Add consistent methods to delete databases

sqlite3/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 2.6.0-dev
+
+- Add `SimpleOpfsFileSystem.deleteFromStorage` to delete OPFS-based file
+  systems.
+
 ## 2.5.0
 
 - Allow registering custom virtual file systems on all platforms. Previously,

sqlite3/lib/src/wasm/vfs/simple_opfs.dart

@@ -7,7 +7,9 @@ import 'package:web/web.dart'
     show
         FileSystemDirectoryHandle,
         FileSystemSyncAccessHandle,
-        FileSystemReadWriteOptions;
+        FileSystemReadWriteOptions,
+        FileSystemRemoveOptions,
+        DOMException;
 
 import '../../constants.dart';
 import '../../vfs.dart';
@@ -68,6 +70,24 @@ final class SimpleOpfsFileSystem extends BaseVirtualFileSystem {
       {String vfsName = 'simple-opfs'})
       : super(name: vfsName);
 
+  static Future<(FileSystemDirectoryHandle?, FileSystemDirectoryHandle)>
+      _resolveDir(String path, {bool create = true}) async {
+    final storage = storageManager;
+    if (storage == null) {
+      throw VfsException(SqlError.SQLITE_ERROR);
+    }
+
+    FileSystemDirectoryHandle? parent;
+    var opfsDirectory = await storage.directory;
+
+    for (final segment in p.split(path)) {
+      parent = opfsDirectory;
+      opfsDirectory = await opfsDirectory.getDirectory(segment, create: create);
+    }
+
+    return (parent, opfsDirectory);
+  }
+
   /// Loads an [SimpleOpfsFileSystem] in the desired [path] under the root directory
   /// for OPFS as given by `navigator.storage.getDirectory()` in JavaScript.
   ///
@@ -81,13 +101,32 @@ final class SimpleOpfsFileSystem extends BaseVirtualFileSystem {
       throw VfsException(SqlError.SQLITE_ERROR);
     }
 
-    var opfsDirectory = await storage.directory;
+    final (_, directory) = await _resolveDir(path);
+    return inDirectory(directory, vfsName: vfsName);
+  }
 
-    for (final segment in p.split(path)) {
-      opfsDirectory = await opfsDirectory.getDirectory(segment, create: true);
+  /// Deletes the file system directory handle that would store sqlite3
+  /// databases when using [loadFromStorage] with the same path.
+  static Future<void> deleteFromStorage(String path) async {
+    final FileSystemDirectoryHandle? parent;
+    final FileSystemDirectoryHandle handle;
+
+    try {
+      (parent, handle) = await _resolveDir(path, create: false);
+    } on DOMException catch (e) {
+      if (e.name == 'NotFoundError' || e.name == 'TypeMismatchError') {
+        // Directory doesn't exist, ignore.
+        return;
+      } else {
+        rethrow;
+      }
     }
 
-    return inDirectory(opfsDirectory, vfsName: vfsName);
+    if (parent != null) {
+      await parent
+          .removeEntry(handle.name, FileSystemRemoveOptions(recursive: true))
+          .toDart;
+    }
   }
 
   /// Loads an [SimpleOpfsFileSystem] in the desired [root] directory, which must be

sqlite3/pubspec.yaml

@@ -1,6 +1,6 @@
 name: sqlite3
 description: Provides lightweight yet convenient bindings to SQLite by using dart:ffi
-version: 2.5.0
+version: 2.6.0-dev
 homepage: https://github.com/simolus3/sqlite3.dart/tree/main/sqlite3
 issue_tracker: https://github.com/simolus3/sqlite3.dart/issues
 

sqlite3_web/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.2.1
+
+- Add `WebSqlite.deleteDatabase` to delete databases.
+
 ## 0.2.0
 
 - Make `FileSystem` implementation functional, add `FileSystem.flush()`.

sqlite3_web/lib/src/client.dart

@@ -3,7 +3,7 @@ import 'dart:js_interop';
 import 'dart:js_interop_unsafe';
 import 'dart:typed_data';
 
-import 'package:sqlite3/common.dart';
+import 'package:sqlite3/wasm.dart' hide WorkerOptions;
 import 'package:web/web.dart'
     hide Response, Request, FileSystem, Notification, Lock;
 
@@ -12,6 +12,7 @@ import 'channel.dart';
 import 'database.dart';
 import 'protocol.dart';
 import 'shared.dart';
+import 'worker.dart';
 
 final class RemoteDatabase implements Database {
   final WorkerConnection connection;
@@ -290,6 +291,18 @@ final class DatabaseClient implements WebSqlite {
     });
   }
 
+  @override
+  Future<void> deleteDatabase(
+      {required String name, required StorageMode storage}) async {
+    switch (storage) {
+      case StorageMode.opfs:
+        await SimpleOpfsFileSystem.deleteFromStorage(pathForOpfs(name));
+      case StorageMode.indexedDb:
+        await IndexedDbFileSystem.deleteDatabase(name);
+      case StorageMode.inMemory:
+    }
+  }
+
   @override
   Future<FeatureDetectionResult> runFeatureDetection(
       {String? databaseName}) async {

sqlite3_web/lib/src/database.dart

@@ -153,6 +153,12 @@ final class ConnectToRecommendedResult {
 /// Please see the readme of the `sqlite3_web` package for an overview on how
 /// to set up and use this package.
 abstract class WebSqlite {
+  /// Deletes a database from the [storage] if it exists.
+  ///
+  /// This method should not be called while the database is still open.
+  Future<void> deleteDatabase(
+      {required String name, required StorageMode storage});
+
   /// Tries to find features related to storing and accessing databases.
   ///
   /// The [databaseName] can optionally be used to make

sqlite3_web/test/integration_test.dart

@@ -128,17 +128,7 @@ void main() {
 
         driver = TestWebDriver(server, rawDriver);
         await driver.driver.get('http://localhost:8080/');
-
-        while (true) {
-          try {
-            // This element is created after main() has completed, make sure
-            // all the callbacks have been installed.
-            await driver.driver.findElement(By.id('ready'));
-            break;
-          } on NoSuchElementException {
-            continue;
-          }
-        }
+        await driver.waitReady();
       });
 
       tearDown(() => driver.driver.quit());
@@ -170,6 +160,26 @@ void main() {
 
           expect(await driver.assertFile(true), isPositive);
           await driver.flush();
+
+          if (storage != StorageMode.inMemory) {
+            await driver.driver.refresh();
+            await driver.waitReady();
+
+            await driver.openDatabase(
+              implementation: (storage, access),
+              onlyOpenVfs: true,
+            );
+            await driver.assertFile(true);
+
+            await driver.driver.refresh();
+            await driver.waitReady();
+            await driver.delete(storage);
+            await driver.openDatabase(
+              implementation: (storage, access),
+              onlyOpenVfs: true,
+            );
+            await driver.assertFile(false);
+          }
         });
       }
     });

sqlite3_web/tool/server.dart

@@ -13,6 +13,7 @@ import 'package:shelf/shelf_io.dart';
 import 'package:shelf_proxy/shelf_proxy.dart';
 import 'package:webdriver/async_io.dart';
 import 'package:sqlite3_web/src/types.dart';
+import 'package:webdriver/support/async.dart';
 
 void main() async {
   await TestAssetServer.start();
@@ -104,6 +105,12 @@ class TestWebDriver {
 
   TestWebDriver(this.server, this.driver);
 
+  /// Wait for the Dart code on the test page to finish its main method, which
+  /// it signals by creating an element.
+  Future<void> waitReady() async {
+    await waitFor(() => driver.findElement(By.id('ready')));
+  }
+
   Future<
       ({
         Set<(StorageMode, AccessMode)> impls,
@@ -201,4 +208,9 @@ class TestWebDriver {
       throw 'flush() failed: $result';
     }
   }
+
+  Future<void> delete(StorageMode mode) async {
+    await driver
+        .executeAsync('delete_db(arguments[0], arguments[1])', [mode.name]);
+  }
 }

sqlite3_web/web/main.dart

@@ -58,6 +58,12 @@ void main() {
     await vfs.flush();
     return true.toJS;
   });
+  _addCallbackForWebDriver('delete_db', (arg) async {
+    final storage = StorageMode.values.byName(arg!);
+    await initializeSqlite()
+        .deleteDatabase(name: databaseName, storage: storage);
+    return true.toJS;
+  });
 
   document.getElementById('selfcheck')?.onClick.listen((event) async {
     print('starting');