Store: add ability to create the Store/MockStore outside of the TestBed

[brandonroberts]

Currently you have to use the TestBed provideMockStore() to get an instance of the MockStore. This would declare static providers when using provideMockStore() so it can be used with Injector.create()

Describe any alternatives/workarounds you're currently using

Other information:

If accepted, I would be willing to submit a PR for this feature

[ ] Yes (Assistance is provided if you need help submitting a pull request)
[ ] No

[amartinelli12]

I managed to achieve this in my project by the following:

import { ActionsSubject } from '@ngrx/store';
import { MockState, MockStore } from '@ngrx/store/testing';

// import local application state model
// import local application state object

const actionSubject$: ActionSubject = new ActionsSubject();
const reducerManager$: ReducerManager = new ReducerManager(null, null, null, () => null); // this could be improved
const mockState$: MockState<LocalApplicationStateModel> = new MockState();

export const MOCK_STORE$: MockStore<LocalApplicationStateModel> = new MockStore(
    mockState$,
    actionSubject$,
    reducerSubject$,
    LOCAL_APPLICATION_STATE_OBJECT
);

[alex-okrushko]

Hey @amartinelli12

Checkout the PR from @markostanimirovic that's attached here: #2759
It's good 🙂