non-exhaustive fix

Author: stephencelis

Sources/ComposableArchitecture/Reducer/Reducers/DebugReducer.swift

@@ -88,7 +88,7 @@ public struct _PrintChangesReducer<Base: Reducer>: Reducer {
           let oldState = state
           let effects = self.base.reduce(into: &state, action: action)
           if self.sharedChangeTracker.hasChanges {
-            SharedLocals.$exhaustivity.withValue(.on) {
+            SharedLocals.$isProcessingChanges.withValue(true) {
               printer.printChange(receivedAction: action, oldState: oldState, newState: state)
             }
             self.sharedChangeTracker.clearChanges()

Sources/ComposableArchitecture/SharedState/Shared.swift

@@ -198,7 +198,7 @@ import Foundation
 
   extension Shared: Equatable where Value: Equatable {
     public static func == (lhs: Shared, rhs: Shared) -> Bool {
-      if SharedLocals.exhaustivity == .on, lhs.reference === rhs.reference {
+      if SharedLocals.isProcessingChanges, lhs.reference === rhs.reference {
         if let lhsReference = lhs.reference as? any Equatable {
           func open<T: Equatable>(_ lhsReference: T) -> Bool {
             lhsReference == rhs.reference as? T
@@ -295,8 +295,7 @@ import Foundation
 #endif
 
 enum SharedLocals {
-  @TaskLocal static var exhaustivity: Exhaustivity?
-  static var isProcessingChanges: Bool { Self.exhaustivity != nil }
+  @TaskLocal static var isProcessingChanges = false
 }
 
 final class SharedChangeTracker {
@@ -321,10 +320,13 @@ final class SharedChangeTracker {
       self.changes[ObjectIdentifier(shared.reference)] = shared.reference
     }
   #endif
-  func clearChanges() {
+  func resetChanges() {
     for change in self.changes.values {
       change.clearSnapshot()
     }
+  }
+  func clearChanges() {
+    self.resetChanges()
     self.changes.removeAll()
   }
   func assertUnchanged() {

Sources/ComposableArchitecture/TestStore.swift

@@ -700,12 +700,10 @@ public final class TestStore<State, Action> {
     _ exhaustivity: Exhaustivity,
     operation: () throws -> R
   ) rethrows -> R {
-    try SharedLocals.$exhaustivity.withValue(exhaustivity) {
-      let previous = self.exhaustivity
-      defer { self.exhaustivity = previous }
-      self.exhaustivity = exhaustivity
-      return try operation()
-    }
+    let previous = self.exhaustivity
+    defer { self.exhaustivity = previous }
+    self.exhaustivity = exhaustivity
+    return try operation()
   }
 
   /// Overrides the store's exhaustivity for a given operation.
@@ -718,12 +716,10 @@ public final class TestStore<State, Action> {
     _ exhaustivity: Exhaustivity,
     operation: @MainActor () async throws -> R
   ) async rethrows -> R {
-    try await SharedLocals.$exhaustivity.withValue(exhaustivity) {
-      let previous = self.exhaustivity
-      defer { self.exhaustivity = previous }
-      self.exhaustivity = exhaustivity
-      return try await operation()
-    }
+    let previous = self.exhaustivity
+    defer { self.exhaustivity = previous }
+    self.exhaustivity = exhaustivity
+    return try await operation()
   }
 }
 
@@ -961,7 +957,10 @@ extension TestStore where State: Equatable {
     let skipUnnecessaryModifyFailure =
       skipUnnecessaryModifyFailure
       || self.reducer.dependencies[SharedChangeTracker.self]?.hasChanges == true
-    try SharedLocals.$exhaustivity.withValue(self.exhaustivity) {
+    if self.exhaustivity != .on {
+      self.reducer.dependencies[SharedChangeTracker.self]?.resetChanges()
+    }
+    try SharedLocals.$isProcessingChanges.withValue(true) {
       let current = expected
       var expected = expected
 

Tests/ComposableArchitectureTests/SharedTests.swift

@@ -69,6 +69,26 @@ final class SharedTests: XCTestCase {
 
     await store.send(.sharedIncrement)
     XCTAssertEqual(store.state.sharedCount, 1)
+
+    XCTExpectFailure {
+      $0.compactDescription == """
+        A state change does not match expectation: …
+
+              SharedFeature.State(
+                _count: 0,
+                _profile: #1 Profile(…),
+            −   _sharedCount: #1 3,
+            +   _sharedCount: #1 2,
+                _stats: #1 Stats(count: 0)
+              )
+
+        (Expected: −, Actual: +)
+        """
+    }
+    await store.send(.sharedIncrement) {
+      $0.sharedCount = 3
+    }
+    XCTAssertEqual(store.state.sharedCount, 2)
   }
 
   func testMultiSharing() async {