Convert datetime.now() to django.utils.timezone.now(). Closes #545

- datetime.now() isn't very safe for timezone enabled scenarios
  so make use of django.utils.timezone.now() which acts according
  to settings
- add new linter to prevent & discover usage of datetime.now()
- how to configure time zone has already been documented so close
  issue #545 with this commit

kiwi_lint/__init__.py

@@ -19,6 +19,7 @@
 from .auto_field import AutoFieldChecker
 from .one_to_one_field import OneToOneFieldChecker
 from .views import ClassBasedViewChecker
+from .datetime import DatetimeChecker
 
 
 def register(linter):
@@ -38,3 +39,4 @@ def register(linter):
     linter.register_checker(AutoFieldChecker(linter))
     linter.register_checker(OneToOneFieldChecker(linter))
     linter.register_checker(ClassBasedViewChecker(linter))
+    linter.register_checker(DatetimeChecker(linter))

kiwi_lint/datetime.py

@@ -0,0 +1,31 @@
+"""
+    Warns against usage of datetime.now() which may not be fully timezone
+    safe. Instead we should use django.utils.timezone.now() which acts
+    according to settings!
+"""
+
+from astroid import nodes
+
+from pylint import checkers
+from pylint import interfaces
+
+
+class DatetimeChecker(checkers.BaseChecker):
+    __implements__ = (interfaces.IAstroidChecker, )
+
+    name = 'datetime-checker'
+
+    msgs = {
+        'R4711': ('Do not use datetime.now(), use django.utils.timezone.now()',
+                  'datetime-now-used',
+                  'Use django.utils.timezone.now()! See: '
+                  'https://docs.djangoproject.com/en/2.2/topics/i18n/timezones/'
+                  '#interpretation-of-naive-datetime-objects')
+    }
+
+    def visit_name(self, node):
+        parent = node.parent
+        while node.name == 'datetime' and isinstance(parent, nodes.Attribute):
+            if parent.attrname == 'now':
+                self.add_message('datetime-now-used', node=node)
+            parent = parent.parent

tcms/core/context_processors.py

@@ -18,4 +18,4 @@ def settings_processor(_request):
 
 
 def server_time_processor(_request):
-    return {'SERVER_TIME': timezone.now() }
+    return {'SERVER_TIME': timezone.now()}

tcms/core/helpers/comments.py

@@ -3,11 +3,10 @@
 Functions that help access comments
 of objects.
 """
-from datetime import datetime
-
 from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
+from django.utils import timezone
 from django_comments.models import Comment
 
 
@@ -41,7 +40,7 @@ def add_comment(objs, comments, user, submit_date=None):
                                object_pk=obj.pk,
                                user=user,
                                comment=comments,
-                               submit_date=submit_date or datetime.now(),
+                               submit_date=submit_date or timezone.now(),
                                user_email=user.email,
                                user_name=user.username)
 

tcms/kiwi_auth/tests.py

@@ -8,6 +8,7 @@
 from django.contrib.sites.models import Site
 from django.test import TestCase, override_settings
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 from mock import patch
 
@@ -28,7 +29,7 @@ def setUpTestData(cls):
 
     @patch('tcms.kiwi_auth.models.datetime')
     def test_set_random_key(self, mock_datetime):
-        now = datetime.datetime.now()
+        now = timezone.now()
         in_7_days = datetime.timedelta(7)
 
         mock_datetime.datetime.today.return_value = now
@@ -229,7 +230,7 @@ def test_fail_if_activation_key_expired(self):
         with patch('tcms.kiwi_auth.models.secrets') as _secrets:
             _secrets.token_hex.return_value = fake_activation_key
             key = UserActivationKey.set_random_key_for_user(self.new_user)
-            key.key_expires = datetime.datetime.now() - datetime.timedelta(days=10)
+            key.key_expires = timezone.now() - datetime.timedelta(days=10)
             key.save()
 
         confirm_url = reverse('tcms-confirm', args=[fake_activation_key])

tcms/kiwi_auth/views.py

@@ -1,14 +1,13 @@
 # -*- coding: utf-8 -*-
 # pylint: disable=missing-permission-required
 
-from datetime import datetime
-
 from django.conf import settings
 from django.contrib import messages
 from django.contrib.auth import get_user_model, views
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.http import require_GET, require_http_methods
 
@@ -105,7 +104,7 @@ def confirm(request, activation_key):
         )
         return HttpResponseRedirect(request.GET.get('next', reverse('core-views-index')))
 
-    if _activation_key.key_expires <= datetime.now():
+    if _activation_key.key_expires <= timezone.now():
         messages.add_message(request, messages.ERROR, _('This activation key has expired'))
         return HttpResponseRedirect(request.GET.get('next', reverse('core-views-index')))
 

tcms/rpc/tests/test_serializer.py

@@ -4,6 +4,7 @@
 import unittest
 
 from django import test
+from django.utils import timezone
 
 from tcms.management.models import Product
 from tcms.rpc.serializer import (QuerySetBasedXMLRPCSerializer, Serializer,
@@ -51,7 +52,7 @@ def test_datetime_to_str(self):
         self.assertEqual(value, None)
 
         from datetime import datetime
-        now = datetime.now()
+        now = timezone.now()
         value = datetime_to_str(now)
         expected_value = datetime.strftime(now, '%Y-%m-%d %H:%M:%S')
         self.assertEqual(expected_value, value)

tcms/rpc/tests/test_testexecution.py

@@ -1,11 +1,11 @@
 # -*- coding: utf-8 -*-
 # pylint: disable=invalid-name, attribute-defined-outside-init, objects-update-used
 
-from datetime import datetime
 from xmlrpc.client import Fault as XmlRPCFault
 from xmlrpc.client import ProtocolError
 
 from django.test import override_settings
+from django.utils import timezone
 
 from tcms.core.contrib.linkreference.models import LinkReference
 from tcms.core.helpers.comments import get_comments
@@ -310,4 +310,4 @@ def test_update_with_no_perm(self):
         self.rpc_client.exec.Auth.logout()
         with self.assertRaisesRegex(ProtocolError, '403 Forbidden'):
             self.rpc_client.exec.TestExecution.update(self.case_run_1.pk,
-                                                      {"close_date": datetime.now()})
+                                                      {"close_date": timezone.now()})

tcms/testplans/views.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 
-import datetime
-
 from django.contrib import messages
 from django.contrib.auth.decorators import permission_required
 from django.core.exceptions import ObjectDoesNotExist
@@ -10,6 +8,7 @@
                          HttpResponseRedirect, JsonResponse)
 from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.decorators import method_decorator
 from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.http import (require_GET, require_http_methods,
@@ -69,7 +68,7 @@ def post(self, request):
                 product_version=form.cleaned_data['product_version'],
                 type=form.cleaned_data['type'],
                 name=form.cleaned_data['name'],
-                create_date=datetime.datetime.now(),
+                create_date=timezone.now(),
                 extra_link=form.cleaned_data['extra_link'],
                 parent=form.cleaned_data['parent'],
                 text=form.cleaned_data['text'],

tcms/testruns/models.py

@@ -1,12 +1,12 @@
 # -*- coding: utf-8 -*-
-import datetime
 from collections import namedtuple
 
 import vinaigrette
 from django.conf import settings
 from django.db import models
 from django.db.models import Count
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.translation import override
 
 from tcms.core.contrib.linkreference.models import LinkReference
@@ -174,7 +174,7 @@ def _get_total_case_run_num(self):
 
     def update_completion_status(self, is_finished):
         if is_finished:
-            self.stop_date = datetime.datetime.now()
+            self.stop_date = timezone.now()
         else:
             self.stop_date = None
 

tcms/testruns/tests/test_update_caserun_status_view.py

@@ -1,10 +1,9 @@
 # -*- coding: utf-8 -*-
 # pylint: disable=too-many-ancestors
 
-from datetime import datetime
-
 from django.conf import settings
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.translation import override
 
 from tcms.testruns.models import TestExecutionStatus
@@ -20,7 +19,7 @@ def setUpTestData(cls):
         cls.url = reverse('testruns-update_caserun_status')
 
     def test_update_status_positive_scenario(self):
-        before_update = datetime.now()
+        before_update = timezone.now()
         status_passed = TestExecutionStatus.objects.get(name=TestExecutionStatus.PASSED)
         post_data = {
             'status_id': status_passed.pk,
@@ -38,7 +37,7 @@ def test_update_status_positive_scenario(self):
             self.assertEqual(caserun.status_id, status_passed.pk)
             self.assertEqual(caserun.tested_by, self.tester)
             self.assertGreater(caserun.close_date, before_update)
-            self.assertLess(caserun.close_date, datetime.now())
+            self.assertLess(caserun.close_date, timezone.now())
 
         # verify we didn't update the last TCR by mistake
         self.execution_3.refresh_from_db()

tcms/testruns/views.py

@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 
-from datetime import datetime
 from http import HTTPStatus
 
 from django.conf import settings
@@ -13,6 +12,7 @@
 from django.http import Http404, HttpResponseRedirect, JsonResponse
 from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
+from django.utils import timezone
 from django.utils.decorators import method_decorator
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic.base import TemplateView, View
@@ -628,7 +628,7 @@ def post(self, request):
             execution = get_object_or_404(TestExecution, pk=int(caserun_pk))
             execution.status_id = status_id
             execution.tested_by = request.user
-            execution.close_date = datetime.now()
+            execution.close_date = timezone.now()
             execution.save()
 
         return JsonResponse({'rc': 0, 'response': 'ok'})

tcms/tests/factories.py

@@ -1,11 +1,10 @@
 # -*- coding: utf-8 -*-
 # pylint: disable=too-few-public-methods, unused-argument
 
-from datetime import datetime
-
 import factory
 from django.conf import settings
 from django.db.models import signals
+from django.utils import timezone
 from factory.django import DjangoModelFactory
 
 from tcms.management.models import Priority
@@ -122,7 +121,7 @@ class Meta:
 
     name = factory.Sequence(lambda n: 'Plan name %d' % n)
     text = factory.Sequence(lambda n: 'Plan document %d' % n)
-    create_date = factory.LazyFunction(datetime.now)
+    create_date = factory.LazyFunction(timezone.now)
     product_version = factory.SubFactory(VersionFactory)
     author = factory.SubFactory(UserFactory)
     product = factory.SubFactory(ProductFactory)