Mocking CKContainer for Unit Testing - ios

Question

I am using CloudKit in my application and am trying to mock CKContainer to test my Managers. Here is what i tried:
func testAccountStatus() {
class MockCloudContainer: CKContainer {
override func accountStatusWithCompletionHandler(completionHandler: ((CKAccountStatus, NSError!) -> Void)!)
{
completionHandler(CKAccountStatus.NoAccount, NSError())
}
}
let loginManager = LoginManager.sharedInstance
let expectation = expectationWithDescription("iCloudStatus")
var isTestFinished = false
loginManager.iCloudStatusWithCompletionHandler { (status, error) -> Void in
if (isTestFinished) {
return
}
expectation.fulfill()
XCTAssertTrue(status.isEqualToString("NoAccount"), "Status is Available")
}
waitForExpectationsWithTimeout(5, { error in
isTestFinished = true
XCTAssertNil(error, "Error")
})
But i am getting error while compiling the code
:0: error: cannot override 'init' which has been marked unavailable
What is best way I am using mock object to test my LoginManager class ?
Thanks

Answer 1

Currently there is no way to mock the CKContainer. The only solution would be to create a thin data access layer between your app and the CloudKit code and then mock that layer. But still you would not be able to unit test that thin layer itself.

Answer 2

I have an idea for this problem. But I'm not good at swift so I provide my code in Objective-C
Firstly , try create CKContainerMock in your testClass like this:
#interface CKContainerMock : CKContainer
#property (nonatomic, copy) void (^mCompletionHandlerMock)(CKAccountStatus accountStatus,NSError *error);
- (void)accountStatusWithCompletionHandler:(void (^)(CKAccountStatus accountStatus, NSError *error))completionHandler
#end
#implementation CKContainerMock
- (void)accountStatusWithCompletionHandler:(void (^)(CKAccountStatus accountStatus, NSError *error))completionHandler {
self.mCompletionHandlerMock = completionHandler;
}
#end
In your testFunction
Example:
Success case:
-(void) testCKContainerResultSucces {
LoginManager loginManager = [LoginManager sharedInstance];
CKContainerMock *ckContainerMock = [[CKContainerMock alloc] init];
[loginManager setCKContainer:ckContainerMock]; // Change your ckContainer object to mockObject.
[loginManager iCloudStatusWithCompletionHandler:^(CKAccountStatus accountStatus,NSError *error) {
XCAssert(accountStatus == CKAccountStatusAvailable);
}];
loginManager.ckContainer.mCompletionHandlerMock(CKAccountStatusAvailable,nil);
}
Error case:
-(void) testCKContainerResultError {
LoginManager loginManager = [LoginManager sharedInstance];
CKContainerMock *ckContainerMock = [[CKContainerMock alloc] init];
[loginManager setCKContainer:ckContainerMock]; //Change your ckContainer object to mockObject.
[loginManager iCloudStatusWithCompletionHandler:^(CKAccountStatus accountStatus,NSError *error) {
XCAssertNotNil(error);
}];
loginManager.ckContainer.mCompletionHandlerMock(nil,[NSError errorWithDomain:NSPOSIXErrorDomain code:22 userInfo:nil]);
}
Greate mock example for you
Hope this help.