IOS Test

iOS Test Skill

Overview

Use this skill to build an iOS/SwiftUI application, launch it in the Simulator, and visually test it using computer use. The skill navigates through every screen, screenshots each state, checks crash logs, and produces a structured test report — without writing a single line of test code.

Options

• --flow=<name>: Test a specific user flow (e.g., onboarding, login, checkout)
• --screen=<ViewName>: Test only a specific screen
• --device=<name>: Choose a Simulator device (e.g., "iPhone 16", "iPhone SE")
• --scheme=<name>: Specify the Xcode scheme
• --states: Test empty, error, and loading states via launch arguments
• --screenshot-all: Screenshot every step
• --performance: Measure RAM per screen and check for memory leaks (skipped by default)

Workflow

1) Project Discovery

• Find .xcodeproj or .xcworkspace in the working directory
  • Prefer .xcworkspace if it exists (CocoaPods/SPM workspace)
  • If multiple exist, ask the user which one to use
  • If none found, stop with an error
• List available schemes:

  xcodebuild -list -workspace MyApp.xcworkspace
  

  • Use --scheme if provided
  • If only one scheme exists, use it automatically
  • If multiple, ask the user

2) Simulator Selection (BEFORE build)

IMPORTANT: Simulator must be selected BEFORE building. The build command uses the selected device name.

• If --device is provided: find that device via xcrun simctl list devices --json
• If --device is not provided, check booted simulators:

  xcrun simctl list devices booted --json
  

  • No booted simulator: list available devices with xcrun simctl list devices available --json, suggest the best iPhone match, ask for confirmation, then boot it
  • One booted simulator: use it directly, no questions
  • Multiple booted: list them and ask the user which one to use

3) Accessibility Check (MANDATORY — DO NOT SKIP)

This step is MANDATORY. Runs BEFORE build. NEVER skip this step.

1. Scan SwiftUI files in the project — look for struct ... : View patterns in *.swift files
2. Count interactive elements: Button, TextField, SecureField, Toggle, Slider, Picker, DatePicker, NavigationLink, Image, .onTapGesture
3. Check how many have .accessibilityIdentifier()
4. ALWAYS ask the user (this question cannot be skipped):

Accessibility Scan Result:
   Total interactive elements: XX
   With identifier: XX
   Missing identifier: XX

Identifiers help me find elements more reliably during testing.

Run /add-accessibility to add identifiers now?
  → Yes: adds identifiers, then builds and continues to testing
  → No: builds directly and uses coordinate-based testing (slower and more fragile)

5. WAIT for the user's response. Do not proceed without an answer.
6. If yes → run the full /add-accessibility workflow (scan, generate, apply), then continue to step 4 (Build)
7. If no → continue to step 4 (Build) directly

4) Build

• Build the selected scheme using the device chosen in step 2:

  xcodebuild build \
    -workspace MyApp.xcworkspace \
    -scheme MyApp \
    -destination 'platform=iOS Simulator,name=<SELECTED_DEVICE>' \
    -derivedDataPath ./DerivedData \
    2>&1
  

  NEVER hardcode a device name. Always use the device selected in step 2.
• If build fails: analyze errors, suggest fixes, and STOP — never proceed to testing with a failed build
• Report build warnings (but don't stop)

5) Install & Launch

• Find the built .app file:

  find ./DerivedData -name "*.app" -path "*/Debug-iphonesimulator/*" | head -1
  

• Get the bundle identifier:

  plutil -p /path/to/MyApp.app/Info.plist | grep CFBundleIdentifier
  

• Install and launch:

  xcrun simctl install booted /path/to/MyApp.app
  xcrun simctl launch booted <BUNDLE_ID>
  

6) Visual Testing with Computer Use

IMPORTANT: This phase requires the computer-use MCP server to be enabled.

If computer use is not enabled, tell the user:

Computer use is not enabled. Required for visual testing.
Run /mcp and enable the computer-use server.

Default test (no arguments)

Discover and test all main screens:

1. TabView present → tap each tab, inspect each screen
2. NavigationStack present → tap each navigation link, go back
3. On each screen check:
   • Layout renders correctly (no overflow, overlapping, or empty areas)
   • Buttons are tappable
   • Scroll works and content is visible
   • Text is readable (not too small, not truncated)
4. Screenshot each screen

With --flow=<name>

Test the specified user flow:

• onboarding: swipe through onboarding screens, complete all steps
• login: fill email/password fields (test@example.com / Test1234), tap login, verify next screen
• signup: fill the registration form, tap signup
• checkout: navigate to cart, complete the payment flow
• settings: open settings, try each toggle/slider, go back
• Other flows: ask the user "What steps should I follow for this flow?"

With --screen=<ViewName>

Find and test only the specified screen. Navigate to it if needed.

7) State Testing (--states only)

Test different app states using launch arguments.

1. Check if the app supports state overrides via CommandLine.arguments:

   • Search SwiftUI files for --show-empty-state, --show-error-state, --show-loading-state
   • Search for @AppStorage or UserDefaults debug flags

2. If not found, ask the user:

   No state test support found. Would you like me to add launch argument
   handling to your @main App struct?
   
   A #if DEBUG block will be added supporting:
   - --show-empty-state
   - --show-error-state
   - --show-loading-state
   
   Only active in DEBUG builds. Add it?
   

3. If available, relaunch the app for each state:

   xcrun simctl terminate booted com.example.MyApp
   xcrun simctl launch booted com.example.MyApp --show-empty-state
   

   For each state verify:

   • Empty state: shows a meaningful message ("No content yet")
   • Error state: clear error message with a retry button
   • Loading state: loading indicator visible, UI not frozen
   • Screenshot each state

8) Crash Log Analysis

Check for crashes during and after testing:

xcrun simctl spawn booted log show --predicate 'process == "MyApp" AND messageType == 21' --last 5m

If a crash is found:

• Analyze the stack trace
• Identify which screen / action triggered it
• Find the relevant source code and report the likely cause

9) Performance Analysis (--performance only)

ONLY run when --performance is provided. SKIP in default tests.

Measure RAM usage per screen and check for memory leaks.

1. Find the app's PID:

   xcrun simctl spawn booted launchctl list | grep <BundleID>
   

2. Take a baseline measurement on launch:

   footprint -all <PID>
   

3. On each screen transition:

   • Navigate to the screen (via computer use)
   • Wait 2 seconds (let rendering complete)
   • Run footprint -all <PID>, record RAM
   • Calculate diff from previous screen

4. Check for leaks on back navigation:

   • Enter a screen → measure RAM
   • Go back → measure RAM
   • If delta > 5MB → flag as potential leak

5. Run a full leak scan at the end:

   leaks <PID>
   

   Report: leak count, object types, stack traces

6. Performance report format:

   Performance Report
   ━━━━━━━━━━━━━━━━━━━━━━━━━
   Baseline (launch):       42 MB
   
   Screen Transitions:
     HomeView:              45 MB (+3 MB)
     SettingsView:          52 MB (+7 MB)
     ProfileView:           68 MB (+16 MB) ⚠️
     → HomeView (back):     61 MB (-7 MB, 16 MB not released) ⚠️
   
   Memory Leaks:            2 found
     - SettingsViewModel: 1 leak (closure retain cycle?)
     - ImageCache: 1 leak
   
   ⚠️ High RAM: ProfileView (+16 MB jump)
   ⚠️ Potential Leak: 16 MB not released on return to HomeView
   

10) Test Report

Show a summary report when testing is complete:

iOS Test Report
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
App:         MyApp (com.example.MyApp)
Device:      iPhone 16 (iOS 18.2)
Scheme:      MyApp
Duration:    2m 34s

Screens Tested: 8
  ✅ HomeView - OK
  ✅ ProfileView - OK
  ⚠️ SettingsView - Toggle "notifications" not tappable
  ✅ OnboardingStep1 - OK
  ✅ OnboardingStep2 - OK
  ✅ OnboardingStep3 - OK
  ❌ CheckoutView - Crash (force unwrap on nil)
  ✅ SearchView - OK

Screenshots: 12 captured

Crashes: 1
  CheckoutView.swift:42 - Force unwrap on nil optional

UI Issues: 1
  SettingsView - notifications toggle not accessible

State Test Results:
  ✅ Empty State - OK
  ⚠️ Error State - Missing retry button
  ✅ Loading State - OK

Important Rules

1. NEVER proceed to testing if the build fails
2. Cannot do visual testing without computer use — tell the user to enable it
3. Don't ask unnecessary questions about Simulator selection — use the one that's booted
4. Report every error and warning but NEVER modify code without user approval
5. Don't delete or modify the app's data during testing
6. Don't suggest adding launch arguments unless --states is provided
7. When a crash is detected, show the stack trace alongside the relevant source code
8. Save screenshots with meaningful names (e.g., test-home-screen.png)
9. Do NOT close the Simulator after testing — the user may want to continue
10. Provide brief status messages at each phase ("Building...", "Launching Simulator...", etc.)