Use experimental wasm backend in new example

drift/lib/wasm.dart

@@ -31,6 +31,17 @@ class WasmDatabase extends DelegatedDatabase {
   WasmDatabase._(DatabaseDelegate delegate, bool logStatements)
       : super(delegate, isSequential: true, logStatements: logStatements);
 
+  /// Creates a wasm database at [path] in the virtual file system of the
+  /// [sqlite3] module.
+  factory WasmDatabase({
+    required CommmonSqlite3 sqlite3,
+    required String path,
+    WasmDatabaseSetup? setup,
+    bool logStatements = false,
+  }) {
+    return WasmDatabase._(_WasmDelegate(sqlite3, path, setup), logStatements);
+  }
+
   /// Creates an in-memory database in the loaded [sqlite3] database.
   factory WasmDatabase.inMemory(
     CommmonSqlite3 sqlite3, {

examples/app/lib/database/connection/web.dart

@@ -1,13 +1,38 @@
+import 'dart:async';
+// ignore: avoid_web_libraries_in_flutter
+import 'dart:html';
+
 import 'package:drift/drift.dart';
+import 'package:drift/remote.dart';
 import 'package:drift/web.dart';
+import 'package:drift/wasm.dart';
+import 'package:http/http.dart' as http;
+import 'package:sqlite3/wasm.dart';
+
+const _useWorker = true;
 
 /// Obtains a database connection for running drift on the web.
 DatabaseConnection connect({bool isInWebWorker = false}) {
-  return DatabaseConnection.delayed(Future.sync(() async {
-    final storage = await DriftWebStorage.indexedDbIfSupported('app_database',
-        inWebWorker: isInWebWorker);
-    final databaseImpl = WebDatabase.withStorage(storage);
+  if (_useWorker && !isInWebWorker) {
+    final worker = SharedWorker('shared_worker.dart.js');
+    return remote(worker.port!.channel());
+  } else {
+    return DatabaseConnection.delayed(Future.sync(() async {
+      // We're using the experimental wasm support in Drift because this gives us
+      // a recent sqlite3 version with fts5 support.
+      // This is still experimental, so consider using the approach described in
+      // https://drift.simonbinder.eu/web/ instead.
 
-    return DatabaseConnection.fromExecutor(databaseImpl);
-  }));
+      final response = await http.get(Uri.parse('sqlite3.wasm'));
+      final fs = await IndexedDbFileSystem.load('/drift/my_app/');
+      final sqlite3 = await WasmSqlite3.load(
+        response.bodyBytes,
+        SqliteEnvironment(fileSystem: fs),
+      );
+
+      final databaseImpl =
+          WasmDatabase(sqlite3: sqlite3, path: '/drift/my_app/app.db');
+      return DatabaseConnection.fromExecutor(databaseImpl);
+    }));
+  }
 }

examples/app/lib/database/database.dart

@@ -93,6 +93,18 @@ class AppDatabase extends _$AppDatabase {
     }).watch();
   }
 
+  Future<void> deleteCategory(Category category) {
+    return transaction(() async {
+      // First, move todo entries that might remain into the default category
+      await (todoEntries.update()
+            ..where((todo) => todo.category.equals(category.id)))
+          .write(const TodoEntriesCompanion(category: Value(null)));
+
+      // Then, delete the category
+      await categories.deleteOne(category);
+    });
+  }
+
   static Provider<AppDatabase> provider = Provider((ref) {
     final database = AppDatabase();
     ref.onDispose(database.close);

examples/app/lib/screens/home/drawer.dart

@@ -139,7 +139,7 @@ class _CategoryDrawerEntry extends ConsumerWidget {
 
             // can be null when the dialog is dismissed
             if (confirmed == true) {
-              ref.read(AppDatabase.provider).categories.deleteOne(category);
+              ref.read(AppDatabase.provider).deleteCategory(category);
             }
           },
         ),

examples/app/pubspec.yaml

@@ -15,7 +15,9 @@ dependencies:
   flutter_riverpod: ^1.0.3
   go_router: ^3.0.6
   intl: ^0.17.0
+  http: ^0.13.4 # used to load sqlite3 wasm files on the web
   sqlite3_flutter_libs: ^0.5.5
+  sqlite3: ^1.6.1
   path_provider: ^2.0.9
   path: ^1.8.0
   riverpod: ^1.0.3
@@ -46,4 +48,4 @@ dependency_overrides:
   drift_dev:
     path: ../../drift_dev
   sqlparser:
-    path: ../../sqlparser
+    path: ../../sqlparser

examples/app/web/sql-wasm.js

@@ -1 +0,0 @@
-../../../extras/integration_tests/web/test/sql-wasm.js

examples/app/web/sql-wasm.wasm

@@ -1 +0,0 @@
-../../../extras/integration_tests/web/test/sql-wasm.wasm

examples/app/web/worker.dart

@@ -7,8 +7,6 @@ import 'package:drift/remote.dart';
 
 void main() {
   final self = SharedWorkerGlobalScope.instance;
-  self.importScripts('sql-wasm.js');
-
   final server = DriftServer(connect(isInWebWorker: true));
 
   self.onConnect.listen((event) {

examples/web_worker_example/lib/worker_channel.dart

@@ -1,5 +1,6 @@
 import 'dart:html';
 
+import 'package:drift/web.dart';
 import 'package:stream_channel/stream_channel.dart';
 
 StreamChannel<Object?> startWorker(String script) {
@@ -8,13 +9,3 @@ StreamChannel<Object?> startWorker(String script) {
 
   return worker.port!.channel();
 }
-
-extension PortToChannel on MessagePort {
-  StreamChannel<Object?> channel() {
-    final controller = StreamChannelController();
-    onMessage.map((event) => event.data).pipe(controller.local.sink);
-    controller.local.stream.listen(postMessage, onDone: close);
-
-    return controller.foreign;
-  }
-}