Fix web database not respecting lock timeouts (#88)

Author: simolus3

packages/sqlite_async/lib/src/web/database.dart

@@ -94,7 +94,7 @@ class WebDatabase
   Future<T> readLock<T>(Future<T> Function(SqliteReadContext tx) callback,
       {Duration? lockTimeout, String? debugContext}) async {
     if (_mutex case var mutex?) {
-      return await mutex.lock(() async {
+      return await mutex.lock(timeout: lockTimeout, () async {
         final context = _SharedContext(this);
         try {
           return await callback(context);
@@ -143,7 +143,7 @@ class WebDatabase
   Future<T> writeLock<T>(Future<T> Function(SqliteWriteContext tx) callback,
       {Duration? lockTimeout, String? debugContext, bool? flush}) async {
     if (_mutex case var mutex?) {
-      return await mutex.lock(() async {
+      return await mutex.lock(timeout: lockTimeout, () async {
         final context = _ExclusiveContext(this);
         try {
           return await callback(context);

packages/sqlite_async/lib/src/web/web_mutex.dart

@@ -16,10 +16,9 @@ external Navigator get _navigator;
 /// Web implementation of [Mutex]
 class MutexImpl implements Mutex {
   late final mutex.Mutex fallback;
-  String? identifier;
   final String resolvedIdentifier;
 
-  MutexImpl({this.identifier})
+  MutexImpl({String? identifier})
 
       /// On web a lock name is required for Navigator locks.
       /// Having exclusive Mutex instances requires a somewhat unique lock name.
@@ -40,7 +39,7 @@ class MutexImpl implements Mutex {
 
   @override
   Future<T> lock<T>(Future<T> Function() callback, {Duration? timeout}) {
-    if ((_navigator as JSObject).hasProperty('locks'.toJS).toDart) {
+    if (_navigator.has('locks')) {
       return _webLock(callback, timeout: timeout);
     } else {
       return _fallbackLock(callback, timeout: timeout);

packages/sqlite_async/test/basic_test.dart

@@ -209,6 +209,27 @@ void main() {
       expect(await db.get('SELECT description FROM test_data'),
           {'description': 'test'});
     });
+
+    test('respects lock timeouts', () async {
+      // Unfortunately this test can't use fakeAsync because it uses actual
+      // lock APIs on the web.
+      final db = await testUtils.setupDatabase(path: path);
+      final lockAcquired = Completer();
+
+      final completion = db.writeLock((context) async {
+        lockAcquired.complete();
+        await Future.delayed(const Duration(seconds: 1));
+      });
+
+      await lockAcquired.future;
+      await expectLater(
+        () => db.writeLock(
+            lockTimeout: Duration(milliseconds: 200), (_) async => {}),
+        throwsA(isA<TimeoutException>()),
+      );
+
+      await completion;
+    });
   });
 }