[+] add ORM registry with migration support, migrate cache/db.py

1. add apps/orm/registry.py with orm_module_t base class and orm_registry_t singleton;
  2. singleton per db path, thread-safe, tracks registered ORM classes;
  3. orm_schema_versions table for per-module version tracking;
  4. classmethods table_prefix(), schema_version(), migrate() for schema management;
  5. registry.module(cls) returns typed ORM instance, cached per registry;
  6. migrate cache_db_t to extend orm_module_t, move schema into classmethod migrate();
  7. cache_db_t constructor accepts Path (legacy, uses registry) or Connection (from registry);
  8. orm_registry_t.register(cache_db_t) at module load time;
  9. add test_orm.py with 12 tests: singleton, migration, multi-module, incremental, failure;

python/online/fxreader/pr34/commands_typed/archlinux/apps/cache/db.py

@@ -24,6 +24,8 @@ from ...models import (
 	package_index_t,
 )
 
+from ..orm.registry import orm_module_t, orm_registry_t
+
 logger = logging.getLogger(__name__)
 
 _T = TypeVar('_T', bound=pydantic.BaseModel)
@@ -117,10 +119,8 @@ def _fetch_one(
 	return model.model_validate(dict(zip(columns, raw)))
 
 
-class cache_db_t:
+class cache_db_t(orm_module_t):
 	class constants_t:
-		schema_version: ClassVar[int] = 1
-
 		list_relation_types: ClassVar[dict[str, str]] = {
 			'license': 'license',
 			'depends': 'depends',
@@ -133,110 +133,107 @@ class cache_db_t:
 			'groups': 'groups',
 		}
 
-	def __init__(self, db_path: pathlib.Path) -> None:
+	# ── orm_module_t interface ──
-		self._db_path = db_path
+
-		self._conn = sqlite3.connect(str(db_path))
+	@classmethod
-		self._conn.execute('PRAGMA journal_mode=WAL')
+	def table_prefix(cls) -> str:
-		self._conn.execute('PRAGMA foreign_keys=ON')
+		return 'cache'
-		self._ensure_schema()
+
+	@classmethod
+	def schema_version(cls) -> int:
+		return 1
+
+	@classmethod
+	def migrate(cls, conn: sqlite3.Connection, from_version: int, to_version: int) -> None:
+		if from_version < 1:
+			conn.executescript("""
+				CREATE TABLE IF NOT EXISTS schema_meta (
+					version INTEGER NOT NULL
+				);
+
+				CREATE TABLE IF NOT EXISTS snapshots (
+					id INTEGER PRIMARY KEY AUTOINCREMENT,
+					date TEXT NOT NULL,
+					repo TEXT NOT NULL,
+					arch TEXT NOT NULL DEFAULT 'x86_64',
+					db_sha256 TEXT NOT NULL,
+					db_rel_path TEXT NOT NULL DEFAULT '',
+					synced_at TEXT NOT NULL,
+					UNIQUE(date, repo, arch)
+				);
+
+				CREATE TABLE IF NOT EXISTS packages (
+					id INTEGER PRIMARY KEY AUTOINCREMENT,
+					snapshot_id INTEGER NOT NULL REFERENCES snapshots(id) ON DELETE CASCADE,
+					name TEXT NOT NULL,
+					version TEXT NOT NULL,
+					base TEXT NOT NULL DEFAULT '',
+					desc TEXT NOT NULL DEFAULT '',
+					filename TEXT NOT NULL DEFAULT '',
+					csize INTEGER NOT NULL DEFAULT 0,
+					isize INTEGER NOT NULL DEFAULT 0,
+					md5sum TEXT NOT NULL DEFAULT '',
+					sha256sum TEXT NOT NULL DEFAULT '',
+					url TEXT NOT NULL DEFAULT '',
+					arch TEXT NOT NULL DEFAULT '',
+					builddate INTEGER NOT NULL DEFAULT 0,
+					packager TEXT NOT NULL DEFAULT '',
+					UNIQUE(snapshot_id, name)
+				);
+
+				CREATE TABLE IF NOT EXISTS package_relations (
+					id INTEGER PRIMARY KEY AUTOINCREMENT,
+					package_id INTEGER NOT NULL REFERENCES packages(id) ON DELETE CASCADE,
+					relation_type TEXT NOT NULL,
+					value TEXT NOT NULL
+				);
+
+				CREATE TABLE IF NOT EXISTS local_packages (
+					id INTEGER PRIMARY KEY AUTOINCREMENT,
+					name TEXT NOT NULL,
+					version TEXT NOT NULL,
+					filename TEXT NOT NULL,
+					sha256sum TEXT NOT NULL DEFAULT '',
+					local_path TEXT NOT NULL,
+					downloaded_at TEXT NOT NULL,
+					UNIQUE(name, version, filename)
+				);
+
+				CREATE TABLE IF NOT EXISTS local_signatures (
+					id INTEGER PRIMARY KEY AUTOINCREMENT,
+					local_package_id INTEGER NOT NULL REFERENCES local_packages(id) ON DELETE CASCADE,
+					sig_path TEXT NOT NULL,
+					keyring_package_version TEXT DEFAULT NULL,
+					gpg_key_id TEXT DEFAULT NULL,
+					verified_at TEXT DEFAULT NULL,
+					UNIQUE(local_package_id)
+				);
+
+				CREATE INDEX IF NOT EXISTS idx_packages_snapshot ON packages(snapshot_id);
+				CREATE INDEX IF NOT EXISTS idx_packages_name ON packages(name);
+				CREATE INDEX IF NOT EXISTS idx_packages_name_version ON packages(name, version);
+				CREATE INDEX IF NOT EXISTS idx_snapshots_date ON snapshots(date);
+				CREATE INDEX IF NOT EXISTS idx_package_relations_pkg
+					ON package_relations(package_id, relation_type);
+				CREATE INDEX IF NOT EXISTS idx_local_packages_name_version
+					ON local_packages(name, version);
+			""")
+			conn.commit()
+
+	# ── constructors ──
+
+	def __init__(self, db_path_or_conn: 'pathlib.Path | sqlite3.Connection') -> None:
+		if isinstance(db_path_or_conn, sqlite3.Connection):
+			# from ORM registry
+			super().__init__(db_path_or_conn)
+		else:
+			# legacy: standalone usage, goes through registry
+			registry = orm_registry_t.get(db_path_or_conn)
+			super().__init__(registry.conn)
 
 	def close(self) -> None:
-		self._conn.close()
+		# no-op when managed by registry; caller should use registry.close()
-
+		pass
-	def _ensure_schema(self) -> None:
-		cur = self._conn.cursor()
-
-		cur.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='schema_meta'")
-		if cur.fetchone() is None:
-			self._create_schema(cur)
-			self._conn.commit()
-			return
-
-		cur.execute('SELECT version FROM schema_meta LIMIT 1')
-		row = cur.fetchone()
-		if row is None or row[0] < cache_db_t.constants_t.schema_version:
-			self._create_schema(cur)
-			self._conn.commit()
-
-	def _create_schema(self, cur: sqlite3.Cursor) -> None:
-		cur.executescript("""
-			CREATE TABLE IF NOT EXISTS schema_meta (
-				version INTEGER NOT NULL
-			);
-
-			CREATE TABLE IF NOT EXISTS snapshots (
-				id INTEGER PRIMARY KEY AUTOINCREMENT,
-				date TEXT NOT NULL,
-				repo TEXT NOT NULL,
-				arch TEXT NOT NULL DEFAULT 'x86_64',
-				db_sha256 TEXT NOT NULL,
-				db_rel_path TEXT NOT NULL DEFAULT '',
-				synced_at TEXT NOT NULL,
-				UNIQUE(date, repo, arch)
-			);
-
-			CREATE TABLE IF NOT EXISTS packages (
-				id INTEGER PRIMARY KEY AUTOINCREMENT,
-				snapshot_id INTEGER NOT NULL REFERENCES snapshots(id) ON DELETE CASCADE,
-				name TEXT NOT NULL,
-				version TEXT NOT NULL,
-				base TEXT NOT NULL DEFAULT '',
-				desc TEXT NOT NULL DEFAULT '',
-				filename TEXT NOT NULL DEFAULT '',
-				csize INTEGER NOT NULL DEFAULT 0,
-				isize INTEGER NOT NULL DEFAULT 0,
-				md5sum TEXT NOT NULL DEFAULT '',
-				sha256sum TEXT NOT NULL DEFAULT '',
-				url TEXT NOT NULL DEFAULT '',
-				arch TEXT NOT NULL DEFAULT '',
-				builddate INTEGER NOT NULL DEFAULT 0,
-				packager TEXT NOT NULL DEFAULT '',
-				UNIQUE(snapshot_id, name)
-			);
-
-			CREATE TABLE IF NOT EXISTS package_relations (
-				id INTEGER PRIMARY KEY AUTOINCREMENT,
-				package_id INTEGER NOT NULL REFERENCES packages(id) ON DELETE CASCADE,
-				relation_type TEXT NOT NULL,
-				value TEXT NOT NULL
-			);
-
-			CREATE TABLE IF NOT EXISTS local_packages (
-				id INTEGER PRIMARY KEY AUTOINCREMENT,
-				name TEXT NOT NULL,
-				version TEXT NOT NULL,
-				filename TEXT NOT NULL,
-				sha256sum TEXT NOT NULL DEFAULT '',
-				local_path TEXT NOT NULL,
-				downloaded_at TEXT NOT NULL,
-				UNIQUE(name, version, filename)
-			);
-
-			CREATE TABLE IF NOT EXISTS local_signatures (
-				id INTEGER PRIMARY KEY AUTOINCREMENT,
-				local_package_id INTEGER NOT NULL REFERENCES local_packages(id) ON DELETE CASCADE,
-				sig_path TEXT NOT NULL,
-				keyring_package_version TEXT DEFAULT NULL,
-				gpg_key_id TEXT DEFAULT NULL,
-				verified_at TEXT DEFAULT NULL,
-				UNIQUE(local_package_id)
-			);
-
-			CREATE INDEX IF NOT EXISTS idx_packages_snapshot ON packages(snapshot_id);
-			CREATE INDEX IF NOT EXISTS idx_packages_name ON packages(name);
-			CREATE INDEX IF NOT EXISTS idx_packages_name_version ON packages(name, version);
-			CREATE INDEX IF NOT EXISTS idx_snapshots_date ON snapshots(date);
-			CREATE INDEX IF NOT EXISTS idx_package_relations_pkg
-				ON package_relations(package_id, relation_type);
-			CREATE INDEX IF NOT EXISTS idx_local_packages_name_version
-				ON local_packages(name, version);
-		""")
-
-		cur.execute('DELETE FROM schema_meta')
-		cur.execute(
-			'INSERT INTO schema_meta (version) VALUES (?)',
-			(cache_db_t.constants_t.schema_version,),
-		)
 
 	# ── helpers ──
 
@@ -581,6 +578,7 @@ class cache_db_t:
 							filename=ppkg.filename,
 							repo=pidx.name,
 							sha256sum=ppkg.sha256sum,
+							csize=ppkg.csize,
 							depends=[pacman_constraint_t.parse(d) for d in ppkg.depends],
 							provides=[pacman_constraint_t.parse(p) for p in ppkg.provides],
 							conflicts=[pacman_constraint_t.parse(c) for c in ppkg.conflicts],
@@ -599,7 +597,7 @@ class cache_db_t:
 		cur = self._conn.cursor()
 		cur.execute(
 			'''
-			SELECT p.id, p.name, p.version, p.filename, p.sha256sum, s.repo
+			SELECT p.id, p.name, p.version, p.filename, p.sha256sum, p.csize, s.repo
 			FROM packages p
 			JOIN snapshots s ON s.id = p.snapshot_id
 			WHERE p.id IN (SELECT MIN(id) FROM packages GROUP BY name, version)
@@ -608,12 +606,13 @@ class cache_db_t:
 
 		pkg_by_id: dict[int, package_desc_t] = {}
 		repo_of: dict[int, str] = {}
-		for pid, name, version, filename, sha256sum, repo in cur.fetchall():
+		for pid, name, version, filename, sha256sum, csize, repo in cur.fetchall():
 			pkg_by_id[pid] = package_desc_t(
 				name=name,
 				version=version,
 				filename=filename,
 				sha256sum=sha256sum,
+				csize=csize,
 			)
 			repo_of[pid] = repo
 
@@ -629,6 +628,7 @@ class cache_db_t:
 					filename=ppkg.filename,
 					repo=repo_of[pid],
 					sha256sum=ppkg.sha256sum,
+					csize=ppkg.csize,
 					depends=[pacman_constraint_t.parse(d) for d in ppkg.depends],
 					provides=[pacman_constraint_t.parse(p) for p in ppkg.provides],
 					conflicts=[pacman_constraint_t.parse(c) for c in ppkg.conflicts],
@@ -776,3 +776,6 @@ class cache_db_t:
 		cur.execute('SELECT COUNT(*) FROM snapshots')
 		row = cur.fetchone()
 		return row is not None and row[0] > 0
+
+
+orm_registry_t.register(cache_db_t)

python/online/fxreader/pr34/commands_typed/archlinux/apps/orm/registry.py

@@ -0,0 +1,154 @@
+"""ORM registry — singleton that manages sqlite connection and registered ORM modules.
+
+Each ORM module (cache, cve, etc.) is a class with:
+  - classmethod schema_version() -> int
+  - classmethod migrate(conn, from_version, to_version) -> None
+  - classmethod table_prefix() -> str
+
+The registry:
+  1. Holds one sqlite connection per db path (singleton per path).
+  2. Tracks registered ORM classes.
+  3. On connect, iterates registered classes and runs migrations if needed.
+  4. Provides typed access to ORM instances and raw cursor fallback.
+"""
+
+import logging
+import pathlib
+import sqlite3
+import threading
+
+from typing import (
+	ClassVar,
+	Optional,
+	Type,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class orm_module_t:
+	"""Base class for ORM modules. Subclass this and implement the classmethods."""
+
+	@classmethod
+	def table_prefix(cls) -> str:
+		raise NotImplementedError
+
+	@classmethod
+	def schema_version(cls) -> int:
+		raise NotImplementedError
+
+	@classmethod
+	def migrate(cls, conn: sqlite3.Connection, from_version: int, to_version: int) -> None:
+		raise NotImplementedError
+
+	def __init__(self, conn: sqlite3.Connection) -> None:
+		self._conn = conn
+
+
+class orm_registry_t:
+	"""Singleton registry per db path."""
+
+	_instances: ClassVar[dict[str, 'orm_registry_t']] = {}
+	_lock: ClassVar[threading.Lock] = threading.Lock()
+	_registered_classes: ClassVar[list[Type[orm_module_t]]] = []
+
+	@classmethod
+	def register(cls, module_class: Type[orm_module_t]) -> Type[orm_module_t]:
+		"""Register an ORM module class. Call at module load time."""
+		if module_class not in cls._registered_classes:
+			cls._registered_classes.append(module_class)
+		return module_class
+
+	@classmethod
+	def get(cls, db_path: pathlib.Path) -> 'orm_registry_t':
+		"""Get or create registry singleton for a db path."""
+		key = str(db_path.resolve())
+		with cls._lock:
+			if key not in cls._instances:
+				cls._instances[key] = cls(db_path)
+			return cls._instances[key]
+
+	@classmethod
+	def reset(cls, db_path: Optional[pathlib.Path] = None) -> None:
+		"""Close and remove singleton(s). For testing."""
+		with cls._lock:
+			if db_path is not None:
+				key = str(db_path.resolve())
+				inst = cls._instances.pop(key, None)
+				if inst is not None:
+					inst._conn.close()
+			else:
+				for inst in cls._instances.values():
+					inst._conn.close()
+				cls._instances.clear()
+
+	def __init__(self, db_path: pathlib.Path) -> None:
+		db_path.parent.mkdir(parents=True, exist_ok=True)
+		self._conn = sqlite3.connect(str(db_path))
+		self._conn.execute('PRAGMA journal_mode=WAL')
+		self._modules: dict[Type[orm_module_t], orm_module_t] = {}
+
+		self._ensure_meta_table()
+		self._run_migrations()
+
+	def _ensure_meta_table(self) -> None:
+		self._conn.execute(
+			'''
+			CREATE TABLE IF NOT EXISTS orm_schema_versions (
+				module_prefix TEXT PRIMARY KEY,
+				version INTEGER NOT NULL
+			)
+			'''
+		)
+		self._conn.commit()
+
+	def _get_current_version(self, prefix: str) -> int:
+		row = self._conn.execute(
+			'SELECT version FROM orm_schema_versions WHERE module_prefix = ?',
+			(prefix,),
+		).fetchone()
+		return row[0] if row is not None else 0
+
+	def _set_version(self, prefix: str, version: int) -> None:
+		self._conn.execute(
+			'''
+			INSERT INTO orm_schema_versions (module_prefix, version)
+			VALUES (?, ?)
+			ON CONFLICT(module_prefix) DO UPDATE SET version = ?
+			''',
+			(prefix, version, version),
+		)
+		self._conn.commit()
+
+	def _run_migrations(self) -> None:
+		for cls in self._registered_classes:
+			prefix = cls.table_prefix()
+			current = self._get_current_version(prefix)
+			target = cls.schema_version()
+
+			if current < target:
+				logger.info(dict(
+					msg='migrating',
+					module=prefix,
+					from_version=current,
+					to_version=target,
+				))
+				cls.migrate(self._conn, current, target)
+				self._set_version(prefix, target)
+				logger.info(dict(msg='migration done', module=prefix, version=target))
+
+	@property
+	def conn(self) -> sqlite3.Connection:
+		return self._conn
+
+	def cursor(self) -> sqlite3.Cursor:
+		return self._conn.cursor()
+
+	def module(self, cls: Type[orm_module_t]) -> orm_module_t:
+		"""Get an ORM module instance. Created once per registry."""
+		if cls not in self._modules:
+			self._modules[cls] = cls(self._conn)
+		return self._modules[cls]
+
+	def close(self) -> None:
+		self._conn.close()

python/online/fxreader/pr34/commands_typed/archlinux/tests/test_orm.py

@@ -0,0 +1,281 @@
+"""Tests for apps/orm/registry.py
+
+Test matrix:
+  - registry singleton: same path returns same instance, different path returns different
+  - reset: clears singleton, closes connection
+  - schema versioning: new module gets migrated, existing at target version skipped
+  - multi-module: two modules registered, both get migrated independently
+  - re-open: close and re-open same db, versions persist, no re-migration
+  - module access: registry.module() returns typed instance, same instance on repeat call
+  - raw cursor: registry.cursor() works for ad-hoc queries
+  - migration ordering: from_version=0 on first run, from_version=N on upgrade
+  - migration failure: exception in migrate rolls back cleanly (no partial version bump)
+"""
+
+import pathlib
+import sqlite3
+import tempfile
+import unittest
+
+from ..apps.orm.registry import orm_module_t, orm_registry_t
+
+
+class items_orm_t(orm_module_t):
+	@classmethod
+	def table_prefix(cls) -> str:
+		return 'items'
+
+	@classmethod
+	def schema_version(cls) -> int:
+		return 1
+
+	@classmethod
+	def migrate(cls, conn: sqlite3.Connection, from_version: int, to_version: int) -> None:
+		if from_version < 1:
+			conn.execute(
+				'CREATE TABLE IF NOT EXISTS items_data (id INTEGER PRIMARY KEY, name TEXT NOT NULL)'
+			)
+			conn.commit()
+
+	def insert(self, name: str) -> None:
+		self._conn.execute('INSERT INTO items_data (name) VALUES (?)', (name,))
+		self._conn.commit()
+
+	def list_all(self) -> list[tuple[int, str]]:
+		return self._conn.execute('SELECT id, name FROM items_data').fetchall()
+
+
+class tags_orm_t(orm_module_t):
+	@classmethod
+	def table_prefix(cls) -> str:
+		return 'tags'
+
+	@classmethod
+	def schema_version(cls) -> int:
+		return 2
+
+	@classmethod
+	def migrate(cls, conn: sqlite3.Connection, from_version: int, to_version: int) -> None:
+		if from_version < 1:
+			conn.execute(
+				'CREATE TABLE IF NOT EXISTS tags_data (id INTEGER PRIMARY KEY, label TEXT NOT NULL)'
+			)
+			conn.commit()
+		if from_version < 2:
+			conn.execute('ALTER TABLE tags_data ADD COLUMN color TEXT DEFAULT ""')
+			conn.commit()
+
+	def insert(self, label: str, color: str = '') -> None:
+		self._conn.execute('INSERT INTO tags_data (label, color) VALUES (?, ?)', (label, color))
+		self._conn.commit()
+
+	def list_all(self) -> list[tuple[int, str, str]]:
+		return self._conn.execute('SELECT id, label, color FROM tags_data').fetchall()
+
+
+class broken_orm_t(orm_module_t):
+	@classmethod
+	def table_prefix(cls) -> str:
+		return 'broken'
+
+	@classmethod
+	def schema_version(cls) -> int:
+		return 1
+
+	@classmethod
+	def migrate(cls, conn: sqlite3.Connection, from_version: int, to_version: int) -> None:
+		raise RuntimeError('intentional migration failure')
+
+
+class TestRegistrySingleton(unittest.TestCase):
+	def setUp(self) -> None:
+		self.tmpdir = tempfile.mkdtemp()
+		orm_registry_t._registered_classes.clear()
+		orm_registry_t._instances.clear()
+
+	def tearDown(self) -> None:
+		orm_registry_t.reset()
+
+	def test_same_path_same_instance(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'a.db'
+		r1 = orm_registry_t.get(p)
+		r2 = orm_registry_t.get(p)
+		self.assertIs(r1, r2)
+
+	def test_different_path_different_instance(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		r1 = orm_registry_t.get(pathlib.Path(self.tmpdir) / 'a.db')
+		r2 = orm_registry_t.get(pathlib.Path(self.tmpdir) / 'b.db')
+		self.assertIsNot(r1, r2)
+
+	def test_reset_clears_singleton(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'a.db'
+		r1 = orm_registry_t.get(p)
+		orm_registry_t.reset(p)
+		r2 = orm_registry_t.get(p)
+		self.assertIsNot(r1, r2)
+
+
+class TestMigration(unittest.TestCase):
+	def setUp(self) -> None:
+		self.tmpdir = tempfile.mkdtemp()
+		orm_registry_t._registered_classes.clear()
+		orm_registry_t._instances.clear()
+
+	def tearDown(self) -> None:
+		orm_registry_t.reset()
+
+	def test_first_migration_creates_table(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		# table should exist
+		rows = reg.conn.execute(
+			"SELECT name FROM sqlite_master WHERE type='table' AND name='items_data'"
+		).fetchall()
+		self.assertEqual(len(rows), 1)
+
+	def test_version_persisted(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		ver = reg._get_current_version('items')
+		self.assertEqual(ver, 1)
+
+	def test_no_remigration_on_reopen(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		mod = reg.module(items_orm_t)
+		assert isinstance(mod, items_orm_t)
+		mod.insert('hello')
+		orm_registry_t.reset(p)
+
+		# reopen — data should survive, no re-migration
+		reg2 = orm_registry_t.get(p)
+		mod2 = reg2.module(items_orm_t)
+		assert isinstance(mod2, items_orm_t)
+		self.assertEqual(len(mod2.list_all()), 1)
+
+	def test_skips_if_at_target(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		# manually set version ahead — should not crash
+		reg._set_version('items', 999)
+		orm_registry_t.reset(p)
+		# re-register with version 1, which is below 999 — no migration
+		reg2 = orm_registry_t.get(p)
+		self.assertEqual(reg2._get_current_version('items'), 999)
+
+
+class TestMultiModule(unittest.TestCase):
+	def setUp(self) -> None:
+		self.tmpdir = tempfile.mkdtemp()
+		orm_registry_t._registered_classes.clear()
+		orm_registry_t._instances.clear()
+
+	def tearDown(self) -> None:
+		orm_registry_t.reset()
+
+	def test_two_modules_migrated_independently(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		orm_registry_t.register(tags_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+
+		self.assertEqual(reg._get_current_version('items'), 1)
+		self.assertEqual(reg._get_current_version('tags'), 2)
+
+		items = reg.module(items_orm_t)
+		tags = reg.module(tags_orm_t)
+		assert isinstance(items, items_orm_t)
+		assert isinstance(tags, tags_orm_t)
+
+		items.insert('pkg')
+		tags.insert('urgent', 'red')
+
+		self.assertEqual(len(items.list_all()), 1)
+		self.assertEqual(len(tags.list_all()), 1)
+		self.assertEqual(tags.list_all()[0][2], 'red')
+
+	def test_incremental_migration(self) -> None:
+		"""tags_orm_t v2 adds color column via from_version < 2 branch."""
+		orm_registry_t.register(tags_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+
+		# simulate v1 already applied
+		conn = sqlite3.connect(str(p))
+		conn.execute(
+			'CREATE TABLE IF NOT EXISTS orm_schema_versions (module_prefix TEXT PRIMARY KEY, version INTEGER NOT NULL)'
+		)
+		conn.execute("INSERT INTO orm_schema_versions VALUES ('tags', 1)")
+		conn.execute('CREATE TABLE tags_data (id INTEGER PRIMARY KEY, label TEXT NOT NULL)')
+		conn.commit()
+		conn.close()
+
+		reg = orm_registry_t.get(p)
+		# should have migrated from 1 -> 2 (added color column)
+		self.assertEqual(reg._get_current_version('tags'), 2)
+
+		tags = reg.module(tags_orm_t)
+		assert isinstance(tags, tags_orm_t)
+		tags.insert('test', 'blue')
+		row = tags.list_all()[0]
+		self.assertEqual(row[2], 'blue')
+
+
+class TestModuleAccess(unittest.TestCase):
+	def setUp(self) -> None:
+		self.tmpdir = tempfile.mkdtemp()
+		orm_registry_t._registered_classes.clear()
+		orm_registry_t._instances.clear()
+
+	def tearDown(self) -> None:
+		orm_registry_t.reset()
+
+	def test_same_instance_on_repeat(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		m1 = reg.module(items_orm_t)
+		m2 = reg.module(items_orm_t)
+		self.assertIs(m1, m2)
+
+	def test_raw_cursor(self) -> None:
+		orm_registry_t.register(items_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		reg = orm_registry_t.get(p)
+		cur = reg.cursor()
+		cur.execute("INSERT INTO items_data (name) VALUES ('raw')")
+		reg.conn.commit()
+		rows = cur.execute('SELECT name FROM items_data').fetchall()
+		self.assertEqual(rows, [('raw',)])
+
+
+class TestMigrationFailure(unittest.TestCase):
+	def setUp(self) -> None:
+		self.tmpdir = tempfile.mkdtemp()
+		orm_registry_t._registered_classes.clear()
+		orm_registry_t._instances.clear()
+
+	def tearDown(self) -> None:
+		orm_registry_t.reset()
+
+	def test_failed_migration_no_version_bump(self) -> None:
+		orm_registry_t.register(broken_orm_t)
+		p = pathlib.Path(self.tmpdir) / 'test.db'
+		with self.assertRaises(RuntimeError):
+			orm_registry_t.get(p)
+
+		# version should not have been bumped
+		conn = sqlite3.connect(str(p))
+		row = conn.execute(
+			"SELECT version FROM orm_schema_versions WHERE module_prefix = 'broken'"
+		).fetchone()
+		# either no row or version 0
+		if row is not None:
+			self.assertEqual(row[0], 0)
+		conn.close()