+ @staticmethod
+ def _within_checked_class(f: Callable[..., None]) -> Callable[..., None]:
+ def wrapper(self: TestCaseWithDB) -> None:
+ if hasattr(self, 'checked_class'):
+ f(self)
+ return wrapper
+
+ def _load_from_db(self, id_: int | str) -> list[object]:
+ db_found: list[object] = []
+ for row in self.db_conn.row_where(self.checked_class.table_name,
+ 'id', id_):
+ db_found += [self.checked_class.from_table_row(self.db_conn,
+ row)]
+ return db_found
+
+ def _change_obj(self, obj: object) -> str:
+ attr_name: str = self.checked_class.to_save[-1]
+ attr = getattr(obj, attr_name)
+ new_attr: str | int | float | bool
+ if isinstance(attr, (int, float)):
+ new_attr = attr + 1
+ elif isinstance(attr, str):
+ new_attr = attr + '_'
+ elif isinstance(attr, bool):
+ new_attr = not attr
+ setattr(obj, attr_name, new_attr)
+ return attr_name
+
+ def check_identity_with_cache_and_db(self, content: list[Any]) -> None:
+ """Test both cache and DB equal content."""
+ expected_cache = {}
+ for item in content:
+ expected_cache[item.id_] = item
+ self.assertEqual(self.checked_class.get_cache(), expected_cache)
+ hashes_content = [hash(x) for x in content]
+ db_found: list[Any] = []
+ for item in content:
+ assert isinstance(item.id_, type(self.default_ids[0]))
+ db_found += self._load_from_db(item.id_)
+ hashes_db_found = [hash(x) for x in db_found]
+ self.assertEqual(sorted(hashes_content), sorted(hashes_db_found))
+
+ @_within_checked_class
+ def test_saving_versioned(self) -> None:
+ """Test storage and initialization of versioned attributes."""
+ def retrieve_attr_vals() -> list[object]:
+ attr_vals_saved: list[object] = []
+ assert hasattr(retrieved, 'id_')
+ for row in self.db_conn.row_where(attr.table_name, 'parent',
+ retrieved.id_):
+ attr_vals_saved += [row[2]]
+ return attr_vals_saved
+ for attr_name, type_ in self.test_versioneds.items():
+ # fail saving attributes on non-saved owner
+ owner = self.checked_class(None, **self.default_init_kwargs)
+ vals: list[Any] = ['t1', 't2'] if type_ == str else [0.9, 1.1]
+ attr = getattr(owner, attr_name)
+ attr.set(vals[0])
+ attr.set(vals[1])
+ with self.assertRaises(NotFoundException):
+ attr.save(self.db_conn)
+ owner.save(self.db_conn)
+ # check stored attribute is as expected
+ retrieved = self._load_from_db(owner.id_)[0]
+ attr = getattr(retrieved, attr_name)
+ self.assertEqual(sorted(attr.history.values()), vals)
+ # check owner.save() created entries in attr table
+ attr_vals_saved = retrieve_attr_vals()
+ self.assertEqual(vals, attr_vals_saved)
+ # check setting new val to attr inconsequential to DB without save
+ attr.set(vals[0])
+ attr_vals_saved = retrieve_attr_vals()
+ self.assertEqual(vals, attr_vals_saved)
+ # check save finally adds new val
+ attr.save(self.db_conn)
+ attr_vals_saved = retrieve_attr_vals()
+ self.assertEqual(vals + [vals[0]], attr_vals_saved)
+
+ @_within_checked_class
+ def test_saving_and_caching(self) -> None:
+ """Test effects of .cache() and .save()."""
+ id1 = self.default_ids[0]
+ # check failure to cache without ID (if None-ID input possible)
+ if isinstance(id1, int):
+ obj0 = self.checked_class(None, **self.default_init_kwargs)
+ with self.assertRaises(HandledException):
+ obj0.cache()
+ # check mere object init itself doesn't even store in cache
+ obj1 = self.checked_class(id1, **self.default_init_kwargs)
+ self.assertEqual(self.checked_class.get_cache(), {})
+ # check .cache() fills cache, but not DB
+ obj1.cache()
+ self.assertEqual(self.checked_class.get_cache(), {id1: obj1})
+ db_found = self._load_from_db(id1)
+ self.assertEqual(db_found, [])
+ # check .save() sets ID (for int IDs), updates cache, and fills DB
+ # (expect ID to be set to id1, despite obj1 already having that as ID:
+ # it's generated by cursor.lastrowid on the DB table, and with obj1
+ # not written there, obj2 should get it first!)
+ id_input = None if isinstance(id1, int) else id1
+ obj2 = self.checked_class(id_input, **self.default_init_kwargs)
+ obj2.save(self.db_conn)
+ obj2_hash = hash(obj2)
+ self.assertEqual(self.checked_class.get_cache(), {id1: obj2})
+ db_found += self._load_from_db(id1)
+ self.assertEqual([hash(o) for o in db_found], [obj2_hash])
+ # check we cannot overwrite obj2 with obj1 despite its same ID,
+ # since it has disappeared now
+ with self.assertRaises(HandledException):
+ obj1.save(self.db_conn)
+
+ @_within_checked_class
+ def test_by_id(self) -> None:
+ """Test .by_id()."""
+ id1, id2, _ = self.default_ids
+ # check failure if not yet saved
+ obj1 = self.checked_class(id1, **self.default_init_kwargs)
+ with self.assertRaises(NotFoundException):
+ self.checked_class.by_id(self.db_conn, id1)
+ # check identity of cached and retrieved
+ obj1.cache()
+ self.assertEqual(obj1, self.checked_class.by_id(self.db_conn, id1))
+ # check identity of saved and retrieved
+ obj2 = self.checked_class(id2, **self.default_init_kwargs)
+ obj2.save(self.db_conn)
+ self.assertEqual(obj2, self.checked_class.by_id(self.db_conn, id2))
+
+ @_within_checked_class
+ def test_by_id_or_create(self) -> None:
+ """Test .by_id_or_create."""
+ # check .by_id_or_create acts like normal instantiation (sans saving)
+ id_ = self.default_ids[0]
+ if not self.checked_class.can_create_by_id:
+ with self.assertRaises(HandledException):
+ self.checked_class.by_id_or_create(self.db_conn, id_)
+ # check .by_id_or_create fails if wrong class
+ else:
+ by_id_created = self.checked_class.by_id_or_create(self.db_conn,
+ id_)
+ with self.assertRaises(NotFoundException):
+ self.checked_class.by_id(self.db_conn, id_)
+ self.assertEqual(self.checked_class(id_), by_id_created)
+
+ @_within_checked_class
+ def test_from_table_row(self) -> None:
+ """Test .from_table_row() properly reads in class directly from DB."""
+ id_ = self.default_ids[0]
+ obj = self.checked_class(id_, **self.default_init_kwargs)
+ obj.save(self.db_conn)
+ assert isinstance(obj.id_, type(id_))
+ for row in self.db_conn.row_where(self.checked_class.table_name,
+ 'id', obj.id_):
+ # check .from_table_row reproduces state saved, no matter if obj
+ # later changed (with caching even)
+ hash_original = hash(obj)
+ attr_name = self._change_obj(obj)
+ obj.cache()
+ to_cmp = getattr(obj, attr_name)
+ retrieved = self.checked_class.from_table_row(self.db_conn, row)
+ self.assertNotEqual(to_cmp, getattr(retrieved, attr_name))
+ self.assertEqual(hash_original, hash(retrieved))
+ # check cache contains what .from_table_row just produced
+ self.assertEqual({retrieved.id_: retrieved},
+ self.checked_class.get_cache())
+ # check .from_table_row also reads versioned attributes from DB
+ for attr_name, type_ in self.test_versioneds.items():
+ owner = self.checked_class(None)
+ vals: list[Any] = ['t1', 't2'] if type_ == str else [0.9, 1.1]
+ attr = getattr(owner, attr_name)
+ attr.set(vals[0])
+ attr.set(vals[1])
+ owner.save(self.db_conn)
+ for row in self.db_conn.row_where(owner.table_name, 'id',
+ owner.id_):
+ retrieved = owner.__class__.from_table_row(self.db_conn, row)
+ attr = getattr(retrieved, attr_name)
+ self.assertEqual(sorted(attr.history.values()), vals)
+
+ @_within_checked_class
+ def test_all(self) -> None:
+ """Test .all() and its relation to cache and savings."""
+ id_1, id_2, id_3 = self.default_ids
+ item1 = self.checked_class(id_1, **self.default_init_kwargs)
+ item2 = self.checked_class(id_2, **self.default_init_kwargs)
+ item3 = self.checked_class(id_3, **self.default_init_kwargs)
+ # check .all() returns empty list on un-cached items
+ self.assertEqual(self.checked_class.all(self.db_conn), [])
+ # check that all() shows only cached/saved items
+ item1.cache()
+ item3.save(self.db_conn)
+ self.assertEqual(sorted(self.checked_class.all(self.db_conn)),
+ sorted([item1, item3]))
+ item2.save(self.db_conn)
+ self.assertEqual(sorted(self.checked_class.all(self.db_conn)),
+ sorted([item1, item2, item3]))
+
+ @_within_checked_class
+ def test_singularity(self) -> None:
+ """Test pointers made for single object keep pointing to it."""
+ id1 = self.default_ids[0]
+ obj = self.checked_class(id1, **self.default_init_kwargs)
+ obj.save(self.db_conn)
+ # change object, expect retrieved through .by_id to carry change
+ attr_name = self._change_obj(obj)
+ new_attr = getattr(obj, attr_name)
+ retrieved = self.checked_class.by_id(self.db_conn, id1)
+ self.assertEqual(new_attr, getattr(retrieved, attr_name))
+
+ @_within_checked_class
+ def test_versioned_singularity_title(self) -> None:
+ """Test singularity of VersionedAttributes on saving (with .title)."""
+ if 'title' in self.test_versioneds:
+ obj = self.checked_class(None)
+ obj.save(self.db_conn)
+ assert isinstance(obj.id_, int)
+ # change obj, expect retrieved through .by_id to carry change
+ obj.title.set('named')
+ retrieved = self.checked_class.by_id(self.db_conn, obj.id_)
+ self.assertEqual(obj.title.history, retrieved.title.history)
+
+ @_within_checked_class
+ def test_remove(self) -> None:
+ """Test .remove() effects on DB and cache."""
+ id_ = self.default_ids[0]
+ obj = self.checked_class(id_, **self.default_init_kwargs)
+ # check removal only works after saving
+ with self.assertRaises(HandledException):
+ obj.remove(self.db_conn)
+ obj.save(self.db_conn)
+ obj.remove(self.db_conn)
+ # check access to obj fails after removal
+ with self.assertRaises(HandledException):
+ print(obj.id_)
+ # check DB and cache now empty
+ self.check_identity_with_cache_and_db([])
+