Add testcase to show incorrect schema generation (#6007)

tests/test_schema_with_single_common_prefix.py

@@ -0,0 +1,105 @@
+import unittest
+
+from django.conf.urls import include, url
+
+from django.test import TestCase, override_settings
+
+from rest_framework import serializers
+from rest_framework.compat import coreapi
+from rest_framework.decorators import action
+from rest_framework.routers import SimpleRouter
+from rest_framework.schemas import get_schema_view
+from rest_framework.response import Response
+from rest_framework.test import APIClient, APIRequestFactory
+from rest_framework.viewsets import GenericViewSet
+
+factory = APIRequestFactory()
+
+
+class MockUser:
+    def is_authenticated(self):
+        return True
+
+
+class ExampleSerializer(serializers.Serializer):
+    a = serializers.CharField(required=True, help_text='A field description')
+    b = serializers.CharField(required=False)
+    read_only = serializers.CharField(read_only=True)
+    hidden = serializers.HiddenField(default='hello')
+
+
+class ExampleViewSet(GenericViewSet):
+    serializer_class = ExampleSerializer
+
+    @action(['GET'], detail=False)
+    def test1(self):
+        return Response({})
+
+    @action(['GET'], detail=False)
+    def test2(self):
+        return Response({})
+
+
+if coreapi:
+    schema_view = get_schema_view(title='Example API')
+else:
+    def schema_view(request):
+        pass
+
+router = SimpleRouter()
+router.register('example', ExampleViewSet, basename='example')
+urlpatterns = [
+    url(r'^$', schema_view),
+    url(r'^example/', include(router.urls))
+]
+
+
+@unittest.skipUnless(coreapi, 'coreapi is not installed')
+@override_settings(ROOT_URLCONF='tests.test_schema_with_single_common_prefix')
+class AnotherTestRouterGeneratedSchema(TestCase):
+    def test_anonymous_request(self):
+        client = APIClient()
+        response = client.get('/', HTTP_ACCEPT='application/coreapi+json')
+        assert response.status_code == 200
+        expected = coreapi.Document(
+            url='http://testserver/',
+            title='Example API',
+            content={
+                'example': {
+                    'test1': coreapi.Link(
+                        url='/example/example/test1/',
+                        action='get'
+                    ),
+                    'test2': coreapi.Link(
+                        url='/example/example/test2/',
+                        action='get'
+                    )
+                }
+            }
+        )
+        print(response.data)
+        assert response.data == expected
+
+    def test_authenticated_request(self):
+        client = APIClient()
+        client.force_authenticate(MockUser())
+        response = client.get('/', HTTP_ACCEPT='application/coreapi+json')
+        assert response.status_code == 200
+
+        expected = coreapi.Document(
+            url='http://testserver/',
+            title='Example API',
+            content={
+                'example': {
+                    'test1': coreapi.Link(
+                        url='/example/example/test1/',
+                        action='get'
+                    ),
+                    'test2': coreapi.Link(
+                        url='/example/example/test2/',
+                        action='get'
+                    )
+                }
+            }
+        )
+        assert response.data == expected