Simplified action dispatcher proxy API

Sources/SwiftDux/Action/ActionDispatcher.swift

@@ -23,12 +23,9 @@ public protocol ActionDispatcher {
   /// Create a new `ActionDispatcher` that acts as a proxy for the current one.
   ///
   /// Actions can be modified by both the new proxy and the original dispatcher it was created from.
-  /// - Parameters
-  ///   - modifyAction: An optional closure to modify the action before it continues up stream.
-  ///   - sentAction: Called directly after an action was sent up stream.
+  /// - Parameter modifyAction: An optional closure to modify the action before it continues up stream.
   /// - Returns: a new action dispatcher.
-  func proxy(modifyAction: ActionModifier?, sentAction: ((Action) -> Void)?) -> ActionDispatcher
-
+  func proxy(modifyAction: ActionModifier?) -> ActionDispatcher
 }
 
 extension ActionDispatcher {
@@ -38,7 +35,7 @@ extension ActionDispatcher {
   public func callAsFunction(_ action: Action) {
     send(action)
   }
-  
+
   /// Send an action that returns a cancellable object.
   /// - Parameter action: The action
   /// - Returns: A cancellable to cancel the action.

Sources/SwiftDux/Store/Store.swift

@@ -48,23 +48,16 @@ public final class Store<State> where State: StateType {
 
 extension Store: ActionDispatcher {
 
-  // swift-format-disable: UseLetInEveryBoundCaseVariable
-
   /// Sends an action to the store to mutate its state.
   /// - Parameter action: The  action to mutate the state.
   public func send(_ action: Action) {
-    switch action {
-    case let action as ActionPlan<State>:
+    if let action = action as? ActionPlan<State> {
       send(actionPlan: action)
-    case let modifiedAction as ModifiedAction:
-      send(modifiedAction: modifiedAction)
-    default:
+    } else {
       reduceAction(action)
     }
   }
 
-  // swift-format-enable: UseLetInEveryBoundCaseVariable
-
   /// Handles the sending of normal action plans.
   private func send(actionPlan: ActionPlan<State>) {
     var cancellable: AnyCancellable? = nil
@@ -81,23 +74,14 @@ extension Store: ActionDispatcher {
     didChangeSubject.send(actionPlan)
   }
 
-  private func send(modifiedAction: ModifiedAction) {
-    send(modifiedAction.action)
-    modifiedAction.previousActions.forEach { self.didChangeSubject.send($0) }
-  }
-
   /// Create a new `ActionDispatcher` that acts as a proxy between the action sender and the store. It optionally allows actions to be
   /// modified or tracked.
-  /// - Parameters
-  ///   - modifyAction: An optional closure to modify the action before it continues up stream.
-  ///   - sentAction: Called directly after an action was sent up stream.
+  /// - Parameter modifyAction: An optional closure to modify the action before it continues up stream.
   /// - Returns: a new action dispatcher.
-  public func proxy(modifyAction: ActionModifier? = nil, sentAction: ((Action) -> Void)? = nil) -> ActionDispatcher {
-    StoreActionDispatcher(
-      upstream: self,
-      modifyAction: modifyAction,
-      sentAction: sentAction
+  public func proxy(modifyAction: ActionModifier? = nil) -> ActionDispatcher {
+    StoreProxy<State>(
+      store: self,
+      modifyAction: modifyAction
     )
   }
-
 }

Sources/SwiftDux/Store/StoreProxy.swift

@@ -12,6 +12,9 @@ public struct StoreProxy<State>: ActionDispatcher where State: StateType {
   /// Subscribe to state changes.
   private unowned var store: Store<State>
 
+  /// Send an action to the next middleware
+  private var modifyAction: ActionModifier?
+
   /// Send an action to the next middleware
   private var nextBlock: SendAction?
 
@@ -27,15 +30,30 @@ public struct StoreProxy<State>: ActionDispatcher where State: StateType {
     store.didChange
   }
 
-  internal init(store: Store<State>, next: SendAction? = nil, done: (() -> Void)? = nil) {
+  internal init(store: Store<State>, modifyAction: ActionModifier? = nil, next: SendAction? = nil, done: (() -> Void)? = nil) {
     self.store = store
+    self.modifyAction = modifyAction
+    self.nextBlock = next
+    self.doneBlock = done
+  }
+
+  internal init(store: StoreProxy<State>, modifyAction: ActionModifier? = nil, next: SendAction? = nil, done: (() -> Void)? = nil) {
+    self.store = store.store
+    self.modifyAction = modifyAction.flatMap { outer in
+      store.modifyAction.map { inner in
+        { action in
+          inner(action).flatMap { outer($0) }
+        }
+      } ?? outer
+    }
     self.nextBlock = next
     self.doneBlock = done
   }
 
   /// Send an action to the store.
   /// - Parameter action: The action to send
   public func send(_ action: Action) {
+    let action = modifyAction.flatMap { $0(action) } ?? action
     store.send(action)
   }
 
@@ -53,7 +71,7 @@ public struct StoreProxy<State>: ActionDispatcher where State: StateType {
     doneBlock?()
   }
 
-  public func proxy(modifyAction: ActionModifier?, sentAction: ((Action) -> Void)?) -> ActionDispatcher {
-    fatalError("StoreProxy cannot create an ActionDispatcher proxy.")
+  public func proxy(modifyAction: ActionModifier?) -> ActionDispatcher {
+    StoreProxy(store: self, modifyAction: modifyAction)
   }
 }

Sources/SwiftDux/UI/Extensions/Environment+ActionDispatcher.swift

@@ -8,7 +8,7 @@ internal struct NoopActionDispatcher: ActionDispatcher {
     print("Tried dispatching an action `\(action)` without providing a store object.")
   }
 
-  func proxy(modifyAction: ActionModifier?, sentAction: ((Action) -> Void)?) -> ActionDispatcher {
+  func proxy(modifyAction: ActionModifier? = nil) -> ActionDispatcher {
     print("Tried proxying an action dispatcher before providing a store object.")
     return self
   }

Sources/SwiftDux/UI/ViewModifiers/OnActionViewModifier.swift

@@ -10,8 +10,11 @@ internal struct OnActionViewModifier: ViewModifier {
   }
 
   public func body(content: Content) -> some View {
-    let proxy = actionDispatcher.proxy(modifyAction: perform, sentAction: nil)
-    return content.environment(\.actionDispatcher, proxy)
+    var nextActionDispatcher = actionDispatcher
+    if let perform = perform {
+      nextActionDispatcher = actionDispatcher.proxy(modifyAction: perform)
+    }
+    return content.environment(\.actionDispatcher, nextActionDispatcher)
   }
 }
 

Sources/SwiftDux/UI/ViewModifiers/StoreProviderViewModifier.swift

@@ -5,7 +5,6 @@ import SwiftUI
 internal struct StoreProviderViewModifier<State>: ViewModifier where State: StateType {
   private var store: Store<State>
   private var connection: StateConnection<State>
-  private var actionDispatcher: ActionDispatcher
 
   internal init(store: Store<State>) {
     self.store = store
@@ -17,13 +16,12 @@ internal struct StoreProviderViewModifier<State>: ViewModifier where State: Stat
       changePublisher: store.didChange,
       emitChanges: false
     )
-    self.actionDispatcher = store.proxy()
   }
 
   public func body(content: Content) -> some View {
     content
       .environmentObject(connection)
-      .environment(\.actionDispatcher, actionDispatcher)
+      .environment(\.actionDispatcher, store)
       .environment(\.storeUpdated, store.didChange)
   }
 

Tests/SwiftDuxTests/Action/ActionPlanTests.swift

@@ -81,7 +81,7 @@ final class ActionPlanTests: XCTestCase {
       }
     }
 
-    let cancellable = actionPlan.sendAsCancellable(store)
+    let cancellable = store.sendAsCancellable(actionPlan)
 
     DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
         cancellable.cancel()

Tests/SwiftDuxTests/StoreActionDispatcherTests.swift

@@ -6,20 +6,20 @@ final class StoreActionDispatcherTests: XCTestCase {
 
   func testBasicActionDispatchingValue() {
     let store = Store(state: TestState.defaultState, reducer: TestReducer())
-    let dispatcher = store.proxy()
-    dispatcher.send(TodoListAction.addTodo(toList: "123", withText: "My Todo"))
+    let dispatch = store.proxy()
+    dispatch(TodoListAction.addTodo(toList: "123", withText: "My Todo"))
     XCTAssertEqual(store.state.todoLists["123"]?.todos.filter { $0.text == "My Todo"}.count, 1)
   }
 
   func testModifyingActionsValue() {
     let store = Store(state: TestState.defaultState, reducer: TestReducer())
-    let dispatcher = store.proxy(modifyAction: {
+    let dispatch = store.proxy {
       if $0 is TodoListAction {
         return TestAction.routeTodoAction(forList: "123", action: $0)
       }
       return $0
-    })
-    dispatcher.send(TodoListAction.addTodo2(withText: "My Todo"))
+    }
+    dispatch(TodoListAction.addTodo2(withText: "My Todo"))
     XCTAssertEqual(store.state.todoLists["123"]?.todos.filter { $0.text == "My Todo"}.count, 1)
   }