UI testing with XCUITest in iOS Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to launch the app in the UI test setup method.

iOS Swift

override func setUp() {
  super.setUp()
  let app = XCUIApplication()
  app.[1]()
}

Drag options to blanks, or click blank then click option'

Aopen

Brun

Claunch

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using start() or run() which do not exist in XCUIApplication.

Forgetting to launch the app before tests.

The correct method to start the app in XCUITest is launch().

2fill in blank

medium

Complete the code to tap a button with accessibility identifier "submitButton".

iOS Swift

let app = XCUIApplication()
app.buttons["[1]"].tap()

Drag options to blanks, or click blank then click option'

AnextButton

BloginButton

CcancelButton

DsubmitButton

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong identifier that does not match the button.

Trying to tap a label or other UI element instead of a button.

To tap the submit button, use its accessibility identifier "submitButton".

3fill in blank

hard

Fix the error in the assertion to check if a label with text "Welcome" exists.

iOS Swift

let app = XCUIApplication()
XCTAssertTrue(app.staticTexts["[1]"].exists)

Drag options to blanks, or click blank then click option'

AWelcome

BHello

CStart

DHome

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different text string that does not exist.

Ignoring case sensitivity in the text.

The label text to check is "Welcome", so the identifier must match exactly.

4fill in blank

hard

Fill both blanks to wait for a button with identifier "loginButton" to appear with a timeout of 5 seconds.

iOS Swift

let app = XCUIApplication()
let loginButton = app.buttons["[1]"]
let exists = loginButton.waitForExistence(timeout: [2])
XCTAssertTrue(exists)

Drag options to blanks, or click blank then click option'

AloginButton

BsubmitButton

C5

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong button identifiers.

Setting timeout too high or too low.

Use the correct button identifier "loginButton" and a timeout of 5 seconds for waiting.

5fill in blank

hard

Fill all three blanks to enter text "hello" into a text field with identifier "usernameField" and then dismiss the keyboard.

iOS Swift

let app = XCUIApplication()
let textField = app.textFields["[1]"]
textField.tap()
textField.typeText("[2]")
app.keyboards.buttons["[3]"].tap()

Drag options to blanks, or click blank then click option'

AusernameField

Bhello

CReturn

DsubmitButton

Attempts:

3 left

💡 Hint

Common Mistakes

Typing text into the wrong field.

Not dismissing the keyboard after typing.

The text field identifier is "usernameField", the text to type is "hello", and the keyboard button to dismiss is "Return".

Practice

1. What is the main purpose of using XCUITest in iOS app development?

easy

A. To automate user interface testing by simulating user actions

B. To write backend server code for the app

C. To design app icons and graphics

D. To manage app database connections

Solution

1. Step 1: Understand XCUITest's role

   XCUITest is a framework designed to automate UI testing by simulating taps, typing, and other user interactions.

2. Step 2: Eliminate unrelated options

   The options for designing app icons/graphics, writing backend server code, and managing database connections are incorrect, as they are not related to XCUITest's purpose of UI testing.

3. Final Answer:

   To automate user interface testing by simulating user actions -> Option A

4. Quick Check:

   UI testing = automate user actions [OK]

Hint: XCUITest automates what users do on the screen [OK]

Common Mistakes:

• Confusing UI testing with backend development
• Thinking XCUITest is for design or graphics
• Assuming it manages databases

2. Which of the following is the correct way to launch the app in an XCUITest case?

easy

A. let app = UIApplication()
app.start()

B. let app = XCUIApplication()
app.launch()

C. let app = XCUIElement()
app.open()

D. let app = XCUIApplication()
app.run()

Solution

1. Step 1: Recall correct class and method

   In XCUITest, XCUIApplication() creates the app instance, and launch() starts it.

2. Step 2: Check method names and classes

   UIApplication and XCUIElement are incorrect for launching tests; start() and run() are not valid methods here.

3. Final Answer:

   let app = XCUIApplication()\napp.launch() -> Option B

4. Quick Check:

   Use XCUIApplication and launch() [OK]

Hint: XCUIApplication().launch() always starts the app in tests [OK]

Common Mistakes:

• Using UIApplication instead of XCUIApplication
• Calling non-existent methods like start() or run()
• Confusing XCUIElement with the app instance

3. Given the following XCUITest code snippet, what will be the result?

let app = XCUIApplication()
app.launch()
let button = app.buttons["submitButton"]
if button.exists {
    button.tap()
    print("Tapped")
} else {
    print("Button not found")
}

medium

A. Always prints "Button not found" regardless of button presence

B. Prints "Tapped" even if the button does not exist

C. Causes a compile-time error due to incorrect syntax

D. Prints "Tapped" if the button with accessibility identifier "submitButton" exists

Solution

1. Step 1: Analyze button existence check

   The code checks if the button with identifier "submitButton" exists using button.exists.

2. Step 2: Understand conditional behavior

   If the button exists, it taps and prints "Tapped"; otherwise, it prints "Button not found".

3. Final Answer:

   Prints "Tapped" if the button with accessibility identifier "submitButton" exists -> Option D

4. Quick Check:

   Button exists? Tap and print "Tapped" [OK]

Hint: Check .exists before tap to avoid errors [OK]

Common Mistakes:

• Assuming print always shows "Button not found"
• Thinking code has syntax errors
• Ignoring the existence check before tap

4. Identify the error in this XCUITest code snippet:

let app = XCUIApplication()
app.launch()
let textField = app.textFields["username"]
textField.typeText("user123")
app.buttons["login"].tap()

medium

A. Incorrect app launch method used

B. Using typeText instead of setText method

C. Missing check if textField exists before typing

D. Buttons cannot be tapped in XCUITest

Solution

1. Step 1: Review element existence checks

   The code types text into a text field without verifying if it exists, which can cause test failures.

2. Step 2: Confirm other method usages

   typeText is the correct method; app.launch() is correct; buttons can be tapped in XCUITest.

3. Final Answer:

   Missing check if textField exists before typing -> Option C

4. Quick Check:

   Always check element exists before interaction [OK]

Hint: Check .exists before typing or tapping [OK]

Common Mistakes:

• Skipping existence checks causing crashes
• Confusing typeText with non-existent methods
• Thinking buttons can't be tapped in tests

5. You want to write an XCUITest that verifies a label updates after tapping a button. Which approach correctly waits for the label to change text before asserting?

let app = XCUIApplication()
app.launch()
let button = app.buttons["updateButton"]
let label = app.staticTexts["statusLabel"]
button.tap()
// What code waits for label text to change to "Done"?

hard

A. let exists = NSPredicate(format: "label == 'Done'")
expectation(for: exists, evaluatedWith: label, handler: nil)
waitForExpectations(timeout: 5, handler: nil)

B. sleep(5)
assert(label.label == "Done")

C. while label.label != "Done" {}
assert(true)

D. assert(label.label == "Done") immediately after tap

Solution

1. Step 1: Understand waiting for UI changes

   Using NSPredicate with expectation waits properly for the label's text to become "Done" within timeout.

2. Step 2: Evaluate other options

   sleep() is unreliable; busy-wait loop blocks test; immediate assert may fail if UI hasn't updated yet.

3. Final Answer:

   let exists = NSPredicate(format: "label == 'Done'")\nexpectation(for: exists, evaluatedWith: label, handler: nil)\nwaitForExpectations(timeout: 5, handler: nil) -> Option A

4. Quick Check:

   Use expectations to wait for UI updates [OK]

Hint: Use XCTest expectations to wait for UI changes [OK]

Common Mistakes:

• Using sleep instead of expectations
• Busy-wait loops freezing tests
• Asserting UI state immediately after action