X-Git-Url: https://plomlompom.com/repos/%7B%7B%20web_path%20%7D%7D/decks/%7B%7Bdeck_id%7D%7D/cards/%7B%7Bcard_id%7D%7D/form?a=blobdiff_plain;ds=sidebyside;f=tests%2Futils.py;h=665436873c27af704a13827715d3c795e04e1fe1;hb=HEAD;hp=55c948a409dbf1b2c43f775c0d39106ba3ed510d;hpb=25b71c6f0b10db05907128daf50c6e543e514c35;p=plomtask

diff --git a/tests/utils.py b/tests/utils.py
index 55c948a..8008033 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -4,6 +4,8 @@ from unittest import TestCase
 from typing import Mapping, Any, Callable
 from threading import Thread
 from http.client import HTTPConnection
+from datetime import datetime, timedelta
+from time import sleep
 from json import loads as json_loads
 from urllib.parse import urlencode
 from uuid import uuid4
@@ -13,41 +15,156 @@ from plomtask.http import TaskHandler, TaskServer
 from plomtask.processes import Process, ProcessStep
 from plomtask.conditions import Condition
 from plomtask.days import Day
+from plomtask.dating import DATE_FORMAT
 from plomtask.todos import Todo
+from plomtask.versioned_attributes import VersionedAttribute, TIMESTAMP_FMT
 from plomtask.exceptions import NotFoundException, HandledException
 
 
-class TestCaseSansDB(TestCase):
-    """Tests requiring no DB setup."""
+VERSIONED_VALS: dict[str,
+                     list[str] | list[float]] = {'str': ['A', 'B'],
+                                                 'float': [0.3, 1.1]}
+
+
+class TestCaseAugmented(TestCase):
+    """Tester core providing helpful basic internal decorators and methods."""
     checked_class: Any
-    do_id_test: bool = False
-    default_init_args: list[Any] = []
-    versioned_defaults_to_test: dict[str, str | float] = {}
+    default_init_kwargs: dict[str, Any] = {}
 
-    def test_id_setting(self) -> None:
-        """Test .id_ being set and its legal range being enforced."""
-        if not self.do_id_test:
-            return
-        with self.assertRaises(HandledException):
-            self.checked_class(0, *self.default_init_args)
-        obj = self.checked_class(5, *self.default_init_args)
-        self.assertEqual(obj.id_, 5)
+    @staticmethod
+    def _run_if_checked_class(f: Callable[..., None]) -> Callable[..., None]:
+        def wrapper(self: TestCase) -> None:
+            if hasattr(self, 'checked_class'):
+                f(self)
+        return wrapper
 
-    def test_versioned_defaults(self) -> None:
-        """Test defaults of VersionedAttributes."""
-        if len(self.versioned_defaults_to_test) == 0:
-            return
-        obj = self.checked_class(1, *self.default_init_args)
-        for k, v in self.versioned_defaults_to_test.items():
-            self.assertEqual(getattr(obj, k).newest, v)
+    @classmethod
+    def _run_on_versioned_attributes(cls,
+                                     f: Callable[..., None]
+                                     ) -> Callable[..., None]:
+        @cls._run_if_checked_class
+        def wrapper(self: TestCase) -> None:
+            assert isinstance(self, TestCaseAugmented)
+            for attr_name in self.checked_class.to_save_versioned():
+                default = self.checked_class.versioned_defaults[attr_name]
+                owner = self.checked_class(None, **self.default_init_kwargs)
+                attr = getattr(owner, attr_name)
+                to_set = VERSIONED_VALS[attr.value_type_name]
+                f(self, owner, attr_name, attr, default, to_set)
+        return wrapper
+
+    @classmethod
+    def _make_from_defaults(cls, id_: float | str | None) -> Any:
+        return cls.checked_class(id_, **cls.default_init_kwargs)
+
+
+class TestCaseSansDB(TestCaseAugmented):
+    """Tests requiring no DB setup."""
+    legal_ids: list[str] | list[int] = [1, 5]
+    illegal_ids: list[str] | list[int] = [0]
+
+    @TestCaseAugmented._run_if_checked_class
+    def test_id_validation(self) -> None:
+        """Test .id_ validation/setting."""
+        for id_ in self.illegal_ids:
+            with self.assertRaises(HandledException):
+                self._make_from_defaults(id_)
+        for id_ in self.legal_ids:
+            obj = self._make_from_defaults(id_)
+            self.assertEqual(obj.id_, id_)
+
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_versioned_set(self,
+                           _: Any,
+                           __: str,
+                           attr: VersionedAttribute,
+                           default: str | float,
+                           to_set: list[str | float]
+                           ) -> None:
+        """Test VersionedAttribute.set() behaves as expected."""
+        attr.set(default)
+        self.assertEqual(list(attr.history.values()), [default])
+        # check same value does not get set twice in a row,
+        # and that not even its timestamp get updated
+        timestamp = list(attr.history.keys())[0]
+        attr.set(default)
+        self.assertEqual(list(attr.history.values()), [default])
+        self.assertEqual(list(attr.history.keys())[0], timestamp)
+        # check that different value _will_ be set/added
+        attr.set(to_set[0])
+        timesorted_vals = [attr.history[t] for
+                           t in sorted(attr.history.keys())]
+        expected = [default, to_set[0]]
+        self.assertEqual(timesorted_vals, expected)
+        # check that a previously used value can be set if not most recent
+        attr.set(default)
+        timesorted_vals = [attr.history[t] for
+                           t in sorted(attr.history.keys())]
+        expected = [default, to_set[0], default]
+        self.assertEqual(timesorted_vals, expected)
+        # again check for same value not being set twice in a row, even for
+        # later items
+        attr.set(to_set[1])
+        timesorted_vals = [attr.history[t] for
+                           t in sorted(attr.history.keys())]
+        expected = [default, to_set[0], default, to_set[1]]
+        self.assertEqual(timesorted_vals, expected)
+        attr.set(to_set[1])
+        self.assertEqual(timesorted_vals, expected)
+
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_versioned_newest(self,
+                              _: Any,
+                              __: str,
+                              attr: VersionedAttribute,
+                              default: str | float,
+                              to_set: list[str | float]
+                              ) -> None:
+        """Test VersionedAttribute.newest."""
+        # check .newest on empty history returns .default
+        self.assertEqual(attr.newest, default)
+        # check newest element always returned
+        for v in [to_set[0], to_set[1]]:
+            attr.set(v)
+            self.assertEqual(attr.newest, v)
+        # check newest element returned even if also early value
+        attr.set(default)
+        self.assertEqual(attr.newest, default)
+
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_versioned_at(self,
+                          _: Any,
+                          __: str,
+                          attr: VersionedAttribute,
+                          default: str | float,
+                          to_set: list[str | float]
+                          ) -> None:
+        """Test .at() returns values nearest to queried time, or default."""
+        # check .at() return default on empty history
+        timestamp_a = datetime.now().strftime(TIMESTAMP_FMT)
+        self.assertEqual(attr.at(timestamp_a), default)
+        # check value exactly at timestamp returned
+        attr.set(to_set[0])
+        timestamp_b = list(attr.history.keys())[0]
+        self.assertEqual(attr.at(timestamp_b), to_set[0])
+        # check earliest value returned if exists, rather than default
+        self.assertEqual(attr.at(timestamp_a), to_set[0])
+        # check reverts to previous value for timestamps not indexed
+        sleep(0.00001)
+        timestamp_between = datetime.now().strftime(TIMESTAMP_FMT)
+        sleep(0.00001)
+        attr.set(to_set[1])
+        timestamp_c = sorted(attr.history.keys())[-1]
+        self.assertEqual(attr.at(timestamp_c), to_set[1])
+        self.assertEqual(attr.at(timestamp_between), to_set[0])
+        sleep(0.00001)
+        timestamp_after_c = datetime.now().strftime(TIMESTAMP_FMT)
+        self.assertEqual(attr.at(timestamp_after_c), to_set[1])
 
 
-class TestCaseWithDB(TestCase):
+class TestCaseWithDB(TestCaseAugmented):
     """Module tests not requiring DB setup."""
-    checked_class: Any
     default_ids: tuple[int | str, int | str, int | str] = (1, 2, 3)
-    default_init_kwargs: dict[str, Any] = {}
-    test_versioneds: dict[str, type] = {}
 
     def setUp(self) -> None:
         Condition.empty_cache()
@@ -62,30 +179,26 @@ class TestCaseWithDB(TestCase):
         self.db_conn.close()
         remove_file(self.db_file.path)
 
-    @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
 
-    @_within_checked_class
-    def test_saving_and_caching(self) -> None:
-        """Test storage and initialization of instances and attributes."""
-        self.check_saving_and_caching(id_=1, **self.default_init_kwargs)
-        obj = self.checked_class(None, **self.default_init_kwargs)
-        obj.save(self.db_conn)
-        self.assertEqual(obj.id_, 2)
-        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)
-            retrieved = owner.__class__.by_id(self.db_conn, owner.id_)
-            attr = getattr(retrieved, attr_name)
-            self.assertEqual(sorted(attr.history.values()), vals)
+    def _change_obj(self, obj: object) -> str:
+        attr_name: str = self.checked_class.to_save_simples[-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."""
@@ -97,79 +210,200 @@ class TestCaseWithDB(TestCase):
         db_found: list[Any] = []
         for item in content:
             assert isinstance(item.id_, type(self.default_ids[0]))
-            for row in self.db_conn.row_where(self.checked_class.table_name,
-                                              'id', item.id_):
-                db_found += [self.checked_class.from_table_row(self.db_conn,
-                                                               row)]
+            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))
 
-    def check_saving_and_caching(self, **kwargs: Any) -> None:
-        """Test instance.save in its core without relations."""
-        obj = self.checked_class(**kwargs)  # pylint: disable=not-callable
-        # check object init itself doesn't store anything yet
-        self.check_identity_with_cache_and_db([])
-        # check saving sets core attributes properly
-        obj.save(self.db_conn)
-        for key, value in kwargs.items():
-            self.assertEqual(getattr(obj, key), value)
-        # check saving stored properly in cache and DB
-        self.check_identity_with_cache_and_db([obj])
+    def check_by_date_range_with_limits(self,
+                                        date_col: str,
+                                        set_id_field: bool = True
+                                        ) -> None:
+        """Test .by_date_range_with_limits."""
+        # pylint: disable=too-many-locals
+        f = self.checked_class.by_date_range_with_limits
+        # check illegal ranges
+        legal_range = ('yesterday', 'tomorrow')
+        for i in [0, 1]:
+            for bad_date in ['foo', '2024-02-30', '2024-01-01 12:00:00']:
+                date_range = list(legal_range[:])
+                date_range[i] = bad_date
+                with self.assertRaises(HandledException):
+                    f(self.db_conn, date_range, date_col)
+        # check empty, translation of 'yesterday' and 'tomorrow'
+        items, start, end = f(self.db_conn, legal_range, date_col)
+        self.assertEqual(items, [])
+        yesterday = datetime.now() + timedelta(days=-1)
+        tomorrow = datetime.now() + timedelta(days=+1)
+        self.assertEqual(start, yesterday.strftime(DATE_FORMAT))
+        self.assertEqual(end, tomorrow.strftime(DATE_FORMAT))
+        # prepare dated items for non-empty results
+        kwargs_with_date = self.default_init_kwargs.copy()
+        if set_id_field:
+            kwargs_with_date['id_'] = None
+        objs = []
+        dates = ['2024-01-01', '2024-01-02', '2024-01-04']
+        for date in ['2024-01-01', '2024-01-02', '2024-01-04']:
+            kwargs_with_date['date'] = date
+            obj = self.checked_class(**kwargs_with_date)
+            objs += [obj]
+        # check ranges still empty before saving
+        date_range = [dates[0], dates[-1]]
+        self.assertEqual(f(self.db_conn, date_range, date_col)[0], [])
+        # check all objs displayed within closed interval
+        for obj in objs:
+            obj.save(self.db_conn)
+        self.assertEqual(f(self.db_conn, date_range, date_col)[0], objs)
+        # check that only displayed what exists within interval
+        date_range = ['2023-12-20', '2024-01-03']
+        expected = [objs[0], objs[1]]
+        self.assertEqual(f(self.db_conn, date_range, date_col)[0], expected)
+        date_range = ['2024-01-03', '2024-01-30']
+        expected = [objs[2]]
+        self.assertEqual(f(self.db_conn, date_range, date_col)[0], expected)
+        # check that inverted interval displays nothing
+        date_range = [dates[-1], dates[0]]
+        self.assertEqual(f(self.db_conn, date_range, date_col)[0], [])
+        # check that "today" is interpreted, and single-element interval
+        today_date = datetime.now().strftime(DATE_FORMAT)
+        kwargs_with_date['date'] = today_date
+        obj_today = self.checked_class(**kwargs_with_date)
+        obj_today.save(self.db_conn)
+        date_range = ['today', 'today']
+        items, start, end = f(self.db_conn, date_range, date_col)
+        self.assertEqual(start, today_date)
+        self.assertEqual(start, end)
+        self.assertEqual(items, [obj_today])
+
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_saving_versioned_attributes(self,
+                                         owner: Any,
+                                         attr_name: str,
+                                         attr: VersionedAttribute,
+                                         _: str | float,
+                                         to_set: list[str | float]
+                                         ) -> None:
+        """Test storage and initialization of versioned attributes."""
 
-    @_within_checked_class
+        def retrieve_attr_vals(attr: VersionedAttribute) -> list[object]:
+            attr_vals_saved: list[object] = []
+            for row in self.db_conn.row_where(attr.table_name, 'parent',
+                                              owner.id_):
+                attr_vals_saved += [row[2]]
+            return attr_vals_saved
+
+        attr.set(to_set[0])
+        # check that without attr.save() no rows in DB
+        rows = self.db_conn.row_where(attr.table_name, 'parent', owner.id_)
+        self.assertEqual([], rows)
+        # fail saving attributes on non-saved owner
+        with self.assertRaises(NotFoundException):
+            attr.save(self.db_conn)
+        # check owner.save() created entries as expected in attr table
+        owner.save(self.db_conn)
+        attr_vals_saved = retrieve_attr_vals(attr)
+        self.assertEqual([to_set[0]], attr_vals_saved)
+        # check changing attr val without save affects owner in memory …
+        attr.set(to_set[1])
+        cmp_attr = getattr(owner, attr_name)
+        self.assertEqual(to_set, list(cmp_attr.history.values()))
+        self.assertEqual(cmp_attr.history, attr.history)
+        # … but does not yet affect DB
+        attr_vals_saved = retrieve_attr_vals(attr)
+        self.assertEqual([to_set[0]], attr_vals_saved)
+        # check individual attr.save also stores new val to DB
+        attr.save(self.db_conn)
+        attr_vals_saved = retrieve_attr_vals(attr)
+        self.assertEqual(to_set, attr_vals_saved)
+
+    @TestCaseAugmented._run_if_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._make_from_defaults(None)
+            with self.assertRaises(HandledException):
+                obj0.cache()
+        # check mere object init itself doesn't even store in cache
+        obj1 = self._make_from_defaults(id1)
+        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})
+        found_in_db = self._load_from_db(id1)
+        self.assertEqual(found_in_db, [])
+        # 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._make_from_defaults(id_input)
+        obj2.save(self.db_conn)
+        self.assertEqual(self.checked_class.get_cache(), {id1: obj2})
+        # NB: we'll only compare hashes because obj2 itself disappears on
+        # .from_table_row-trioggered database reload
+        obj2_hash = hash(obj2)
+        found_in_db += self._load_from_db(id1)
+        self.assertEqual([hash(o) for o in found_in_db], [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)
+
+    @TestCaseAugmented._run_if_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)
+        obj1 = self._make_from_defaults(id1)
         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 = self._make_from_defaults(id2)
         obj2.save(self.db_conn)
         self.assertEqual(obj2, self.checked_class.by_id(self.db_conn, id2))
-        # obj1.save(self.db_conn)
-        # self.check_identity_with_cache_and_db([obj1, obj2])
 
-    @_within_checked_class
+    @TestCaseAugmented._run_if_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]
+        # check .by_id_or_create fails if wrong class
         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)
+                self.checked_class.by_id_or_create(self.db_conn, None)
+            return
+        # check ID input of None creates, on saving, ID=1,2,… for int IDs
+        if isinstance(self.default_ids[0], int):
+            for n in range(2):
+                item = self.checked_class.by_id_or_create(self.db_conn, None)
+                self.assertEqual(item.id_, None)
+                item.save(self.db_conn)
+                self.assertEqual(item.id_, n+1)
+        # check .by_id_or_create acts like normal instantiation (sans saving)
+        id_ = self.default_ids[2]
+        item = self.checked_class.by_id_or_create(self.db_conn, id_)
+        self.assertEqual(item.id_, id_)
+        with self.assertRaises(NotFoundException):
+            self.checked_class.by_id(self.db_conn, item.id_)
+        self.assertEqual(self.checked_class(item.id_), item)
 
-    @_within_checked_class
+    @TestCaseAugmented._run_if_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 = self._make_from_defaults(id_)
         obj.save(self.db_conn)
-        assert isinstance(obj.id_, type(self.default_ids[0]))
+        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)
+            # NB: we'll only compare hashes because obj itself disappears on
+            # .from_table_row-triggered database reload
             hash_original = hash(obj)
-            attr_name = self.checked_class.to_save[-1]
-            attr = getattr(obj, attr_name)
-            if isinstance(attr, (int, float)):
-                setattr(obj, attr_name, attr + 1)
-            elif isinstance(attr, str):
-                setattr(obj, attr_name, attr + "_")
-            elif isinstance(attr, bool):
-                setattr(obj, attr_name, not attr)
+            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)
@@ -179,27 +413,36 @@ class TestCaseWithDB(TestCase):
             self.assertEqual({retrieved.id_: retrieved},
                              self.checked_class.get_cache())
 
-    def check_versioned_from_table_row(self, attr_name: str,
-                                       type_: type) -> None:
-        """Test .from_table_row() reads versioned attributes from DB."""
-        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])
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_versioned_history_from_row(self,
+                                        owner: Any,
+                                        _: str,
+                                        attr: VersionedAttribute,
+                                        default: str | float,
+                                        to_set: list[str | float]
+                                        ) -> None:
+        """"Test VersionedAttribute.history_from_row() knows its DB rows."""
+        attr.set(to_set[0])
+        attr.set(to_set[1])
         owner.save(self.db_conn)
+        # make empty VersionedAttribute, fill from rows, compare to owner's
         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)
+            loaded_attr = VersionedAttribute(owner, attr.table_name, default)
+            for row in self.db_conn.row_where(attr.table_name, 'parent',
+                                              owner.id_):
+                loaded_attr.history_from_row(row)
+            self.assertEqual(len(attr.history.keys()),
+                             len(loaded_attr.history.keys()))
+            for timestamp, value in attr.history.items():
+                self.assertEqual(value, loaded_attr.history[timestamp])
 
-    @_within_checked_class
+    @TestCaseAugmented._run_if_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)
+        id1, id2, id3 = self.default_ids
+        item1 = self._make_from_defaults(id1)
+        item2 = self._make_from_defaults(id2)
+        item3 = self._make_from_defaults(id3)
         # 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
@@ -211,42 +454,48 @@ class TestCaseWithDB(TestCase):
         self.assertEqual(sorted(self.checked_class.all(self.db_conn)),
                          sorted([item1, item2, item3]))
 
-    @_within_checked_class
+    @TestCaseAugmented._run_if_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 = self._make_from_defaults(id1)
         obj.save(self.db_conn)
-        attr_name = 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)
+        # 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))
 
-    def check_versioned_singularity(self) -> None:
-        """Test singularity of VersionedAttributes on saving (with .title)."""
-        obj = self.checked_class(None)  # pylint: disable=not-callable
-        obj.save(self.db_conn)
-        assert isinstance(obj.id_, int)
-        obj.title.set('named')
-        retrieved = self.checked_class.by_id(self.db_conn, obj.id_)
-        self.assertEqual(obj.title.history, retrieved.title.history)
+    @TestCaseAugmented._run_on_versioned_attributes
+    def test_versioned_singularity(self,
+                                   owner: Any,
+                                   attr_name: str,
+                                   attr: VersionedAttribute,
+                                   _: str | float,
+                                   to_set: list[str | float]
+                                   ) -> None:
+        """Test singularity of VersionedAttributes on saving."""
+        owner.save(self.db_conn)
+        # change obj, expect retrieved through .by_id to carry change
+        attr.set(to_set[0])
+        retrieved = self.checked_class.by_id(self.db_conn, owner.id_)
+        attr_retrieved = getattr(retrieved, attr_name)
+        self.assertEqual(attr.history, attr_retrieved.history)
 
-    def check_remove(self, *args: Any) -> None:
+    @TestCaseAugmented._run_if_checked_class
+    def test_remove(self) -> None:
         """Test .remove() effects on DB and cache."""
         id_ = self.default_ids[0]
-        obj = self.checked_class(id_, *args)  # pylint: disable=not-callable
+        obj = self._make_from_defaults(id_)
+        # 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([])
 
 
@@ -269,6 +518,71 @@ class TestCaseWithServer(TestCaseWithDB):
         self.server_thread.join()
         super().tearDown()
 
+    @staticmethod
+    def as_id_list(items: list[dict[str, object]]) -> list[int | str]:
+        """Return list of only 'id' fields of items."""
+        id_list = []
+        for item in items:
+            assert isinstance(item['id'], (int, str))
+            id_list += [item['id']]
+        return id_list
+
+    @staticmethod
+    def as_refs(items: list[dict[str, object]]
+                ) -> dict[str, dict[str, object]]:
+        """Return dictionary of items by their 'id' fields."""
+        refs = {}
+        for item in items:
+            refs[str(item['id'])] = item
+        return refs
+
+    @staticmethod
+    def cond_as_dict(id_: int = 1,
+                     is_active: bool = False,
+                     titles: None | list[str] = None,
+                     descriptions: None | list[str] = None
+                     ) -> dict[str, object]:
+        """Return JSON of Condition to expect."""
+        d = {'id': id_,
+             'is_active': is_active,
+             '_versioned': {
+                 'title': {},
+                 'description': {}}}
+        titles = titles if titles else []
+        descriptions = descriptions if descriptions else []
+        assert isinstance(d['_versioned'], dict)
+        for i, title in enumerate(titles):
+            d['_versioned']['title'][i] = title
+        for i, description in enumerate(descriptions):
+            d['_versioned']['description'][i] = description
+        return d
+
+    @staticmethod
+    def proc_as_dict(id_: int = 1,
+                     title: str = 'A',
+                     description: str = '',
+                     effort: float = 1.0,
+                     conditions: None | list[int] = None,
+                     disables: None | list[int] = None,
+                     blockers: None | list[int] = None,
+                     enables: None | list[int] = None
+                     ) -> dict[str, object]:
+        """Return JSON of Process to expect."""
+        # pylint: disable=too-many-arguments
+        d = {'id': id_,
+             'calendarize': False,
+             'suppressed_steps': [],
+             'explicit_steps': [],
+             '_versioned': {
+                 'title': {0: title},
+                 'description': {0: description},
+                 'effort': {0: effort}},
+             'conditions': conditions if conditions else [],
+             'disables': disables if disables else [],
+             'enables': enables if enables else [],
+             'blockers': blockers if blockers else []}
+        return d
+
     def check_redirect(self, target: str) -> None:
         """Check that self.conn answers with a 302 redirect to target."""
         response = self.conn.getresponse()
@@ -281,7 +595,7 @@ class TestCaseWithServer(TestCaseWithDB):
         self.assertEqual(self.conn.getresponse().status, expected_code)
 
     def check_post(self, data: Mapping[str, object], target: str,
-                   expected_code: int, redirect_location: str = '') -> None:
+                   expected_code: int = 302, redir: str = '') -> None:
         """Check that POST of data to target yields expected_code."""
         encoded_form_data = urlencode(data, doseq=True).encode('utf-8')
         headers = {'Content-Type': 'application/x-www-form-urlencoded',
@@ -289,9 +603,8 @@ class TestCaseWithServer(TestCaseWithDB):
         self.conn.request('POST', target,
                           body=encoded_form_data, headers=headers)
         if 302 == expected_code:
-            if redirect_location == '':
-                redirect_location = target
-            self.check_redirect(redirect_location)
+            redir = target if redir == '' else redir
+            self.check_redirect(redir)
         else:
             self.assertEqual(self.conn.getresponse().status, expected_code)
 
@@ -309,8 +622,8 @@ class TestCaseWithServer(TestCaseWithDB):
         """POST basic Process."""
         if not form_data:
             form_data = {'title': 'foo', 'description': 'foo', 'effort': 1.1}
-        self.check_post(form_data, f'/process?id={id_}', 302,
-                        f'/process?id={id_}')
+        self.check_post(form_data, f'/process?id={id_}',
+                        redir=f'/process?id={id_}')
         return form_data
 
     def check_json_get(self, path: str, expected: dict[str, object]) -> None:
@@ -320,6 +633,7 @@ class TestCaseWithServer(TestCaseWithDB):
         timestamp keys of VersionedAttribute history keys into integers
         counting chronologically forward from 0.
         """
+
         def rewrite_history_keys_in(item: Any) -> Any:
             if isinstance(item, dict):
                 if '_versioned' in item.keys():
@@ -334,6 +648,7 @@ class TestCaseWithServer(TestCaseWithDB):
             elif isinstance(item, list):
                 item[:] = [rewrite_history_keys_in(i) for i in item]
             return item
+
         self.conn.request('GET', path)
         response = self.conn.getresponse()
         self.assertEqual(response.status, 200)