Clean-up and test relational fields

Author: oxan

rest_framework_dataclasses/field_utils.py

@@ -72,14 +72,19 @@ def get_type_info(tp: type, default_value_type: typing.Optional[type] = None) ->
     return TypeInfo(is_many, is_mapping, is_final, is_optional, tp)
 
 
-def get_relation_info(definition: DataclassDefinition, type_info: TypeInfo) -> RelationInfo:
-    # TODO needs checks first
+def get_relation_info(type_info: TypeInfo) -> RelationInfo:
+    """
+    Given a type_info that references a Model, extract the RelationInfo.
+    """
     return RelationInfo(
+        # there's no foreign key field
         model_field=None,
         related_model=type_info.base_type,
         to_many=type_info.is_many,
+        # as there's no foreign key, it also cannot reference a field on the referenced model
         to_field=None,
         has_through_model=False,
+        # we're never the model
         reverse=False
     )
 

rest_framework_dataclasses/serializers.py

@@ -404,7 +404,7 @@ def build_relational_field(self, field_name: str, type_info: TypeInfo) -> Serial
         """
         Create fields for models.
         """
-        relation_info = field_utils.get_relation_info(self.dataclass_definition, type_info)
+        relation_info = field_utils.get_relation_info(type_info)
         field_class = self.serializer_related_field
         field_kwargs = get_relation_kwargs(field_name, relation_info)
 

tests/test_fields.py

@@ -8,7 +8,9 @@
 import uuid
 from collections import abc
 
-from rest_framework import fields
+import django
+from django.db import models
+from rest_framework import fields, relations
 
 from rest_framework_dataclasses import field_utils
 from rest_framework_dataclasses.serializers import DataclassSerializer
@@ -101,8 +103,18 @@ def test_nested(self):
                          {'dataclass': refclass, 'many': False, 'required': False, 'allow_null': True})
 
     def test_relational(self):
-        # TODO
-        pass
+        django.setup()
+
+        class Person(models.Model):
+            name = models.CharField(max_length=30)
+
+            class Meta:
+                app_label = 'tests'
+
+        self.check_field(Person, relations.PrimaryKeyRelatedField,
+                         {'queryset': Person._default_manager})
+        self.check_field(typing.Optional[Person], relations.PrimaryKeyRelatedField,
+                         {'queryset': Person._default_manager, 'required': False, 'allow_null': True})
 
     def test_literal(self):
         self.check_field(Literal['a', 'b'], fields.ChoiceField,