How to inject a service into a constant in angular

Constants in Angular may be constructed using InjectionToken:

export const USER_CONFIG = new InjectionToken('User Configuration', {
  factory: () => {
    return {
      // You can inject the UserService to get the username
      username: inject(UserService).getUsername()
    }
  }
});

Since the constant is an injection token, it can be injected in other parts of your application:

export class AppComponent {

  constructor(@Inject(USER_CONFIG) config) {
    console.log(config.username)
  }
}

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