View Controller TDD - ios

I am trying to add some unit tests to my project to test view controllers. However I seem to be having problems with seemingly simple things. I have created a sample project which I will refer to. https://github.com/pangers/ViewControllerTesting
The sample contains a UINavigationController as the initial view controller. The root view controller of the UINavigationController is FirstViewController. There is a button on FirstViewController that segues to SecondViewController. In SecondViewController there is an empty textfield.
The two tests I am trying to add are:
1) Check button title in FirstViewController is "Next Screen".
2) Check textfield in SecondViewController is empty, "".
I have heard reports of adding your swift files to both the main target and the test target is not good practice. But rather it is better to make whatever you want to access in your tests public and import the main target into the tests. So that is what I have done. (I have also set the "Defines Module" for the main target to YES as that is what I have read in a few articles aswell).
In FirstViewControllerTests I have instantiated the first view controller with the following:
var viewController: FirstViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
viewController = navigationController.topViewController as FirstViewController
viewController.viewDidLoad()
}
And I have added the test:
func testCheckButtonHasTextNextScreen() {
XCTAssertEqual(viewController.button.currentTitle!, "Next Screen", "Button should say Next Screen")
}
Similarly, for SecondViewControllerTest, I have set it up using:
var secondViewController:SecondViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
let firstviewController = navigationController.topViewController as FirstViewController
firstviewController.performSegueWithIdentifier("FirstToSecond", sender: nil)
secondViewController = navigationController.topViewController as SecondViewController
secondViewController.viewDidLoad()
}
And the test:
func testTextFieldIsBlank() {
XCTAssertEqual(secondViewController.textField.text, "", "Nothing in textfield")
}
They both fail and I am not too sure as to why. My suspicion is that the way I am instantiating the view controllers is not correct. Is the best way to instantiate the view controllers is to use the storyboard (just like it would if it were to run in real life)? Or is it acceptable to be instantiated via:
var viewController = FirstViewController()
What are you guys' experience with TDD and view controllers in swift?
I am using Swift with XCode 6.1.1.
Thanks in advance.
Solved
Ok after considering the answers from modocache and Mike Taverne, I've found my solution and I've learnt a few things which I will write down below.
1) I made anything class/method/variable that I want to test public. I do not need to add the swift files to the test target.
2) I only needed to set "Defines Module" for the "Main" target (as opposed to the "Test" target or the entire project)
3) When instantiating the storyboard, the bundle should be set to nil rather than NSBundle(forClass: self.dynamicType), otherwise tests will fail.
4) As modocache stated, it is good to give your view controller's a StoryboardID and instantiate them like so:
viewController = storyboard.instantiateViewControllerWithIdentifier("FirstViewController") as FirstViewController
However, instantiating the view controller like this ONLY instantiates the view controller alone, and not any navigation controllers that it may be embedded in. That means, attempting to do
XCTAssertFalse(viewController.navigationController!.navigationBarHidden, "Bar should show by default")
will result in a nil exception. I confirmed this with
XCTAssertNil(viewController.navigationController?, "navigation controller doesn't exist")
which resulted in a successful test.
Since I wanted to check the state of the navigation bar in FirstViewController, you must instantiate the view controller like so:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
viewController = navigationController.topViewController as FirstViewController
Now performing the test
XCTAssertFalse(viewController.navigationController!.navigationBarHidden, "nav bar should be showing by default")
results in a successful test.
5) let _ = viewController.view does indeed trigger viewDidLoad() which was confirmed by a test
6) let _ = viewController.view does not trigger viewWillAppear(), and I presume anything afterwards aswell. viewController.viewWillAppear(false/true) needs to be called manually to trigger it (Confirmed by a test).
Hopefully this will be of help to people. I will push the updated project to GitHub (link above) if anyone would like to play around with it.
Update #2
After all the above, I still could not figure out how to transition from the first view controller to the second view controller (so that I may test navigation bar properties in SecondViewControllerTests.swift). I tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
let firstVC = nc.topViewController as FirstViewController
firstVC.performSegueWithIdentifier("FirstToSecond", sender: nil)
secondVC = nc.topViewController as SecondViewController
which caused an error.
I also tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
let firstVC = nc.topViewController as FirstViewController
firstVC.toSecondVCButton.sendActionsForControlEvents(UIControlEvents.TouchUpInside)
secondVC = nc.topViewController as SecondViewController
which did not work.
I eventually tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
vc = storyboard.instantiateViewControllerWithIdentifier("Second") as SecondViewController
nc.pushViewController(vc, animated: false)
let _ = vc.view
vc.viewWillAppear(false)
which worked perfectly with my tests (allowed me to access navigation bar properties)!

I agree with #MikeTaverne's answer: I prefer accessing -[UIViewController view] in order to trigger -[UIViewController viewDidLoad], rather than calling it directly. See if the test failures for FirstViewController go away once you use this instead:
viewController = navigationController.topViewController as FirstViewController
let _ = viewController.view
I'd also recommend giving both view controllers identifiers in your storyboard. This will allow you to instantiate them directly, without accessing them via UINavigationController:
var secondViewController: SecondViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
secondViewController = storyboard.instantiateViewControllerWithIdentifier("SecondViewController")
as SecondViewController
let _ = secondViewController.view
}
Check out my talk on testing UIViewController at Brooklyn Swift for details: https://vimeo.com/115671189#t=37m50s (my presentation begins around the 37'50" mark).

I've begun unit testing view controllers recently, and it poses some unique challenges.
One challenge is getting the view to load. Looking at your set up for FirstViewController, you are trying to do this with viewController.viewDidLoad().
My suggestion is to replace that line with this:
let dummy = viewController.view
Accessing the .view property will force the view to load. This will trigger the .viewDidLoad in your ViewController, so don't call that method explicitly in your test.
This approach is considered hacky by some people, but it is simple and effective. (See Clean way to force view to load subviews early)
As an aside, I am finding the best way to test view controllers is to move as much code out of the view controllers as possible into other classes that are more easily tested.
If your view controller is defined in a storyboard, then you need to instantiate it that way for your outlets to be set up properly. Trying to initialize it like an ordinary class won't work.

Related

Instantiate view controller created in storyboard from a storyboard less view controller

I have two View Controllers:
MainController.swift - Soryboard less view controller
SecondController.swift - Storyboard view controller
How can I instantiate SecondController in MainController?
storyboard?.instantiateViewController(withIdentifier: _) does not work because MainController has no storyboard.
How can I open SecondController in MainController?
It depends what “open” means. You can, for example, say
present(SecondController(), animated:true)
Or you might push it onto a navigation controller if there is one in the interface. That sort of thing, and similar, are quite standard. Storyboards are a relatively recent innovation; when I started programming iOS everything was done without them.
Use init(name:bundle:):
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondVC = storyboard.instantiateViewController(withIdentifier: "SecondController") as! SecondController
If you want to see example usage in an app then take a look at this file.

How to dismiss any popover viewcontrollers when activated in iOS?

I have some ViewControlls for settings, info etc.
Users can close the app settings ViewController open(I mean popover the ViewController).
When local notification is received I want the the app go to the root viewcontroller and dismiss any popovers.
EDIT
this answer is only good if the VC you are trying to go back to does not need any special initialization, since this method creates a new instance of it. keep that in mind.
Try this method, it will remove anything in your stack of View Controllers and make a specific View Controller presented on screen:
func dismissAllAndNavigate(){
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let window = appDelegate.window
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let rootController = mainStoryboard.instantiateViewController(withIdentifier: "some identifier") as! UIViewController
window?.rootViewController = rootController
}
Just make sure that the name of the storyboard is correct and the identifier of the view controller in that storyboard is defined.

Programatically creating Segues in ios swift

In my app I use side bar as in facebook. when the user slides out the side bar a uiimageview is displayed. when user taps on the image it takes hm to a different viewcontroller. the problem i am facing is that I have created sidebar programatically and the other view to which I want to navigate the user is created using storyboard. So my source view is created programatically and destination view is created using storyboard. So can someone explain me if there is any way of using "Segue" in this scenario. Since i can not create segue using storyboard I need to do it programatically but even after a lot of googling i could not find the answer.
Well, to get another instance of another storyboard programmatically you can use something like:
let newController = UIStoryboard(name: "MyStoryboard", bundle: nil).instantiateViewControllerWithIdentifier("MyIdentifier") as! MyViewController
and then you push to your navigation controller, or add as a child view controller or something...
If you don't wanna bother with identifiers you can just use the instantiateInitialViewController instead of instantiateViewControllerWithIdentifier
Might help
"userSB" is the viewcontroller storyboard identifier
#IBAction func tapSearchCriteria(_ sender: Any?) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let aVC = storyboard.instantiateViewController(withIdentifier: "userSB") as? AViewController
aVC?.modalPresentationStyle = UIModalPresentationStyle.custom
aVC?.transitioningDelegate = self
aVC?.udelegate = self
self.present(aVC!, animated: true, completion: nil)
}

Best way to conditionally switch root view controller at iOS app start-up

New iOS developer here. I am working on a project which requires that the user log-in when they first open the app. From then on, I want the app to open directly to the main flow of the app (a tab bar controller in my case). After doing some research, I have come across what seems to be two main ways to do implement this functionality:
1) Conditionally set the root view controller of the app's window in the app delegate. For example:
if userLoggedIn {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let tabBarController: UITabBarController = storyboard.instantiateViewControllerWithIdentifier("TabBarController") as! UITabBarController
self.window?.makeKeyAndVisible()
self.window?.rootViewController = tabBarController
} else {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let logInViewController: LogInViewController = storyboard.instantiateViewControllerWithIdentifier("LogInViewController") as! LogInViewController
self.window?.makeKeyAndVisible()
self.window?.rootViewController = logInViewController
}
2) Use a navigation controller as the app's root view controller, and conditionally set the view controllers managed by the navigation controller in the app delegate. For example:
if userLoggedIn {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let tabBarController: UITabBarController = storyboard.instantiateViewControllerWithIdentifier("TabBarController") as! UITabBarController
let navigationController = self.window?.rootViewController as! UINavigationController
navigationController.navigationBarHidden = true
navigationController.setViewControllers([tabBarController], animated: true)
} else {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let tabBarController: ViewController = storyboard.instantiateViewControllerWithIdentifier("LoginViewController") as! ViewController
let navigationController = self.window?.rootViewController as! UINavigationController
navigationController.navigationBarHidden = true
navigationController.setViewControllers([tabBarController], animated: true)
}
If I go with the second option, I can easily transition to the app's main flow (let's say a tab bar controller) after I'm done logging in the user. In an appropriate place in the LogInViewController, I can say:
// Transition to tab bar controller
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let tabBarController: UITabBarController = storyboard.instantiateViewControllerWithIdentifier("TabBarController") as! UITabBarController
self.navigationController?.setViewControllers([tabBarController], animated: true)
Pretty easy.
As for the first method, I am not sure how I would transition to the main content of the app after logging the user in.
What I am looking for here is the "best" way to handle login flow. I've listed two methods but maybe there is another that is even better. Also, if the "best" method is the first I have listed, how can I get to my tab bar controller after I finish logging the user in? Thanks!
Those are both fine options. One thing that I've done that has worked well is implemented a custom container view controller as the root of my app (this might be a subclass of my main view controller like a tab bar controller or navigation controller).
In this container view controller, I can put code to display and dismiss a login view controller based on the user's login status. Note: you can also use temporary full-screen views here to hide your app's main content while the login screen is shown/dismissed - this is an easy way to get very smooth app launch transitions.
I particularly like this method, because the rest of the app doesn't need to worry about the details. Your container can act like a normal tab bar controller or navigation controller, but underneath, you get to encapsulate all of the login UI logic in one place.

ios swift uitabbar replace view controllers crashes

I am really struggling with what should be a simple bit of code.
I have an ios app that has 4 tabs in the uitabcontroller, depending on the a setting in another tab I wanted to replace the controller the first tab goes to. I found that I couldnt simply replace this first tab (although i managed it somehow for a couple of builds then it stopped working after a clean).
So I went for the option of replacing the viewcontrollers that the tab controller references with the .setViewControllers method. I call this from my viewcontroller after the viewdidload method.
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc0 = storyboard.instantiateViewControllerWithIdentifier("collection")
let vc4 = storyboard.instantiateViewControllerWithIdentifier("profilenews1")
let vc1: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("news") as UIViewController
let vc2: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("create") as UIViewController
let vc3: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("search") as UIViewController
let controllers = [vc0,vc4]
self.tabBarController?.setViewControllers(controllers, animated: true)
From the research I have done this should work, setViewControllers is documented and I have seen numerous objective c examples but I get EXEC_BAD_INSTRUCTION thrown.
I have checked that the tabcontroller is correct before I replace by doing
println("number of navs: \(self.tabBarController?.viewControllers?.count)")
And that prints the correct number of controllers.
Any ideas?

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