[Feature Request] Allow for a single reducer to be registered in a feature module

[delasteve]

Problem:

Currently, you must pass an ActionReducerMap to StoreModule.forFeature(featureName: string, reducers: ActionReducerMap<any, any>). Sometimes, a feature module only needs a single reducer to be registered. By not allowing this, it will add an unnecessary intermediate step to get to the desired state.

Proposal:

Allow for StoreModule.forFeature(featureName: string, reducer: ActionReducer<any, any>).

Current functionality:

State interfaces

export interface PilotsModuleState {
  pilot: PilotState;
}

export interface PilotState {
  pilots: Pilot[]
}

feature.module.ts

imports: [
  ...,
  StoreModule.forFeature('pilotsModule', { pilot: pilotReducer })
]

Feature selectors:

const selectPilotsModule = createFeatureSelector<PilotsModuleState>('pilotsModule');
const selectPilotsState = createSelector(selectPilotsModule, (state: PilotsModuleState) => state.pilot);
const selectPilots = createSelector(selectPilotsState, (state: PilotState) => state.pilots);

Desired functionality:

State interfaces

export interface PilotsModuleState {
  pilots: Pilot[]
}

feature.module.ts

imports: [
  ...,
  StoreModule.forFeature('pilotsModule', pilotReducer)
]

Feature selectors:

const selectPilotsModule = createFeatureSelector<PilotsModuleState>('pilotsModule');
const selectPilots = createSelector(selectPilotsState, (state: PilotsModuleState) => state.pilots);