Fix: Retry when inserting records offline (#2)

* Fix: Retry when inserting records offline

* Update workflow dart version

* Fix dart formatting

* Fix dart analysis

Author: mugikhan

.github/workflows/test.yaml

@@ -15,8 +15,8 @@ jobs:
       - name: Install Flutter
         uses: subosito/flutter-action@v2
         with:
-          flutter-version: '3.10.6'
-          channel: 'stable'
+          flutter-version: "3.24.0"
+          channel: "stable"
 
       - name: Install dependencies
         run: flutter pub get

analysis_options.yaml

@@ -22,8 +22,11 @@ linter:
   # `// ignore_for_file: name_of_lint` syntax on the line or in the file
   # producing the lint.
   rules:
-    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    avoid_print: false # Uncomment to disable the `avoid_print` rule
     # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
-
 # Additional information about this file can be found at
 # https://dart.dev/guides/language/analysis-options
+
+analyzer:
+  exclude:
+    - lib/firebase.dart # Exclude this as it imports a file that is not checked in

android/app/build.gradle

@@ -49,7 +49,7 @@ android {
         applicationId "co.powersync.demotodolist"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
-        minSdkVersion 19
+        minSdkVersion 23
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

android/build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.7.10'
+    ext.kotlin_version = '2.0.0'
     repositories {
         google()
         mavenCentral()

android/gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.1-bin.zip

lib/app_config.dart

@@ -1,5 +1,6 @@
 /// Update these values
 class AppConfig {
   static const String backendUrl = 'https://4be6-71-211-245-221.ngrok-free.app';
-  static const String powersyncUrl = 'https://65663910ce6b81ac131b8c62.powersync.journeyapps.com';
+  static const String powersyncUrl =
+      'https://65663910ce6b81ac131b8c62.powersync.journeyapps.com';
 }

lib/powersync.dart

@@ -29,18 +29,17 @@ final List<RegExp> fatalResponseCodes = [
 /// Use Custom Node.js backend for authentication and data upload.
 class BackendConnector extends PowerSyncBackendConnector {
   PowerSyncDatabase db;
-
+  //ignore: unused_field
   Future<void>? _refreshFuture;
 
   BackendConnector(this.db);
 
   /// Get a token to authenticate against the PowerSync instance.
   @override
   Future<PowerSyncCredentials?> fetchCredentials() async {
-
     final user = FirebaseAuth.instance.currentUser;
-    if(user == null) {
-    // Not logged in
+    if (user == null) {
+      // Not logged in
       return null;
     }
     final idToken = await user.getIdToken();
@@ -64,14 +63,16 @@ class BackendConnector extends PowerSyncBackendConnector {
       // userId and expiresAt are for debugging purposes only
       final expiresAt = parsedBody['expiresAt'] == null
           ? null
-          : DateTime.fromMillisecondsSinceEpoch(parsedBody['expiresAt']! * 1000);
+          : DateTime.fromMillisecondsSinceEpoch(
+              parsedBody['expiresAt']! * 1000);
       return PowerSyncCredentials(
           endpoint: parsedBody['powerSyncUrl'],
           token: parsedBody['token'],
           userId: parsedBody['userId'],
           expiresAt: expiresAt);
     } else {
       print('Request failed with status: ${response.statusCode}');
+      return null;
     }
   }
 
@@ -109,33 +110,44 @@ class BackendConnector extends PowerSyncBackendConnector {
 
         var row = Map<String, dynamic>.of(op.opData!);
         row['id'] = op.id;
-        Map<String, dynamic> data = {
-          "table": op.table,
-          "data": row
-        };
-
+        Map<String, dynamic> data = {"table": op.table, "data": row};
         if (op.op == UpdateType.put) {
           await upsert(data);
         } else if (op.op == UpdateType.patch) {
           await update(data);
         } else if (op.op == UpdateType.delete) {
+          data = {
+            "table": op.table,
+            "data": {"id": op.id}
+          };
           await delete(data);
         }
       }
 
       // All operations successful.
       await transaction.complete();
+    } on http.ClientException catch (e) {
+      // Error may be retryable - e.g. network error or temporary server error.
+      // Throwing an error here causes this call to be retried after a delay.
+      log.warning('Client exception', e);
+      rethrow;
     } catch (e) {
-      log.severe('Failed to update object $e');
-      transaction.complete();
+      /// Instead of blocking the queue with these errors,
+      /// discard the (rest of the) transaction.
+      ///
+      /// Note that these errors typically indicate a bug in the application.
+      /// If protecting against data loss is important, save the failing records
+      /// elsewhere instead of discarding, and/or notify the user.
+      log.severe('Data upload error - discarding $lastOp', e);
+      await transaction.complete();
     }
   }
 }
 
 /// Global reference to the database
 late final PowerSyncDatabase db;
 
-upsert (data) async {
+upsert(data) async {
   var url = Uri.parse("${AppConfig.backendUrl}/api/data");
 
   try {
@@ -154,10 +166,11 @@ upsert (data) async {
     }
   } catch (e) {
     log.severe('Exception occurred: $e');
+    rethrow;
   }
 }
 
-update (data) async {
+update(data) async {
   var url = Uri.parse("${AppConfig.backendUrl}/api/data");
 
   try {
@@ -176,10 +189,11 @@ update (data) async {
     }
   } catch (e) {
     log.severe('Exception occurred: $e');
+    rethrow;
   }
 }
 
-delete (data) async {
+delete(data) async {
   var url = Uri.parse("${AppConfig.backendUrl}/api/data");
 
   try {
@@ -198,6 +212,7 @@ delete (data) async {
     }
   } catch (e) {
     log.severe('Exception occurred: $e');
+    rethrow;
   }
 }
 
@@ -219,7 +234,11 @@ Future<String> getDatabasePath() async {
 
 Future<void> openDatabase() async {
   // Open the local database
-  db = PowerSyncDatabase(schema: schema, path: await getDatabasePath());
+  db = PowerSyncDatabase(
+    schema: schema,
+    path: await getDatabasePath(),
+    logger: attachedLogger,
+  );
   await db.initialize();
   BackendConnector? currentConnector;
 
@@ -235,9 +254,7 @@ Future<void> openDatabase() async {
     log.info('User not logged in, setting connection');
   }
 
-  FirebaseAuth.instance
-      .authStateChanges()
-      .listen((User? user) async {
+  FirebaseAuth.instance.authStateChanges().listen((User? user) async {
     if (user != null) {
       // Connect to PowerSync when the user is signed in
       currentConnector = BackendConnector(db);
@@ -252,5 +269,5 @@ Future<void> openDatabase() async {
 /// Explicit sign out - clear database and log out.
 Future<void> logout() async {
   await FirebaseAuth.instance.signOut();
-  await db.disconnectedAndClear();
+  await db.disconnectAndClear();
 }

lib/widgets/list_item.dart

@@ -17,13 +17,6 @@ class ListItemWidget extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    viewList() {
-      var navigator = Navigator.of(context);
-
-      navigator.push(
-          MaterialPageRoute(builder: (context) => TodoListPage(list: list)));
-    }
-
     final subtext =
         '${list.pendingCount} pending, ${list.completedCount} completed';
 
@@ -32,7 +25,10 @@ class ListItemWidget extends StatelessWidget {
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           ListTile(
-              onTap: viewList,
+              onTap: () {
+                Navigator.of(context).push(MaterialPageRoute(
+                    builder: (context) => TodoListPage(list: list)));
+              },
               leading: const Icon(Icons.list),
               title: Text(list.name),
               subtitle: Text(subtext)),

lib/widgets/login_page.dart

@@ -29,35 +29,33 @@ class _LoginPageState extends State<LoginPage> {
       _busy = true;
       _error = null;
     });
-   try {
-     final credential = await FirebaseAuth.instance.signInWithEmailAndPassword(
-       email: _usernameController.text,
-       password: _passwordController.text
-     );
-     if(mounted) {
+    try {
+      await FirebaseAuth.instance.signInWithEmailAndPassword(
+          email: _usernameController.text, password: _passwordController.text);
+      if (context.mounted) {
         Navigator.of(context).pushReplacement(MaterialPageRoute(
           builder: (context) => listsPage,
         ));
-     }
-   } on FirebaseAuthException catch (e) {
-     if (e.code == 'user-not-found') {
-         setState(() {
-            _error = 'No user found for that email.';
-         });
-     } else if (e.code == 'wrong-password') {
+      }
+    } on FirebaseAuthException catch (e) {
+      if (e.code == 'user-not-found') {
         setState(() {
-            _error = 'Wrong password provided for that user.';
+          _error = 'No user found for that email.';
         });
-     }
-   } catch (e) {
+      } else if (e.code == 'wrong-password') {
+        setState(() {
+          _error = 'Wrong password provided for that user.';
+        });
+      }
+    } catch (e) {
       setState(() {
         _error = e.toString();
       });
-   } finally {
-    setState(() {
-       _busy = false;
-    });
-   }
+    } finally {
+      setState(() {
+        _busy = false;
+      });
+    }
   }
 
   @override

lib/widgets/signup_page.dart

@@ -29,35 +29,35 @@ class _SignupPageState extends State<SignupPage> {
       _busy = true;
       _error = null;
     });
-   try {
-     final credential = await FirebaseAuth.instance.createUserWithEmailAndPassword(
-       email: _usernameController.text,
-       password: _passwordController.text,
-     );
-     if(mounted) {
+    try {
+      await FirebaseAuth.instance.createUserWithEmailAndPassword(
+        email: _usernameController.text,
+        password: _passwordController.text,
+      );
+      if (context.mounted) {
         Navigator.of(context).pushReplacement(MaterialPageRoute(
-            builder: (context) => homePage,
+          builder: (context) => homePage,
         ));
-     }
-   } on FirebaseAuthException catch (e) {
-     if (e.code == 'weak-password') {
-         setState(() {
-            _error = 'The password provided is too weak.';
-         });
-     } else if (e.code == 'email-already-in-use') {
+      }
+    } on FirebaseAuthException catch (e) {
+      if (e.code == 'weak-password') {
         setState(() {
-            _error = 'The account already exists for that email.';
+          _error = 'The password provided is too weak.';
         });
-     }
-   } catch (e) {
-       setState(() {
-         _error = e.toString();
-       });
-   } finally {
-    setState(() {
+      } else if (e.code == 'email-already-in-use') {
+        setState(() {
+          _error = 'The account already exists for that email.';
+        });
+      }
+    } catch (e) {
+      setState(() {
+        _error = e.toString();
+      });
+    } finally {
+      setState(() {
         _busy = false;
-    });
-   }
+      });
+    }
   }
 
   @override