Merge pull request #10 from wlsdms0122/develop

[RELEASE] Reducer/2.0.0

.swiftpm/xcode/xcshareddata/xcschemes/Reducer.xcscheme

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1420"
-   version = "1.3">
+   LastUpgradeVersion = "1500"
+   version = "1.7">
    <BuildAction
       parallelizeBuildables = "YES"
       buildImplicitDependencies = "YES">
@@ -20,18 +20,55 @@
                ReferencedContainer = "container:">
             </BuildableReference>
          </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "MacroTests"
+               BuildableName = "MacroTests"
+               BlueprintName = "MacroTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "ReducerTests"
+               BuildableName = "ReducerTests"
+               BlueprintName = "ReducerTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </BuildActionEntry>
       </BuildActionEntries>
    </BuildAction>
    <TestAction
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES"
-      codeCoverageEnabled = "YES">
+      shouldAutocreateTestPlan = "YES">
       <Testables>
          <TestableReference
-            skipped = "NO"
-            parallelizable = "YES">
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "MacroTests"
+               BuildableName = "MacroTests"
+               BlueprintName = "MacroTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </TestableReference>
+         <TestableReference
+            skipped = "NO">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "ReducerTests"

Package.resolved

@@ -0,0 +1,14 @@
+{
+  "pins" : [
+    {
+      "identity" : "swift-syntax",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-syntax.git",
+      "state" : {
+        "revision" : "e42bece52df2496d60b1b2a762fee9ffde7fc205",
+        "version" : "509.0.0-swift-DEVELOPMENT-SNAPSHOT-2023-08-07-a"
+      }
+    }
+  ],
+  "version" : 2
+}

Package.swift

@@ -1,7 +1,8 @@
-// swift-tools-version: 5.7
+// swift-tools-version: 5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
+import CompilerPluginSupport
 
 let package = Package(
     name: "Reducer",
@@ -19,13 +20,20 @@ let package = Package(
         )
     ],
     dependencies: [
-
+        .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0")
     ],
     targets: [
+        .macro(
+            name: "ReducerMacro",
+            dependencies: [
+                .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
+                .product(name: "SwiftCompilerPlugin", package: "swift-syntax")
+            ]
+        ),
         .target(
             name: "Reducer",
             dependencies: [
-
+                "ReducerMacro"
             ]
         ),
         .testTarget(
@@ -34,5 +42,12 @@ let package = Package(
                 "Reducer"
             ]
         ),
+        .testTarget(
+            name: "MacroTests",
+            dependencies: [
+                "ReducerMacro",
+                .product(name: "SwiftSyntaxMacrosTestSupport", package: "swift-syntax"),
+            ]
+        )
     ]
 )

README.md

@@ -24,60 +24,65 @@
 ## Swift Package Manager
 ```swift
 dependencies: [
-    .package(url: "https://github.com/wlsdms0122/Reducer.git", exact: "1.1.0")
+    .package(url: "https://github.com/wlsdms0122/Reducer.git", exact: "1.4.0")
 ]
 ```
 
 # Getting Started
 > This guide dose not cover the detailed principles of state design.
 > For more information, plrease refer to the [ReactorKit](https://github.com/ReactorKit/ReactorKit) or [TCA](https://github.com/pointfreeco/swift-composable-architecture) README.
 
-To get started, you'll need to define a class that adopts the `Reduce` protocol.
+To get started, You can define it via the `@Reduce` macro. or you can adopt the `Reduce` protocol.
+
+By default, `Reducer` runs on the UI's main thread, while `Reduce` does not. It's fine to use `Reduce` without the `@MainActor` constraint, but if you want the actions to run sequentially, add the `@MainActor` annotation.
+
+> ⚠️ When implementing `Reduce`, there is a slight difference in the use of macro and protocol.
 
 ```swift
-final class CounterReduce: Reduce {
+@Reduce
+@MainActor
+final class CounterReduce {
     // User interaction input.
     enum Action {
         case increase
     }
 
     // Unit of state mutation.
     enum Mutation {
-        case addOne
+        case setCount(Int)
     }
 
     // Reducer state.
     struct State {
         var count: Int
     }
 
-    var mutator: (any Mutator<Mutation, State>)?
-    var initialState: State
+    let initialState: State
 
-    init(initialState: State) {
-        self.initialState = initialState
+    init() {
+        self.initialState = State()
     }
 
-    func mutate(state: State, action: Action) async throws {
+    func mutate(action: Action) async throws {
         switch action {
         case .increase:
-            mutate(.addOne)
+            mutate(.setCount(currentState.count + 1))
         }
     }
 
     func reduce(state: State, mutation: Mutation) -> State {
         var state = state
 
         switch mutation {
-        case .addOne:
-            state.count += 1
+        case let .setCount(count):
+            state.count = count
             return state
         }
     }
 }
 ```
 
-The `mutate(state:action) async throws` method defines what to mutate when an action received with the current state. You can call `mutate(_:)`(an extended function) to mutate. and `Swift Concurrency` can be used within the mutate method as well.
+The `mutate(action:) async throws` method defines what to mutate when an action received with the current state. You can call `mutate(_:)`(an extended function) to mutate. and `Swift Concurrency` can be used within the mutate method as well.
 
 `reduce(state:mutation)` describe how to mutate the state from a mutation. It should be a pure function.
 
@@ -135,10 +140,19 @@ You can cancel running action task using `shouldCancel(_:_:) -> Bool`.
 
 For example, if you want to cancel validating user input for each keystroke to efficiently use resources, `Reducer` can determine whether the current running task should be canceled before creating a new task action. If `shouldCancel(_:_:)` returns `true`, the current action should be canceled.
 
+⚠️ The first thing to note about canceling a task is that the general expectation is that the comparison of actions should return `false` except for the case you want to cancel.
+
+The second thing to note that canceling a Task doesn't stop your code from progressing. In swift concurrency, [cancel](https://developer.apple.com/documentation/swift/task/cancel()) of task doesn't has no effect basically.
+
+If you want to make canceling a task meaningful, you'll need to [create a cancelable async method](https://developer.apple.com/documentation/swift/withtaskcancellationhandler(operation:oncancel:)) or utilize something like [`Task.checkCancellation()`](https://developer.apple.com/documentation/swift/task/checkcancellation()).
+
 ```swift
-final class SignUpReduce: Reduce {
+@Reduce
+@MainActor
+final class SignUpReduce {
     enum Action {
-        case emailChanged(String)
+        case updateEmail(String)
+        case anyAction
     }
 
     enum Mutation {
@@ -149,27 +163,36 @@ final class SignUpReduce: Reduce {
         var canSignUp: Bool
     }
 
-    var mutator: (any Mutator<Mutation, State>)?
-    var initialState: State
+    let initialState: State
 
     private let validator = EmailValidator()
 
     init() {
         initialState = State(canSignUp: false)
     }
 
-    func mutate(state: State, action: Action) async throws {
+    func mutate(action: Action) async throws {
         switch action {
-        case let .emailChanged(email):
+        case let .updateEmail(email):
             let result = try await validator.validate(email)
+            try Task.checkCancellation()
+
             mutate(.canSignUp(result))
+
+        case .anyAction:
+            ...
         }
     }
 
-    func shouldCancel(_ current: ActionItem, _ upcoming: ActionItem) -> Bool {
-        switch (current.action, upcoming.action) {
+    ...
+
+    func shouldCancel(_ current: Action, _ upcoming: Action) -> Bool {
+        switch (current, upcoming) {
         case (.emailChanged, .emailChanged):
             return true
+
+        default:
+            return false
         }
     }
 }
@@ -178,10 +201,12 @@ final class SignUpReduce: Reduce {
 ### Internal Mutating
 The reducer sometimes needs to mutate state without explicit outside action like some domain data changed.
 
-In these case, you can use `start(with:)` function. It call once when `Reducer` set `Reduce`. So you can any initialize process with mutations.
+In these case, you can use `start()` function. It call once when `Reducer` set `Reduce`. So you can any initialize process with mutations.
 
 ```swift
-final class ListReduce: Reduce {
+@Reduce
+@MainActor
+final class ListReduce {
     enum Action { ... }
 
     enum Mutation {
@@ -194,20 +219,21 @@ final class ListReduce: Reduce {
         ...
     }
 
-    var mutator: (any Mutator<Mutation, State>)?
-    var initialState: State
+    let initialState: State
+    private var cancellableBag = Set<AnyCancellable>()
 
     init() { ... }
 
-    func start(with mutator: any Mutator<Mutation, State>) async throws {
+    func start() async throws {
+        // Reset subscription when reduce re-start by reducer.
+        cancellableBag.removeAll()
+
         NotificationCenter.default.publisher(for: .init("data_changed"))
-            .sink { data in 
-                /* Write any mutates here. */
-                mutator(.setList($0.object))
+            .sink { [weak self] data in 
+                // Write any mutates here.
+                self?.mutate(.setList(data.object))
             }
-            // You can mutator scope cancellable bag.
-            // It all cancel when mutator(reducer) deinit.
-            .store(in: mutator.cancellableBag)
+            .store(in: &cancellableBag)
     }
 }
 ```
@@ -243,15 +269,10 @@ It maipulate all of `Reduce` even the `initialState`.
 ```swift
 CounterView(reducer: .init(proxy: .init(
     initialState: .init(count: 100),
-    mutate: { state, action, mutate in
-
-    },
-    reduce: { state, mutation in
-        // Return the state of result of mutating.
-    },
-    shouldCancel: { current, upcoming in
-        // Return wether the current action should be canceled via the upcoming action.
-    }
+    start: { mutate in ... }
+    mutate: { state, action, mutate in ... },
+    reduce: { state, mutation in ... },
+    shouldCancel: { current, upcoming in ... }
 )))
 ```
 

Sources/Reducer/Macro/ReduceMacro.swift

@@ -0,0 +1,10 @@
+//
+//  ReduceMacro.swift
+//
+//
+//  Created by JSilver on 2023/06/09.
+//
+
+@attached(member, names: named(mutator))
+@attached(extension, conformances: Reduce)
+public macro Reduce() = #externalMacro(module: "ReducerMacro", type: "ReduceMacro")