Fix missing description for ManyRelatedField and tested for SlugField (…

…#895)

* Fix missing description for ManyRelatedField and tested for SlugField

* Don't use braces for lists

* differentiate outer/inner help_text & more compact impl

* adapt test

Co-authored-by: ruben <ruben.simons@web.de>
Co-authored-by: T. Franzel <tfranzel@users.noreply.github.com>

drf_spectacular/openapi.py

@@ -655,8 +655,9 @@ def _map_serializer_field(self, field, direction, bypass_extensions=False):
         if isinstance(field, serializers.ManyRelatedField):
             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)
+            if meta.get('description') == schema.get('description'):
+                schema.pop('description', None)
             return append_meta(build_array_type(schema), meta)
 
         if isinstance(field, (serializers.PrimaryKeyRelatedField, serializers.SlugRelatedField)):

tests/test_fields.py

@@ -35,7 +35,7 @@
 class Aux(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     field_foreign = models.ForeignKey('Aux', null=True, on_delete=models.CASCADE)
-    url = models.URLField(unique=True)
+    url = models.URLField(unique=True, help_text="URL identifier for Aux")
 
 
 class AuxSerializer(serializers.ModelSerializer):

tests/test_fields.yml

@@ -127,12 +127,14 @@ components:
         field_related_slug:
           type: string
           format: uri
+          description: URL identifier for Aux
           readOnly: true
         field_related_slug_many:
           type: array
           items:
             type: string
             format: uri
+            description: URL identifier for Aux
           readOnly: true
         field_related_string:
           type: string
@@ -368,6 +370,7 @@ components:
         url:
           type: string
           format: uri
+          description: URL identifier for Aux
           maxLength: 200
         field_foreign:
           type: string