How to Test APIs in Swift 4? - ios

Question

I am new to Unit Testing. I have tested a lot of functions and I understood the concept, now I want to check the APIs. Is it possible? I guess so. This is the API:
func sendRequest(path: String, params: Dictionary<String, Any>, showSpinner: Bool, completionHandler: #escaping (JSON, Error?) -> Void) {
if Constants.IS_SIMULATOR {
print("Path: \(path)")
print("Params: \(params)")
}
if Constants.APP_DEL.reachability?.connection == .none {
completionHandler(JSON.null, NSError(domain: "No internet", code: 4, userInfo: nil))
return
}
UIApplication.shared.isNetworkActivityIndicatorVisible = true
if showSpinner {
HUD.show(.labeledProgress(title: "Loading...", subtitle: "Please wait"))
}
if let jsonData = try? JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) {
let url = NSURL(string: String(format: "%#%#", Constants.TEST_URL, path))!
let request = NSMutableURLRequest(url: url as URL)
request.httpMethod = "POST"
request.httpBody = jsonData
request.timeoutInterval = 120
let task = URLSession.shared.dataTask(with: request as URLRequest){ data, response, error in
DispatchQueue.main.async {
if error != nil {
print(" ........ \(String(describing: error?.localizedDescription))")
UIApplication.shared.isNetworkActivityIndicatorVisible = false
if showSpinner {
HUD.flash(.labeledError(title: "Server issue", subtitle: "Invalid response"), delay: 2.0)
}
completionHandler(JSON.null, NSError(domain: "Invalid response", code: 420, userInfo: nil))
return
}
if (data?.isGzipped)! {
let decompressedData: Data = try! data!.gunzipped()
var json: JSON = JSON.null
do {
json = try JSON(data: decompressedData)
}
catch {
print(error)
}
if Constants.IS_SIMULATOR {
print("Response: \(json)")
}
UIApplication.shared.isNetworkActivityIndicatorVisible = false
if json["status"].int == 200 {
if showSpinner {
HUD.flash(.success, delay: 0.5)
}
completionHandler(json["data"], nil)
}
else if json["status"].int == 202 {
if showSpinner {
HUD.hide()
}
completionHandler(JSON.null, NSError(domain: json["message"].string!, code: json["status"].int!, userInfo: nil))
}
else if json["status"].int == 310 {
if showSpinner {
HUD.hide()
}
completionHandler(json["data"], nil)
}
else if json["status"].int == 403 {
if showSpinner {
HUD.hide()
}
GeneralHelper.sharedInstance.displayAlertMessage(titleStr: "Session expired", messageStr: "Kindly login again.")
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
let domain = Bundle.main.bundleIdentifier!
UserDefaults.standard.removePersistentDomain(forName: domain)
UserDefaults.standard.synchronize()
Constants.APP_DEL.navC?.popToRootViewController(animated: false)
})
completionHandler(JSON.null, NSError(domain: json["message"].string!, code: json["status"].int!, userInfo: nil))
}
else {
if showSpinner {
HUD.flash(.labeledError(title: "", subtitle: json["message"].string!), delay: 2.0)
}
completionHandler(JSON.null, NSError(domain: json["message"].string!, code: json["status"].int!, userInfo: nil))
}
}
else {
let backToString = String(data: data!, encoding: String.Encoding.utf8) as String?
if Constants.IS_SIMULATOR {
print("Invalid response: \(String(describing: backToString))")
}
UIApplication.shared.isNetworkActivityIndicatorVisible = false
if showSpinner {
HUD.flash(.labeledError(title: "Server issue", subtitle: "Invalid response"), delay: 2.0)
}
completionHandler(JSON.null, NSError(domain: "Invalid response", code: 420, userInfo: nil))
}
}
}
task.resume()
}
}
So, to test this I have done this:
func testAPIWorking() {
params = ["ios_token": "dq6YJkKwEx0:APA91bFeOTfJRFd5G78xMkv3AvjSLA7ey2dJxTZZAtMuuC50CqWILNzNjdgqVpNpDn7R4I0DLoydIVDYKubpGfgfu1bwz1H3VNU4D88ek8PJTAjxrd3CWkW78g0sNv6EZDLlTqUFeNxh", "api_token": "kfRSHL0bVP1fSmxNY3NfEGs8g0ktKCbTsPRRbfarh3a5ISIcZLu3qdK07MJ9H4rJ", "player_id": 8083]
ServiceHelper.sharedInstance.sendRequest(path: "home", params: self.params, showSpinner: false) { (result, error) in
if error != nil {
XCTFail("Fail")
}
else {
}
}
}
I have added a breakpoint at task and it prints the task but then when I try to move to next line, instead of going into Dispatch it takes me out of that and stops at task.resume() and because of this I am not able to test the errors or expected results. Any help?

Answer 1

Here you have a completion handler, the api call in not sync. So you should to wait the result in your test. In Xcode you could use XCTestExpectation.
For example:
func testAPIWorking()
{
let expectation = XCTestExpectation.init(description: "Your expectation")
params = ["ios_token": "dq6YJkKwEx0:APA91bFeOTfJRFd5G78xMkv3AvjSLA7ey2dJxTZZAtMuuC50CqWILNzNjdgqVpNpDn7R4I0DLoydIVDYKubpGfgfu1bwz1H3VNU4D88ek8PJTAjxrd3CWkW78g0sNv6EZDLlTqUFeNxh", "api_token": "kfRSHL0bVP1fSmxNY3NfEGs8g0ktKCbTsPRRbfarh3a5ISIcZLu3qdK07MJ9H4rJ", "player_id": 8083]
ServiceHelper.sharedInstance.sendRequest(path: "home", params: self.params, showSpinner: false) { (result, error) in
if error != nil
{
XCTFail("Fail")
}
// The request is finished, so our expectation
expectation.fulfill()
}
// We ask the unit test to wait our expectation to finish.
self.waitForExpectations(timeout: 20)
}