fix: Avoid pagination failures when filtering connection by last with…

…out before/after (#585)

strawberry_django/pagination.py

@@ -1,3 +1,4 @@
+import sys
 from typing import TYPE_CHECKING, List, Optional, TypeVar, Union
 
 import strawberry
@@ -103,9 +104,13 @@ def apply_window_pagination(
             partition_by=related_field_id,
         ),
     )
+
     if offset:
         queryset = queryset.filter(_strawberry_row_number__gt=offset)
-    if limit >= 0:
+
+    # Limit == -1 means no limit. sys.maxsize is set by relay when paginating
+    # from the end to as a way to mimic a "not limit" as well
+    if limit >= 0 and limit != sys.maxsize:
         queryset = queryset.filter(_strawberry_row_number__lte=offset + limit)
 
     return queryset

tests/test_pagination.py

@@ -1,3 +1,4 @@
+import sys
 from typing import List, cast
 
 import pytest
@@ -6,7 +7,11 @@
 from strawberry.types import ExecutionResult
 
 import strawberry_django
-from strawberry_django.pagination import OffsetPaginationInput, apply
+from strawberry_django.pagination import (
+    OffsetPaginationInput,
+    apply,
+    apply_window_pagination,
+)
 from tests import models, utils
 from tests.projects.faker import MilestoneFactory, ProjectFactory
 
@@ -96,3 +101,47 @@ def fruits(self, pagination: OffsetPaginationInput) -> List[Fruit]:
     assert result.data["fruits"] == [
         {"id": "1", "name": "strawberry"},
     ]
+
+
+@pytest.mark.django_db(transaction=True)
+def test_apply_window_pagination():
+    color = models.Color.objects.create(name="Red")
+
+    for i in range(10):
+        models.Fruit.objects.create(name=f"fruit{i}", color=color)
+
+    queryset = apply_window_pagination(
+        models.Fruit.objects.all(),
+        related_field_id="color_id",
+        offset=1,
+        limit=1,
+    )
+
+    assert queryset.count() == 1
+    fruit = queryset.get()
+    assert fruit.name == "fruit1"
+    assert fruit._strawberry_row_number == 2  # type: ignore
+    assert fruit._strawberry_total_count == 10  # type: ignore
+
+
+@pytest.mark.parametrize("limit", [-1, sys.maxsize])
+@pytest.mark.django_db(transaction=True)
+def test_apply_window_pagination_with_no_limites(limit):
+    color = models.Color.objects.create(name="Red")
+
+    for i in range(10):
+        models.Fruit.objects.create(name=f"fruit{i}", color=color)
+
+    queryset = apply_window_pagination(
+        models.Fruit.objects.all(),
+        related_field_id="color_id",
+        offset=2,
+        limit=limit,
+    )
+
+    assert queryset.count() == 8
+    first_fruit = queryset.first()
+    assert first_fruit is not None
+    assert first_fruit.name == "fruit2"
+    assert first_fruit._strawberry_row_number == 3  # type: ignore
+    assert first_fruit._strawberry_total_count == 10  # type: ignore

tests/test_queries.py

@@ -1,6 +1,7 @@
 import io
 import textwrap
 from typing import List, Optional, cast
+from unittest import mock
 
 import pytest
 import strawberry
@@ -312,4 +313,4 @@ def fruit(self) -> Fruit:
         }
       }
     """)
-    assert result.data == {"fruit": {"colorId": 1, "name": "Banana"}}
+    assert result.data == {"fruit": {"colorId": mock.ANY, "name": "Banana"}}