Added an explicit test that URL checks are recursive.

tests/check_framework/test_urls.py

@@ -10,6 +10,14 @@ class CheckUrlsTest(SimpleTestCase):
         result = check_url_config(None)
         self.assertEqual(result, [])
 
+    @override_settings(ROOT_URLCONF='check_framework.urls.warning_in_include')
+    def test_check_resolver_recursive(self):
+        # The resolver is checked recursively (examining url()s in include()).
+        result = check_url_config(None)
+        self.assertEqual(len(result), 1)
+        warning = result[0]
+        self.assertEqual(warning.id, 'urls.W001')
+
     @override_settings(ROOT_URLCONF='check_framework.urls.include_with_dollar')
     def test_include_with_dollar(self):
         result = check_url_config(None)

tests/check_framework/urls/beginning_with_slash.py

-from django.conf.urls import include, url
+from django.conf.urls import url
 
 urlpatterns = [
-    url('^', include([
-        url(r'/starting-with-slash/$', lambda x: x),
-    ])),
+    url(r'/starting-with-slash/$', lambda x: x),
 ]

tests/check_framework/urls/include_with_dollar.py

 from django.conf.urls import include, url
 
 urlpatterns = [
-    url(r'^', include([
-        url(r'^include-with-dollar$', include([])),
-    ])),
+    url(r'^include-with-dollar$', include([])),
 ]

tests/check_framework/urls/name_with_colon.py

-from django.conf.urls import include, url
+from django.conf.urls import url
 
 urlpatterns = [
-    url('^', include([
-        url(r'^$', lambda x: x, name='name_with:colon'),
-    ])),
+    url(r'^$', lambda x: x, name='name_with:colon'),
 ]

tests/check_framework/urls/warning_in_include.py

+from django.conf.urls import include, url
+
+urlpatterns = [
+    url(r'^', include([
+        url(r'^include-with-dollar$', include([])),
+    ])),
+]