how to create custom parameter decorators with createParamDecorator, and how to compose decorators with applyDecorators to reduce boilerplate and avoid common pitfalls.

Core Features & Use Cases

• Built-in class-, method-, and parameter-level decorators and how to apply them to controllers, services, and routes.
• Custom param decorators via createParamDecorator and integration with Reflector to read metadata at runtime.
• Metadata composition with applyDecorators and example meta-decorators to reduce boilerplate.
• Guidance on common patterns and anti-patterns to avoid misconfigurations and DI/routing bugs.

Quick Start

Review the examples and implement a small NestJS demo with a custom @CurrentUser decorator and a Roles guard applied to a controller.