Extract out common filter class for parent object filtering

api/conf/settings_test.py

@@ -8,3 +8,7 @@
 SUPPRESS_TEST_OUTPUT = True
 
 AWS_ENDPOINT_URL = None
+
+INSTALLED_APPS += [
+    "api.core.tests.apps.CoreTestsConfig",
+]

api/core/filters.py

@@ -0,0 +1,17 @@
+from rest_framework import filters
+
+from django.core.exceptions import ImproperlyConfigured
+
+
+class ParentFilter(filters.BaseFilterBackend):
+    def filter_queryset(self, request, queryset, view):
+        parent_id_lookup_field = getattr(view, "parent_id_lookup_field", None)
+        if not parent_id_lookup_field:
+            raise ImproperlyConfigured(
+                f"Cannot use {self.__class__.__name__} on a view which does not have a parent_id_lookup_field attribute"
+            )
+
+        lookup = {
+            parent_id_lookup_field: view.kwargs["pk"],
+        }
+        return queryset.filter(**lookup)

api/core/tests/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class CoreTestsConfig(AppConfig):
+    name = "api.core.tests"

api/core/tests/migrations/0001_initial.py

@@ -0,0 +1,29 @@
+# Generated by Django 4.2.9 on 2024-02-09 14:01
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = []
+
+    operations = [
+        migrations.CreateModel(
+            name="ParentModel",
+            fields=[
+                ("id", models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("name", models.CharField(max_length=255)),
+            ],
+        ),
+        migrations.CreateModel(
+            name="ChildModel",
+            fields=[
+                ("id", models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("name", models.CharField(max_length=255)),
+                ("parent", models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to="tests.parentmodel")),
+            ],
+        ),
+    ]

api/core/tests/models.py

@@ -0,0 +1,10 @@
+from django.db import models
+
+
+class ParentModel(models.Model):
+    name = models.CharField(max_length=255)
+
+
+class ChildModel(models.Model):
+    name = models.CharField(max_length=255)
+    parent = models.ForeignKey(ParentModel, on_delete=models.CASCADE)

api/core/tests/serializers.py

@@ -0,0 +1,9 @@
+from rest_framework import serializers
+
+from api.core.tests.models import ChildModel
+
+
+class ChildModelSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ChildModel
+        fields = ["id", "name"]

api/core/tests/test_filters.py

@@ -0,0 +1,62 @@
+import uuid
+
+from django.core.exceptions import ImproperlyConfigured
+from django.test import (
+    override_settings,
+    SimpleTestCase,
+    TestCase,
+)
+from django.urls import reverse
+
+from api.core.tests.models import (
+    ChildModel,
+    ParentModel,
+)
+
+
+@override_settings(
+    ROOT_URLCONF="api.core.tests.urls",
+)
+class TestMisconfiguredParentFilter(SimpleTestCase):
+    def test_misconfigured_parent_filter(self):
+        url = reverse(
+            "test-misconfigured-parent-filter",
+            kwargs={
+                "pk": str(uuid.uuid4()),
+                "child_pk": str(uuid.uuid4()),
+            },
+        )
+        with self.assertRaises(ImproperlyConfigured):
+            self.client.get(url)
+
+
+@override_settings(
+    ROOT_URLCONF="api.core.tests.urls",
+)
+class TestParentFilter(TestCase):
+    def test_parent_filter(self):
+        parent = ParentModel.objects.create(name="parent")
+        child = ChildModel.objects.create(parent=parent, name="child")
+        url = reverse(
+            "test-parent-filter",
+            kwargs={
+                "pk": str(parent.pk),
+                "child_pk": str(child.pk),
+            },
+        )
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+
+    def test_parent_other_parent_filter(self):
+        parent = ParentModel.objects.create(name="parent")
+        child = ChildModel.objects.create(parent=parent, name="child")
+        other_parent = ParentModel.objects.create(name="other_parent")
+        url = reverse(
+            "test-parent-filter",
+            kwargs={
+                "pk": str(other_parent.pk),
+                "child_pk": str(child.pk),
+            },
+        )
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 404)

api/core/tests/urls.py

@@ -0,0 +1,19 @@
+from django.urls import path
+
+from .views import (
+    MisconfiguredParentFilterView,
+    ParentFilterView,
+)
+
+urlpatterns = [
+    path(
+        "misconfigured-parent/<str:pk>/child/<str:child_pk>/",
+        MisconfiguredParentFilterView.as_view(),
+        name="test-misconfigured-parent-filter",
+    ),
+    path(
+        "parent/<str:pk>/child/<str:child_pk>/",
+        ParentFilterView.as_view(),
+        name="test-parent-filter",
+    ),
+]

api/core/tests/views.py

@@ -0,0 +1,17 @@
+from rest_framework.generics import RetrieveAPIView
+
+from api.core.filters import ParentFilter
+from api.core.tests.models import ChildModel
+from api.core.tests.serializers import ChildModelSerializer
+
+
+class MisconfiguredParentFilterView(RetrieveAPIView):
+    filter_backends = (ParentFilter,)
+    queryset = ChildModel.objects.all()
+
+
+class ParentFilterView(RetrieveAPIView):
+    filter_backends = (ParentFilter,)
+    parent_id_lookup_field = "parent_id"
+    queryset = ChildModel.objects.all()
+    serializer_class = ChildModelSerializer

api/goods/views.py

@@ -18,11 +18,11 @@
 from api.core.authentication import ExporterAuthentication, SharedAuthentication, GovAuthentication
 from api.core.exceptions import BadRequestError
 from api.core.helpers import str_to_bool
+from api.core.filters import ParentFilter
 from api.core.views import DocumentStreamAPIView
 from api.documents.libraries.delete_documents_on_bad_request import delete_documents_on_bad_request
 from api.documents.models import Document
 from api.goods.enums import GoodStatus, GoodPvGraded, ItemCategory
-from api.goods.filters import GoodFilter
 from api.goods.goods_paginator import GoodListPaginator
 from api.goods.helpers import (
     FIREARMS_CORE_TYPES,
@@ -547,7 +547,8 @@ def delete(self, request, pk, doc_pk):
 
 class GoodDocumentStream(DocumentStreamAPIView):
     authentication_classes = (ExporterAuthentication,)
-    filter_backends = (GoodFilter,)
+    filter_backends = (ParentFilter,)
+    parent_id_lookup_field = "good_id"
     lookup_url_kwarg = "doc_pk"
     queryset = GoodDocument.objects.all()
     permission_classes = (

api/organisations/views/documents.py

@@ -5,9 +5,9 @@
 from api.audit_trail import service as audit_trail_service
 from api.audit_trail.enums import AuditType
 from api.core.authentication import SharedAuthentication
+from api.core.filters import ParentFilter
 from api.core.views import DocumentStreamAPIView
 from api.organisations import (
-    filters,
     models,
     permissions,
     serializers,
@@ -16,8 +16,9 @@
 
 class DocumentOnOrganisationView(viewsets.ModelViewSet):
     authentication_classes = (SharedAuthentication,)
-    filter_backends = (filters.OrganisationFilter,)
+    filter_backends = (ParentFilter,)
     lookup_url_kwarg = "document_on_application_pk"
+    parent_id_lookup_field = "organisation_id"
     permission_classes = (permissions.IsCaseworkerOrInDocumentOrganisation,)
     queryset = models.DocumentOnOrganisation.objects.all()
     serializer_class = serializers.DocumentOnOrganisationSerializer
@@ -86,8 +87,9 @@ def update(self, request, pk, document_on_application_pk):
 
 class DocumentOnOrganisationStreamView(DocumentStreamAPIView):
     authentication_classes = (SharedAuthentication,)
-    filter_backends = (filters.OrganisationFilter,)
+    filter_backends = (ParentFilter,)
     lookup_url_kwarg = "document_on_application_pk"
+    parent_id_lookup_field = "organisation_id"
     permission_classes = (permissions.IsCaseworkerOrInDocumentOrganisation,)
     queryset = models.DocumentOnOrganisation.objects.all()