Testing the presented UITableViewCell in a UITableView - ios

Question

I'm testing a simple tableView in a UIViewController for fun
class ViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
setup()
}
func setup() {
tableView.dataSource = self
tableView.delegate = self
tableView.register(CustomTableViewCell.self, forCellReuseIdentifier: "CustomTableViewCell")
}
var data = [1,2,3,4,5,6,7]
}
extension ViewController : UITableViewDelegate {
}
extension ViewController : UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomTableViewCell", for: indexPath)
cell.textLabel?.text = data[indexPath.row].description
return cell
}
}
and I want to write a test to check that the correct data is being displayed in a presented cell.
My test looks like the following:
var controller: ViewController?
override func setUp() {
controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ViewController") as? ViewController
}
func testViewCell() {
guard let controller = controller else {
return XCTFail("Could not instantiate ViewController")
}
let tableCell = Bundle(for: CustomTableViewCell.self).loadNibNamed("CustomTableViewCell", owner: nil)?.first as! CustomTableViewCell
tableCell.textLabel?.text = "2"
controller.loadViewIfNeeded()
let actualCell = controller.tableView!.cellForRow(at: IndexPath(row: 0, section: 0) )
XCTAssertEqual(actualCell, tableCell)
}
But the actual cell is nil. How can I test the presented cell in my view controller against an expected cell?

Answer 1

In your case I believe you will need to call reloadData on the table view as well. Try:
func testViewCell() {
guard let controller = controller else {
return XCTFail("Could not instantiate ViewController")
}
let tableCell = Bundle(for: CustomTableViewCell.self).loadNibNamed("CustomTableViewCell", owner: nil)?.first as! CustomTableViewCell
tableCell.textLabel?.text = "2"
controller.loadViewIfNeeded()
controller.tableView!.reloadData()
let actualCell = controller.tableView!.cellForRow(at: IndexPath(row: 0, section: 0) )
XCTAssertEqual(actualCell, tableCell)
}
In general for these cases I would also be worried about the view controller size. Since this is not put to any window it might in some cases use some intrinsic size and if that is for instance set to 0 your cells will not be there either. Maybe you should consider creating a window with fixed size (the size you want to test on) and apply your view controller as a root to it.
Also what do you expect to get from XCTAssertEqual(actualCell, tableCell)? Not sure but I would say this tests only pointers and will always fail. You will need to implement your own logic to check equality.