Navigation case study fixes (#130)

* Fix navigation case study cancellation

Fixes #129.

* Fix

* move

Author: stephencelis

Examples/CaseStudies/SwiftUICaseStudies/00-RootView.swift

@@ -304,9 +304,15 @@ struct RootView: View {
         }
       }
       .navigationBarTitle("Case Studies")
+      .onAppear { self.id = UUID() }
+
+      Text("\(self.id)")
     }
     .navigationViewStyle(StackNavigationViewStyle())
   }
+  // NB: This is a hack to force the root view to re-compute itself each time it appears so that
+  //     each demo is provided a fresh store each time.
+  @State var id = UUID()
 }
 
 struct RootView_Previews: PreviewProvider {

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Lists-LoadThenNavigate.swift

@@ -34,6 +34,8 @@ let lazyListNavigationReducer = Reducer<
   LazyListNavigationState, LazyListNavigationAction, LazyListNavigationEnvironment
 >.combine(
   Reducer { state, action, environment in
+    struct CancelId: Hashable {}
+
     switch action {
     case .counter:
       return .none
@@ -43,8 +45,6 @@ let lazyListNavigationReducer = Reducer<
         state.rows[index].isActivityIndicatorVisible = state.rows[index].id == id
       }
 
-      struct CancelId: Hashable {}
-
       return Effect(value: .setNavigationSelectionDelayCompleted(id))
         .delay(for: 1, scheduler: environment.mainQueue)
         .eraseToEffect()
@@ -53,9 +53,9 @@ let lazyListNavigationReducer = Reducer<
     case .setNavigation(selection: .none):
       if let selection = state.selection {
         state.rows[id: selection.id]?.count = selection.count
-        state.selection = nil
       }
-      return .none
+      state.selection = nil
+      return .cancel(id: CancelId())
 
     case let .setNavigationSelectionDelayCompleted(id):
       state.rows[id: id]?.isActivityIndicatorVisible = false

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Lists-NavigateAndLoad.swift

@@ -50,8 +50,8 @@ let eagerListNavigationReducer = Reducer<
     case .setNavigation(selection: .none):
       if let selection = state.selection, let count = selection.value?.count {
         state.rows[id: selection.id]?.count = count
-        state.selection = nil
       }
+      state.selection = nil
       return .cancel(id: CancelId())
 
     case .setNavigationSelectionDelayCompleted:

Sources/ComposableArchitecture/Debugging/ReducerDebugging.swift

@@ -4,7 +4,7 @@ import Dispatch
 extension Reducer {
   /// Prints debug messages describing all received actions and state mutations.
   ///
-  /// Printing is only done in DEBUG builds.
+  /// Printing is only done in debug (`#if DEBUG`) builds.
   ///
   /// - Parameters:
   ///   - prefix: A string with which to prefix all debug messages.
@@ -24,7 +24,7 @@ extension Reducer {
 
   /// Prints debug messages describing all received actions.
   ///
-  /// Printing is only done in DEBUG builds.
+  /// Printing is only done in debug (`#if DEBUG`) builds.
   ///
   /// - Parameters:
   ///   - prefix: A string with which to prefix all debug messages.