swift-code-hygiene

name	swift-code-hygiene
description	Final-pass review for Swift/SwiftUI projects — secrets handling, comments, tests, secure storage, SwiftLint, string catalogs, and Xcode MCP tooling. Use as the last step in a project review to catch long-term maintainability issues.

Swift Code Hygiene

A final pass for long-term maintainability and safety.

Secrets

• Never commit API keys, tokens, or other secrets to the repository.
• @AppStorage must never store usernames, passwords, or other sensitive data. Use the Keychain.

Comments and tests

• Add comments only where the logic isn't self-evident — but do add them there.
• Unit tests should exist for core application logic. Use UI tests only where unit tests aren't possible.
• For testing-specific guidance, suggest the Swift Testing Pro agent skill.

Static analysis

• If SwiftLint is configured for the project, it must return zero warnings and zero errors.

Localization

• If the project uses Localizable.xcstrings, prefer symbol keys with extractionState set to "manual":

  // String catalog key: "helloWorld" (extractionState: manual)
  Text(.helloWorld)
  

• Offer to translate new keys into all languages the project already supports.

Xcode MCP

If the Xcode MCP server is configured, prefer its tools over generic alternatives:

• RenderPreview — captures rendered SwiftUI preview images for inspection.
• DocumentationSearch — searches Apple's documentation for current API.

Learn More

This guidance is adapted from the SwiftUI Pro agent skill by Paul Hudson (MIT-licensed).