Fix oppia#21203 :Mock datetime in stats model test (oppia#21208)

* fix: mock datetime to ensure consistent date comparison in stats model test

* fix: Mock datetime to ensure consistent timestamp comparison in suggestion stats tests

* fix: Mock datetime to ensure consistent timestamp comparison in suggestion stats tests

* fix: Mock datetime to ensure consistent timestamp comparison in suggestion stats tests

* fix: Mock datetime to ensure consistent timestamp comparison in suggestion stats tests

* fix: Mock datetime to ensure consistent timestamp comparison in suggestion stats tests

* fix: refactor datetime mocking to AppTestBase for streamlined usage in tests

* fix: lint checks

core/jobs/batch_jobs/suggestion_stats_computation_jobs_test.py

@@ -712,65 +712,69 @@ def test_creates_translation_stats_models_from_two_accepted_suggestions(
     def test_creates_multiple_stats_models_from_multiple_users(
         self
     ) -> None:
-        opportunity_model = self.create_model(
-            opportunity_models.ExplorationOpportunitySummaryModel,
-            id=self.EXP_1_ID,
-            topic_id=self.TOPIC_1_ID,
-            chapter_title='irelevant',
-            content_count=1,
-            story_id='irelevant',
-            story_title='irelevant',
-            topic_name='irelevant'
-        )
-        opportunity_model.update_timestamps()
-        opportunity_model.put()
-        first_suggestion_model = self.create_model(
-            suggestion_models.GeneralSuggestionModel,
-            suggestion_type=feconf.SUGGESTION_TYPE_TRANSLATE_CONTENT,
-            author_id=self.VALID_USER_ID_1,
-            change_cmd={
-                'cmd': exp_domain.CMD_ADD_WRITTEN_TRANSLATION,
-                'state_name': 'state',
-                'content_id': 'content_id',
-                'language_code': 'lang',
-                'content_html': '111 222 333',
-                'translation_html': '111 222 333',
-                'data_format': 'unicode'
-            },
-            score_category='irelevant',
-            status=suggestion_models.STATUS_ACCEPTED,
-            target_type='exploration',
-            target_id=self.EXP_1_ID,
-            target_version_at_submission=0,
-            language_code=self.LANG_1,
-            final_reviewer_id='reviewer1'
-        )
-        first_suggestion_model.update_timestamps()
-        first_suggestion_model.put()
-
-        second_suggestion_model = self.create_model(
-            suggestion_models.GeneralSuggestionModel,
-            suggestion_type=feconf.SUGGESTION_TYPE_TRANSLATE_CONTENT,
-            author_id=self.VALID_USER_ID_2,
-            change_cmd={
-                'cmd': exp_domain.CMD_ADD_WRITTEN_TRANSLATION,
-                'state_name': 'state',
-                'content_id': 'content_id',
-                'language_code': 'lang',
-                'content_html': '111 222 333',
-                'translation_html': '111 222 333',
-                'data_format': 'unicode'
-            },
-            score_category='irelevant',
-            status=suggestion_models.STATUS_ACCEPTED,
-            target_type='exploration',
-            target_id=self.EXP_1_ID,
-            target_version_at_submission=0,
-            language_code=self.LANG_1,
-            final_reviewer_id='reviewer1'
-        )
-        second_suggestion_model.update_timestamps()
-        second_suggestion_model.put()
+        # Define a fixed datetime.
+        mocked_now = datetime.datetime(2024, 10, 28)
+
+        with self.mock_datetime_utcnow(mocked_now):
+            opportunity_model = self.create_model(
+                opportunity_models.ExplorationOpportunitySummaryModel,
+                id=self.EXP_1_ID,
+                topic_id=self.TOPIC_1_ID,
+                chapter_title='irelevant',
+                content_count=1,
+                story_id='irelevant',
+                story_title='irelevant',
+                topic_name='irelevant'
+            )
+            opportunity_model.update_timestamps()
+            opportunity_model.put()
+            first_suggestion_model = self.create_model(
+                suggestion_models.GeneralSuggestionModel,
+                suggestion_type=feconf.SUGGESTION_TYPE_TRANSLATE_CONTENT,
+                author_id=self.VALID_USER_ID_1,
+                change_cmd={
+                    'cmd': exp_domain.CMD_ADD_WRITTEN_TRANSLATION,
+                    'state_name': 'state',
+                    'content_id': 'content_id',
+                    'language_code': 'lang',
+                    'content_html': '111 222 333',
+                    'translation_html': '111 222 333',
+                    'data_format': 'unicode'
+                },
+                score_category='irelevant',
+                status=suggestion_models.STATUS_ACCEPTED,
+                target_type='exploration',
+                target_id=self.EXP_1_ID,
+                target_version_at_submission=0,
+                language_code=self.LANG_1,
+                final_reviewer_id='reviewer1'
+            )
+            first_suggestion_model.update_timestamps()
+            first_suggestion_model.put()
+
+            second_suggestion_model = self.create_model(
+                suggestion_models.GeneralSuggestionModel,
+                suggestion_type=feconf.SUGGESTION_TYPE_TRANSLATE_CONTENT,
+                author_id=self.VALID_USER_ID_2,
+                change_cmd={
+                    'cmd': exp_domain.CMD_ADD_WRITTEN_TRANSLATION,
+                    'state_name': 'state',
+                    'content_id': 'content_id',
+                    'language_code': 'lang',
+                    'content_html': '111 222 333',
+                    'translation_html': '111 222 333',
+                    'data_format': 'unicode'
+                },
+                score_category='irelevant',
+                status=suggestion_models.STATUS_ACCEPTED,
+                target_type='exploration',
+                target_id=self.EXP_1_ID,
+                target_version_at_submission=0,
+                language_code=self.LANG_1,
+                final_reviewer_id='reviewer1'
+            )
+            second_suggestion_model.update_timestamps()
+            second_suggestion_model.put()
 
         self.assert_job_output_is([
             job_run_result.JobRunResult(
@@ -879,11 +883,11 @@ def test_creates_multiple_stats_models_from_multiple_users(
             translation_review_stats_model.accepted_translation_word_count, 6)
         self.assertEqual(
             translation_review_stats_model.first_contribution_date,
-            datetime.datetime.utcnow().date()
+            mocked_now.date()
         )
         self.assertEqual(
             translation_review_stats_model.last_contribution_date,
-            datetime.datetime.utcnow().date()
+            mocked_now.date()
         )
 
     def _create_valid_question_data(

core/tests/test_utils.py

@@ -2089,6 +2089,58 @@ def mock_set_constants_to_default(self) -> None:
         """
         raise Exception('Please mock this method in the test.')
 
+    @contextlib.contextmanager
+    def mock_datetime_utcnow(
+        self, mocked_now: datetime.datetime
+    ) -> Iterator[None]:
+        """Mocks parts of the datastore to accept a fake datetime type that
+        always returns the same value for utcnow.
+
+        Example:
+            import datetime
+            mocked_now = datetime.datetime.utcnow() - datetime.timedelta(days=1)
+            with mock_datetime_utcnow(mocked_now):
+                self.assertEqual(datetime.datetime.utcnow(), mocked_now)
+            actual_now = datetime.datetime.utcnow() # Returns actual time.
+
+        Args:
+            mocked_now: datetime.datetime. The datetime which will be used
+                instead of the current UTC datetime.
+
+        Yields:
+            None. Empty yield statement.
+
+        Raises:
+            Exception. Given argument is not a datetime.
+        """
+        if not isinstance(mocked_now, datetime.datetime):
+            raise Exception('mocked_now must be datetime, got: %r' % mocked_now)
+
+        old_datetime = datetime.datetime
+
+        class MockDatetimeType(type):
+            """Overrides isinstance() behavior."""
+
+            @classmethod
+            def __instancecheck__(mcs, instance: datetime.datetime) -> bool:
+                return isinstance(instance, old_datetime)
+
+        class MockDatetime(datetime.datetime, metaclass=MockDatetimeType):
+            """Always returns mocked_now as the current UTC time."""
+
+            # Here we use MyPy ignore because the signature of this
+            # method doesn't match with datetime.datetime's utcnow().
+            @classmethod
+            def utcnow(cls) -> datetime.datetime:  # type: ignore[override]
+                """Returns the mocked datetime."""
+                return mocked_now
+
+        setattr(datetime, 'datetime', MockDatetime)
+        try:
+            yield
+        finally:
+            setattr(datetime, 'datetime', old_datetime)
+
 
 class GenericTestBase(AppEngineTestBase):
     """Base test class with common/generic helper methods.
@@ -2524,58 +2576,6 @@ def logout(self) -> None:
         os.environ['USER_EMAIL'] = ''
         os.environ['USER_IS_ADMIN'] = '0'
 
-    @contextlib.contextmanager
-    def mock_datetime_utcnow(
-        self, mocked_now: datetime.datetime
-    ) -> Iterator[None]:
-        """Mocks parts of the datastore to accept a fake datetime type that
-        always returns the same value for utcnow.
-
-        Example:
-            import datetime
-            mocked_now = datetime.datetime.utcnow() - datetime.timedelta(days=1)
-            with mock_datetime_utcnow(mocked_now):
-                self.assertEqual(datetime.datetime.utcnow(), mocked_now)
-            actual_now = datetime.datetime.utcnow() # Returns actual time.
-
-        Args:
-            mocked_now: datetime.datetime. The datetime which will be used
-                instead of the current UTC datetime.
-
-        Yields:
-            None. Empty yield statement.
-
-        Raises:
-            Exception. Given argument is not a datetime.
-        """
-        if not isinstance(mocked_now, datetime.datetime):
-            raise Exception('mocked_now must be datetime, got: %r' % mocked_now)
-
-        old_datetime = datetime.datetime
-
-        class MockDatetimeType(type):
-            """Overrides isinstance() behavior."""
-
-            @classmethod
-            def __instancecheck__(mcs, instance: datetime.datetime) -> bool:
-                return isinstance(instance, old_datetime)
-
-        class MockDatetime(datetime.datetime, metaclass=MockDatetimeType):
-            """Always returns mocked_now as the current UTC time."""
-
-            # Here we use MyPy ignore because the signature of this
-            # method doesn't match with datetime.datetime's utcnow().
-            @classmethod
-            def utcnow(cls) -> datetime.datetime:  # type: ignore[override]
-                """Returns the mocked datetime."""
-                return mocked_now
-
-        setattr(datetime, 'datetime', MockDatetime)
-        try:
-            yield
-        finally:
-            setattr(datetime, 'datetime', old_datetime)
-
     @contextlib.contextmanager
     def login_context(
         self, email: str, is_super_admin: bool = False