DidSet Support

Sources/StateStruct/Source.swift

@@ -72,6 +72,12 @@ struct HashableState: Hashable {
     var stored_1: Int = 18
 
     var stored_2: Int
+
+    var stored_3: Int = 10 {
+      didSet {
+        print("stored_3 did set")
+      }
+    }
 
     var computed_1: Int {
       stored_1
@@ -108,6 +114,12 @@ struct HashableState: Hashable {
       var stored_2: Int
 
       var stored_3: Int?
+
+      var stored_4: Int = 10 {
+        didSet {
+          print("stored_4 did set")
+        }
+      }
 
       var name = ""
 

Sources/StateStructMacros/COWTrackingPropertyMacro.swift

@@ -52,6 +52,7 @@ extension COWTrackingPropertyMacro: PeerMacro {
           return "_BackingStorage<\(type.trimmed)>"
         })
 
+      // add init
       _variableDecl = _variableDecl.with(
         \.bindings,
         .init(
@@ -68,9 +69,23 @@ extension COWTrackingPropertyMacro: PeerMacro {
           return "_BackingStorage<\(type.trimmed)>"
         })
         .modifyingInit({ initializer in
-          return .init(value: "_BackingStorage.init(\(initializer.value))" as ExprSyntax)
+          return .init(value: "_BackingStorage.init(\(initializer.trimmed.value))" as ExprSyntax)
         })
     }
+
+    do {
+
+      // remove accessors
+      _variableDecl = _variableDecl.with(
+        \.bindings,
+         .init(
+          _variableDecl.bindings.map { binding in
+            binding.with(\.accessorBlock, nil)
+          }
+         )           
+      )
+
+    }
 
     newMembers.append(DeclSyntax(_variableDecl))
 
@@ -94,10 +109,11 @@ extension COWTrackingPropertyMacro: AccessorMacro {
     else {
       return []
     }
-
+    
     let isConstant = variableDecl.bindingSpecifier.tokenKind == .keyword(.let)
     let propertyName = identifierPattern.identifier.text
     let backingName = "_backing_" + propertyName
+    let hasWillSet = variableDecl.willSetBlock != nil
 
     let initAccessor = AccessorDeclSyntax(
       """
@@ -122,17 +138,23 @@ extension COWTrackingPropertyMacro: AccessorMacro {
 
     let setAccessor = AccessorDeclSyntax(
       """
-      set {      
+      set { 
+
+        // willset
+        \(variableDecl.makeWillSetDoBlock())
+
         (\(raw: backingName).value as? TrackingObject)?._tracking_context.path = _tracking_context.path?.pushed(.init("\(raw: propertyName)"))
         _Tracking._tracking_modifyStorage {
           $0.accessorSet(path: _tracking_context.path?.pushed(.init("\(raw: propertyName)")))
         }
         if !isKnownUniquelyReferenced(&\(raw: backingName)) {
           \(raw: backingName) = .init(newValue)
         } else {
-          \(raw: backingName).value = newValue
+          \(raw: backingName).value = newValue             
         }
 
+        // didSet 
+        \(variableDecl.makeDidSetDoBlock())
       }
       """
     )
@@ -148,6 +170,9 @@ extension COWTrackingPropertyMacro: AccessorMacro {
           \(raw: backingName) = .init(\(raw: backingName).value)
         }
         yield &\(raw: backingName).value
+
+        // didSet   
+        \(variableDecl.makeDidSetDoBlock())
       }
       """
     )
@@ -162,7 +187,10 @@ extension COWTrackingPropertyMacro: AccessorMacro {
 
     if !isConstant {
       accessors.append(setAccessor)
-      accessors.append(modifyAccessor)
+
+      if hasWillSet == false {
+        accessors.append(modifyAccessor)
+      }
     }
 
     return accessors
@@ -244,3 +272,58 @@ extension VariableDeclSyntax {
   }
 
 }
+
+extension VariableDeclSyntax {
+
+  func makeDidSetDoBlock() -> DoStmtSyntax {
+    guard let didSetBlock = self.didSetBlock else {
+      return .init(body: "{}")
+    }
+
+    return .init(body: didSetBlock)    
+  }
+
+  func makeWillSetDoBlock() -> DoStmtSyntax {
+    guard let willSetBlock = self.willSetBlock else {
+      return .init(body: "{}")
+    }
+
+    return .init(body: willSetBlock)    
+  }
+
+  var didSetBlock: CodeBlockSyntax? {
+    for binding in self.bindings {
+      if let accessorBlock = binding.accessorBlock {
+        switch accessorBlock.accessors {
+        case .accessors(let accessors):
+          for accessor in accessors {
+            if accessor.accessorSpecifier.tokenKind == .keyword(.didSet) {
+              return accessor.body
+            }
+          }
+        case .getter:
+          return nil
+        }       
+      }
+    }
+    return nil
+  }
+
+  var willSetBlock: CodeBlockSyntax? {
+    for binding in self.bindings {
+      if let accessorBlock = binding.accessorBlock {
+        switch accessorBlock.accessors {
+        case .accessors(let accessors):
+          for accessor in accessors {
+            if accessor.accessorSpecifier.tokenKind == .keyword(.willSet) {
+              return accessor.body
+            }
+          }
+        case .getter:
+          return nil
+        }       
+      }
+    }
+    return nil
+  }
+}

Sources/StateStructMacros/TrackingMacro.swift

@@ -70,8 +70,22 @@ extension TrackingMacro: MemberAttributeMacro {
 
     // to ignore computed properties
     for binding in variableDecl.bindings {
-      if binding.accessorBlock != nil {
-        return []
+      if let accessorBlock = binding.accessorBlock {
+        // Check if this is a computed property (has a 'get' accessor)
+        // If it has only property observers like didSet/willSet, it's still a stored property
+
+        switch accessorBlock.accessors {
+        case .accessors(let accessors):
+          let hasGetter = accessors.contains { syntax in
+            syntax.accessorSpecifier.tokenKind == .keyword(.get)
+          }
+          if hasGetter {
+            return []
+          }
+          continue
+        case .getter:
+          return []
+        }        
       }
     }