trove-swift

Session Init

This skill ships Trove conventions. Prefer existing project patterns over generic best practices when they conflict.

Swift 6 / SwiftUI Conventions

@Observable (Preferred over ObservableObject)

@Observable
final class UserViewModel {
    var name = ""
    var isLoading = false

    func load() async {
        isLoading = true
        defer { isLoading = false }
        name = try await fetchUserName()
    }
}

Use @Observable instead of ObservableObject + @Published in new code.

Async/Await

• Use structured concurrency (async let, TaskGroup)
• Annotate main-actor-bound code with @MainActor
• Use Task { } only at boundaries (view lifecycle, button actions)

// Parallel fetching
async let user = fetchUser(id)
async let posts = fetchPosts(userId: id)
let (userData, postsData) = try await (user, posts)

NavigationStack

NavigationStack(path: $router.path) {
    ContentView()
        .navigationDestination(for: Route.self) { route in
            switch route {
            case .detail(let id): DetailView(id: id)
            case .settings: SettingsView()
            }
        }
}

Error Handling

• Use typed throws where possible
• Define domain-specific error enums conforming to LocalizedError
• Never force-unwrap (!) outside of tests

AI Gotchas

• Sendable: Mark types shared across concurrency domains as Sendable
• MainActor: UI updates must happen on @MainActor
• Observation: @Observable replaces ObservableObject in Swift 5.9+
• SwiftUI previews: Use #Preview macro instead of PreviewProvider