Testing blocks with Xcode 6 and OCMockito - ios

Question

I am starting in Unit testing with objective-c and I need to know how to test blocks with OCMockito and Xcode 6.
I am testing an Interactor, this interactor should return an array as a block argument and I has to ask the Provider file for the elements.
This is the method I want to test:
- (void)userPoiListsWithSuccessBlock:(MNBSavePoisInteractorSuccess)success {
self.poiListEntityArray = [self.poiListProvider poiListsForUser:self.loggedUser];
self.poiListViewObjectArray = [self viewPoiListObjectListWithPoiLists:self.poiListEntityArray];
success(self.poiListViewObjectArray);
}
First, I setup the elements that I am going to use
self.mockPoiListProvider = mock([PoiListProvider class]);
self.sut = [[MNBSavePoisInteractor alloc] initWithManagedObjectContext:self.coreDataStack.managedObjectContext andPoiListProvider:self.mockPoiListProvider];
- (UserEntity *)loggedUserMock {
UserEntity *mockLoggedUser = [NSEntityDescription insertNewObjectForEntityForName:NSStringFromClass([UserEntity class]) inManagedObjectContext:self.coreDataStack.managedObjectContext];
mockLoggedUser.userId=#"1";
mockLoggedUser.username=#"user";
mockLoggedUser.loggedUser=#YES;
return mockLoggedUser;
}
- (InMemoryCoreDataStack *)coreDataStack{
if (!_coreDataStack) {
_coreDataStack = [[InMemoryCoreDataStack alloc] init];
}
return _coreDataStack;
}
- (PoiListEntity *)poiListFake {
PoiListEntity *fake = [NSEntityDescription insertNewObjectForEntityForName:#"PoiListEntity" inManagedObjectContext:self.coreDataStack.managedObjectContext];
fake.name = #"Test";
fake.poisCount = #2;
[fake addContributorsObject:[self loggedUserMock]];
return fake;
}
Then, I do the test. I am using Xcode 6 waitForExpectation to manage the asynchronous methods. I think I am doing something wrong.
- (void)waitForExpectation {
[self waitForExpectationsWithTimeout:5.0 handler:^(NSError *error) {
if (error) {
NSLog(#"Timeout Error: %#", error);
}
}];
}
- (void)testShouldReturnPoiLists {
XCTestExpectation *expectation = [self expectationWithDescription:#"Waiting method ends"];
[given([self.mockPoiListProvider poiListsForUser:[self loggedUserMock]]) willReturn:#[[self poiListFake]]];
[self.sut userPoiListsWithSuccessBlock:^(NSArray *results) {
[expectation fulfill];
XCTAssert(resutls.count == 1, #"Results %zd", resutls.count);
}];
[self waitForExpectation];
}
I understood if I give the object in willReturn in the given method, when I call the sut method that I want to test it should return what I give before. Is that true?
Thank you

Answer 1

I see no asynchronous code. You just want a block that captures the results, so use a __block variable to make the results available outside of the block. Then you can assert whatever you want:
- (void)testShouldReturnPoiLists {
[given([self.mockPoiListProvider poiListsForUser:[self loggedUserMock]]) willReturn:#[[self poiListFake]]];
__block NSArray *capturedResults;
[self.sut userPoiListsWithSuccessBlock:^(NSArray *results) {
capturedResults = results;
}];
assertThat(capturedResults, hasLengthOf(1));
}
The relationship between the length of 1 and the fake is hard to tell. Let's also parameterize the faking code:
- (PoiListEntity *)poiListFakeWithName:(NSString *)name count:(NSNumber *)count {
PoiListEntity *fake = [NSEntityDescription insertNewObjectForEntityForName:#"PoiListEntity" inManagedObjectContext:self.coreDataStack.managedObjectContext];
fake.name = name;
fake.poisCount = count;
[fake addContributorsObject:[self loggedUserMock]];
return fake;
}
With that, we can write more interesting tests.
I do want to add that it's important to "listen to the tests." There's a lot of convoluted set-up to dance around Core Data. That tells me that if you can rewrite things to be independent of Core Data — completely ignorant of it — everything will be much simpler.