# \[iOS] UnitTest With XCode 此篇, 將利用1個簡單的project來介紹Xcode內建的Unit Test, 該project只會做簡單的幾件事情: (1.) 當user按下Calculate Button時計算2個輸入數字X與Y的總和, 並將結果顯示在resultLabel上. (2.) 當user按下Request Button時發送get request, 並將response data顯示在responseTextView上. (3.) 在viewWillAppear生命週期時清空resultLabel與responseTextView的文字 ![](/files/-LI1YHOA6q106VkgiuYk) **你可以在**[**這裡**](https://drive.google.com/drive/folders/1aULKZb5uy58U-0kSEMlhffvHoXXHt_lP?usp=sharing)**下載完整的project.** 此Project裡有3個主要的classes, (1.) ViewController (在viewWillAppear時呼叫clearData function將label與textView清空) ```swift class ViewController: UIViewController { @IBOutlet weak var xTextField: UITextField! @IBOutlet weak var yTextField: UITextField! @IBOutlet weak var resultLabel: UILabel! @IBOutlet weak var urlTextField: UITextField! @IBOutlet weak var responseTextView: UITextView! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. }​ override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) self.clearData() } override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. }​ func clearData(){ self.resultLabel.text = "" self.responseTextView.text = "" } @IBAction func calculateButton_Touch(_ sender: Any) { let x = Math.stringToInt(string: self.xTextField.text) let y = Math.stringToInt(string: self.yTextField.text) var outputString = "invalid input" if let x = x, let y = y { let result = Math.add(x: x, y: y) outputString = "\(result)" } self.resultLabel.text = outputString } @IBAction func requestButton_Touch(_ sender: Any) { if let url = urlTextField.text { Network.dataTask(urlString: url) { (data, response, error) in guard error == nil else { self.responseTextView.text = "\(error!.localizedDescription)" return } if let data = data { if let jsonString = String(data: data, encoding: .utf8){ DispatchQueue.main.async { self.responseTextView.text = jsonString class ViewController: UIViewController { @IBOutlet weak var xTextField: UITextField! @IBOutlet weak var yTextField: UITextField! @IBOutlet weak var resultLabel: UILabel! @IBOutlet weak var urlTextField: UITextField! @IBOutlet weak var responseTextView: UITextView! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. } ​ override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) self.clearData() } override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } ​ func clearData(){ self.resultLabel.text = "" self.responseTextView.text = "" } @IBAction func calculateButton_Touch(_ sender: Any) { let x = Math.stringToInt(string: self.xTextField.text) let y = Math.stringToInt(string: self.yTextField.text) var outputString = "invalid input" if let x = x, let y = y { let result = Math.add(x: x, y: y) outputString = "\(result)" } self.resultLabel.text = outputString } @IBAction func requestButton_Touch(_ sender: Any) { if let url = urlTextField.text { Network.dataTask(urlString: url) { (data, response, error) in guard error == nil else { self.responseTextView.text = "\(error!.localizedDescription)" return } if let data = data { if let jsonString = String(data: data, encoding: .utf8){ DispatchQueue.main.async { self.responseTextView.text = jsonString } } } } } } } ``` ​ (2.) Math add: 將2個數字相加並回傳 stringToInt: string轉int並回傳結果, 若失敗回傳nil ```swift class Math: NSObject { class func add(x: Int, y: Int) -> Int { let result = x + y return result } class func stringToInt(string: String?) -> Int? { var result:Int? = nil if let string = string { result = Int(string) } return result } } ``` (3.) Network dataTask: 發送一個request並回傳response ```swift class Network: NSObject { ​ class func dataTask(urlString: String, responseHandler: @escaping (Data?, URLResponse?, Error?) -> Swift.Void) { let url = URL(string: urlString) if let url = url { let request = URLRequest(url: url) let task = URLSession.shared.dataTask(with: request) { (data, response, error) in print("Retrieved data") responseHandler(data, response, error) } task.resume() } else { let myError = NSError(domain:"", code: -9999, userInfo:nil) responseHandler(nil, nil, myError) } } } ``` ​ ## **建置Unit Test** 首先, 如果您的project尚未加入Unit Test, 可以從**File -> New -> Target** 新建一個Unit Test Bundle. ![File -> New -> Target](/files/-LI1Y9WYO0300R4677K1) ![](/files/-LHqLsmit2t7H6nvsW9r) ![選擇iOS Unit Testing Bundle](/files/-LI1YS22uqDYw3JDbknN) 完成後, 在XCode左側目錄欄會發現多了一個Tests的目錄, 且裡面已經幫你建立好了1個default的測試class. ![](/files/-LI1YbknOEv6Xe1JqpWK) ​ 該class的預設內容為: ```swift import XCTest ​ class TestProjectTests: XCTestCase { override func setUp() { super.setUp() // Put setup code here. This method is called before the invocation of each test method in the class. } override func tearDown() { // Put teardown code here. This method is called after the invocation of each test method in the class. super.tearDown() } func testExample() { // This is an example of a functional test case. // Use XCTAssert and related functions to verify your tests produce the correct results. } func testPerformanceExample() { // This is an example of a performance test case. self.measure { // Put the code you want to measure the time of here. } } } ``` 我們可以注意到, Unit Test用的class必須import **XCTest**並extend **XCTestCase,** 這邊有4個function, **setUp:** 測試class生命週期, 在**測試開始之前被呼叫** **tearDown:** 測試class生命週期, 在**測試完成之後被呼叫** **testExample:** 預設的test function**,** 注意到所有的test function命名都必須以**tes**t開頭 **testPerformanceExample:** 預設的test function, 在**meaure** block裡面的動作皆會執行10次, 用以測試performance ​ 接著, 我們也可以新增新的Test Class分別去測試我們的不同class **MathTest**: 用來測試Math class的functions ```swift import XCTest class MathTest: XCTestCase { override func setUp() { super.setUp() // Put setup code here. This method is called before the invocation of each test method in the class. } override func tearDown() { // Put teardown code here. This method is called after the invocation of each test method in the class. super.tearDown() } func testAdd() { let a = Math.add(x: 3, y: 5) let b = Math.add(x: 64, y: -70) let c = Math.add(x: 999, y: 0) XCTAssert(a == 8, "a should be 8") XCTAssert(b == -6, "b should be -6") XCTAssert(c == 999, "c should be 999") } func testStringToInt() { let a = Math.stringToInt(string: "9") let b = Math.stringToInt(string: "-55") let c = Math.stringToInt(string: "sdfsks") XCTAssert(a == 9, "a should be 8") XCTAssert(b == -55, "b should be -55") XCTAssert(c == nil, "c should be nil") } } ``` **​** **TestNetwork**: 用來測試Network class的dataTask function, 關於網路測試是否成功有2個重點 (1.) request要有發送出去 (2.) 發送出去的url, parameters, headers是否正確 在這個例子裡面我們在response的時候檢查 response?.url?.absoluteString是否跟原本的相同. 然而, 更嚴謹的網路測試通常不會真的發送request出去, 因為這樣會影響測試時間並可能污染server端的資料, 此時就可以用**Dependency Injection(DI)**等方法來達到測試目的, 詳情可以參考以下連結: ​[The complete guide to Network Unit Testing in Swift](https://medium.com/flawless-app-stories/the-complete-guide-to-network-unit-testing-in-swift-db8b3ee2c327)​ ```swift import XCTest class TestNetwork: XCTestCase { override func setUp() { super.setUp() // Put setup code here. This method is called before the invocation of each test method in the class. } override func tearDown() { // Put teardown code here. This method is called after the invocation of each test method in the class. super.tearDown() } func testDataTask() { let urlString = "http://opendata2.epa.gov.tw/UV/UV.json" Network.dataTask(urlString: urlString) { (data, response, error) in let requestUrl = response?.url?.absoluteString XCTAssert(requestUrl == urlString, "wrong URL!") } } } ``` ​ **TestViewController**: 用來測試Viewcontroller class, 因Viewcontroller在viewWillAppear裡面呼叫了clearData function, 所以我們在testClearData() 裡面測試相關元件的text是否為空. **這邊需注意:** (1.) test class的Viewcontroller需要用**storyboard.instantiateViewController**的方式去宣告, 否則IBOutlet元件會為nil (2. ) 必須呼叫 vc.loadView() 才能啟動Viewcontroller的生命週期 ```swift import XCTest class TestViewController: XCTestCase { override func setUp() { super.setUp() } override func tearDown() { // Put teardown code here. This method is called after the invocation of each test method in the class. super.tearDown() } func testClearData() { let storyboard = UIStoryboard(name: "Main", bundle: Bundle(for: ViewController.self)) let vc = storyboard.instantiateViewController(withIdentifier: "ViewController") as! ViewController vc.loadView() // call life cycle vc.clearData() XCTAssert(vc.resultLabel!.text == "", "vc.resultLabel!.text should be empty ") XCTAssert(vc.responseTextView!.text == "", "vc.responseTextView!.text should be empty ") } } ``` ​ ## 進行測試 點擊Xcode的測試按鈕就能開始測試, 結束後可以在這個頁面看到完整的測試結果, 點擊每個function的綠色勾勾也可以個別測試單個function ![](/files/-LI1Yt0ODAvNlcHJbekw) ​ ## 測試覆蓋率 (1.) 進入**Edit Scheme -> Test -> Options**頁面將**Gather coverage for all targets**選項打勾 ![](/files/-LI1YwMtqw6vO-l6BbgC) ​ (2.) 完成測試後就可以在這裡看到目前測試的coverage rate ![](/files/-LI1YzGsxbcETqDUUEGy) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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