Revert "Remove child store from parent when invalidated (pointfreeco#3729)"

This reverts commit d83d00c.

Author: lukeredpath

Sources/ComposableArchitecture/Store.swift

@@ -99,14 +99,8 @@ import SwiftUI
 #else
   @preconcurrency@MainActor
 #endif
-public final class Store<State, Action>: _Store {
+public final class Store<State, Action> {
   var children: [ScopeID<State, Action>: AnyObject] = [:]
-  private weak var parent: (any _Store)?
-  private let scopeID: AnyHashable?
-
-  func removeChild(scopeID: AnyHashable) {
-    children[scopeID as! ScopeID<State, Action>] = nil
-  }
 
   let core: any Core<State, Action>
   @_spi(Internals) public var effectCancellables: [UUID: AnyCancellable] { core.effectCancellables }
@@ -146,7 +140,6 @@ public final class Store<State, Action>: _Store {
 
   init() {
     self.core = InvalidCore()
-    self.scopeID = nil
   }
 
   deinit {
@@ -280,7 +273,7 @@ public final class Store<State, Action>: _Store {
       let id,
       let child = children[id] as? Store<ChildState, ChildAction>
     else {
-      let child = Store<ChildState, ChildAction>(core: childCore(), scopeID: id, parent: self)
+      let child = Store<ChildState, ChildAction>(core: childCore())
       if core.canStoreCacheChildren, let id {
         children[id] = child
       }
@@ -327,24 +320,18 @@ public final class Store<State, Action>: _Store {
     core.send(action)
   }
 
-  private init(core: some Core<State, Action>, scopeID: AnyHashable?, parent: (any _Store)?) {
+  private init(core: some Core<State, Action>) {
     defer { Logger.shared.log("\(storeTypeName(of: self)).init") }
     self.core = core
-    self.parent = parent
-    self.scopeID = scopeID
 
     if let stateType = State.self as? any ObservableState.Type {
       func subscribeToDidSet<T: ObservableState>(_ type: T.Type) -> AnyCancellable {
         return core.didSet
-          .prefix { [weak self] _ in self?.core.isInvalid == false }
-          .compactMap { [weak self] in (self?.withState(\.self) as? T)?._$id }
+          .prefix { [weak self] _ in self?.core.isInvalid != true }
+          .compactMap { [weak self] in (self?.currentState as? T)?._$id }
           .removeDuplicates()
           .dropFirst()
-          .sink { [weak self, weak parent] _ in
-            guard let scopeID = self?.scopeID
-            else { return }
-            parent?.removeChild(scopeID: scopeID)
-          } receiveValue: { [weak self] _ in
+          .sink { [weak self] _ in
             guard let self else { return }
             self._$observationRegistrar.withMutation(of: self, keyPath: \.currentState) {}
           }
@@ -357,11 +344,7 @@ public final class Store<State, Action>: _Store {
     initialState: R.State,
     reducer: R
   ) {
-    self.init(
-      core: RootCore(initialState: initialState, reducer: reducer),
-      scopeID: nil,
-      parent: nil
-    )
+    self.init(core: RootCore(initialState: initialState, reducer: reducer))
   }
 
   /// A publisher that emits when state changes.
@@ -589,8 +572,3 @@ let _isStorePerceptionCheckingEnabled: Bool = {
   @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
   extension Store: Observable {}
 #endif
-
-@MainActor
-private protocol _Store: AnyObject {
-  func removeChild(scopeID: AnyHashable)
-}