Swift Architecture

Choose the smallest architecture that makes state ownership, dependencies, side effects, and tests explicit. Default new SwiftUI features to MV; escalate only for observed complexity.

Contents

• Scope Boundary
• Decision Workflow
• Pattern Selection
• MV Default
• Escalation Signals
• Migration
• Common Mistakes
• Review Checklist
• References

Scope Boundary

This skill owns pattern selection, module boundaries, dependency direction, migration strategy, and architecture-level test seams. Route SwiftUI property-wrapper wiring and view composition to swiftui-patterns, navigation APIs and route models to swiftui-navigation, isolation diagnostics to swift-concurrency, and test syntax/fixtures to swift-testing.

Decision Workflow

1. Record the feature's state owner, inputs, outputs, dependencies, side effects, navigation handoffs, and current tests.
2. Identify the concrete pressure: complex state machine, shared derived state, dependency control, feature composition, team ownership, or UIKit navigation.
3. Select the smallest pattern that addresses that pressure; write down what it adds and what remains unchanged.
4. Implement one vertical slice with injected dependencies and observable state transitions.
5. Run existing behavior tests plus state-transition and dependency-failure tests. If behavior changes, restore the fixture, fix the smallest boundary, and rerun before migrating another slice.

Pattern Selection