ios

Use this skill when working on iOS client (大前端 / 移动端) codebases.

Defaults (unless repo dictates otherwise)

• Language: Swift
• UI: SwiftUI (if UIKit exists, follow existing architecture and integrate incrementally)
• Architecture: MVVM + unidirectional state where appropriate
• Concurrency: async/await, Task, Actor as needed
• Modularization: Swift Package Manager (SPM) if present

Project structure (recommended)

• App/: application entry, app lifecycle, root navigation
• Features/<Name>/: feature modules (UI + ViewModel + domain models)
• Core/: shared utilities, design system, logging, networking primitives
• Data/: API clients, persistence implementations
• Resources/: assets, localization

Workflow

1. Establish constraints

• iOS deployment target, supported devices, required permissions.
• SwiftUI vs UIKit and existing patterns (coordinator, reducers, etc.).

2. Define app flows

• Identify screens and navigation.
• Define ViewState/Action for each screen; keep states serializable and testable.

3. Networking

• Prefer URLSession + typed request/response models.
• Centralize auth headers, retries, and error mapping.
• Avoid leaking raw transport errors into UI; map to domain errors.

4. Persistence

• Choose one consistent approach: SwiftData/Core Data for structured data; UserDefaults for small prefs; Keychain for secrets/tokens.
• Add migration strategy notes if schema evolves.

5. UI & state

• Views should be mostly declarative; business logic lives in ViewModel.
• Make loading/error/empty states explicit.
• Use @MainActor for UI-facing state updates.

6. Performance & UX

• Minimize unnecessary view updates; use value types, Equatable states where helpful.
• Images: async loading/caching; list virtualization with List best practices.
• Accessibility: VoiceOver labels, Dynamic Type, sufficient contrast.

7. Quality gates

• Unit tests for ViewModels and domain logic.
• Snapshot/UI tests where valuable.
• Ensure release config (entitlements, signing, privacy strings) is correct.

Output expectations when making changes

• Keep diffs localized; avoid broad refactors unless requested.
• Add/adjust tests when changing behavior.
• For new features: include navigation entry, state contract, and data wiring.