Avoid shared cache for verifier

Author: simolus3

docs/pubspec.yaml

@@ -49,6 +49,8 @@ dev_dependencies:
  sass_builder: ^2.2.1
 
 dependency_overrides:
+ # Due to https://github.com/dart-lang/sdk/issues/60553#issuecomment-2818927538
+ analyzer: '>=7.3.0 <7.4.0'
  drift_flutter:
  path: ../drift_flutter
  drift:

drift_dev/CHANGELOG.md

@@ -1,6 +1,8 @@
 ## 2.26.1-dev
 
 - Fix `generatedAs` not being generated for versioned schema imports.
+- Avoid the use of the shared database cache in the `SchemaVerifier`
+ implementation.
 
 ## 2.26.0
 

drift_dev/lib/api/migrations_common.dart

@@ -146,4 +146,13 @@ class InitializedSchema<DB extends CommonDatabase> {
  /// });
  /// ```
  DatabaseConnection newConnection() => _createConnection();
+
+ /// [CommonDatabase.dispose]s the underlying [rawDatabase] backing the initial
+ /// schema.
+ ///
+ /// Not calling this method technically leaks resources, but [rawDatabase] is
+ /// an in-memory database that also has finalizers closing it when it's not
+ /// used anymore. Further, unit tests are typically short-lived processes, so
+ /// forgetting to call [close] does not have terrible side-effects.
+ void close() => rawDatabase.dispose();
 }

drift_dev/lib/src/services/schema/verifier_common.dart

@@ -1,5 +1,3 @@
-import 'dart:math';
-
 import 'package:drift/drift.dart';
 import 'package:drift_dev/api/migrations_common.dart';
 import 'package:sqlite3/common.dart';
@@ -79,15 +77,14 @@ Expando<List<Input>> expectedSchema = Expando();
 abstract base class VerifierImplementation<DB extends CommonDatabase>
  implements SchemaVerifier<DB> {
  final SchemaInstantiationHelper helper;
- final Random _random = Random();
 
  final void Function(DB)? setup;
 
  VerifierImplementation(this.helper, {this.setup});
 
- DB newInMemoryDatabase(String uri);
+ DB newInMemoryDatabase();
 
- QueryExecutor wrapOpened(DB db);
+ QueryExecutor wrapOpened(DB db, {required bool closeUnderlyingOnClose});
 
  @override
  Future<void> migrateAndValidate(GeneratedDatabase db, int expectedVersion,
@@ -116,22 +113,8 @@ abstract base class VerifierImplementation<DB extends CommonDatabase>
  verify(referenceSchema, actualSchema, validateDropped);
  }
 
- String _randomString() {
- const charCodeLowerA = 97;
- const charCodeLowerZ = 122;
- const length = 16;
-
- final buffer = StringBuffer();
- for (var i = 0; i < length; i++) {
- buffer.writeCharCode(
- _random.nextInt(charCodeLowerZ - charCodeLowerA) + charCodeLowerA);
- }
-
- return buffer.toString();
- }
-
- DB _setupDatabase(String uri) {
- final database = newInMemoryDatabase(uri);
+ DB _setupDatabase() {
+ final database = newInMemoryDatabase();
  try {
  database.config.doubleQuotedStringLiterals = false;
  } on SqliteException {
@@ -148,23 +131,18 @@ abstract base class VerifierImplementation<DB extends CommonDatabase>
 
  @override
  Future<InitializedSchema<DB>> schemaAt(int version) async {
- // Use distinct executors for setup and use, allowing us to close the helper
- // db here and avoid creating it twice.
- // https://www.sqlite.org/inmemorydb.html#sharedmemdb
- final uri = 'file:mem${_randomString()}?mode=memory&cache=shared';
- final dbForSetup = _setupDatabase(uri);
- final dbForUse = _setupDatabase(uri);
-
- final executor = wrapOpened(dbForSetup);
+ final rawDb = _setupDatabase();
+
+ final executor = wrapOpened(rawDb, closeUnderlyingOnClose: false);
  final db = helper.databaseForVersion(executor, version);
 
  // Opening the helper database will instantiate the schema for us
  await executor.ensureOpen(db);
  await db.close();
 
- return InitializedSchema(dbForUse, () {
- final db = _setupDatabase(uri);
- return DatabaseConnection(wrapOpened(db));
+ return InitializedSchema(rawDb, () {
+ return DatabaseConnection(
+  wrapOpened(rawDb, closeUnderlyingOnClose: false));
  });
  }
 

drift_dev/lib/src/services/schema/verifier_native.dart

@@ -10,12 +10,14 @@ final class NativeSchemaVerifier extends VerifierImplementation<Database>
  NativeSchemaVerifier(super.helper, {super.setup});
 
  @override
- Database newInMemoryDatabase(String uri) {
- return sqlite3.open(uri, uri: true);
+ Database newInMemoryDatabase() {
+ return sqlite3.openInMemory();
  }
 
  @override
- QueryExecutor wrapOpened(Database db) {
- return NativeDatabase.opened(db);
+ QueryExecutor wrapOpened(Database db,
+ {required bool closeUnderlyingOnClose}) {
+ return NativeDatabase.opened(db,
+ closeUnderlyingOnClose: closeUnderlyingOnClose);
  }
 }

drift_dev/lib/src/services/schema/verifier_web.dart

@@ -12,12 +12,14 @@ final class WebSchemaVerifier extends VerifierImplementation<CommonDatabase>
  WebSchemaVerifier(this.sqlite3, super.helper, {super.setup});
 
  @override
- CommonDatabase newInMemoryDatabase(String uri) {
- return sqlite3.open(uri, uri: true);
+ CommonDatabase newInMemoryDatabase() {
+ return sqlite3.openInMemory();
  }
 
  @override
- QueryExecutor wrapOpened(CommonDatabase db) {
- return WasmDatabase.opened(db);
+ QueryExecutor wrapOpened(CommonDatabase db,
+ {required bool closeUnderlyingOnClose}) {
+ return WasmDatabase.opened(db,
+ closeUnderlyingOnClose: closeUnderlyingOnClose);
  }
 }