Swift Review

Swift Code Review

Perform comprehensive code reviews for Swift macOS/iOS applications by launching parallel exploration agents and producing a prioritized findings report with actionable fix plans.

When to Use

Trigger this skill when:

• Reviewing a Swift codebase for quality issues
• Auditing an app before release
• Investigating crashes, memory leaks, or race conditions
• Checking accessibility compliance
• Validating platform version compatibility

Review Process

Phase 0: Project Discovery

Before launching agents, quickly assess the project to customize the review:

1. Check for Package.swift, project.yml, or *.xcodeproj to understand build system
2. Identify deployment target (iOS vs macOS, minimum version)
3. Detect frameworks in use (CoreAudio, CoreData, CloudKit, HealthKit, etc.)
4. Note app type (standard app, menu bar app, widget, extension)

This determines which specialized checks to emphasize.

Phase 1: Launch Parallel Analysis Agents

Launch 6 exploration agents in parallel using the Task tool with subagent_type=Explore. Each agent analyzes a specific aspect of the codebase.

Agent prompts to use:

1. System Frameworks & Native APIs Agent

Analyze system framework and native API usage in this Swift project. Search for:
- C/Objective-C API bridging (AudioObject*, AVAudioSession, CoreData, HealthKit, etc.)
- Callback/delegate registration without cleanup (observers, listeners, delegates)
- Status/error codes ignored (OSStatus, NSError, Result types with let _ =)
- CF types memory handling (Unmanaged, CFRetain/CFRelease, takeRetainedValue)
- Callbacks/delegates performing work on unexpected threads
- Classes registering system callbacks without deinit cleanup
- Notification center observers without removal
- KVO observations without invalidation
Report file:line references for each finding.

2. Threading & Concurrency Agent

Analyze threading and concurrency patterns in this Swift project. Search for:
- @MainActor usage and potential violations
- Properties accessed from multiple threads without synchronization
- DispatchQueue patterns (sync vs async correctness, deadlock risks)
- Task/async-await spawning without cancellation tracking
- Race conditions in shared mutable state
- Actor isolation issues
- UserDefaults/Keychain thread safety
- Singleton patterns and their thread safety
- Combine publisher thread safety
Report file:line references for each finding.

3. State Management Agent

Analyze state management and persistence in this Swift project. Search for:
- SwiftUI: @State, @StateObject, @ObservedObject, @Published, @Environment patterns
- Local @State copies that could become stale vs source of truth
- Persistence: UserDefaults, CoreData, FileManager, Keychain usage
- Codable encoding/decoding with try? (silent failures)
- Data sync issues between views and managers/stores
- ObservableObject/Observable property publishing problems
- Binding misuse or unnecessary state duplication
Report file:line references for each finding.

4. UI & UX Patterns Agent

Analyze UI and UX patterns in this Swift project. Search for:
- Controls updating on every change vs debounced/on release
- Missing loading states for async operations
- Errors logged to console but not shown to users
- Force unwraps (!) in UI code that could crash
- Main thread blocking (sync network calls, heavy computation)
- Navigation state management issues
- Modal/sheet presentation edge cases
- Platform-specific: Menu bar apps (MenuBarExtra), widgets, extensions
Report file:line references for each finding.

5. Platform Compatibility Agent

Analyze platform version compatibility in this Swift project. Search for:
- API availability vs deployment target mismatches
- onChange(of:) syntax differences (iOS 17+/macOS 14+ uses two params)
- @Environment property availability by version
- @Observable vs ObservableObject (iOS 17+/macOS 14+)
- @available annotations correctness and completeness
- Deprecated APIs without migration path
- Platform-specific code (#if os(macOS)) correctness
Report file:line references for each finding.

6. Accessibility Agent

Analyze accessibility compliance in this Swift project. Search for:
- .labelsHidden() without .accessibilityLabel()
- Interactive controls (Button, Toggle, Slider, Picker) missing accessibility labels
- Images without .accessibilityLabel() or not marked .accessibilityHidden()
- Missing .accessibilityValue() on controls with dynamic values
- Missing .accessibilityHint() for non-obvious interactions
- Custom controls without proper accessibility traits
- Color-only information (needs text/icon alternative)
- Touch target sizes (minimum 44x44 points)
Report file:line references for each finding.

Phase 2: Compile Findings

After all agents complete, organize findings by severity:

Critical - Crashes, memory leaks, data loss:

• Memory leaks (unreleased observers, retain cycles)
• Race conditions causing crashes
• Force unwraps that can fail at runtime
• Data corruption or loss
• Undefined behavior

High-Severity - State bugs, silent failures:

• State synchronization problems
• Silent failures (swallowed errors)
• Thread safety violations
• Poor error recovery
• Security issues (hardcoded secrets, insecure storage)

Medium - UI/UX, accessibility:

• VoiceOver/accessibility failures
• Confusing user experience
• Missing user feedback
• Performance issues
• Platform guideline violations

Low - Code quality:

• Style inconsistencies
• Minor optimizations
• Documentation gaps

Phase 3: Generate Implementation Plan

For each issue, provide:

1. Specific file:line references
2. Code snippets showing fix approach
3. Dependency order (which fixes must come first)
4. Testing steps to verify

Output Format

Structure the final report as:

# Code Review: [Project Name]

## Project Profile
- **Platform:** macOS/iOS/multiplatform
- **Deployment Target:** [version]
- **App Type:** Standard app / Menu bar / Widget / Extension
- **Key Frameworks:** [detected frameworks]

## Summary
- Critical: X issues
- High: X issues
- Medium: X issues
- Low: X issues

## Critical Issues

### 1. [Issue Title]
**File:** `path/to/file.swift:XX-YY`
**Problem:** [Description]
**Impact:** [Consequences]
**Fix:**
[Code snippet or steps]

## High-Severity Issues
[Same format]

## Medium Issues
[Same format]

## Low Issues
[Brief descriptions]

## Files to Modify
| File | Changes |
|------|---------|
| file.swift | Description |

## Implementation Order
1. **[Fix Name]** (blocks: 2, 3)
2. **[Fix Name]** (depends on: 1)

## Verification Plan
### Phase 1 (Critical)
- [ ] Test step
### Phase 2 (High)
- [ ] Test step

Additional Resources

Reference Files

• references/checklist.md - Complete Swift verification checklist
• references/patterns.md - Common issue patterns and fix approaches
• references/frameworks.md - Framework-specific guidance (CoreAudio, CoreData, etc.)

Example Reports

• examples/sample-report.md - Example of a completed review report

Source: adairrr/macos-volume-guard — distributed by TomeVault.