Use create_engine_url to add prefix to previous/next links (#553)

* Use create_engine_url to add prefix to previous/next links

* Remove override of get_paginated_response since it is unchanged from parent

* More concise override

* Make both overrides behave the same

* add test for public API alert groups pagination

Co-authored-by: Vadim Stepanov <vadimkerr@gmail.com>

engine/apps/public_api/tests/test_incidents.py

@@ -1,4 +1,5 @@
 from unittest import mock
+from unittest.mock import patch
 
 import pytest
 from django.urls import reverse
@@ -186,6 +187,24 @@ def test_delete_incident_invalid_request(incident_public_api_setup):
     assert response.status_code == status.HTTP_400_BAD_REQUEST
 
 
+@pytest.mark.django_db
+def test_pagination(settings, incident_public_api_setup):
+    settings.BASE_URL = "https://test.com/test/prefixed/urls"
+
+    token, incidents, _, _ = incident_public_api_setup
+    client = APIClient()
+
+    url = reverse("api-public:alert_groups-list")
+
+    with patch("common.api_helpers.paginators.PathPrefixedPagination.get_page_size", return_value=1):
+        response = client.get(url, HTTP_AUTHORIZATION=f"{token}")
+
+    assert response.status_code == status.HTTP_200_OK
+    result = response.json()
+
+    assert result["next"].startswith("https://test.com/test/prefixed/urls")
+
+
 # This is test from old django-based tests
 # TODO: uncomment with date checking in delete mode
 # def test_delete_incident_invalid_date(self):

engine/common/api_helpers/paginators.py

@@ -1,19 +1,33 @@
 from rest_framework.pagination import CursorPagination, PageNumberPagination
 
+from common.api_helpers.utils import create_engine_url
 
-class HundredPageSizePaginator(PageNumberPagination):
+
+class PathPrefixedPagination(PageNumberPagination):
+    def paginate_queryset(self, queryset, request, view=None):
+        request.build_absolute_uri = lambda: create_engine_url(request.get_full_path())
+        return super().paginate_queryset(queryset, request, view)
+
+
+class PathPrefixedCursorPagination(CursorPagination):
+    def paginate_queryset(self, queryset, request, view=None):
+        request.build_absolute_uri = lambda: create_engine_url(request.get_full_path())
+        return super().paginate_queryset(queryset, request, view)
+
+
+class HundredPageSizePaginator(PathPrefixedPagination):
     page_size = 100
 
 
-class FiftyPageSizePaginator(PageNumberPagination):
+class FiftyPageSizePaginator(PathPrefixedPagination):
     page_size = 50
 
 
-class TwentyFivePageSizePaginator(PageNumberPagination):
+class TwentyFivePageSizePaginator(PathPrefixedPagination):
     page_size = 25
 
 
-class TwentyFiveCursorPaginator(CursorPagination):
+class TwentyFiveCursorPaginator(PathPrefixedCursorPagination):
     page_size = 25
     max_page_size = 100
     page_size_query_param = "perpage"