I'm trying to write some UnitTests for the first time. My pattern is MVP and I'm trying to test my Presenter. I've created mock class: class TeamViewMock: TeamViewPresenterProtocol { }. It contains all the methods from my real Presenter. Inside the each method I'm trying to set the new value for the property, so when the method called - property should get a new value.
Only one property gets new value out of 4 and I've no clue why the other ones didn't get it.
You may see it in the following code
import XCTest
#testable import NHL
class TeamViewPresenterTest: XCTestCase {
var presenter: TeamViewPresenter!
var viewMock: TeamViewMock!
func setupPresenter() {
viewMock = TeamViewMock()
presenter = TeamViewPresenter(with: viewMock)
}
func testGetData() {
setupPresenter()
presenter.getData(completion: {_ in })
XCTAssertTrue(viewMock.isStart) // This one works and returns true
XCTAssertTrue(viewMock.isStop) // Return error
XCTAssertTrue(viewMock.isEndRefreshing) // Return error
XCTAssertTrue(viewMock.isReload) // Return error
}
}
class TeamViewMock: TeamViewPresenterProtocol {
var isStart = false
var isStop = false
var isEndRefreshing = false
var isReload = false
func startAnimating() {
self.isStart = true // Testing stops here and doesn't go any further...
}
func stopAnimating() {
self.isStop = true
}
func endRefreshing() {
self.isEndRefreshing = true
}
func reloadView(_ teams: NHLDTO) {
self.isReload = true
}
}
class TeamViewPresenter {
// MARK: - Public Properties
private weak var view: TeamViewPresenterProtocol?
public let dataFetcherService = DataFetcherService()
// MARK: - Initializers
init(with view: TeamViewPresenterProtocol) {
self.view = view
}
// MARK: - Public Methods
public func getData(completion: #escaping (AppError) -> Void) {
view?.startAnimating() // Testing stops here and doesn't go any further, but still returns true for the property isStart and error for the rest
dataFetcherService.fetchTeamData { [weak self] result in
guard let self = self else { return }
switch result {
case .failure(let error):
completion(error)
print(error)
case .success(let teams):
guard let teams = teams else { return }
self.view?.reloadView(teams)
self.view?.stopAnimating()
self.view?.endRefreshing()
}
}
}
}
protocol TeamViewPresenterProtocol: AnyObject {
func startAnimating()
func stopAnimating()
func reloadView(_ teams: NHLDTO)
func endRefreshing()
}
Related
In my swift code below the goal is to delete the first item in the core data boolean attribute. My code is not working below but its close to what I used to successfully fetch a boolean value. I don't really know what to add. There is a base class and a helper class.
class ViewController: UIViewController {
func deleteBool(imageNo:Int) {
// first check the array bounds
let info = helpBool.shareInstance.fetchBool()
if info.count > imageNo {
}
}
override func viewDidLoad() {
super.viewDidLoad()
deleteBool(imageNo: 1)}}
HELPER CLASS
class helpBool: UIViewController{
static let shareInstance = helpBool()
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
func deleteBool(_ boolean: Bool) {
let imageInstance = OnOff(context: context)
imageInstance.bool = boolean
do {
try context.delete()
print("text is saved")
} catch {
print(error.localizedDescription)
}
}
I am building a simple currency converter app. When ViewController gets opened it calls a function from CoinManager.swift:
class ViewController: UIViewController {
var coinManager = CoinManager()
override func viewDidLoad() {
super.viewDidLoad()
coinManager.delegate = self
coinManager.getCoinPrice(for: "AUD", "AZN", firstCall: true)
}
...
}
CoinManager.swift:
protocol CoinManagerDelegate {
func didUpdatePrice(price1: Double, currency1: String, price2: Double, currency2: String)
func tellTableView(descriptions: [String], symbols: [String])
func didFailWithError(error: Error)
}
struct CoinManager {
var delegate: CoinManagerDelegate?
let baseURL = "https://www.cbr-xml-daily.ru/daily_json.js"
func getCoinPrice (for currency1: String,_ currency2: String, firstCall: Bool) {
if let url = URL(string: baseURL) {
let session = URLSession(configuration: .default)
let task = session.dataTask(with: url) { (data, response, error) in
if error != nil {
self.delegate?.didFailWithError(error: error!)
return
}
if let safeData = data {
if let coinData = self.parseJSON(safeData) {
if firstCall {
var descriptions = [""]
let listOfCoins = Array(coinData.keys)
for key in listOfCoins {
descriptions.append(coinData[key]!.Name)
}
descriptions.removeFirst()
self.delegate?.tellTableView(descriptions: descriptions, symbols: listOfCoins)
}
if let coinInfo1 = coinData[currency1] {
let value1 = coinInfo1.Value
if let coinInfo2 = coinData[currency2] {
let value2 = coinInfo2.Value
//this line does not do anything the second time I call getCoinPrice:
self.delegate?.didUpdatePrice(price1: value1, currency1: currency1, price2: value2, currency2: currency2)
//And this one does work
print("delegate:\(currency1)")
} else {
print("no name matches currency2")
}
} else {
print("no name matches currency1")
}
}
}
}
task.resume()
}
}
func ParseJSON....
}
The method it calls (ViewController.swift):
extension ViewController: CoinManagerDelegate {
func didUpdatePrice(price1: Double, currency1: String, price2: Double, currency2: String) {
print("didUpdatePrice called")
DispatchQueue.main.async {
let price1AsString = String(price1)
let price2AsString = String(price2)
self.leftTextField.text = price1AsString
self.rightTextField.text = price2AsString
self.leftLabel.text = currency1
self.rightLabel.text = currency2
}
}
...
}
and finally, CurrencyViewController.swift:
var coinManager = CoinManager()
#IBAction func backButtonPressed(_ sender: UIBarButtonItem) {
dismiss(animated: true, completion: nil)
coinManager.getCoinPrice(for: "USD", "AZN", firstCall: false)
}
So when I launch the app i get following in my debug console:
didUpdatePrice called
delegate:AUD
And when I call getCoinPrice() from CurrencyViewController the delegate method does not get called. I know that my code goes through the delegate function line as I get this in debug console:
delegate:USD
I just can't wrap my head around it. The delegate method does not work when gets called second time. Even though it is called by the same algorithm
It's because you're creating a new object of CoinManager in CurrencyViewController where the delegate is not set. So you've to set the delegate every time you create a new instance of CoinManager.
#IBAction func backButtonPressed(_ sender: UIBarButtonItem) {
dismiss(animated: true, completion: nil)
coinManager.delegate = self
coinManager.getCoinPrice(for: "USD", "AZN", firstCall: false)
}
Update: So, the above solution would require for you to make the delegate conformance in CurrencyViewController. If you're looking for an alternate solution you should probably pass the instance of coinManager in ViewController to CurrencyViewController. For that here are the things you need to update.
In CurrencyViewController:
class CurrencyViewController: UIViewController {
var coinManager: CoinManager! // you can optional unwrap if you intent to use CurrencyViewController without coinManager
//...
And in ViewController:
currencyViewController.coinManager = coinManager // passing the instance of coinManager
Can you share the full code of CoinManager? I see this part
if firstCall {
...
}
Maybe some block logic here or unhandled cases? And can you share the full code of protocol?
Also try to print something before this code:
if error != nil {
self.delegate?.didFailWithError(error: error!)
return
}
As I understand, it is best to only test public methods of a class.
Let's have a look at this example. I have a view model for the view controller.
protocol MyViewModelProtocol {
var items: [SomeItem] { get }
var onInsertItemsAtIndexPaths: (([IndexPath]) -> Void)? { get set }
func viewLoaded()
}
class MyViewModel: MyViewModelProtocol {
func viewLoaded() {
let items = createDetailsCellModels()
updateCellModels(with: items)
requestDetails()
}
}
I want to test class viewLoaded(). This class calls two other methods - updateItems() and requestDetails()
One of the methods sets up the items and the other one call API to retrieve data and update those items. Items array us updated two times and onInsertItemsAtIndexPaths are called two times - when setting up those items and when updating with new data.
I can test whether after calling viewLoaded() expected items are set up and that onInsertItemsAtIndexPaths is called.
However, the test method will become rather complex.
What is your view, should I test those two methods separately or just write this one huge test?
By testing only viewLoaded(), my idea is that the implementation can change and I only care that results are what I expect.
I think the same thing, only public functions should be tested, since public ones use private ones, and your view on MVVM is correct. You can improve it by adding a DataSource and a Mapper that allows you to improve testing.
However, yes, the test seems huge to me, the tests should test simple units and ensure that small parts of the code work well, with the example you show is difficult, you need to divide by layers (clean code).
In the example you load the data into the viewModel and make it difficult to mockup the data. But if you have a Domain layer you can pass the UseCase mock to the viewModel and control the result. If you run a test on your example, the result will also depend on what the endpoint returns. (404, 200, empty array, data with error ...). So it is important, for testing purposes, to have a good separation by layers. (Presentation, Domain and Data) to be able to test each one separately.
I give you an example of how I would test a view mode, sure there are better and cooler examples, but it's an approach.
Here you can see a viewModel
protocol BeersListViewModel: BeersListViewModelInput, BeersListViewModelOutput {}
protocol BeersListViewModelInput {
func viewDidLoad()
func updateView()
func image(url: String?, index: Int) -> Cancellable?
}
protocol BeersListViewModelOutput {
var items: Box<BeersListModel?> { get }
var loadingStatus: Box<LoadingStatus?> { get }
var error: Box<Error?> { get }
}
final class DefaultBeersListViewModel {
private let beersListUseCase: BeersListUseCase
private var beersLoadTask: Cancellable? { willSet { beersLoadTask?.cancel() }}
var items: Box<BeersListModel?> = Box(nil)
var loadingStatus: Box<LoadingStatus?> = Box(.stop)
var error: Box<Error?> = Box(nil)
#discardableResult
init(beersListUseCase: BeersListUseCase) {
self.beersListUseCase = beersListUseCase
}
func viewDidLoad() {
updateView()
}
}
// MARK: Update View
extension DefaultBeersListViewModel: BeersListViewModel {
func updateView() {
self.loadingStatus.value = .start
beersLoadTask = beersListUseCase.execute(completion: { (result) in
switch result {
case .success(let beers):
let beers = beers.map { DefaultBeerModel(beer: $0) }
self.items.value = DefaultBeersListModel(beers: beers)
case .failure(let error):
self.error.value = error
}
self.loadingStatus.value = .stop
})
}
}
// MARK: - Images
extension DefaultBeersListViewModel {
func image(url: String?, index: Int) -> Cancellable? {
guard let url = url else { return nil }
return beersListUseCase.image(with: url, completion: { (result) in
switch result {
case .success(let imageData):
self.items.value?.items?[index].image.value = imageData
case .failure(let error ):
print("image error: \(error)")
}
})
}
}
Here you can see the viewModel test using mocks for the data and view.
class BeerListViewModelTest: XCTestCase {
private enum ErrorMock: Error {
case error
}
class BeersListUseCaseMock: BeersListUseCase {
var error: Error?
var expt: XCTestExpectation?
func execute(completion: #escaping (Result<[BeerEntity], Error>) -> Void) -> Cancellable? {
let beersMock = BeersMock.makeBeerListEntityMock()
if let error = error {
completion(.failure(error))
} else {
completion(.success(beersMock))
}
expt?.fulfill()
return nil
}
func image(with imageUrl: String, completion: #escaping (Result<Data, Error>) -> Void) -> Cancellable? {
return nil
}
}
func testWhenAPIReturnAllData() {
let beersListUseCaseMock = BeersListUseCaseMock()
beersListUseCaseMock.expt = self.expectation(description: "All OK")
beersListUseCaseMock.error = nil
let viewModel = DefaultBeersListViewModel(beersListUseCase: beersListUseCaseMock)
viewModel.items.bind { (_) in}
viewModel.updateView()
waitForExpectations(timeout: 10, handler: nil)
XCTAssertNotNil(viewModel.items.value)
XCTAssertNil(viewModel.error.value)
XCTAssert(viewModel.loadingStatus.value == .stop)
}
func testWhenDataReturnsError() {
let beersListUseCaseMock = BeersListUseCaseMock()
beersListUseCaseMock.expt = self.expectation(description: "Error")
beersListUseCaseMock.error = ErrorMock.error
let viewModel = DefaultBeersListViewModel(beersListUseCase: beersListUseCaseMock)
viewModel.updateView()
waitForExpectations(timeout: 10, handler: nil)
XCTAssertNil(viewModel.items.value)
XCTAssertNotNil(viewModel.error.value)
XCTAssert(viewModel.loadingStatus.value == .stop)
}
}
in this way you can test the view, the business logic and the data separately, in addition to being a code that is very reusable.
Hope this helps you, I have it posted on github in case you need it.
https://github.com/cardona/MVVM
I have a usermodel that checks the backend if the email exists - then I drill back into a viewcontroller and set a boolean value that should trigger a function run. However the value is unchanged and I am trying to change this value from the usermodel but it is not accessible. I understand why it does not work.. but do not know how to resolve the issue.
static func sendEmailWithResetLink(email: String) {
let params : Parameters = [
PARAM_EMAIL : email
]
request(URL_RESET_PASSWORD as String, method: .post, parameters: params, headers: nil).responseJSON {
(response: DataResponse<Any>) in
hideProgress()
print("this is response \(response)")
switch(response.result)
{
case .success(_):
print("it did not fail")
let passwordResetVC = PasswordResetViewController()
passwordResetVC.hasFailed = false
break
case .failure(_):
print("it failed")
let passwordResetVC = PasswordResetViewController()
//here boolean is set that I am trying to access in viewcontroller
passwordResetVC.hasFailed = true
break
}
}
}
Here's what I would suggest. You probably have some of these in place already:
Create an PasswordResetViewController object has an #IBAction func resetButtonClicked triggered by a button or whatever, which kicks off the password reset process.
Create a UserManager class. This class is responsible for all profile management activies in your app. Among other things, it has the ability to reset user passwords. This UserManager would probably be a singleton, that' sprobably good enough for now.
Create a new UserManagerDelegate protocol. Add to it all capabilities that are required by the UserManager to inform them of whatever happened. For example: var passwordResetHasFailed: Bool { get set }.
Extend your PasswordResetViewController conform to this protocol.
Your VC gets a reference to the singleton UserManager object, stores it in an instance variable, and uses that to access the shared object from then on.
Make your PasswordResetViewController register itself as the delegate to the user manager, with userManager.delegate = self
The #IBAction func resetButtonClicked will just call userManager.resetPassword()
Your UserManager does whatever it needs to do to reset the user's password.
When it's done, it'll call self.delegate?.passwordResetHasFailed = true/false.
Since your PasswordResetViewController registered itself as the delegate of the UserManager, when the operation is done, its passwordResetHasFailed property will be changed, giving it a chance to respond (by updating some UI or whatever).
There are some limitations to this approach, but it's a decent way to get started. Some thing to note:
This lets you unit test your PasswordResetViewController. You can create a MockUserManager, and set tesPasswordResetViewController.userManager = MockUserManager(), allowing you to separate out the user manager, and test PasswordResetViewController in isolation.
You'll run into issues if you need multiple objects to subscribe to receive delegate call backs (since there can only be 1 delegate object). At that point, you can switch to using something like Promises, RxSwift or Combine. But that's a problem for a later time, and the migration would be easy.
Going off of #Alexander - Reinstate Monica and what I assume what the code to look like to approach your problem.
Using MVC:
In Models folder (data/ logic part)
public class User {
private var name: String!
private var userEmail: String!
public var hasFailed: Bool?
init() {
name = ""
userEmail = ""
hasFailed = nil
}
public func setName(name: String) { self.name = name }
public func getName() -> String { return name }
public func setEmail(email: String) { userEmail = email }
public func getEmail() ->String { return userEmail }
public static func sendEmailWithRestLing(email: String) {
// your other code
switch response.result {
case .success(_):
//your code
hasFailed = false
break
case .failuare(_):
// your code
hasFailed = true
break
}
}
}
User Manager class applying singleton design
final class UserManager {
private var user = User()
static let instance = UserManager()
private init(){}
public func userName(name: String) {
if (name.count > 3) {
user.setName(name: name)
}
else { print("user name is too short") }
}
public func userEmail(email: String) {
if (email.count > 3) {
user.setEmail(email: email)
}
else { print("user email is too short") }
}
public func getUserName() -> String {
let name = user.getName()
if (name.isEmpty) { return "user name is Empty" }
return name
}
public func getUserEmail() -> String {
let email = user.getEmail()
if (email.isEmpty) { return "user email is Empty" }
return email
}
public func doKatieTask(link: String) -> Int {
guard let myValue = user.hasFailed else {
return -1
}
if (myValue) { return 1}
return 0
}
}
So, Now in the Controllers folder and since we a one-to-one relation we will use delegate design pattern. If had had one-to-many with the view controller. Use observers.
class ViewController: UIViewController {
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var emailTextField: UITextField!
var _hasFail: Bool!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func doTask() {
UserManager.instance.userName(name: nameTextField.text!)
UserManager.instance.userEmail(email: emailTextField.text!)
switch UserManager.instance.doKatieTask(link: emailTextField.text!) {
case 0:
_hasFail = false
break
case 1:
_hasFail = true
break
default:
print("hasFailed is nil")
break
}
if let vc = storyboard?.instantiateViewController(identifier: "passwordVC") as? PasswordResetViewController {
vc.modalPresentationStyle = .fullScreen
vc.delegate = self
self.present(vc, animated: true, completion: nil)
}
}
}
extension ViewController: KatieDelegate {
var hasFailed: Bool {
get {
return _hasFail
}
set {
_hasFail = newValue
}
}
}
In PasswordReset UIViewController
protocol KatieDelegate {
var hasFailed: Bool { get set }
}
class PasswordResetViewController: UIViewController {
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var emailLabel: UILabel!
var delegate: KatieDelegate?
override func viewDidLoad() {
super.viewDidLoad()
nameLabel.text = UserManger.instance.getUserName()
emailLabel.text = UserManger.instance.getUserEmail()
if let delegate = delegate {
print("The value for has failed is: .....\(delegate.hasFailed)!")
}
else { print("error with delegate") }
}
}
I am using RxSwift and Moya. I am getting
fatal error: unexpectedly found nil while unwrapping an Optional value
error at line authors.map {... in tableViewController. When I print authors I found out it is nil. And I couldn't find where the problem is. I am using Moya-ObjectMapper/RxSwift library. In the latest release Observable+Objectmapper.swift file is missing so I found it on github and replaced it.
//import libraries
class AuthorsTableViewController: UITableViewController {
var viewModel: AuthorsViewModelType!
var authors: Driver<RequestResult<[Author]>>!
private let disposeBag = DisposeBag()
override func viewDidLoad() {
super.viewDidLoad()
setUpBindings()
}
func setUpBindings() {
tableView.dataSource = nil
tableView.delegate = nil
authors.map { result -> [Author] in ---> Here
...
}.disposed(by: disposeBag)
}
}
My ViewModel:
//import libraries
public protocol AuthorsViewModelType {
func getAuthors(destination: YazarAPI) -> Driver<RequestResult<[Author]>>
}
public class AuthorsViewModel: AuthorsViewModelType {
fileprivate var provider = YazarAPI.sharedProviderInstance
public func getAuthors(destination: YazarAPI) -> Driver<RequestResult<[Author]>> {
return provider.request(destination)
.observeOn(MainScheduler.instance)
.filterSuccessfulStatusCodes()
.mapAuthors(destination: destination)
.map { .Success($0) }
.asDriver(onErrorRecover: { error in
return .just(.Error(ReqestError(description: error.localizedDescription, code: .requestError)))
})
}
}
private extension Observable where E == Response {
func mapAuthors(destination: YazarAPI) -> Observable<[Author]> {
let authors: Observable<[Author]>
switch destination {
case .authors:
authors = self.mapObject(Authors.self).map { $0.authors ?? [] }
default:
fatalError("Unexpected request type \"\(destination)\"")
}
return authors
}
}
You should assign values to viewModel and authors properties, or if you're assigning them somewhere, move setupBindings() there too.
P.S.: It is not RxSwift question