completely fix tests on Python 3.12

CHANGELOG.rst

@@ -23,6 +23,8 @@ Changelog
 **Bugfixes**:
 
 - Tests were failing on Windows OS
+- Tests were failing on Python 3.12 (`Issue #332 <https://github.com/maxtepkeev/python-redmine/pull/332>`__)
+  (thanks to `Michał Górny <https://github.com/mgorny>`__)
 - Some closed Issues weren't converted to Resource objects using ``redmine.search()``
 - *Pro Edition:* RedmineUP CrmQuery resource ``deals`` and ``contacts`` relation attributes didn't work
 - *Pro Edition:* RedmineUP DealStatus resource ``deals`` relation attribute didn't work

redminelib/resources/base.py

@@ -417,7 +417,8 @@ def save(self, **attrs):
         if not self.is_new():
             self.pre_update()
             self.manager.update(self.internal_id, **self._changes)
-            self._decoded_attrs['updated_on'] = datetime.utcnow().strftime(self.manager.redmine.datetime_format)
+            self._decoded_attrs['updated_on'] = datetime.now(timezone.utc).strftime(
+                self.manager.redmine.datetime_format)
             self.post_update()
         else:
             self.pre_create()

tests/test_engines.py

@@ -101,7 +101,7 @@ def test_redirect_warning(self):
         with warnings.catch_warnings(record=True) as w:
             warnings.simplefilter('always')
             self.redmine.engine.request('get', self.url)
-            self.assertEquals(len(w), 1)
+            self.assertEqual(len(w), 1)
             self.assertIs(w[0].category, exceptions.PerformanceWarning)
 
     def test_engine_is_picklable(self):