angular-di

You use inject() to retrieve Angular dependencies by calling it within component or service properties instead of constructor parameters. This approach simplifies wiring dependencies and clarifies provider scopes across your application.

The best way to configure Angular providers is by managing their scopes across root, component, and route levels. Setting providedIn: root creates a singleton, while configuring component or route providers generates per-instance services for hierarchical injection.

You create InjectionTokens to decouple implementations by defining abstract interfaces and providing concrete classes for them. This pattern allows you to manage multiple provider configurations and swap dependencies seamlessly without modifying the consuming components.

Yes, Angular dependency injection supports hierarchical injection across route scopes. You can configure providers at the root, component, or route level to manage singleton versus per-instance services and establish complex testing patterns throughout your application.

Using inject() instead of constructor parameters prevents inheritance issues and simplifies testing patterns. It allows you to retrieve services directly within properties, making your Angular components and services cleaner and easier to wire across varying provider scopes.