test(e2e): SQL transaction controls and destructive guard

test/e2e/02_sql_workspaces/e2e_transaction_guard_test.dart

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+import 'dart:async';
+
+import 'package:flutter/material.dart' as material;
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../support/fake_sql_execution_delegate.dart';
+import '../helpers/e2e_app_harness.dart';
+import '../helpers/e2e_sql_workspace_helper.dart';
+
+const _timeout = Timeout(Duration(seconds: 60));
+
+/// A database that really tracks `BEGIN` / `COMMIT` / `ROLLBACK`.
+class _TxDelegate extends FakeSqlExecutionDelegate {
+  var open = false;
+  final commands = <String>[];
+
+  @override
+  bool get supportsTransactions => true;
+
+  @override
+  Future<void> runTransactionCommand(String command,
+      {Duration? timeout}) async {
+    commands.add(command);
+    open = command == 'BEGIN';
+  }
+
+  @override
+  Future<bool?> checkTransactionOpen() async => open;
+}
+
+void main() {
+  final app = E2eAppHarness(prefix: 'querya_e2e_tx_');
+  late E2eSqlWorkspace ws;
+  setUpAll(() async {
+    await app.setUpAll();
+    ws = await E2eSqlWorkspace.create();
+  });
+  tearDownAll(app.tearDownAll);
+
+  Future<void> tapAndSettle(WidgetTester tester, String label) async {
+    await tester.tap(find.text(label));
+    await E2eSqlWorkspace.settle(tester);
+  }
+
+  testWidgets('Begin opens a transaction, Rollback and Commit close it',
+      timeout: _timeout, (tester) async {
+    final delegate = _TxDelegate();
+    await ws.pump(tester, delegate);
+    await E2eSqlWorkspace.settle(tester);
+    // Unknown until the first command refreshes the state.
+    expect(find.text('Transaction: —'), findsOneWidget);
+
+    await tapAndSettle(tester, 'Begin');
+    expect(find.text('Transaction: open'), findsOneWidget);
+    expect(find.text('OK: BEGIN'), findsWidgets);
+
+    await tapAndSettle(tester, 'Rollback');
+    expect(find.text('Transaction: none'), findsOneWidget);
+
+    await tapAndSettle(tester, 'Begin');
+    await tapAndSettle(tester, 'Commit');
+    expect(find.text('Transaction: none'), findsOneWidget);
+
+    expect(delegate.commands, ['BEGIN', 'ROLLBACK', 'BEGIN', 'COMMIT']);
+  });
+
+  testWidgets('a database without transactions shows no transaction controls',
+      timeout: _timeout, (tester) async {
+    await ws.pump(tester, FakeSqlExecutionDelegate());
+
+    expect(find.text('Begin'), findsNothing);
+    expect(find.text('Commit'), findsNothing);
+    expect(find.text('Rollback'), findsNothing);
+  });
+
+  testWidgets('a destructive statement waits for confirmation',
+      timeout: _timeout, (tester) async {
+    final delegate = FakeSqlExecutionDelegate();
+    await ws.pump(tester, delegate, initialSql: 'DELETE FROM users');
+
+    await E2eSqlWorkspace.ctrl(tester, LogicalKeyboardKey.enter);
+    await E2eSqlWorkspace.settle(tester);
+    expect(find.text('Execute Destructive Statement'), findsOneWidget);
+    expect(delegate.executed, isEmpty);
+
+    await tester.tap(find.text('Cancel'));
+    await E2eSqlWorkspace.settle(tester);
+    expect(delegate.executed, isEmpty);
+
+    await E2eSqlWorkspace.ctrl(tester, LogicalKeyboardKey.enter);
+    await E2eSqlWorkspace.settle(tester);
+    // The button stays disabled until the warning is acknowledged.
+    await tester.tap(find.text('Execute Destructive Statement'),
+        warnIfMissed: false);
+    await E2eSqlWorkspace.settle(tester);
+    expect(delegate.executed, isEmpty);
+    await tester.tap(find.byType(material.Checkbox));
+    await tester.pump();
+    await tester.tap(find.text('Execute Destructive Statement'));
+    await E2eSqlWorkspace.settle(tester);
+    expect(delegate.executed, ['DELETE FROM users']);
+  });
+
+  testWidgets('closing the workspace while a query runs cancels it',
+      timeout: _timeout, (tester) async {
+    final delegate = FakeSqlExecutionDelegate()..gate = Completer<void>();
+    await ws.pump(tester, delegate, initialSql: 'SELECT pg_sleep(60)');
+
+    await E2eSqlWorkspace.ctrl(tester, LogicalKeyboardKey.enter);
+    await E2eSqlWorkspace.settle(tester);
+    expect(delegate.executed, ['SELECT pg_sleep(60)']);
+    expect(delegate.cancelCount, 0);
+
+    await tester.pumpWidget(const material.SizedBox());
+    await tester.pump();
+
+    expect(delegate.cancelCount, 1);
+    delegate.gate!.complete();
+    await E2eSqlWorkspace.settle(tester);
+  });
+}