drift/moor/test/transactions_test.dart

import 'package:test_api/test_api.dart';

import 'data/tables/todos.dart';
import 'data/utils/mocks.dart';

void main() {
  TodoDb db;
  MockExecutor executor;
  MockStreamQueries streamQueries;

  setUp(() {
    executor = MockExecutor();
    streamQueries = MockStreamQueries();
    db = TodoDb(executor)..streamQueries = streamQueries;
  });

  test("transactions don't allow creating streams", () {
    expect(() async {
      await db.transaction((t) {
        t.select(db.users).watch();
      });
    }, throwsStateError);

    verify(executor.transactions.send());
  });

  test('transactions cannot be nested', () {
    expect(() async {
      await db.transaction((t) async {
        await t.transaction((t2) {
          fail('nested transactions were allowed');
        });
      });
    }, throwsStateError);
  });

  test('transactions notify about table udpates after completing', () async {
    when(executor.transactions.runUpdate(any, any))
        .thenAnswer((_) => Future.value(2));

    await db.transaction((t) async {
      await t.update(db.users).write(User(name: 'Updated name'));

      // Even though we just wrote to users, this only happened inside the
      // transaction, so the top level stream queries should not be updated.
      verifyNever(streamQueries.handleTableUpdates(any));
    });

    // After the transaction completes, the queries should be updated
    verify(streamQueries.handleTableUpdates({db.users})).called(1);
    verify(executor.transactions.send());
  });

  test('the database is opened before starting a transaction', () async {
    await db.transaction((t) async {
      verify(executor.doWhenOpened(any));
    });
  });
}