Fix more state sync issues.

flutterapp/lib/db/completedtasks.dart

@@ -1,4 +1,5 @@
 import 'package:clock/clock.dart';
+import 'package:docket/models/task.dart';
 import 'package:json_cache/json_cache.dart';
 
 import 'package:docket/db/repository.dart';
@@ -40,6 +41,20 @@ class CompletedTasksRepo extends Repository<ProjectWithTasks> {
     return ProjectWithTasks.fromMap(data[slug]);
   }
 
+  /// Remove a task and notify listeners.
+  Future<void> removeTask(Task task) async {
+    var data = await getMap() ?? {};
+    var slug = task.projectSlug;
+    if (data[slug] == null || data[slug]['tasks'] == null) {
+      return;
+    }
+    List<Map<String, dynamic>> tasks = data[slug]['tasks'];
+    tasks.removeWhere((item) => item['id'] == task.id);
+    await setMap(data);
+
+    notifyListeners();
+  }
+
   Future<void> remove(String slug) async {
     var data = await getMap() ?? {};
 

flutterapp/lib/providers/tasks.dart

@@ -38,7 +38,7 @@ class TasksProvider extends ChangeNotifier {
       await _database.deleteTask(task);
     } else {
       await _database.updateTask(task);
-      _database.completedTasks.expireSlug(task.projectSlug);
+      await _database.completedTasks.removeTask(task);
     }
     notifyListeners();
   }

flutterapp/test/providers/tasks_test.dart

@@ -80,25 +80,40 @@ void main() {
         expect(request.url.path, contains('/tasks/1/complete'));
         return Response('', 204);
       });
-      var completedListener = CallCounter();
-
       var tasks = parseTaskList(tasksTodayResponseFixture);
       setTodayView(tasks);
 
       db.dailyTasks.addListener(listener);
-      db.completedTasks.addListener(completedListener);
       var provider = TasksProvider(db);
 
       await provider.toggleComplete(tasks[0]);
 
       expect(listener.callCount, greaterThan(0));
-      expect(completedListener.callCount, greaterThan(0));
       expect(db.dailyTasks.isDayExpired(tasks[0].dueOn!), isTrue);
-      expect(db.completedTasks.isFreshSlug(tasks[0].projectSlug), isFalse);
 
       var viewData = await db.dailyTasks.get();
       expect(viewData[todayStr]?.tasks.length, equals(1));
-      db.completedTasks.removeListener(completedListener);
+    });
+
+    test('toggleComplete() removes from completed task list', () async {
+      actions.client = MockClient((request) async {
+        expect(request.url.path, contains('/tasks/1/incomplete'));
+        return Response('', 204);
+      });
+      var tasks = parseTaskList(tasksTodayResponseFixture);
+      tasks[0].completed = true;
+
+      var taskView = ProjectWithTasks(tasks: tasks, project: Project(slug: 'home', name: 'Home'));
+      await db.completedTasks.set(taskView);
+
+      db.completedTasks.addListener(listener);
+      var provider = TasksProvider(db);
+
+      await provider.toggleComplete(tasks[0]);
+
+      expect(listener.callCount, greaterThan(0));
+      var completed = await db.completedTasks.get('home');
+      expect(completed.tasks.length, equals(1));
     });
 
     test('toggleComplete() sends request to incomplete and expires data', () async {

flutterapp/test/viewmodels/projectcompleted_test.dart

@@ -72,7 +72,7 @@ void main() {
       db.completedTasks.expireSlug('home');
       await viewmodel.loadData();
       expect(viewmodel.tasks.length, equals(2));
-      expect(callCounter.callCount, equals(2));
+      expect(callCounter.callCount, equals(4));
     });
 
     test('refresh() loads data from the server', () async {