Clever Geek Handbook

XCTestExpectation - calling async method twice breaks API

I am writing units of tests in swifts and testing a unique workflow.

  • In the A () method, I am loading the object incorrectly (say with the wrong credentials) using the async method. Also start waiting

        func methodA(withCred credential: NSURLCredential) {
    var objA = ObjectA()
    // Set objA.a, objA.b, objA.c, 
    objA.credential = credential //Incorrect credential First time, Correct Credential second time 
    objA.delegate = self 
    expectation = expectationWithDescription("Aync")
    objA.callAsyncMethod() //This fires successDelegate() or failureDelegate()}

  • When FailureDelegate () is fired, I reload the object, correctly this time. To do this, I need to call MethodA () again (so I can reuse all the other stuff in there).

    func failureDelegate(error: NSError!) {

XCTAssertTrue(error.localizedDescription == "Invalid Credentials")
//Now that I’ve verified correct error is returned, I need to reload objA
methodA(withCred:correctCredential) 
}

func successDelegate(obj : ObjectA) {
  XCTAssert("Object is loaded")
  expectation.fulfill()
}

3. This again raises the same expectation in method A and results in the following error:

API violation - creating pending wait.

I understand that this is not allowed by swift. Is there a workaround or better way to test these async looping methods with Swift using XCTest?

Thank!

+3


source to share


2 answers


Don't use instances expectation

for testing. You must declare expectation

(i.e. C let

) in the body of each test, not as a property on XCTestCase

. If you really need to use the delegation pattern (closure would be much, much simpler and more conditional), you can pass this as an additional parameter to your delegate method.



+2


source


I think your example code is incomplete, could you provide the complete code?

As @mattt suggests, each test should be unique and should not reuse another test variable.



As for your problem, you must declare all your expectations before launching waitForExpectationsWithTimeout:handler:

. You cannot create a new expectation after you start waiting for another.

0


source






More articles:


All Articles