bugfix read-only many2many relation processing #79

tfranzel · Jun 7, 2020 · e7c8108 · e7c8108
1 parent 6ea5223
commit e7c8108
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Showing 2 changed files with 34 additions and 2 deletions.
diff --git a/drf_spectacular/openapi.py b/drf_spectacular/openapi.py
@@ -397,18 +397,24 @@ def _map_serializer_field(self, field, direction):
             schema = self._map_serializer_field(field.child_relation, direction)
             # remove hand-over initkwargs applying only to outer scope
             schema.pop('description', None)
+            schema.pop('readOnly', None)
             return append_meta(build_array_type(schema), meta)
 
         if isinstance(field, serializers.PrimaryKeyRelatedField):
             # read_only fields do not have a Manager by design. go around and get field
             # from parent. also avoid calling Manager. __bool__ as it might be customized
             # to hit the database.
             if getattr(field, 'queryset', None) is not None:
-                schema = self._map_model_field(field.queryset.model._meta.pk, direction)
+                model_field = field.queryset.model._meta.pk
             else:
-                schema = self._map_model_field(field.parent.Meta.model._meta.pk, direction)
+                if isinstance(field.parent, serializers.ManyRelatedField):
+                    model_field = field.parent.parent.Meta.model._meta.pk
+                else:
+                    model_field = field.parent.Meta.model._meta.pk
+
             # primary keys are usually non-editable (readOnly=True) and map_model_field correctly
             # signals that attribute. however this does not apply in the context of relations.
+            schema = self._map_model_field(model_field, direction)
             schema.pop('readOnly', None)
             return append_meta(schema, meta)
 

diff --git a/tests/test_regressions.py b/tests/test_regressions.py
@@ -591,3 +591,29 @@ class XView(generics.ListCreateAPIView):
 
     assert schema['components']['schemas']['X']['properties']['file']['format'] == 'uri'
     assert schema['components']['schemas']['XRequest']['properties']['file']['format'] == 'binary'
+
+
+def test_read_only_many_related_field(no_warnings):
+    class ManyRelatedTargetModel(models.Model):
+        field = models.IntegerField()
+
+    class ManyRelatedModel(models.Model):
+        field_m2m = models.ManyToManyField(ManyRelatedTargetModel)
+        field_m2m_ro = models.ManyToManyField(ManyRelatedTargetModel)
+
+    class XSerializer(serializers.ModelSerializer):
+        class Meta:
+            model = ManyRelatedModel
+            fields = '__all__'
+            read_only_fields = ['field_m2m_ro']
+
+    class XAPIView(APIView):
+        @extend_schema(responses=XSerializer)
+        def get(self, request):
+            pass  # pragma: no cover
+
+    schema = generate_schema('x', view=XAPIView)
+    assert schema['components']['schemas']['X']['properties']['field_m2m_ro']['readOnly'] is True
+    # readOnly only needed on outer object, not in items
+    assert 'readOnly' not in schema['components']['schemas']['X']['properties']['field_m2m_ro']['items']
+    assert 'readOnly' not in schema['components']['schemas']['X']['properties']['field_m2m']