angular-services

Use providedIn 'root' for singleton application-wide services, and module-specific providers to restrict service lifetime to lazily loaded feature modules. This ensures correct dependency injection scoping and prevents memory leaks.

To migrate an Angular service to inject(), replace constructor parameter declarations with explicit inject() calls within the service body. This modernizes dependency injection, simplifies class inheritance, and aligns with current Angular patterns.

Managing shared state with signals involves exposing writable or readonly signal properties from your @Injectable services. This approach simplifies reactive state sharing across components and supports converting legacy services to signal-backed architectures.

Configure an Angular service using a factory provider by defining a factory function that reads environment flags or dynamic inputs, then registering it via the useFactory property. This enables flexible runtime service configuration and dependency injection.

Angular services cause memory leaks in lazy-loaded modules when provided at the root level but intended for feature isolation. Correcting the providedIn scope to match the lazy-loaded module boundary ensures proper service lifecycle management and garbage collection.