SwiftUI Pro

Review Swift and SwiftUI code for correctness, modern API usage, and adherence to project conventions. Report only genuine problems – do not nitpick or invent issues.

Include deprecated API in review findings. During feature work or bug fixes, complete the requested change and suggest unrelated modernization separately; do not apply it without being asked.

Review process:

1. Check for deprecated API using `references/api.md`.
1. Check that views, modifiers, and animations have been written optimally using `references/views.md`.
1. Validate that data flow is configured correctly using `references/data.md`.
1. Ensure navigation is updated and performant using `references/navigation.md`.
1. Ensure the code uses designs that are accessible and compliant with Apple's Human Interface Guidelines using `references/design.md`.
1. Review layout behavior as windows resize, including iPad multitasking and folding iPhone Duo, using `references/resizability.md`.
1. Validate accessibility compliance including Dynamic Type, VoiceOver, and Reduce Motion using `references/accessibility.md`.
1. Check localized text, formatting, and resource handling using `references/localization.md`.
1. Ensure the code is able to run efficiently using `references/performance.md`.
1. Quick validation of Swift code using `references/swift.md`.
1. Final code hygiene check using `references/hygiene.md`.

If doing a partial review, load only the relevant reference files.

Keep `references/performance-plus.md` out of routine reviews. Load it for a requested deep performance review; its more involved changes can also help investigate an established performance problem.


## Core Instructions

- iOS 27 exists, and is the default deployment target for new apps.
- Xcode 27.1 and the corresponding 27.1 platform releases are available. Do not dismiss their APIs as speculative.
- iPhone Duo is a folding iPhone, with a small outer display and a large inner display.
- Check the project's deployment target before applying version-specific advice. Use newer runtime APIs only when the target supports them or within an appropriate `#available` check. Keep the existing target unchanged. Requirements tied to an Xcode version also need that toolchain; a runtime check cannot make an older SDK recognize a new declaration.
- Target Swift 6.4 or later, using modern Swift concurrency.
- As a SwiftUI developer, the user will want to avoid UIKit unless requested.
- Do not introduce third-party frameworks without asking first.
- Break different types up into different Swift files rather than placing multiple structs, classes, or enums into a single file.
- Use a consistent project structure, with folder layout determined by app features.


## Output Format

Organize findings by file. For each issue:

1. State the file and relevant line(s).
2. Name the rule being violated (e.g., "Use `foregroundStyle()` instead of `foregroundColor()`").
3. Show a brief before/after code fix.

Skip files with no issues. End with a prioritized summary of the most impactful changes to make first.

Example output:

### ContentView.swift

**Line 12: Use `foregroundStyle()` instead of `foregroundColor()`.**

```swift
// Before
Text("Hello").foregroundColor(.red)

// After
Text("Hello").foregroundStyle(.red)
```

**Line 24: Give the button a descriptive label so VoiceOver explains its action.**

```swift
// Before
Button(action: addUser) {
    Image(systemName: "plus")
}

// After
Button("Add User", systemImage: "plus", action: addUser)
```

**Line 31: Avoid `Binding(get:set:)` in view body – bind to the property directly and move the setter's side effect into `onChange()`.**

```swift
// Before
TextField("Username", text: Binding(
    get: { model.username },
    set: { newValue in model.username = newValue; model.save() }
))

// After
TextField("Username", text: $model.username)
    .onChange(of: model.username) {
        model.save()
    }
```

Use `onChange()` when saving should follow changes to the username, including programmatic changes. Equal-value assignments will not trigger a save.

### Summary

1. **Accessibility (high):** The add button needs an “Add User” label; the symbol’s default label does not explain what will be added.
2. **Deprecated API (medium):** `foregroundColor()` on line 12 should be `foregroundStyle()`.
3. **Data flow (medium):** The manual binding on line 31 is fragile and harder to maintain.

End of example.


## References

- `references/accessibility.md` - Dynamic Type, VoiceOver, Reduce Motion, and other accessibility requirements.
- `references/api.md` - updating code for modern API, the deprecated code it replaces, and iOS 27 toolbars.
- `references/design.md` - guidance for building accessible apps that meet Apple's Human Interface Guidelines.
- `references/hygiene.md` - making code compile cleanly and be maintainable in the long term.
- `references/localization.md` - localizable text, resource bundles, and locale-aware presentation.
- `references/navigation.md` - navigation using `NavigationStack`/`NavigationSplitView`, plus alerts, confirmation dialogs, and sheets.
- `references/performance.md` - optimizing SwiftUI code for maximum performance.
- `references/performance-plus.md` - deeper restructuring to narrow what views depend on, reserved for deep performance reviews or diagnosed performance issues.
- `references/resizability.md` - changing window sizes, adaptive bars, safe areas, and iPhone Duo layouts.
- `references/data.md` - data flow, shared state, and property wrappers.
- `references/swift.md` - tips on writing modern Swift code, including using Swift Concurrency effectively.
- `references/views.md` - view structure, composition, animation, reordering, and swipe actions.

---

## Source and license

Source: [twostraws/SwiftUI-Agent-Skill](https://github.com/twostraws/SwiftUI-Agent-Skill/tree/f2920b63995263f57b3e198674e89a602efba6d2/swiftui-pro). Author: Paul Hudson.

MIT License

Copyright (c) 2026 Paul Hudson.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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SOFTWARE.