fix(app-check, web): fixed broken onTokenChanged and ensured it is properly cleaned up. Streams are also cleaned up on "hot restart" (#12933)

russellwheatley · web-flow · commit 093b5fef8c3b · 2024-06-11T15:26:53.000+02:00
* chore: reinsert debug token initialiser

* fix(app-check): broken stream handling

* fix: app check stream clean up on hot restart

* chore: format
diff --git a/packages/firebase_app_check/firebase_app_check/example/web/index.html b/packages/firebase_app_check/firebase_app_check/example/web/index.html
@@ -33,6 +33,9 @@
   <link rel="manifest" href="manifest.json">
 </head>
 <body>
+  <script>
+    self.FIREBASE_APPCHECK_DEBUG_TOKEN = true;
+  </script>
   <script src="flutter_bootstrap.js" async></script>
 </body>
 </html>
diff --git a/packages/firebase_app_check/firebase_app_check_web/lib/firebase_app_check_web.dart b/packages/firebase_app_check/firebase_app_check_web/lib/firebase_app_check_web.dart
@@ -19,7 +19,6 @@ import 'src/interop/app_check.dart' as app_check_interop;
 class FirebaseAppCheckWeb extends FirebaseAppCheckPlatform {
   static const recaptchaTypeV3 = 'recaptcha-v3';
   static const recaptchaTypeEnterprise = 'enterprise';
-
   static Map<String, StreamController<String?>> _tokenChangesListeners = {};
 
   /// Stub initializer to allow the [registerWith] to create an instance without
@@ -121,17 +120,25 @@ class FirebaseAppCheckWeb extends FirebaseAppCheckPlatform {
     return convertWebExceptions<Future<void>>(() async {
       _webAppCheck ??= app_check_interop.getAppCheckInstance(
           core_interop.app(app.name), webProvider);
-      if (_tokenChangesListeners[app.name] == null) {
-        _tokenChangesListeners[app.name] =
-            StreamController<String?>.broadcast();
-
-        _delegate!.onTokenChanged().map((event) {
-          _tokenChangesListeners[app.name]!.add(event.token.toDart);
-        });
-      }
+      _initialiseStreamController();
     });
   }
 
+  void _initialiseStreamController() {
+    if (_tokenChangesListeners[app.name] == null) {
+      _tokenChangesListeners[app.name] = StreamController<String?>.broadcast(
+        onCancel: () {
+          _tokenChangesListeners[app.name]!.close();
+          _tokenChangesListeners.remove(app.name);
+          _delegate!.idTokenChangedController?.close();
+        },
+      );
+      _delegate!.onTokenChanged(app.name).listen((event) {
+        _tokenChangesListeners[app.name]!.add(event.token.toDart);
+      });
+    }
+  }
+
   @override
   Future<String?> getToken(bool forceRefresh) async {
     return convertWebExceptions<Future<String?>>(() async {
@@ -162,6 +169,9 @@ class FirebaseAppCheckWeb extends FirebaseAppCheckPlatform {
 
   @override
   Stream<String?> get onTokenChange {
-    return _tokenChangesListeners[app.name]!.stream;
+    _initialiseStreamController();
+    return convertWebExceptions(
+      () => _tokenChangesListeners[app.name]!.stream,
+    );
   }
 }
diff --git a/packages/firebase_app_check/firebase_app_check_web/lib/src/interop/app_check.dart b/packages/firebase_app_check/firebase_app_check_web/lib/src/interop/app_check.dart
@@ -69,11 +69,18 @@ class AppCheck extends JsObjectWrapper<app_check_interop.AppCheckJsImpl> {
 
   JSFunction? _idTokenChangedUnsubscribe;
 
+  StreamController<app_check_interop.AppCheckTokenResult>?
+      get idTokenChangedController => _idTokenChangedController;
+
   StreamController<app_check_interop.AppCheckTokenResult>?
       // ignore: close_sinks
       _idTokenChangedController;
 
-  Stream<app_check_interop.AppCheckTokenResult> onTokenChanged() {
+  String _appCheckWindowsKey(String appName) =>
+      'flutterfire-${appName}_onTokenChanged';
+  Stream<app_check_interop.AppCheckTokenResult> onTokenChanged(String appName) {
+    final appCheckWindowsKey = _appCheckWindowsKey(appName);
+    unsubscribeWindowsListener(appCheckWindowsKey);
     if (_idTokenChangedController == null) {
       final nextWrapper = ((app_check_interop.AppCheckTokenResult result) {
         _idTokenChangedController!.add(result);
@@ -83,17 +90,19 @@ class AppCheck extends JsObjectWrapper<app_check_interop.AppCheckJsImpl> {
           ((JSError e) => _idTokenChangedController!.addError(e)).toJS;
 
       void startListen() {
-        assert(_idTokenChangedUnsubscribe == null);
         _idTokenChangedUnsubscribe = app_check_interop.onTokenChanged(
           jsObject,
           nextWrapper,
           errorWrapper,
         );
+        setWindowsListener(appCheckWindowsKey, _idTokenChangedUnsubscribe!);
       }
 
       void stopListen() {
         _idTokenChangedUnsubscribe?.callAsFunction();
         _idTokenChangedUnsubscribe = null;
+        _idTokenChangedController = null;
+        removeWindowsListener(appCheckWindowsKey);
       }
 
       _idTokenChangedController =
