Unit Testing a method that uses REST calls in Swift - json

Question

Let me start out by stating I'm still unfamiliar with what I'm trying to do, but striving to get better!
I'm working on a project that I'm writing unit tests for and I'm having some trouble with how to approach the problem.
The method I'm testing utilizes a RESTAPI call to verify a users credentials. I'm not sure what the best way to unit test would be.
Here is the method I'm looking to make the Unit test for:
#IBAction func loginBtnActivate(sender: UIButton) {
let enteredEmail: String = emailField.text!
let enteredPassword: String = passwordField.text!
let testInfo:[String: AnyObject] = ["User": enteredEmail, "Password": enteredPassword]
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
if statusCode == 200 {
let AuthToken: TokenObject = (TokenObject(json: json))
try! self.keychain.set(AuthToken.Authorization, key:"Authorization")
try! self.keychain.set(AuthToken.LifeTime, key: "LifeTime")
try! self.keychain.set(AuthToken.UUID, key: "UUID")
NSOperationQueue.mainQueue().addOperationWithBlock {
self.performSegueWithIdentifier("loginToMyHealth", sender: nil)
}
} else if statusCode == 401 {
self.incorrectLoginAlert()
} else if statusCode == 503 {
print("Service Unavailable Please Try Again Later")
}
}
}
This is currently the approach I'm taking:
func testLoginInfoMatchesDataOnServer(){
let enteredEmail: String = "user"
let enteredPassword: String = "password"
let testInfo:[String: AnyObject] = ["User": enteredEmail, "Password": enteredPassword]
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
XCTAssert(statusCode == 200, "statusCode is not matching the server data")
}
I'm simply verifying that the Rest call is successful and that the credentials are matching the JSON. The XCTAssert call doesn't appear to be working correctly. No matter what I put as the first parameter, XCTAssert doesn't affect whether the test is successful or not.
Example, if I put:
XCTAssert(false, "statusCode is not matching the server data")
The test will still pass regardless of what I put. If I place the Assert function outside the brackets then it appears the variable "statusCode" is out of scope so I'm stuck with a
Use of unresolved identifier 'statusCode'.
func testLoginInfoMatchesDataOnServer(){
let enteredEmail: String = "user"
let enteredPassword: String = "password"
let testInfo:[String: AnyObject] = ["User": enteredEmail, "Password": enteredPassword]
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
}
XCTAssert(statusCode == 200, "statusCode is not matching the server data")
}
I was looking at this guide for help.. Would this be a better approach for what I'm trying to do?
http://roadfiresoftware.com/2016/06/how-do-you-unit-test-rest-calls-in-swift/
Again my understanding of some core concepts might be entirely off so I really appreciate your advice here!
Thanks in advance!
Sean W.

Answer 1

First Few problems with your code
function test(){
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
}//PostLogin call ends
XCTAssert(statusCode == 200, "statusCode is not matching the server data") // Here StatusCode is not accessible as outside the block
}// end function
If you want to use Status Code you should do
function test(){
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
XCTAssert(statusCode == 200, "statusCode is not matching the server data") // Here StatusCode is accessible inside the block
}//PostLogin call ends
}// end function
But this will fail since you need to wait for the response. That can be done using
waitForExpectationsWithTimeout(5)
So proper way to call this would be --
function test(){
let URL = NSURL(string: "http://google.com/")!
let expectation = expectationWithDescription("GET \(URL)")
RestApiManager.sharedInstance.postLogin(testInfo) { (json, statusCode) in
XCTAssert(statusCode == 200, "statusCode is not matching the server data") // Here StatusCode is accessible inside the block
expectation.fulfill()
}//PostLogin call ends
waitForExpectationsWithTimeout(5){ error in
if let error = error {
print("Error: \(error.localizedDescription)")
}
}//Wait block end
}// end function
Important lines here are
expectation.fulfill() // tells process is complete
and
waitForExpectationsWithTimeout(5){} //tells wait for 5secs or throw error
For more info