Cannot read property of map of undefined when using featureSelector ngrx

Question

REPO: https://github.com/morningharwood/platform/tree/feature/ngrx-firebase

When I try to subscribe to my selectAll of my post ngrx entity feature I get the error:

Cannot read property of map of undefined

It has to be a simple typo I'm following tutorials verbatim.

Weird part is if I use string selector:

 this.selected$ = this.store.select('post');

 this.selected$.subscribe(console.log); // no error here.

I get a no error.

Question: When using ngrx entity, How can I get my selectAll selector to log out the all posts from ngrx store collection post?

My post.reducer.ts

import {
  PostActions,
  PostActionTypes,
} from './post.actions';

import {
  ActionReducerMap,
  createFeatureSelector,
} from '@ngrx/store';
import {
  createEntityAdapter,
  EntityState,
} from '@ngrx/entity';
import { Post } from './post.interfaces';

export const postAdapter = createEntityAdapter<Post>();
export interface PostState extends EntityState<Post> {}

export const postInitialState: PostState = {
  ids: [ '1234' ],
  entities: {
    '1234': {
      id: '1234',
      header: {
        title: 'title 1',
        subtitle: 'subtitle 1',
      },
      body: {
        sections: [],
      },
    },
  },
};

export const initialState: PostState = postAdapter.getInitialState(postInitialState);

export function postReducer(state: PostState = initialState, action: PostActions): PostState {
  switch (action.type) {
    case PostActionTypes.ADD_ONE:
      return postAdapter.addOne(action.post, state);
    default:
      return state;
  }
}

export const getPostState = createFeatureSelector<PostState>('post');
export const {
  selectIds,
  selectEntities,
  selectAll: selectAllPosts,
  selectTotal,
} = postAdapter.getSelectors(getPostState);

export const postReducersMap: ActionReducerMap<any> = {
  post: postReducer,
};

And app.component:

import {
  Component,
  OnInit,
} from '@angular/core';
import { AppState } from './app.interfaces';
import { Store } from '@ngrx/store';
import { selectAllPosts } from './post/post.reducer';

import { Observable } from 'rxjs/Observable';


@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ],
})
export class AppComponent implements OnInit {
  public selected$: Observable<any>;

  constructor(private store: Store<AppState>) {
  }

  ngOnInit() {

    this.selected$ = this.store.select(selectAllPosts);
    this.selected$.subscribe(console.log); // error here
  }
}

My forFeatureand forRoot modules:

@NgModule({
  imports: [
    BrowserModule.withServerTransition({ appId: 'portfolio-app' }),
    StoreModule.forRoot({ reducers }),
    EffectsModule.forRoot([]),
    PostModule,
  ],
  declarations: [ AppComponent ],
  bootstrap: [ AppComponent ],
  providers: [],
})
export class AppModule {
}

import { StoreModule } from '@ngrx/store';
import { postReducers } from './post.reducer';


@NgModule({
  exports: [],
  declarations: [],
  imports: [StoreModule.forFeature('post', postReducersMap)],
})
export class PostModule {
}

Answer 1

It was the creation of the ActionMapReducer in the forFeature('post', postReducerMap); I still need to figure out how to use entity and ActionMapReducer together.