Myujth

Previously I could test the below store select

this.store.select(fromRoot.someselector).pipe(map(r => this.store.dispatch(new Action())));

This was in my test

{provide: Store, useValue: jasmine.createSpyObj('store', ['select']);

store.select.and.returnValue(of());

But now it has changed to pipes

this.store.pipe(select(fromRoot.someselector));

this.store.pipe(
 select(fromRoot.someselector), 
 filter(result => !!result), 
 map(r => 
 if (result === ' hello') 
 this.store.dispatch(new Action()); 
 
 
 ));

How to test this especially when you have map after select and within it you are dispatching an action and you want verify action was called.

Skip the operators and test directly the result of the stream :

store
 .pipe(select('selector'))
 .subscribe(val => expect(val).toBe(theMockedValSentToTheSpy))

To explain further :

• create a mock of your store


• create a mock of your value


• return this mocked value in your mocked store


• expect your component variable to return the mocked value

This gives :

const mockedValue = id: 1 ;
const storeSubjectMock = new BehaviorSubject(mockedValue);
const mockedStore = 
 pipe: () => storeSubjectMock.asObservable(),
;

// provide: Sotre, useValue: mockedStore ; in your testbed

it('should return an unaltered value', () => 
 component.variableReferencingStore
 .pipe(select('selector'))
 .subscribe(val => expect(val).toBe(mockedValue))
);

Now the good thing about that is that you can test all operators like that. Say your component variable is

storeValue$ = this.store.pipe(
 select('selector'),
 map(value => ( ...value, name: 'customName' ))
)

Then your tests just changes to

it('should return an altered value with a name property set to customName', () => {
 component.variableReferencingStore
 .pipe(select('selector'))
 .subscribe(val => expect(val).toEqual( ...mockedValue, name: 'customName'))
);