Improve hook behaviors when it is disposed

Author: ra1028

Sources/Hooks/Hook/UseReducer.swift

@@ -37,11 +37,19 @@ private struct ReducerHook<State, Action>: Hook {
         Ref(initialState: initialState)
     }
 
-    func makeValue(coordinator: Coordinator) -> (state: State, dispatch: (Action) -> Void) {
+    func makeValue(coordinator: Coordinator) -> (
+        state: State,
+        dispatch: (Action) -> Void
+    ) {
         (
             state: coordinator.state.state,
             dispatch: { action in
                 assertMainThread()
+
+                guard !coordinator.state.isDisposed else {
+                    return
+                }
+
                 coordinator.state.nextAction = action
                 coordinator.updateView()
             }
@@ -56,12 +64,18 @@ private struct ReducerHook<State, Action>: Hook {
         coordinator.state.state = reducer(coordinator.state.state, action)
         coordinator.state.nextAction = nil
     }
+
+    func dispose(state: Ref) {
+        state.isDisposed = true
+        state.nextAction = nil
+    }
 }
 
 private extension ReducerHook {
     final class Ref {
         var state: State
         var nextAction: Action?
+        var isDisposed = false
 
         init(initialState: State) {
             state = initialState

Sources/Hooks/Hook/UseState.swift

@@ -26,16 +26,27 @@ private struct StateHook<State>: Hook {
                 state
             },
             set: { newState in
+                assertMainThread()
+
+                guard !coordinator.state.isDisposed else {
+                    return
+                }
+
                 coordinator.state.state = newState
                 coordinator.updateView()
             }
         )
     }
+
+    func dispose(state: Ref) {
+        state.isDisposed = true
+    }
 }
 
 private extension StateHook {
     final class Ref {
         var state: State
+        var isDisposed = false
 
         init(initialState: State) {
             state = initialState

Tests/HooksTests/Hook/UseEffectTests.swift

@@ -95,6 +95,7 @@ final class UseEffectTests: XCTestCase {
 
         tester.update()
         tester.dispose()
+
         XCTAssertEqual(cleanupCount, 2)
     }
 

Tests/HooksTests/Hook/UsePublisherSubscribeTests.swift

@@ -57,22 +57,28 @@ final class UsePublisherSubscribeTests: XCTestCase {
     }
 
     func testDispose() {
+        var isSubscribed = false
         let subject = PassthroughSubject<Int, Never>()
         let tester = HookTester {
             usePublisherSubscribe {
-                subject
+                subject.handleEvents(receiveSubscription: { _ in
+                    isSubscribed = true
+                })
             }
         }
 
         XCTAssertEqual(tester.value.phase, .pending)
 
-        tester.value.subscribe()
-
-        XCTAssertEqual(tester.value.phase, .running)
-
         tester.dispose()
         subject.send(1)
 
-        XCTAssertEqual(tester.value.phase, .running)
+        XCTAssertEqual(tester.value.phase, .pending)
+        XCTAssertFalse(isSubscribed)
+
+        tester.value.subscribe()
+        subject.send(2)
+
+        XCTAssertEqual(tester.value.phase, .pending)
+        XCTAssertFalse(isSubscribed)
     }
 }

Tests/HooksTests/Hook/UsePublisherTests.swift

@@ -104,7 +104,7 @@ final class UsePublisherTests: XCTestCase {
     func testDispose() {
         let subject = PassthroughSubject<Int, Never>()
         let tester = HookTester {
-            usePublisher(.once) {
+            usePublisher(.always) {
                 subject
             }
         }

Tests/HooksTests/Hook/UseReducerTests.swift

@@ -49,4 +49,23 @@ final class UseReducerTests: XCTestCase {
 
         XCTAssertEqual(tester.value.state, 0)
     }
+
+    func testDispose() {
+        var isReduced = false
+
+        func reducer(state: Int, action: Int) -> Int {
+            isReduced = true
+            return state + action
+        }
+
+        let tester = HookTester {
+            useReducer(reducer, initialState: 0)
+        }
+
+        tester.dispose()
+        tester.value.dispatch(1)
+
+        XCTAssertEqual(tester.value.state, 0)
+        XCTAssertFalse(isReduced)
+    }
 }

Tests/HooksTests/Hook/UseStateTests.swift

@@ -41,4 +41,15 @@ final class UseStateTests: XCTestCase {
 
         XCTAssertEqual(tester.value.wrappedValue, 0)
     }
+
+    func testDispose() {
+        let tester = HookTester {
+            useState(0)
+        }
+
+        tester.dispose()
+        tester.value.wrappedValue = 1
+
+        XCTAssertEqual(tester.value.wrappedValue, 0)
+    }
 }