test(T3): add contract test suites for Account/Mailbox/Email repositories

Each abstract *Contract class defines the observable-state invariants of
the corresponding repository interface. The concrete *Impl is run against
the suite via a thin subclass. Future fakes or alternative impls can be
verified by subclassing the same contract.

24 new tests across 3 files.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plan-claude.md

@@ -86,9 +86,7 @@ Files: `lib/ui/screens/search_screen.dart`, `lib/data/db/database.dart`.
 
 ### U4 — Done: https://codeberg.org/guettli/sharedinbox/pulls/28
 
-### U5 🟡 Accessible swipe actions on email list items
+### U5 — Already implemented (Dismissible archive/delete swipes with undo, found in email_list_screen.dart)
-Delete and Move are hidden behind long-press or detail-screen menus. Add leading/trailing swipe actions on the `EmailListScreen` tile (archive / delete) matching Material 3 patterns.
-Files: `lib/ui/screens/email_list_screen.dart`.
 
 ### U6 — Done: https://codeberg.org/guettli/sharedinbox/pulls/29
 

test/unit/account_repository_contract_test.dart

@@ -0,0 +1,107 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/account_repository.dart';
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the [AccountRepository] interface contract.
+///
+/// Subclass this and override [makeRepo] to run the same suite against any
+/// concrete implementation.
+abstract class AccountRepositoryContract {
+  AccountRepository makeRepo();
+
+  static const _a = Account(
+    id: 'c-1',
+    displayName: 'Contract',
+    email: 'c@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  void run() {
+    test('observeAccounts starts empty', () async {
+      final repo = makeRepo();
+      expect(await repo.observeAccounts().first, isEmpty);
+    });
+
+    test('addAccount makes account visible via observeAccounts', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final list = await repo.observeAccounts().first;
+      expect(list, hasLength(1));
+      expect(list.first.id, _a.id);
+    });
+
+    test('getAccount returns null for unknown id', () async {
+      final repo = makeRepo();
+      expect(await repo.getAccount('no-such'), isNull);
+    });
+
+    test('getAccount returns added account', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final a = await repo.getAccount(_a.id);
+      expect(a, isNotNull);
+      expect(a!.email, _a.email);
+    });
+
+    test('getPassword returns stored password', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'secret123');
+      expect(await repo.getPassword(_a.id), 'secret123');
+    });
+
+    test('updateAccount reflects changes in observeAccounts', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final updated = _a.copyWith(displayName: 'Updated');
+      await repo.updateAccount(updated);
+      final list = await repo.observeAccounts().first;
+      expect(list.first.displayName, 'Updated');
+    });
+
+    test('updateAccount with password updates stored password', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'old');
+      await repo.updateAccount(_a, password: 'new');
+      expect(await repo.getPassword(_a.id), 'new');
+    });
+
+    test('removeAccount makes account disappear from observeAccounts',
+        () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      await repo.removeAccount(_a.id);
+      expect(await repo.observeAccounts().first, isEmpty);
+    });
+
+    test('getAccount returns null after removeAccount', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      await repo.removeAccount(_a.id);
+      expect(await repo.getAccount(_a.id), isNull);
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _AccountRepositoryImplContract extends AccountRepositoryContract {
+  @override
+  AccountRepository makeRepo() =>
+      AccountRepositoryImpl(openTestDatabase(), MapSecureStorage());
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('AccountRepositoryImpl satisfies AccountRepository contract', () {
+    _AccountRepositoryImplContract().run();
+  });
+}

test/unit/email_repository_contract_test.dart

@@ -0,0 +1,193 @@
+import 'package:drift/drift.dart' show Value;
+import 'package:enough_mail/enough_mail.dart' as imap;
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/email_repository.dart';
+import 'package:sharedinbox/data/db/database.dart' hide Account;
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+import 'package:sharedinbox/data/repositories/email_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the observable / local-state portion of the [EmailRepository]
+/// interface contract.
+///
+/// Network-dependent methods (syncEmails, sendEmail, etc.) are intentionally
+/// excluded — they are covered by the concrete impl tests.
+abstract class EmailRepositoryContract {
+  static const _account = Account(
+    id: 'er-acc',
+    displayName: 'Contract',
+    email: 'er@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  /// Return a fresh [EmailRepository] with [_account] already persisted.
+  Future<EmailRepository> makeRepo();
+
+  /// Insert a raw email row so tests can assert on observable state without
+  /// triggering a network sync.
+  Future<void> insertEmail(
+    EmailRepository repo, {
+    required String id,
+    required String mailboxPath,
+    bool isSeen = true,
+    bool isFlagged = false,
+    DateTime? receivedAt,
+  });
+
+  void run() {
+    test('observeEmails starts empty', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.observeEmails(_account.id, 'INBOX').first,
+        isEmpty,
+      );
+    });
+
+    test('observeEmails emits inserted email', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:1', mailboxPath: 'INBOX');
+      final emails = await repo.observeEmails(_account.id, 'INBOX').first;
+      expect(emails, hasLength(1));
+      expect(emails.first.id, 'er-acc:1');
+    });
+
+    test('observeEmails only returns emails for the given mailbox', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:1', mailboxPath: 'INBOX');
+      expect(
+        await repo.observeEmails(_account.id, 'Sent').first,
+        isEmpty,
+      );
+    });
+
+    test('observeEmails orders by receivedAt descending', () async {
+      final repo = await makeRepo();
+      final older = DateTime(2024);
+      final newer = DateTime(2024, 6);
+      await insertEmail(
+        repo,
+        id: 'er-acc:1',
+        mailboxPath: 'INBOX',
+        receivedAt: older,
+      );
+      await insertEmail(
+        repo,
+        id: 'er-acc:2',
+        mailboxPath: 'INBOX',
+        receivedAt: newer,
+      );
+      final emails = await repo.observeEmails(_account.id, 'INBOX').first;
+      expect(emails.first.id, 'er-acc:2');
+      expect(emails.last.id, 'er-acc:1');
+    });
+
+    test('getEmail returns null for unknown id', () async {
+      final repo = await makeRepo();
+      expect(await repo.getEmail('no-such'), isNull);
+    });
+
+    test('getEmail returns inserted email', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:7', mailboxPath: 'INBOX');
+      final email = await repo.getEmail('er-acc:7');
+      expect(email, isNotNull);
+      expect(email!.accountId, _account.id);
+    });
+
+    test('setFlag seen updates isSeen', () async {
+      final repo = await makeRepo();
+      await insertEmail(
+        repo,
+        id: 'er-acc:10',
+        mailboxPath: 'INBOX',
+        isSeen: false,
+      );
+      await repo.setFlag('er-acc:10', seen: true);
+      final email = await repo.getEmail('er-acc:10');
+      expect(email!.isSeen, isTrue);
+    });
+
+    test('setFlag flagged updates isFlagged', () async {
+      final repo = await makeRepo();
+      await insertEmail(
+        repo,
+        id: 'er-acc:11',
+        mailboxPath: 'INBOX',
+      );
+      await repo.setFlag('er-acc:11', flagged: true);
+      final email = await repo.getEmail('er-acc:11');
+      expect(email!.isFlagged, isTrue);
+    });
+
+    test('observeThreads starts empty', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.observeThreads(_account.id, 'INBOX').first,
+        isEmpty,
+      );
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _EmailRepositoryImplContract extends EmailRepositoryContract {
+  static const _account = EmailRepositoryContract._account;
+
+  late AppDatabase _db;
+  late AccountRepositoryImpl _accountRepo;
+
+  @override
+  Future<EmailRepository> makeRepo() async {
+    _db = openTestDatabase();
+    _accountRepo = AccountRepositoryImpl(_db, MapSecureStorage());
+    await _accountRepo.addAccount(_account, 'pw');
+    return EmailRepositoryImpl(
+      _db,
+      _accountRepo,
+      imapConnect: (_, __, ___) => Future<imap.ImapClient>.error(
+        UnsupportedError('no IMAP in unit tests'),
+      ),
+      smtpConnect: (_, __, ___) => Future<imap.SmtpClient>.error(
+        UnsupportedError('no SMTP in unit tests'),
+      ),
+    );
+  }
+
+  @override
+  Future<void> insertEmail(
+    EmailRepository repo, {
+    required String id,
+    required String mailboxPath,
+    bool isSeen = true,
+    bool isFlagged = false,
+    DateTime? receivedAt,
+  }) async {
+    await _db.into(_db.emails).insert(
+          EmailsCompanion.insert(
+            id: id,
+            accountId: _account.id,
+            mailboxPath: mailboxPath,
+            uid: int.parse(id.split(':').last),
+            receivedAt: receivedAt ?? DateTime.now(),
+            isSeen: Value(isSeen),
+            isFlagged: Value(isFlagged),
+          ),
+        );
+  }
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('EmailRepositoryImpl satisfies EmailRepository contract', () {
+    _EmailRepositoryImplContract().run();
+  });
+}

test/unit/mailbox_repository_contract_test.dart

@@ -0,0 +1,137 @@
+import 'package:drift/drift.dart' show Value;
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/mailbox_repository.dart';
+import 'package:sharedinbox/data/db/database.dart' hide Account;
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+import 'package:sharedinbox/data/repositories/mailbox_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the [MailboxRepository] interface contract.
+///
+/// Tests cover only the locally-observable part of the interface
+/// (observe / find) since sync methods require live IMAP/JMAP servers.
+abstract class MailboxRepositoryContract {
+  static const _account = Account(
+    id: 'm-acc',
+    displayName: 'Contract',
+    email: 'm@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  /// Return a fresh [MailboxRepository] with [_account] already persisted.
+  Future<MailboxRepository> makeRepo();
+
+  /// Insert a mailbox row into the backing store so tests can verify
+  /// observeMailboxes without triggering a network sync.
+  Future<void> insertMailbox(
+    MailboxRepository repo, {
+    required String id,
+    required String path,
+    String? role,
+    int unread = 0,
+    int total = 0,
+  });
+
+  void run() {
+    test('observeMailboxes starts empty', () async {
+      final repo = await makeRepo();
+      expect(await repo.observeMailboxes(_account.id).first, isEmpty);
+    });
+
+    test('observeMailboxes emits inserted rows ordered by path', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'z', path: 'Z');
+      await insertMailbox(repo, id: 'a', path: 'A');
+      final boxes = await repo.observeMailboxes(_account.id).first;
+      expect(boxes.map((b) => b.path), ['A', 'Z']);
+    });
+
+    test('observeMailboxes only returns rows for the given account', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'mb1', path: 'INBOX');
+      expect(await repo.observeMailboxes('other-acc').first, isEmpty);
+    });
+
+    test('findMailboxByRole returns null when no match', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.findMailboxByRole(_account.id, 'archive'),
+        isNull,
+      );
+    });
+
+    test('findMailboxByRole returns the matching mailbox', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'arch', path: 'Archive', role: 'archive');
+      final box = await repo.findMailboxByRole(_account.id, 'archive');
+      expect(box, isNotNull);
+      expect(box!.role, 'archive');
+    });
+
+    test('clearForResync removes all mailboxes for the account', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'mb', path: 'INBOX');
+      await repo.clearForResync(_account.id);
+      expect(await repo.observeMailboxes(_account.id).first, isEmpty);
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _MailboxRepositoryImplContract extends MailboxRepositoryContract {
+  static const _account = MailboxRepositoryContract._account;
+
+  late AppDatabase _db;
+  late AccountRepositoryImpl _accountRepo;
+
+  @override
+  Future<MailboxRepository> makeRepo() async {
+    _db = openTestDatabase();
+    _accountRepo = AccountRepositoryImpl(_db, MapSecureStorage());
+    await _accountRepo.addAccount(_account, 'pw');
+    return MailboxRepositoryImpl(
+      _db,
+      _accountRepo,
+      imapConnect: (_, __, ___) =>
+          Future.error(UnsupportedError('no IMAP in unit tests')),
+    );
+  }
+
+  @override
+  Future<void> insertMailbox(
+    MailboxRepository repo, {
+    required String id,
+    required String path,
+    String? role,
+    int unread = 0,
+    int total = 0,
+  }) async {
+    await _db.into(_db.mailboxes).insert(
+          MailboxesCompanion.insert(
+            id: id,
+            accountId: _account.id,
+            path: path,
+            name: path.split('/').last,
+            unreadCount: Value(unread),
+            totalCount: Value(total),
+            role: Value(role),
+          ),
+        );
+  }
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('MailboxRepositoryImpl satisfies MailboxRepository contract', () {
+    _MailboxRepositoryImplContract().run();
+  });
+}