fix(auth, web): ensure exact same streams are not unsubscribed (#13033)

Author: russellwheatley

packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart

@@ -10,6 +10,7 @@ import 'dart:async';
 import 'dart:js_interop';
 import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
 import 'package:firebase_core_web/firebase_core_web_interop.dart';
+import 'package:flutter/foundation.dart';
 import 'package:http_parser/http_parser.dart';
 
 import 'auth_interop.dart' as auth_interop;
@@ -392,9 +393,35 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   // ignore: close_sinks
   StreamController<User?>? _changeController;
 
-  String get _authStateWindowsKey => 'flutterfire-${app.name}_authStateChanges';
-  String get _idTokenStateWindowsKey =>
-      'flutterfire-${app.name}_idTokenChanges';
+  // purely for debug mode and tracking listeners to clean up on "hot restart"
+  final Map<String, int> _authStateListeners = {};
+  String _authStateWindowsKey() {
+    if (kDebugMode) {
+      final key = 'flutterfire-${app.name}_authStateChanges';
+      if (_authStateListeners.containsKey(key)) {
+        _authStateListeners[key] = _authStateListeners[key]! + 1;
+      } else {
+        _authStateListeners[key] = 0;
+      }
+      return '$key-${_authStateListeners[key]}';
+    }
+    return 'no-op';
+  }
+
+// purely for debug mode and tracking listeners to clean up on "hot restart"
+  final Map<String, int> _idTokenStateListeners = {};
+  String _idTokenStateWindowsKey() {
+    if (kDebugMode) {
+      final key = 'flutterfire-${app.name}_idTokenChanges';
+      if (_idTokenStateListeners.containsKey(key)) {
+        _idTokenStateListeners[key] = _idTokenStateListeners[key]! + 1;
+      } else {
+        _idTokenStateListeners[key] = 0;
+      }
+      return '$key-${_idTokenStateListeners[key]}';
+    }
+    return 'no-op';
+  }
 
   /// Sends events when the users sign-in state changes.
   ///
@@ -403,7 +430,8 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   ///
   /// If the value is `null`, there is no signed-in user.
   Stream<User?> get onAuthStateChanged {
-    unsubscribeWindowsListener(_authStateWindowsKey);
+    final authStateKey = _authStateWindowsKey();
+    unsubscribeWindowsListener(authStateKey);
 
     if (_changeController == null) {
       final nextWrapper = (auth_interop.UserJsImpl? user) {
@@ -417,14 +445,17 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
         final unsubscribe =
             jsObject.onAuthStateChanged(nextWrapper.toJS, errorWrapper.toJS);
         _onAuthUnsubscribe = unsubscribe;
-        setWindowsListener(_authStateWindowsKey, unsubscribe);
+        setWindowsListener(
+          authStateKey,
+          unsubscribe,
+        );
       }
 
       void stopListen() {
         _onAuthUnsubscribe!.callAsFunction();
         _onAuthUnsubscribe = null;
         _changeController = null;
-        removeWindowsListener(_authStateWindowsKey);
+        removeWindowsListener(authStateKey);
       }
 
       _changeController = StreamController<User?>.broadcast(
@@ -450,7 +481,8 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   ///
   /// If the value is `null`, there is no signed-in user.
   Stream<User?> get onIdTokenChanged {
-    unsubscribeWindowsListener(_idTokenStateWindowsKey);
+    final idTokenKey = _idTokenStateWindowsKey();
+    unsubscribeWindowsListener(idTokenKey);
     if (_idTokenChangedController == null) {
       final nextWrapper = (auth_interop.UserJsImpl? user) {
         _idTokenChangedController!.add(User.getInstance(user));
@@ -463,14 +495,17 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
         final unsubscribe =
             jsObject.onIdTokenChanged(nextWrapper.toJS, errorWrapper.toJS);
         _onIdTokenChangedUnsubscribe = unsubscribe;
-        setWindowsListener(_idTokenStateWindowsKey, unsubscribe);
+        setWindowsListener(
+          idTokenKey,
+          unsubscribe,
+        );
       }
 
       void stopListen() {
         _onIdTokenChangedUnsubscribe!.callAsFunction();
         _onIdTokenChangedUnsubscribe = null;
         _idTokenChangedController = null;
-        removeWindowsListener(_idTokenStateWindowsKey);
+        removeWindowsListener(idTokenKey);
       }
 
       _idTokenChangedController = StreamController<User?>.broadcast(