Added tests for the date_hierarchy template tag.

tests/admin_views/test_templatetags.py

@@ -1,10 +1,15 @@
+import datetime
+
+from django.contrib.admin import ModelAdmin
+from django.contrib.admin.templatetags.admin_list import date_hierarchy
 from django.contrib.admin.templatetags.admin_modify import submit_row
 from django.contrib.auth.admin import UserAdmin
 from django.contrib.auth.models import User
-from django.test import RequestFactory
+from django.test import RequestFactory, TestCase
 from django.urls import reverse
 
 from .admin import site
+from .models import Question
 from .tests import AdminViewBasicTestCase
 
 
@@ -22,3 +27,41 @@ class AdminTemplateTagsTest(AdminViewBasicTestCase):
         template_context = submit_row(response.context_data)
         self.assertIs(template_context['extra'], True)
         self.assertIs(template_context['show_save'], True)
+
+
+class DateHierarchyTests(TestCase):
+    factory = RequestFactory()
+
+    def test_choice_links(self):
+        modeladmin = ModelAdmin(Question, site)
+        modeladmin.date_hierarchy = 'posted'
+
+        posted_dates = (
+            datetime.date(2017, 10, 1),
+            datetime.date(2017, 10, 1),
+            datetime.date(2017, 12, 15),
+            datetime.date(2017, 12, 15),
+            datetime.date(2017, 12, 31),
+            datetime.date(2018, 2, 1),
+        )
+        Question.objects.bulk_create(Question(question='q', posted=posted) for posted in posted_dates)
+
+        tests = (
+            ({}, [['year=2017'], ['year=2018']]),
+            ({'year': 2016}, []),
+            ({'year': 2017}, [['month=10', 'year=2017'], ['month=12', 'year=2017']]),
+            ({'year': 2017, 'month': 9}, []),
+            ({'year': 2017, 'month': 12}, [['day=15', 'month=12', 'year=2017'], ['day=31', 'month=12', 'year=2017']]),
+        )
+        for query, expected_choices in tests:
+            with self.subTest(query=query):
+                query = {'posted__%s' % q: val for q, val in query.items()}
+                request = self.factory.get('/', query)
+                changelist = modeladmin.get_changelist_instance(request)
+                spec = date_hierarchy(changelist)
+                choices = [choice['link'] for choice in spec['choices']]
+                expected_choices = [
+                    '&'.join('posted__%s' % c for c in choice) for choice in expected_choices
+                ]
+                expected_choices = [('?' + choice) if choice else '' for choice in expected_choices]
+                self.assertEqual(choices, expected_choices)