swiftui-simulator-ui_skill

Overview

This skill runs SwiftUI apps in the iOS Simulator and captures screenshots for visual verification. It provides a repeatable workflow to build, install, launch, and image your app across devices and appearances. Use it to get fast visual feedback during UI development, testing, and documentation.

How this skill works

The skill uses xcodebuild to compile a specified scheme into a DerivedData build output, then locates the .app bundle. It uses xcrun simctl to resolve a simulator UDID, boot or prepare the simulator, install and launch the app, and capture screenshots or recordings. It supports deep links, environment overrides, status bar overrides, appearance toggles, and multiple device loops for comprehensive visual checks.

When to use it

• After changing SwiftUI views to verify layout, spacing, and typography
• When validating designs against specs or QA acceptance criteria
• To debug visual issues like clipping, alignment, or missing assets
• Preparing screenshots for documentation, handoffs, or release notes
• Testing UI across device sizes, dark mode, and Dynamic Type

Best practices

• Ensure Xcode and iOS Simulator are installed and the project builds locally
• Resolve the exact simulator UDID and use it explicitly to avoid wrong targets
• Override the status bar for clean, consistent screenshots
• Use environment variables or deep links to reach specific screens deterministically
• Test on a small set of representative devices rather than every simulator

Example use cases

• Run a PreviewLab target to show an isolated view, then screenshot for a design review
• Boot iPhone 16 and iPhone SE, install the app, and capture both screenshots for responsive checks
• Set UserDefaults mocks via simctl spawn, relaunch the app, and verify onboarding is skipped
• Toggle dark and light appearances and capture screenshots for theme QA
• Record a short video of an interaction to demonstrate an animation or bug