Revert "Schemas: Improved decimal handling when mapping ChoiceField. (#7264)"

This reverts commit 1872bde.

Author: carltongibson

rest_framework/schemas/openapi.py

@@ -330,29 +330,30 @@ def _get_pagination_parameters(self, path, method):
 
     def _map_choicefield(self, field):
         choices = list(OrderedDict.fromkeys(field.choices))  # preserve order and remove duplicates
-        mapping = {
-            # The value of `enum` keyword MUST be an array and SHOULD be unique.
-            # Ref: https://tools.ietf.org/html/draft-wright-json-schema-validation-00#section-5.20
-            'enum': choices
-        }
-
         if all(isinstance(choice, bool) for choice in choices):
-            mapping['type'] = 'boolean'
+            type = 'boolean'
         elif all(isinstance(choice, int) for choice in choices):
-            mapping['type'] = 'integer'
-        elif all(isinstance(choice, Decimal) for choice in choices):
-            mapping['format'] = 'decimal'
-            if api_settings.COERCE_DECIMAL_TO_STRING:
-                mapping['enum'] = [str(choice) for choice in mapping['enum']]
-                mapping['type'] = 'string'
-            else:
-                mapping['type'] = 'number'
+            type = 'integer'
         elif all(isinstance(choice, (int, float, Decimal)) for choice in choices):  # `number` includes `integer`
             # Ref: https://tools.ietf.org/html/draft-wright-json-schema-validation-00#section-5.21
-            mapping['type'] = 'number'
+            type = 'number'
         elif all(isinstance(choice, str) for choice in choices):
-            mapping['type'] = 'string'
+            type = 'string'
+        else:
+            type = None
+
+        mapping = {
+            # The value of `enum` keyword MUST be an array and SHOULD be unique.
+            # Ref: https://tools.ietf.org/html/draft-wright-json-schema-validation-00#section-5.20
+            'enum': choices
+        }
 
+        # If We figured out `type` then and only then we should set it. It must be a string.
+        # Ref: https://swagger.io/docs/specification/data-models/data-types/#mixed-type
+        # It is optional but it can not be null.
+        # Ref: https://tools.ietf.org/html/draft-wright-json-schema-validation-00#section-5.21
+        if type:
+            mapping['type'] = type
         return mapping
 
     def _map_field(self, field):

tests/schemas/test_openapi.py

@@ -1,6 +1,5 @@
 import uuid
 import warnings
-from decimal import Decimal
 
 import pytest
 from django.conf.urls import url
@@ -79,25 +78,13 @@ def test_list_field_mapping(self):
                 (1, 'One'), (2, 'Two'), (3, 'Three'), (2, 'Two'), (3, 'Three'), (1, 'One'),
             ])),
                 {'items': {'enum': [1, 2, 3], 'type': 'integer'}, 'type': 'array'}),
-            (serializers.ListField(child=
-                                   serializers.ChoiceField(choices=[(Decimal('1.111'), 'one'), (Decimal('2.222'), 'two')])),
-             {'items': {'enum': ['1.111', '2.222'], 'type': 'string', 'format': 'decimal'}, 'type': 'array'}),
             (serializers.IntegerField(min_value=2147483648),
              {'type': 'integer', 'minimum': 2147483648, 'format': 'int64'}),
         ]
         for field, mapping in cases:
             with self.subTest(field=field):
                 assert inspector._map_field(field) == mapping
 
-    @override_settings(REST_FRAMEWORK={'COERCE_DECIMAL_TO_STRING': False})
-    def test_decimal_schema_for_choice_field(self):
-        inspector = AutoSchema()
-        field = serializers.ListField(
-            child=serializers.ChoiceField(choices=[(Decimal('1.111'), 'one'), (Decimal('2.222'), 'two')]))
-        mapping = {'items': {'enum': [Decimal('1.111'), Decimal('2.222')], 'type': 'number'}, 'type': 'array'}
-        assert inspector._map_field(field) == mapping
-
-
     def test_lazy_string_field(self):
         class ItemSerializer(serializers.Serializer):
             text = serializers.CharField(help_text=_('lazy string'))