Extend @ngrx/router-store routerReducer to modify fields added to RouterStateUrl

Question

How to extend logic of the With Angular 8, ngrx 8 I keep a router state using custom serializer

export class CustomSerializer implements RouterStateSerializer<RouterStateUrl> Where the custom state

export interface RouterStateUrl {
url: string;
path?: string[];
params: Params;
queryParams: Params;
breadcrumbs: Breadcrumb[];

} adds a new field - breadcrumbs

For the whole store I have a reducer map like this:

export interface State {
  router: fromRouter.RouterReducerState<any>;
  //... other feature states
}

export const reducers: ActionReducerMap<State> = {
router: fromRouter.routerReducer,
 // ...other feature reducers
};

I would like to manipulate the custom part of my router state( the breadcrumbs field). Is there a standard way of extending the routerReducer in a way that will allow changing the custom field?

UPDATE: One possible workaround I see is to create a separate feature in the store for breadcrumbs, keeping router state feature pure. That would require the new feature to reduce router actions. To my mind, this is a hack though. It seems illogical that router state allows extending the state with extra fields, but not the reducer

Answer 1

It isn't possible (at the moment) to add custom actions to the built-in router reducer.

Depending on what you need you can either:

• create your own reducer based on router actions, as you've mentioned
• create a selector based on the router state to build up the breadcumbs