fix(ImmerComponentStore): set defaultState (via constructor) as immut…

…able (#27)

src/component-store/immer-component-store.ts

@@ -1,8 +1,9 @@
-import { Injectable } from '@angular/core';
+import { Inject, Injectable, Optional } from '@angular/core';
 import { Observable, Subscription } from 'rxjs';
-import { ComponentStore } from '@ngrx/component-store';
+import { ComponentStore, INITIAL_STATE_TOKEN } from '@ngrx/component-store';
 
 import { immerReducer } from 'ngrx-immer/shared';
+import { produce } from 'immer';
 
 /**
  * Immer wrapper around `ImmerComponentStore` to mutate state
@@ -12,6 +13,10 @@ import { immerReducer } from 'ngrx-immer/shared';
 export class ImmerComponentStore<
 	State extends object
 > extends ComponentStore<State> {
+	constructor(@Optional() @Inject(INITIAL_STATE_TOKEN) defaultState?: State) {
+		super(produce(defaultState, s => s));
+	}
+
 	updater<
 		ProvidedType = void,
 		OriginType = ProvidedType,