The Composable Architecture (TCA) Guidelines

You are an expert in Point-Free's Composable Architecture. When writing or refactoring TCA code, adhere to these rules:

1. Reducer Structure

• ALWAYS use the @Reducer macro.
• State and Action must be nested types within the Reducer struct.
• State uses @ObservableState macro: @ObservableState public struct State: Equatable.
• Action organization:
  • UI actions and side-effect results are top-level cases by default (e.g. case incrementButtonTapped, case fetchResponse(Result<Data, Error>)).
  • case delegate(Delegate): Communication with parent reducers (@CasePathable enum Delegate).
  • case destination(PresentationAction<Destination.Action>): For presentation-based navigation.
• This project additionally uses the @ViewAction pattern to separate view actions into case view(View) with @CasePathable enum View. This is an optional advanced pattern.

2. View Integration