Swift code style conventions for clean, readable code. Use when writing Swift code to ensure consistent formatting, naming, organization, and idiomatic patterns.
Enforces Swift style conventions for clean, idiomatic code. Applies when writing Swift to ensure proper naming, spacing, organization, and common patterns like guard clauses and weak self capture.
/plugin marketplace add johnrogers/claude-swift-engineering/plugin install swift-engineering@claude-swift-engineeringThis skill inherits all available tools. When active, it can use any tool Claude has access to.
Code style conventions for clean, readable Swift code.
Clarity > Brevity > Consistency
Code should compile without warnings.
UpperCamelCase — Types, protocolslowerCamelCase — Everything else// Preferred
let maximumWidgetCount = 100
func fetchUser(byID id: String) -> User
Left-hand margin is the happy path. Don't nest if statements.
// Preferred
func process(value: Int?) throws -> Result {
guard let value = value else {
throw ProcessError.nilValue
}
guard value > 0 else {
throw ProcessError.invalidValue
}
return compute(value)
}
Use extensions and MARK comments:
class MyViewController: UIViewController {
// Core implementation
}
// MARK: - UITableViewDataSource
extension MyViewController: UITableViewDataSource { }
Avoid self unless required by compiler.
// Preferred
func configure() {
backgroundColor = .systemBackground
}
Omit get for read-only:
var diameter: Double {
radius * 2
}
Trailing closure only for single closure parameter.
Let compiler infer when clear. For empty collections, use type annotation:
var names: [String] = []
// Preferred
var items: [String]
var cache: [String: Int]
var name: String?
private over fileprivateinternal (it's the default)resource.request().onComplete { [weak self] response in
guard let self else { return }
self.updateModel(response)
}
// or ///, avoid /* */Use case-less enum for namespacing:
enum Math {
static let pi = 3.14159
}
Abbreviations beyond URL, ID, UUID — Abbreviations like cfg, mgr, ctx, desc hurt readability. Spell them out: configuration, manager, context, description. The three exceptions are URL, ID, UUID.
Nested guard/if statements — Deep nesting makes code hard to follow. Use early returns and guards to keep the happy path left-aligned.
Inconsistent self usage — Either always omit self (preferred) or always use it. Mixing makes code scanning harder and confuses capture semantics.
Overly generic type names — Manager, Handler, Helper, Coordinator are too vague. Names should explain responsibility: PaymentProcessor, EventDispatcher, ImageCache, NavigationCoordinator.
Implied access control — Don't skip access control. Explicit private, public helps future maintainers understand module boundaries. internal is default, so omit it.
This skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.
This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.