UI testing with XCUITest in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is XCUITest in iOS development?

XCUITest is a framework by Apple used to write UI tests for iOS apps. It simulates user interactions to check if the app behaves correctly.

beginner

How do you launch the app in an XCUITest case?

You create an XCUIApplication instance and call its launch() method to start the app before testing UI elements.

intermediate

What is the role of XCUIElement in XCUITest?

XCUIElement represents UI elements like buttons, labels, or text fields. You use it to interact with or verify UI components in tests.

intermediate

How can you check if a button exists and is hittable in XCUITest?

Use the exists property to check if the button is present and the isHittable property to check if it can be tapped.

beginner

Why is it important to use accessibility identifiers in UI testing?

Accessibility identifiers uniquely identify UI elements, making tests reliable and less likely to break if the UI layout changes.

Which class do you use to represent the app in XCUITest?

A UIViewController

B XCUIApplication

C XCTestCase

D UIWindow

XCUIApplication represents the app and is used to launch and interact with it in UI tests.

How do you simulate a tap on a button in XCUITest?

A button.press()

B button.select()

C button.click()

D button.tap()

The tap() method simulates a user tapping the button.

What property would you check to verify if a UI element is visible and interactive?

A exists

B isEnabled

C isHittable

D isHidden

isHittable means the element is visible and can be tapped or interacted with.

Why should you assign accessibility identifiers to UI elements?

A To help UI tests find elements reliably

B To disable user interaction

C To change the element's color

D To improve app performance

Accessibility identifiers help tests locate UI elements even if the layout changes.

Which method starts the app in an XCUITest?

A launch()

B run()

C start()

D open()

launch() starts the app so tests can interact with it.

Explain how to write a simple XCUITest that taps a button and verifies a label changes.

Think about the steps a user would do and how to check the result.

Describe why accessibility identifiers are crucial for UI testing and how to set them in your app.

Consider how tests find buttons or labels to tap or check.

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