Remove _onUpdate from on change modifier

Sources/TokamakCore/Modifiers/OnChangeModifier.swift

@@ -16,39 +16,30 @@
 //
 
 import Foundation
+import OpenCombineShim
 
 struct OnChangeModifier<V: Equatable>: ViewModifier {
   @State
-  var oldValue: V? = nil
+  private var oldValue: V?
 
   let value: V
   let initial: Bool
   let action: (V, V) -> ()
 
-  init(value: V, initial: Bool, action: @escaping (V, V) -> ()) {
-    self.value = value
-    self.initial = initial
-    self.action = action
-
-    if value != oldValue {
-      action(oldValue ?? value, value)
-      oldValue = value
-    }
-  }
-
   func body(content: Content) -> some View {
     content
-      .task {
-        if initial {
-          action(value, value)
+      .onReceive(Just(value)) { newValue in
+        // TODO: Fix, when @State if working with in a ViewModifier
+        // ignore first call when oldValue == nil. For now old value is always nil
+        if newValue != oldValue {
+          action(oldValue ?? value, newValue)
         }
         oldValue = value
       }
-      ._onUpdate {
-        if value != oldValue {
-          action(oldValue ?? value, value)
+      .onAppear {
+        if initial {
+          action(value, value)
         }
-        oldValue = value
       }
   }
 }

Sources/TokamakCore/Modifiers/OnReceiveModifier.swift

@@ -18,17 +18,29 @@
 import Foundation
 import OpenCombineShim
 
-struct OnReceiveModifier<P: Publisher>: ViewModifier where P.Failure == Never {
-  @State
-  var cancellable: AnyCancellable
+private struct OnReceiveModifier<P: Publisher>: ViewModifier where P.Failure == Never {
+  @ObservedObject
+  var cancellableHolder = CancellableHolder()
 
   init(publisher: P, action: @escaping (P.Output) -> ()) {
-    _cancellable = State(initialValue: publisher.sink(receiveValue: action))
+    cancellableHolder.cancellable = publisher.sink(receiveValue: action)
   }
 
   func body(content: Content) -> some View {
-    content.onDisappear {
-      cancellable.cancel()
+    content
+  }
+
+  // MARK: Types
+
+  final class CancellableHolder: ObservableObject {
+    var cancellable: AnyCancellable? {
+      didSet {
+        oldValue?.cancel()
+      }
+    }
+
+    deinit {
+      cancellable?.cancel()
     }
   }
 }

Tests/TokamakTests/ViewReactToDataChangesTests.swift

@@ -32,11 +32,11 @@ class ViewModifierTests: XCTestCase {
 
     // Simulate publisher emitting a value
     publisher.send("Testing onReceive")
-
-    // Re-evaluate the view
-    let reconciler = TestFiberRenderer(.root, size: .zero).render(contentView)
-
     XCTAssertEqual(receivedValue, "Testing onReceive")
+
+    // Simulate publisher emitting a value
+    publisher.send("Second onReceive")
+    XCTAssertEqual(receivedValue, "Second onReceive")
   }
 
   func testOnChangeWithValue() {