Update

Author: muukii

Sources/StructTransaction/Tracking.swift

@@ -0,0 +1,44 @@
+import Foundation
+
+public struct Storage: Equatable {
+  
+  public struct Identifier: Hashable {
+    public let name: String
+    
+    public init(name: String) {
+      self.name = name
+    }
+  }
+  
+  public private(set) var readIdentifiers: Set<Identifier> = []
+  public private(set) var writeIdentifiers: Set<Identifier> = []
+  
+  public mutating func read(identifier: Identifier) {
+    readIdentifiers.insert(identifier)
+  }
+  
+  public mutating func write(identifier: Identifier) {
+    writeIdentifiers.insert(identifier)
+  }
+}
+
+public func _tracking_modifyStorage(_ modifier: (inout Storage) -> Void) {
+  guard Thread.current.threadDictionary["tracking"] != nil else {
+    return
+  }
+  var storage = Thread.current.threadDictionary["tracking"] as! Storage
+  modifier(&storage)
+  Thread.current.threadDictionary["tracking"] = storage      
+}
+
+public func withTracking(_ perform: () -> Void) -> Storage {
+  let current = Thread.current.threadDictionary["tracking"] as? Storage
+  defer {
+    Thread.current.threadDictionary["tracking"] = current
+  }
+  
+  Thread.current.threadDictionary["tracking"] = Storage()  
+  perform()  
+  let result = Thread.current.threadDictionary["tracking"] as! Storage
+  return result
+}

Sources/StructTransactionMacros/COWTrackingPropertyMacro.swift

@@ -95,13 +95,21 @@ extension COWTrackingPropertyMacro: AccessorMacro {
 
     let getAccessor = AccessorDeclSyntax(
       """
-      get { \(raw: backingName).value }
+      get {
+        _tracking_modifyStorage {
+          $0.read(identifier: .init(name: "\(raw: propertyName)"))
+        }
+        return \(raw: backingName).value 
+      }
       """
     )
 
     let setAccessor = AccessorDeclSyntax(
       """
-      set {       
+      set {    
+        _tracking_modifyStorage {
+          $0.write(identifier: .init(name: "\(raw: propertyName)"))
+        }
         if !isKnownUniquelyReferenced(&\(raw: backingName)) {
           \(raw: backingName) = .init(\(raw: backingName).value)
         } else {
@@ -114,6 +122,9 @@ extension COWTrackingPropertyMacro: AccessorMacro {
     let modifyAccessor = AccessorDeclSyntax(
       """
       _modify {
+        _tracking_modifyStorage {
+          $0.write(identifier: .init(name: "\(raw: propertyName)"))
+        }
         if !isKnownUniquelyReferenced(&\(raw: backingName)) {
           \(raw: backingName) = .init(\(raw: backingName).value)
         }

Tests/StructTransactionMacroTests/COWTrackingProperyMacroTests.swift

@@ -38,16 +38,25 @@ final class COWTrackingProperyMacroTests: XCTestCase {
         
         private var stored_0: Int = 18 {
           get {
-            _backing_stored_0.value
+            _tracking_modifyStorage {
+              $0.read(identifier: .init(name: "stored_0"))
+            }
+            return _backing_stored_0.value
           }
           set {
+            _tracking_modifyStorage {
+              $0.write(identifier: .init(name: "stored_0"))
+            }
             if !isKnownUniquelyReferenced(&_backing_stored_0) {
               _backing_stored_0 = .init(_backing_stored_0.value)
             } else {
               _backing_stored_0.value = newValue
             }
           }
           _modify {
+            _tracking_modifyStorage {
+              $0.write(identifier: .init(name: "stored_0"))
+            }
             if !isKnownUniquelyReferenced(&_backing_stored_0) {
               _backing_stored_0 = .init(_backing_stored_0.value)
             }

Tests/StructTransactionMacroTests/TrackingMacroTests.swift

@@ -44,13 +44,13 @@ final class TrackingMacroTests: XCTestCase {
     } expansion: {
       """
       struct MyState {
-        @TrackingProperty
+        @COWTrackingProperty
 
         private var stored_0: Int = 18
-        @TrackingProperty
+        @COWTrackingProperty
 
         var stored_1: String
-        @TrackingProperty
+        @COWTrackingProperty
 
         let stored_2: Int = 0
 
@@ -60,7 +60,7 @@ final class TrackingMacroTests: XCTestCase {
           get { 0 }
           set { }
         }
-        @TrackingProperty
+        @COWTrackingProperty
 
         var height: Int
 

Tests/StructTransactionTests/Tests.swift

@@ -0,0 +1,6 @@
+import Testing
+
+@Suite("Tests")
+enum Tests {
+   
+}