Merge pull request #2510 from brian-superlist/fix-opfs-issue

Bugfix: Only remove available implementations entries if they're available

docs/pages/docs/Other engines/web.md

@@ -108,10 +108,22 @@ Unfortunately, there's no way (that I'm aware of) to add these headers onto `flu
 Drift will fall back to a (slightly slower) implementation in that case (see [storages](#storages)),
 but we recommend researching and enabling these headers in production if possible.
 
-Note that Safari 16 has an [unfortunate bug](https://bugs.webkit.org/show_bug.cgi?id=245346)
+{% block "blocks/alert" title="Downsides of COOP and COEP" color="danger" %}
+While these headers are required for the origin-private FileSystem Access API
+and bring a security benefit, there are some known problems:
+
+- These headers are incompatible with some other packages opening popups,
+   such as the ones used for [Google Auth](https://developers.google.com/identity/gsi/web/guides/get-google-api-clientid?hl=en#cross_origin_opener_policy).
+- Safari 16 has an [unfortunate bug](https://bugs.webkit.org/show_bug.cgi?id=245346)
 preventing dedicated workers to be loaded from cache with these headers. However, shared and service workers
 are unaffected by this.
 
+Please carefully test your app with these headers to evaluate whether you might
+be affected by these limitations.
+If the headers break your app, you should not enable them - drift will fall back
+to another (potentially slower) implementation in that case.
+{% endblock %}
+
 ### Setup in Dart
 
 From a perspective of the Dart code used, drift on the web is similar to drift on other platforms.

drift/lib/src/web/wasm_setup.dart

@@ -93,11 +93,19 @@ class WasmDatabaseOpener {
     // format to avoid data loss (e.g. after a browser update that enables a
     // otherwise preferred storage implementation). In the future, we might want
     // to consider migrating between storage implementations as well.
-    if (_existsInIndexedDb) {
+    if (_existsInIndexedDb &&
+        (availableImplementations
+                .contains(WasmStorageImplementation.sharedIndexedDb) ||
+            availableImplementations
+                .contains(WasmStorageImplementation.unsafeIndexedDb))) {
       availableImplementations.removeWhere((element) =>
           element != WasmStorageImplementation.sharedIndexedDb &&
           element != WasmStorageImplementation.unsafeIndexedDb);
-    } else if (_existsInOpfs) {
+    } else if (_existsInOpfs &&
+        (availableImplementations
+                .contains(WasmStorageImplementation.opfsShared) ||
+            availableImplementations
+                .contains(WasmStorageImplementation.opfsLocks))) {
       availableImplementations.removeWhere((element) =>
           element != WasmStorageImplementation.opfsShared &&
           element != WasmStorageImplementation.opfsLocks);

extras/integration_tests/web_wasm/lib/driver.dart

@@ -20,8 +20,6 @@ class TestAssetServer {
   final BuildDaemonClient buildRunner;
   late final HttpServer server;
 
-  bool addCoopAndCoepHeaders = true;
-
   TestAssetServer(this.buildRunner);
 
   Future<void> close() async {
@@ -69,9 +67,16 @@ class TestAssetServer {
     final proxy = proxyHandler('http://localhost:$assetServerPort/web/');
     server.server = await serve(
       (request) async {
+        final pathSegments = request.url.pathSegments;
+
+        if (pathSegments.isNotEmpty && pathSegments[0] == 'no-coep') {
+          // Serve stuff under /no-coep like the regular website, but without
+          // adding the security headers.
+          return await proxy(request.change(path: 'no-coep'));
+        } else {
           final response = await proxy(request);
 
-        if (server.addCoopAndCoepHeaders) {
+          if (!request.url.path.startsWith('/no-coep')) {
             return response.change(headers: {
               // Needed for shared array buffers to work
               'Cross-Origin-Opener-Policy': 'same-origin',
@@ -80,6 +85,7 @@ class TestAssetServer {
           }
 
           return response;
+        }
       },
       'localhost',
       8080,

extras/integration_tests/web_wasm/test/drift_wasm_test.dart

@@ -176,6 +176,22 @@ void main() {
             expect(await driver.amountOfRows, 1);
           },
         );
+
+        if (!browser.supports(WasmStorageImplementation.opfsShared)) {
+          test('uses indexeddb after OPFS becomes unavailable', () async {
+            // This browser only supports OPFS with the right headers. If they
+            // are ever removed, data is lost (nothing we could do about that),
+            // but drift should continue to work.
+            await driver.openDatabase(WasmStorageImplementation.opfsLocks);
+            await driver.insertIntoDatabase();
+            expect(await driver.amountOfRows, 1);
+            await Future.delayed(const Duration(seconds: 2));
+
+            await driver.driver.get('http://localhost:8080/no-coep');
+            await driver.openDatabase();
+            expect(await driver.amountOfRows, isZero);
+          });
+        }
       }
     });
   }