Fix update notifications missing the first update.

Author: rkistner

.github/workflows/test.yaml

@@ -12,9 +12,18 @@ jobs:
       - uses: actions/checkout@v3
       - uses: dart-lang/setup-dart@v1
 
-      - run: dart pub get
-      - run: dart format --output=none --set-exit-if-changed .
-      - run: dart analyze
+      - name: Install dependencies
+        run: dart pub get
+      - name: Check formatting
+        run: dart format --output=none --set-exit-if-changed .
+      - name: Lint
+        run: dart analyze
+      - name: Publish dry-run
+        run: dart pub publish --dry-run
+      - name: Check publish score
+        run: |
+          dart pub global activate pana
+          dart pub global run pana --no-warning --exit-code-threshold 0
 
   test:
     runs-on: ubuntu-latest

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.2.1
+
+- Fix update notifications missing the first update.
+
 ## 0.2.0
 
 - Initial version.

lib/src/sqlite_connection_impl.dart

@@ -218,13 +218,30 @@ void _sqliteConnectionIsolate(_SqliteConnectionParams params) async {
   final server = params.portServer;
   final commandPort = ReceivePort();
 
+  Timer? updateDebouncer;
   Set<String> updatedTables = {};
   int? txId;
   Object? txError;
 
+  void maybeFireUpdates() {
+    if (updatedTables.isNotEmpty) {
+      client.fire(UpdateNotification(updatedTables));
+      updatedTables.clear();
+      updateDebouncer?.cancel();
+      updateDebouncer = null;
+    }
+  }
+
   db.updates.listen((event) {
     updatedTables.add(event.tableName);
+
+    // This handles two cases:
+    // 1. Update arrived after _SqliteIsolateClose (not sure if this could happen).
+    // 2. Long-running _SqliteIsolateClosure that should fire updates while running.
+    updateDebouncer ??=
+        Timer(const Duration(milliseconds: 10), maybeFireUpdates);
   });
+
   server.open((data) async {
     if (data is _SqliteIsolateClose) {
       if (txId != null) {
@@ -238,6 +255,8 @@ void _sqliteConnectionIsolate(_SqliteConnectionParams params) async {
         throw sqlite.SqliteException(
             0, 'Transaction must be closed within the read or write lock');
       }
+      // We would likely have received updates by this point - fire now.
+      maybeFireUpdates();
       return null;
     } else if (data is _SqliteIsolateStatement) {
       if (data.sql == 'BEGIN' || data.sql == 'BEGIN IMMEDIATE') {
@@ -261,10 +280,6 @@ void _sqliteConnectionIsolate(_SqliteConnectionParams params) async {
       }
       try {
         final result = db.select(data.sql, mapParameters(data.args));
-        if (updatedTables.isNotEmpty) {
-          client.fire(UpdateNotification(updatedTables));
-          updatedTables = {};
-        }
         return result;
       } catch (err) {
         if (txId != null) {
@@ -276,10 +291,7 @@ void _sqliteConnectionIsolate(_SqliteConnectionParams params) async {
       try {
         return await data.cb(db);
       } finally {
-        if (updatedTables.isNotEmpty) {
-          client.fire(UpdateNotification(updatedTables));
-          updatedTables = {};
-        }
+        maybeFireUpdates();
       }
     } else if (data is _SqliteIsolateConnectionClose) {
       db.dispose();

pubspec.yaml

@@ -1,13 +1,12 @@
 name: sqlite_async
 description: High-performance asynchronous interface for SQLite on Dart and Flutter.
-version: 0.2.0
+version: 0.2.1
 repository: https://github.com/journeyapps/sqlite_async.dart
 environment:
   sdk: '>=2.19.1 <3.0.0'
 
 dependencies:
   sqlite3: ^1.10.1
-  logging: ^1.1.1
   async: ^2.10.0
   collection: ^1.17.0
 

test/watch_test.dart

@@ -164,6 +164,28 @@ void main() {
           ]));
     });
 
+    test('single onChange', () async {
+      final db = await setupDatabase(path: path);
+      await createTables(db);
+
+      const baseTime = 20;
+
+      const throttleDuration = Duration(milliseconds: baseTime);
+
+      final stream = db.onChange({'assets', 'customers'},
+          throttle: throttleDuration,
+          triggerImmediately: false).asyncMap((event) async {
+        // This is where queries would typically be executed
+        return event;
+      });
+
+      var eventsFuture = stream.take(1).toList();
+      await db.execute('INSERT INTO assets(make) VALUES (?)', ['test']);
+      var events = await eventsFuture;
+
+      expect(events, equals([UpdateNotification.single('assets')]));
+    });
+
     test('watch in isolate', () async {
       final db = await setupDatabase(path: path);
       await createTables(db);