Improve remote tester line decoding and iOS min version

FeodorFitsner · FeodorFitsner · commit 5c36b0a4ff6d · 2025-10-22T11:59:29.000-07:00
Introduces a custom ChunkedLineDecoder for robust UTF-8 line splitting with max length enforcement in Dart and Python remote tester implementations. Updates iOS minimum deployment target to 13.0 in project files. Refactors remote tester logic to handle large messages and prevent buffer overflows.
diff --git a/client/integration_test/app_test.dart b/client/integration_test/app_test.dart
@@ -47,10 +47,13 @@ void main() {
 
       app.main(args);
 
-      await Future.delayed(const Duration(milliseconds: 500));
-      await widgetTester?.pump(duration: const Duration(seconds: 1));
-      await widgetTester?.pumpAndSettle(
-          duration: const Duration(milliseconds: 100));
+      if (testerServerUrl.isEmpty) {
+        await Future.delayed(const Duration(milliseconds: 500));
+        await widgetTester?.pump(duration: const Duration(seconds: 1));
+        await widgetTester?.pumpAndSettle(
+          duration: const Duration(milliseconds: 100),
+        );
+      }
       await widgetTester?.waitForTeardown();
     });
   });
diff --git a/client/ios/Flutter/AppFrameworkInfo.plist b/client/ios/Flutter/AppFrameworkInfo.plist
@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>12.0</string>
+  <string>13.0</string>
 </dict>
 </plist>
diff --git a/client/ios/Podfile b/client/ios/Podfile
@@ -1,5 +1,5 @@
 # Uncomment this line to define a global platform for your project
-# platform :ios, '12.0'
+# platform :ios, '13.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
diff --git a/client/ios/Podfile.lock b/client/ios/Podfile.lock
@@ -62,7 +62,7 @@ PODS:
     - FlutterMacOS
   - permission_handler_apple (9.3.0):
     - Flutter
-  - record_ios (1.0.0):
+  - record_ios (1.1.0):
     - Flutter
   - rive_common (0.0.1):
     - Flutter
@@ -169,7 +169,7 @@ SPEC CHECKSUMS:
   DKImagePickerController: 946cec48c7873164274ecc4624d19e3da4c1ef3c
   DKPhotoGallery: b3834fecb755ee09a593d7c9e389d8b5d6deed60
   file_picker: a0560bc09d61de87f12d246fc47d2119e6ef37be
-  Flutter: e0871f40cf51350855a761d2e70bf5af5b9b5de7
+  Flutter: cabc95a1d2626b1b06e7179b784ebcf0c0cde467
   geolocator_apple: ab36aa0e8b7d7a2d7639b3b4e48308394e8cef5e
   Google-Mobile-Ads-SDK: 1dfb0c3cb46c7e2b00b0f4de74a1e06d9ea25d67
   google_mobile_ads: 535223588a6791b7a3cc3513a1bc7b89d12f3e62
@@ -180,7 +180,7 @@ SPEC CHECKSUMS:
   package_info_plus: af8e2ca6888548050f16fa2f1938db7b5a5df499
   path_provider_foundation: 080d55be775b7414fd5a5ef3ac137b97b097e564
   permission_handler_apple: 4ed2196e43d0651e8ff7ca3483a069d469701f2d
-  record_ios: fee1c924aa4879b882ebca2b4bce6011bcfc3d8b
+  record_ios: f75fa1d57f840012775c0e93a38a7f3ceea1a374
   rive_common: dd421daaf9ae69f0125aa761dd96abd278399952
   SDWebImage: 73c6079366fea25fa4bb9640d5fb58f0893facd8
   sensors_plus: 6a11ed0c2e1d0bd0b20b4029d3bad27d96e0c65b
@@ -190,8 +190,8 @@ SPEC CHECKSUMS:
   url_launcher_ios: 694010445543906933d732453a59da0a173ae33d
   volume_controller: 3657a1f65bedb98fa41ff7dc5793537919f31b12
   wakelock_plus: e29112ab3ef0b318e58cfa5c32326458be66b556
-  webview_flutter_wkwebview: 1821ceac936eba6f7984d89a9f3bcb4dea99ebb2
+  webview_flutter_wkwebview: 8ebf4fded22593026f7dbff1fbff31ea98573c8d
 
-PODFILE CHECKSUM: 6e0773c9c44c19ccfa69850451666ad1d1af99d1
+PODFILE CHECKSUM: 462a5b249f9f1900cbd87af7b6af48272dc2df5a
 
 COCOAPODS: 1.14.3
diff --git a/client/ios/Runner.xcodeproj/project.pbxproj b/client/ios/Runner.xcodeproj/project.pbxproj
@@ -360,7 +360,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
@@ -441,7 +441,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -490,7 +490,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
diff --git a/packages/flet_integration_test/lib/src/chunked_line_decoder.dart b/packages/flet_integration_test/lib/src/chunked_line_decoder.dart
@@ -0,0 +1,72 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:typed_data';
+
+/// Stream transformer which decodes UTF-8 bytes into newline-delimited strings
+/// while enforcing a maximum line length.
+class ChunkedLineDecoder extends StreamTransformerBase<Uint8List, String> {
+  final int maxLineLength;
+
+  const ChunkedLineDecoder({this.maxLineLength = 16 * 1024 * 1024});
+
+  @override
+  Stream<String> bind(Stream<Uint8List> stream) {
+    final stringStream = stream.cast<List<int>>().transform(utf8.decoder);
+    late StreamSubscription<String> subscription;
+    late StreamController<String> controller;
+    var pending = "";
+
+    void emitLine(String line) {
+      if (line.length > maxLineLength) {
+        throw StateError(
+          "Line length exceeds allowed limit of $maxLineLength characters.",
+        );
+      }
+      controller.add(line);
+    }
+
+    controller = StreamController<String>(
+      onListen: () {
+        subscription = stringStream.listen(
+          (chunk) {
+            pending += chunk;
+            while (true) {
+              final newlineIndex = pending.indexOf('\n');
+              if (newlineIndex == -1) {
+                if (pending.length > maxLineLength) {
+                  controller.addError(StateError(
+                    "Line length exceeds allowed limit of $maxLineLength characters.",
+                  ));
+                  subscription.cancel();
+                }
+                break;
+              }
+              final line = pending.substring(0, newlineIndex);
+              emitLine(line);
+              pending = pending.substring(newlineIndex + 1);
+            }
+          },
+          onError: controller.addError,
+          onDone: () {
+            if (pending.isNotEmpty) {
+              if (pending.length > maxLineLength) {
+                controller.addError(StateError(
+                  "Line length exceeds allowed limit of $maxLineLength characters.",
+                ));
+              } else {
+                controller.add(pending);
+              }
+            }
+            controller.close();
+          },
+          cancelOnError: false,
+        );
+      },
+      onPause: () => subscription.pause(),
+      onResume: () => subscription.resume(),
+      onCancel: () => subscription.cancel(),
+    );
+
+    return controller.stream;
+  }
+}
diff --git a/packages/flet_integration_test/lib/src/remote_widget_tester.dart b/packages/flet_integration_test/lib/src/remote_widget_tester.dart
@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:convert';
 
 import 'package:flet/flet.dart';
+import 'package:flet_integration_test/src/chunked_line_decoder.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
@@ -42,25 +43,25 @@ class RemoteWidgetTester extends FlutterWidgetTester {
   }
 
   void _startListening() {
-    final lines = utf8.decoder.bind(_socket).transform(const LineSplitter());
-    _subscription = lines.listen(
-      (line) {
-        _commandQueue = _commandQueue.then((_) => _processLine(line));
-      },
-      onError: (error, stackTrace) {
-        if (!_connectionClosed.isCompleted) {
-          _connectionClosed.completeError(error, stackTrace);
-        }
-        _closeSilently();
-      },
-      onDone: () {
-        _closeSilently();
-        if (!_connectionClosed.isCompleted) {
-          _connectionClosed.complete();
-        }
-      },
-      cancelOnError: true,
-    );
+    final stream = _socket
+        .transform(const ChunkedLineDecoder(maxLineLength: 16 * 1024 * 1024));
+    _subscription = stream.listen(null, onError: (error, stackTrace) {
+      if (!_connectionClosed.isCompleted) {
+        _connectionClosed.completeError(error, stackTrace);
+      }
+      _closeSilently();
+    }, onDone: () {
+      _closeSilently();
+      if (!_connectionClosed.isCompleted) {
+        _connectionClosed.complete();
+      }
+    }, cancelOnError: true);
+    _subscription!.onData((line) {
+      _subscription?.pause();
+      final Future<void> pending = _processLine(line);
+      _commandQueue = _commandQueue.then((_) => pending);
+      pending.whenComplete(() => _subscription?.resume());
+    });
   }
 
   Future<void> _processLine(String line) async {
diff --git a/sdk/python/packages/flet/src/flet/testing/remote_tester.py b/sdk/python/packages/flet/src/flet/testing/remote_tester.py
@@ -82,21 +82,38 @@ async def _handle_client(
 
     async def _read_loop(self):
         assert self._reader is not None
+        buffer = bytearray()
+        max_line_length = 16 * 1024 * 1024
         while True:
-            line = await self._reader.readline()
-            if not line:
+            chunk = await self._reader.read(4096)
+            if not chunk:
+                if buffer:
+                    message = json.loads(buffer.decode("utf-8"))
+                    self._dispatch_message(message)
                 break
-            message = json.loads(line.decode("utf-8"))
-            request_id = message.get("id")
-            future = self._pending.pop(request_id, None)
-            if future is None:
-                continue
-            if "error" in message:
-                future.set_exception(
-                    RemoteTesterError(message["error"], message.get("stack"))
-                )
-            else:
-                future.set_result(message.get("result"))
+            buffer.extend(chunk)
+            while True:
+                newline_index = buffer.find(b"\n")
+                if newline_index == -1:
+                    if len(buffer) > max_line_length:
+                        raise ValueError("Incoming message exceeds allowed size.")
+                    break
+                line = buffer[:newline_index]
+                del buffer[: newline_index + 1]
+                message = json.loads(line.decode("utf-8"))
+                self._dispatch_message(message)
+
+    def _dispatch_message(self, message: Any):
+        request_id = message.get("id")
+        future = self._pending.pop(request_id, None)
+        if future is None:
+            return
+        if "error" in message:
+            future.set_exception(
+                RemoteTesterError(message["error"], message.get("stack"))
+            )
+        else:
+            future.set_result(message.get("result"))
 
     def _cleanup_connection(self):
         for future in self._pending.values():
