Devtools extension: Button to clear database

This drops contents and then calls beforeOpen, reinitializing the
database with the current migration.

Closes #3276

drift/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - To infer whether serialization is required for inter-isolate communication,
  drift now sends a test message instead serializing by default.
+- The DevTools extension can now clear drift databases.
 
 ## 2.20.2
 

drift/lib/src/runtime/devtools/service_extension.dart

@@ -73,6 +73,28 @@ class DriftServiceExtension {
  });
 
  return executor.statements;
+ case 'clear':
+ final database = tracked.database;
+ await database.exclusively(() async {
+ // https://stackoverflow.com/a/65743498/25690041
+ await database.customStatement('PRAGMA writable_schema = 1;');
+ await database.customStatement('DELETE FROM sqlite_master;');
+ await database.customStatement('VACUUM;');
+ await database.customStatement('PRAGMA writable_schema = 0;');
+ await database.customStatement('PRAGMA integrity_check');
+
+ await database.customStatement('PRAGMA user_version = 0');
+ await database.beforeOpen(database.resolvedEngine.executor,
+ OpeningDetails(null, database.schemaVersion));
+ await database.customStatement(
+ 'PRAGMA user_version = ${database.schemaVersion}');
+
+ // Refresh all stream queries
+ database.notifyUpdates({
+ for (final table in database.allTables) TableUpdate.onTable(table)
+ });
+ });
+ return true;
  default:
  throw UnsupportedError('Method $action');
  }

extras/drift_devtools_extension/lib/src/clear_button.dart

@@ -0,0 +1,60 @@
+import 'package:devtools_app_shared/ui.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import 'details.dart';
+
+class ClearDatabaseButton extends ConsumerStatefulWidget {
+ const ClearDatabaseButton({super.key});
+
+ @override
+ ConsumerState<ClearDatabaseButton> createState() =>
+ _ClearDatabaseButtonState();
+}
+
+class _ClearDatabaseButtonState extends ConsumerState<ClearDatabaseButton> {
+ Future<void>? _pendingClear = null;
+
+ @override
+ Widget build(BuildContext context) {
+ return DevToolsButton(
+ onPressed: () {
+ showDevToolsDialog(
+ context: context,
+ title: 'Confirm deletion',
+ content: const Text(
+ 'This will delete contents of the database and then re-create it. '
+ 'All current database data will be lost. Continue?',
+ ),
+ actions: [
+ DevToolsButton(
+ onPressed: _pendingClear != null
+ ? null
+ : () {
+ setState(() {
+ _pendingClear = Future(() async {
+ final database = ref.read(loadedDatabase);
+ await database.value!.clear();
+ })
+ .whenComplete(
+ () => setState(() => _pendingClear = null))
+ .then((_) {
+ if (mounted) {
+ // ignore: use_build_context_synchronously
+ Navigator.pop(context);
+ }
+ });
+ });
+ },
+ label: 'Confirm deletion',
+ color: Colors.redAccent,
+ ),
+ ],
+ );
+ },
+ label: 'Clear database',
+ color: Colors.redAccent,
+ icon: Icons.delete,
+ );
+ }
+}

extras/drift_devtools_extension/lib/src/details.dart

@@ -3,6 +3,7 @@ import 'package:drift_devtools_extension/src/schema_validator.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import 'clear_button.dart';
 import 'db_viewer/viewer.dart';
 import 'list.dart';
 import 'remote_database.dart';
@@ -65,6 +66,14 @@ class _DatabaseDetailsState extends ConsumerState<DatabaseDetails> {
  padding: EdgeInsets.all(8),
  child: DatabaseSchemaCheck(),
  ),
+ const Padding(
+ padding: EdgeInsets.all(8),
+ child: Row(
+ children: [
+ ClearDatabaseButton(),
+ ],
+ ),
+ ),
  Padding(
  padding: const EdgeInsets.all(8.0),
  child: Column(

extras/drift_devtools_extension/lib/src/remote_database.dart

@@ -77,6 +77,10 @@ class RemoteDatabase {
  return (res as List).cast();
  }
 
+ Future<void> clear() async {
+ await _driftRequest('clear');
+ }
+
  Future<int> _newTableSubscription() async {
  final result = await _driftRequest('subscribe-to-tables');
  return result as int;