Avoid calling get_serializer during error handling

Author: amw

example/tests/__snapshots__/test_errors.ambr

@@ -61,6 +61,17 @@
     ],
   }
 ---
+# name: test_404_during_serializer_context
+  <class 'dict'> {
+    'errors': <class 'list'> [
+      <class 'dict'> {
+        'code': 'not_found',
+        'detail': 'Not found.',
+        'status': '404',
+      },
+    ],
+  }
+---
 # name: test_second_level_array_error
   <class 'dict'> {
     'errors': <class 'list'> [

example/tests/test_errors.py

@@ -1,4 +1,5 @@
 import pytest
+from django.http import Http404
 from django.test import override_settings
 from django.urls import path, reverse
 from rest_framework import generics
@@ -48,7 +49,10 @@ class DummyTestView(generics.CreateAPIView):
     resource_name = "entries"
 
     def get_serializer_context(self):
-        return {}
+        if self.request.GET.get("fail"):
+            raise Http404
+        else:
+            return {}
 
 
 urlpatterns = [
@@ -211,3 +215,20 @@ def test_relationship_errors_has_correct_pointers(client, some_blog, snapshot):
     }
 
     assert snapshot == perform_error_test(client, data)
+
+
+def test_404_during_serializer_context(client, some_blog, snapshot):
+    data = {
+        "data": {
+            "type": "entries",
+            "attributes": {
+                "blog": some_blog.pk,
+                "bodyText": "body_text",
+            },
+        }
+    }
+    with override_settings(ROOT_URLCONF=__name__):
+        url = reverse("entries-nested-list")
+        response = client.post(f"{url}?fail=1", data=data)
+
+    assert snapshot == response.json()

rest_framework_json_api/utils.py

@@ -377,8 +377,12 @@ def format_drf_errors(response, context, exc):
 
         has_serializer = isinstance(context["view"], generics.GenericAPIView)
         if has_serializer:
-            serializer = context["view"].get_serializer()
-            fields = get_serializer_fields(serializer) or dict()
+            try:
+                serializer_class = context["view"].get_serializer_class()
+                serializer = serializer_class()
+                fields = get_serializer_fields(serializer) or dict()
+            except Exception:
+                fields = []
             relationship_fields = [
                 name for name, field in fields.items() if is_relationship_field(field)
             ]