Mocking in Swift for XCTest - ios

Question

I am writing test cases for my project which is mix up with Objective C as well as Swift code. I am aware about OCMock framework which I have used previously for mocking/Stubbing for writing Test cases in Objective C.
But I googled and found that it doesn't support fully for swift, since it is based on Objective C runtime.
I am trying to write test cases in swift language. Is there way I can do mocking/Stubbing for service level layer. For eg.
func getPersonData(id:String, success: (ReponseEnum) -> Void, failure: (error: NSError) -> Void) {
let requestPara:NSDictionary = ["id": id]
let manager: MyRequestManager = MyRequestManager.sharedManager()
//MyRequestManager is nothing but AFNetworking class
let jsonRequest
/// Service request creation code here
// Service Call
manager.POST(url, parameters: jsonRequest, success: { (task: NSURLSessionDataTask!, responseObject: AnyObject!) -> () in
// Some business logic
//success block call
success (successEnum)
}) {(task: NSURLSessionDataTask!, error: NSError!) -> () in
// failure block call
failure (failureEnum)
}
}
Here how to mock post method call for dummy responseObject So I can write test cases?

Answer 1

You need to use dependency injection to be able to mock the POST method.
Your class, where you defined the getPersonData(id:success:failure) method, needs to accept MyRequestManager as a parameter in constructor:
class MyClass {
private let requestManager: MyRequestManager
init(requestManager: MyRequestManager) {
self.requestManager = requestManager
}
}
Then you create a mock for your request manager:
class MockMyRequestManager: MyRequestManager {
// not sure about correct method signature
override func POST(url: NSURL, parameters: [String: AnyObject], success: (() -> Void)?) {
//implement any custom logic that you want to expect when executing test
}
}
And in the tests you initialise your class with a mock:
let myClass = MyClass(requestManager: MockMyRequestManager())
You can find more details about dependency injection here:
http://martinfowler.com/articles/injection.html