Ensured that patching a To-Many relationship correctly raises request error (django-json-api#1251)

Author: sliverc

CHANGELOG.md

@@ -13,6 +13,8 @@ any parts of the framework not mentioned in the documentation should generally b
 ### Fixed
 
 * Handled zero as a valid ID for resource (regression since 6.1.0)
+* Ensured that patching a To-Many relationship with the `RelationshipView` correctly raises request error when passing in `None`.
+  For emptying a To-Many relationship an empty array should be used as per [JSON:API spec](https://jsonapi.org/format/#crud-updating-to-many-relationships)
 
 ### Added
 

example/tests/test_views.py

@@ -2,6 +2,7 @@
 
 from django.test import RequestFactory, override_settings
 from django.utils import timezone
+from rest_framework import status
 from rest_framework.exceptions import NotFound
 from rest_framework.request import Request
 from rest_framework.reverse import reverse
@@ -174,16 +175,30 @@ def test_patch_one_to_many_relationship(self):
         response = self.client.get(url)
         assert response.data == request_data["data"]
 
-    def test_patch_one_to_many_relaitonship_with_none(self):
+    def test_patch_one_to_many_relaitonship_with_empty(self):
         url = f"/blogs/{self.first_entry.id}/relationships/entry_set"
-        request_data = {"data": None}
+
+        request_data = {"data": []}
         response = self.client.patch(url, data=request_data)
-        assert response.status_code == 200, response.content.decode()
+        assert response.status_code == status.HTTP_200_OK
         assert response.data == []
 
         response = self.client.get(url)
         assert response.data == []
 
+    def test_patch_one_to_many_relaitonship_with_none(self):
+        """
+        None for a to many relationship is invalid and should return a request error.
+
+        see https://jsonapi.org/format/#crud-updating-to-many-relationships
+        """
+
+        url = f"/blogs/{self.first_entry.id}/relationships/entry_set"
+
+        request_data = {"data": None}
+        response = self.client.patch(url, data=request_data)
+        assert response.status_code == status.HTTP_400_BAD_REQUEST
+
     def test_patch_many_to_many_relationship(self):
         url = f"/entries/{self.first_entry.id}/relationships/authors"
         request_data = {

rest_framework_json_api/parsers.py

@@ -98,7 +98,7 @@ def parse_data(self, result, parser_context):
                             "Received data contains one or more malformed JSON:API "
                             "Resource Identifier Object(s)"
                         )
-            elif not (data.get("id") and data.get("type")):
+            elif isinstance(data, dict) and not (data.get("id") and data.get("type")):
                 raise ParseError(
                     "Received data is not a valid JSON:API Resource Identifier Object"
                 )