ngrx-store-freeze

ngrx-store-freeze is a meta-reducer that prevents state from being mutated

• Recursively freezes the current state, the dispatched action payload if provided and the new state.
• When mutation occurs, an exception will be thrown.
• Should be used only in development to ensure that the state remains immutable.

Installation

npm i --save-dev ngrx-store-freeze

OR

yarn add ngrx-store-freeze --dev

Setup

import { StoreModule, MetaReducer, ActionReducerMap } from '@ngrx/store';
import { storeFreeze } from 'ngrx-store-freeze';
import { environment } from '../environments/environment'; // Angular CLI environment

export interface State {
  // reducer interfaces
}

export const reducers: ActionReducerMap<State> = {
  // reducers
}

export const metaReducers: MetaReducer<State>[] = !environment.production ? [storeFreeze]: [];

@NgModule({
  imports: [
    StoreModule.forRoot(reducers, { metaReducers }),
  ]
})
export class AppModule {}

Additional Documentation

• Usage with @ngrx/router-store

Credits

redux-freeze - Redux middleware that prevents state from being mutated
Attila Egyed - The original maintainer of this project