iOS Simulator Testing Skill — Quick Reference

This skill enables iOS app development and testing automation via Xcode Simulator. Claude should apply these patterns when users need to build, test, or debug iOS apps, capture screenshots, or automate mobile UI testing on macOS.

Note: Requires macOS with Xcode installed.

Quick Reference

When to Use This Skill

Claude should invoke this skill when a user requests:

• Build and run iOS app in simulator
• Test iOS app functionality
• Capture screenshots for documentation
• Automate UI testing with XCTest
• Debug iOS app behavior
• Set up iOS CI/CD pipeline

Simulator Management

List Available Simulators

# List all devices
xcrun simctl list devices

# List available runtimes
xcrun simctl list runtimes

# List booted devices only
xcrun simctl list devices | grep "Booted"

Boot and Manage Simulators

# Boot a specific simulator
xcrun simctl boot "iPhone 16 Pro"

# Open Simulator app
open -a Simulator

# Shutdown simulator
xcrun simctl shutdown "iPhone 16 Pro"

# Shutdown all simulators
xcrun simctl shutdown all

# Erase simulator (reset to clean state)
xcrun simctl erase "iPhone 16 Pro"

# Create new simulator
xcrun simctl create "My iPhone" "iPhone 16" "iOS-18-0"

Build and Deploy

Build iOS App

# Build for simulator (Debug)
xcodebuild build \
  -project MyApp.xcodeproj \
  -scheme MyApp \
  -sdk iphonesimulator \
  -configuration Debug \
  -destination 'platform=iOS Simulator,name=iPhone 16'

# Build with workspace (CocoaPods/SPM)
xcodebuild build \
  -workspace MyApp.xcworkspace \
  -scheme MyApp \
  -sdk iphonesimulator \
  -configuration Debug

# Clean build folder
xcodebuild clean \
  -project MyApp.xcodeproj \
  -scheme MyApp

Install and Launch App

# Install app on booted simulator
xcrun simctl install booted /path/to/MyApp.app

# Launch app
xcrun simctl launch booted com.example.myapp

# Launch and wait for debugger
xcrun simctl launch --wait-for-debugger booted com.example.myapp

# Terminate app
xcrun simctl terminate booted com.example.myapp

# Uninstall app
xcrun simctl uninstall booted com.example.myapp

Testing

Run XCTest Suite

# Run all tests
xcodebuild test \
  -project MyApp.xcodeproj \
  -scheme MyApp \
  -sdk iphonesimulator \
  -destination 'platform=iOS Simulator,name=iPhone 16'

# Run specific test class
xcodebuild test \
  -project MyApp.xcodeproj \
  -scheme MyApp \
  -sdk iphonesimulator \
  -destination 'platform=iOS Simulator,name=iPhone 16' \
  -only-testing:MyAppTests/LoginTests

# Run specific test method
xcodebuild test \
  -project MyApp.xcodeproj \
  -scheme MyApp \
  -sdk iphonesimulator \
  -destination 'platform=iOS Simulator,name=iPhone 16' \
  -only-testing:MyAppTests/LoginTests/testValidLogin

# Run UI tests
xcodebuild test \
  -project MyApp.xcodeproj \
  -scheme MyAppUITests \
  -sdk iphonesimulator \
  -destination 'platform=iOS Simulator,name=iPhone 16'

XCTest Example

// MyAppTests/LoginTests.swift
import XCTest
@testable import MyApp

final class LoginTests: XCTestCase {
    var sut: LoginViewModel!

    override func setUp() {
        super.setUp()
        sut = LoginViewModel()
    }

    override func tearDown() {
        sut = nil
        super.tearDown()
    }

    func testValidLogin() async throws {
        // Given
        let email = "user@example.com"
        let password = "password123"

        // When
        let result = try await sut.login(email: email, password: password)

        // Then
        XCTAssertTrue(result.isSuccess)
        XCTAssertNotNil(sut.currentUser)
    }

    func testInvalidEmail() {
        // Given
        let email = "invalid-email"

        // When
        let error = sut.validateEmail(email)

        // Then
        XCTAssertEqual(error, .invalidEmail)
    }
}

XCUITest Example

// MyAppUITests/LoginUITests.swift
import XCTest

final class LoginUITests: XCTestCase {
    var app: XCUIApplication!

    override func setUp() {
        super.setUp()
        continueAfterFailure = false
        app = XCUIApplication()
        app.launch()
    }

    func testLoginFlow() {
        // Navigate to login
        app.buttons["Login"].tap()

        // Enter credentials
        let emailField = app.textFields["email"]
        emailField.tap()
        emailField.typeText("user@example.com")

        let passwordField = app.secureTextFields["password"]
        passwordField.tap()
        passwordField.typeText("password123")

        // Submit
        app.buttons["Submit"].tap()

        // Verify navigation to dashboard
        XCTAssertTrue(app.navigationBars["Dashboard"].waitForExistence(timeout: 5))
    }

    func testLoginValidation() {
        app.buttons["Login"].tap()
        app.buttons["Submit"].tap()

        // Verify error message
        XCTAssertTrue(app.staticTexts["Email is required"].exists)
    }
}

Screenshots and Recording

Capture Screenshots

# Take screenshot (PNG)
xcrun simctl io booted screenshot screenshot.png

# Screenshot with specific device
xcrun simctl io "iPhone 16 Pro" screenshot home.png

# Screenshot to clipboard
xcrun simctl io booted screenshot --type=png | pbcopy

Record Video

# Start recording
xcrun simctl io booted recordVideo recording.mov

# Press Ctrl+C to stop recording

# Record with codec
xcrun simctl io booted recordVideo --codec=h264 recording.mp4

Automated Screenshot Script

#!/bin/bash
# capture-screens.sh

DEVICE="iPhone 16 Pro"
OUTPUT_DIR="./screenshots"
APP_BUNDLE="com.example.myapp"

mkdir -p "$OUTPUT_DIR"

# Boot and launch
xcrun simctl boot "$DEVICE"
sleep 5
xcrun simctl install booted ./build/MyApp.app
xcrun simctl launch booted "$APP_BUNDLE"
sleep 3

# Capture screens
xcrun simctl io booted screenshot "$OUTPUT_DIR/01-home.png"

# Navigate and capture
xcrun simctl io booted tap 200 400  # Tap coordinates
sleep 1
xcrun simctl io booted screenshot "$OUTPUT_DIR/02-login.png"

# Cleanup
xcrun simctl shutdown "$DEVICE"

Simulator Interaction

Touch and Input

# Tap at coordinates
xcrun simctl io booted tap 200 400

# Swipe
xcrun simctl io booted swipe 100 500 100 200

# Type text
xcrun simctl io booted type "Hello World"

# Paste from clipboard
xcrun simctl io booted paste

# Press home button
xcrun simctl io booted home

Device Settings

# Set location
xcrun simctl location booted set 37.7749,-122.4194

# Clear location
xcrun simctl location booted clear

# Open URL
xcrun simctl openurl booted "myapp://deep-link"

# Add photo to library
xcrun simctl addmedia booted photo.jpg

# Push notification
xcrun simctl push booted com.example.myapp notification.apns

Notification Payload

// notification.apns
{
  "aps": {
    "alert": {
      "title": "Test Notification",
      "body": "This is a test push notification"
    },
    "badge": 1,
    "sound": "default"
  }
}

CI/CD Integration

GitHub Actions

# .github/workflows/ios.yml
name: iOS Build and Test
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  build-and-test:
    runs-on: macos-15
    steps:
      - uses: actions/checkout@v4

      - name: Select Xcode
        run: sudo xcode-select -s /Applications/Xcode_16.0.app

      - name: Install dependencies
        run: |
          brew install xcbeautify
          pod install || true

      - name: Build
        run: |
          xcodebuild build \
            -scheme MyApp \
            -sdk iphonesimulator \
            -destination 'platform=iOS Simulator,name=iPhone 16' \
            | xcbeautify

      - name: Test
        run: |
          xcodebuild test \
            -scheme MyApp \
            -sdk iphonesimulator \
            -destination 'platform=iOS Simulator,name=iPhone 16' \
            -resultBundlePath TestResults \
            | xcbeautify

      - name: Upload Test Results
        uses: actions/upload-artifact@v4
        if: always()
        with:
          name: test-results
          path: TestResults

Navigation

Resources

• resources/simulator-commands.md — Complete simctl reference
• resources/xctest-patterns.md — Testing patterns and fixtures
• data/sources.json — Apple documentation links

Related Skills

• ../software-mobile/SKILL.md — iOS/Swift development
• ../qa-testing-strategy/SKILL.md — General testing strategies
• ../ops-devops-platform/SKILL.md — CI/CD pipelines