fix: Deserialization of optional nullable properties when no value is returned from the API [openapi-generators#420 & openapi-generators#381]. Thanks @forest-benchling!

* Handle optional nullable deserialization

* Fix test

Author: forest-benchling

end_to_end_tests/golden-record/my_test_api_client/models/a_model.py

@@ -186,7 +186,6 @@ def from_dict(cls: Type[T], src_dict: Dict[str, Any]) -> T:
 
         def _parse_a_camel_date_time(data: object) -> Union[datetime.date, datetime.datetime]:
             try:
-                a_camel_date_time_type_0: datetime.datetime
                 if not isinstance(data, str):
                     raise TypeError()
                 a_camel_date_time_type_0 = isoparse(data)
@@ -196,7 +195,6 @@ def _parse_a_camel_date_time(data: object) -> Union[datetime.date, datetime.date
                 pass
             if not isinstance(data, str):
                 raise TypeError()
-            a_camel_date_time_type_1: datetime.date
             a_camel_date_time_type_1 = isoparse(data).date()
 
             return a_camel_date_time_type_1
@@ -209,7 +207,6 @@ def _parse_a_camel_date_time(data: object) -> Union[datetime.date, datetime.date
 
         def _parse_one_of_models(data: object) -> Union[FreeFormModel, ModelWithUnionProperty]:
             try:
-                one_of_models_type_0: FreeFormModel
                 if not isinstance(data, dict):
                     raise TypeError()
                 one_of_models_type_0 = FreeFormModel.from_dict(data)
@@ -219,7 +216,6 @@ def _parse_one_of_models(data: object) -> Union[FreeFormModel, ModelWithUnionPro
                 pass
             if not isinstance(data, dict):
                 raise TypeError()
-            one_of_models_type_1: ModelWithUnionProperty
             one_of_models_type_1 = ModelWithUnionProperty.from_dict(data)
 
             return one_of_models_type_1
@@ -228,9 +224,11 @@ def _parse_one_of_models(data: object) -> Union[FreeFormModel, ModelWithUnionPro
 
         model = ModelWithUnionProperty.from_dict(d.pop("model"))
 
-        an_optional_allof_enum: Union[Unset, AnAllOfEnum] = UNSET
         _an_optional_allof_enum = d.pop("an_optional_allof_enum", UNSET)
-        if not isinstance(_an_optional_allof_enum, Unset):
+        an_optional_allof_enum: Union[Unset, AnAllOfEnum]
+        if isinstance(_an_optional_allof_enum, Unset):
+            an_optional_allof_enum = UNSET
+        else:
             an_optional_allof_enum = AnAllOfEnum(_an_optional_allof_enum)
 
         nested_list_of_enums = []
@@ -245,14 +243,18 @@ def _parse_one_of_models(data: object) -> Union[FreeFormModel, ModelWithUnionPro
 
             nested_list_of_enums.append(nested_list_of_enums_item)
 
-        a_nullable_date = None
         _a_nullable_date = d.pop("a_nullable_date")
-        if _a_nullable_date is not None:
+        a_nullable_date: Optional[datetime.date]
+        if _a_nullable_date is None:
+            a_nullable_date = None
+        else:
             a_nullable_date = isoparse(_a_nullable_date).date()
 
-        a_not_required_date: Union[Unset, datetime.date] = UNSET
         _a_not_required_date = d.pop("a_not_required_date", UNSET)
-        if not isinstance(_a_not_required_date, Unset):
+        a_not_required_date: Union[Unset, datetime.date]
+        if isinstance(_a_not_required_date, Unset):
+            a_not_required_date = UNSET
+        else:
             a_not_required_date = isoparse(_a_not_required_date).date()
 
         attr_1_leading_digit = d.pop("1_leading_digit", UNSET)
@@ -267,7 +269,6 @@ def _parse_nullable_one_of_models(data: object) -> Union[FreeFormModel, ModelWit
             if data is None:
                 return data
             try:
-                nullable_one_of_models_type_0: FreeFormModel
                 if not isinstance(data, dict):
                     raise TypeError()
                 nullable_one_of_models_type_0 = FreeFormModel.from_dict(data)
@@ -277,7 +278,6 @@ def _parse_nullable_one_of_models(data: object) -> Union[FreeFormModel, ModelWit
                 pass
             if not isinstance(data, dict):
                 raise TypeError()
-            nullable_one_of_models_type_1: ModelWithUnionProperty
             nullable_one_of_models_type_1 = ModelWithUnionProperty.from_dict(data)
 
             return nullable_one_of_models_type_1
@@ -288,23 +288,25 @@ def _parse_not_required_one_of_models(data: object) -> Union[FreeFormModel, Mode
             if isinstance(data, Unset):
                 return data
             try:
-                not_required_one_of_models_type_0: Union[Unset, FreeFormModel]
                 if not isinstance(data, dict):
                     raise TypeError()
-                not_required_one_of_models_type_0 = UNSET
                 _not_required_one_of_models_type_0 = data
-                if not isinstance(_not_required_one_of_models_type_0, Unset):
+                not_required_one_of_models_type_0: Union[Unset, FreeFormModel]
+                if isinstance(_not_required_one_of_models_type_0, Unset):
+                    not_required_one_of_models_type_0 = UNSET
+                else:
                     not_required_one_of_models_type_0 = FreeFormModel.from_dict(_not_required_one_of_models_type_0)
 
                 return not_required_one_of_models_type_0
             except:  # noqa: E722
                 pass
             if not isinstance(data, dict):
                 raise TypeError()
-            not_required_one_of_models_type_1: Union[Unset, ModelWithUnionProperty]
-            not_required_one_of_models_type_1 = UNSET
             _not_required_one_of_models_type_1 = data
-            if not isinstance(_not_required_one_of_models_type_1, Unset):
+            not_required_one_of_models_type_1: Union[Unset, ModelWithUnionProperty]
+            if isinstance(_not_required_one_of_models_type_1, Unset):
+                not_required_one_of_models_type_1 = UNSET
+            else:
                 not_required_one_of_models_type_1 = ModelWithUnionProperty.from_dict(_not_required_one_of_models_type_1)
 
             return not_required_one_of_models_type_1
@@ -319,12 +321,13 @@ def _parse_not_required_nullable_one_of_models(
             if isinstance(data, Unset):
                 return data
             try:
-                not_required_nullable_one_of_models_type_0: Union[Unset, FreeFormModel]
                 if not isinstance(data, dict):
                     raise TypeError()
-                not_required_nullable_one_of_models_type_0 = UNSET
                 _not_required_nullable_one_of_models_type_0 = data
-                if not isinstance(_not_required_nullable_one_of_models_type_0, Unset):
+                not_required_nullable_one_of_models_type_0: Union[Unset, FreeFormModel]
+                if isinstance(_not_required_nullable_one_of_models_type_0, Unset):
+                    not_required_nullable_one_of_models_type_0 = UNSET
+                else:
                     not_required_nullable_one_of_models_type_0 = FreeFormModel.from_dict(
                         _not_required_nullable_one_of_models_type_0
                     )
@@ -333,12 +336,13 @@ def _parse_not_required_nullable_one_of_models(
             except:  # noqa: E722
                 pass
             try:
-                not_required_nullable_one_of_models_type_1: Union[Unset, ModelWithUnionProperty]
                 if not isinstance(data, dict):
                     raise TypeError()
-                not_required_nullable_one_of_models_type_1 = UNSET
                 _not_required_nullable_one_of_models_type_1 = data
-                if not isinstance(_not_required_nullable_one_of_models_type_1, Unset):
+                not_required_nullable_one_of_models_type_1: Union[Unset, ModelWithUnionProperty]
+                if isinstance(_not_required_nullable_one_of_models_type_1, Unset):
+                    not_required_nullable_one_of_models_type_1 = UNSET
+                else:
                     not_required_nullable_one_of_models_type_1 = ModelWithUnionProperty.from_dict(
                         _not_required_nullable_one_of_models_type_1
                     )
@@ -352,19 +356,27 @@ def _parse_not_required_nullable_one_of_models(
             d.pop("not_required_nullable_one_of_models", UNSET)
         )
 
-        nullable_model = None
         _nullable_model = d.pop("nullable_model")
-        if _nullable_model is not None:
+        nullable_model: Optional[ModelWithUnionProperty]
+        if _nullable_model is None:
+            nullable_model = None
+        else:
             nullable_model = ModelWithUnionProperty.from_dict(_nullable_model)
 
-        not_required_model: Union[Unset, ModelWithUnionProperty] = UNSET
         _not_required_model = d.pop("not_required_model", UNSET)
-        if not isinstance(_not_required_model, Unset):
+        not_required_model: Union[Unset, ModelWithUnionProperty]
+        if isinstance(_not_required_model, Unset):
+            not_required_model = UNSET
+        else:
             not_required_model = ModelWithUnionProperty.from_dict(_not_required_model)
 
-        not_required_nullable_model = None
         _not_required_nullable_model = d.pop("not_required_nullable_model", UNSET)
-        if _not_required_nullable_model is not None and not isinstance(_not_required_nullable_model, Unset):
+        not_required_nullable_model: Union[Unset, None, ModelWithUnionProperty]
+        if _not_required_nullable_model is None:
+            not_required_nullable_model = None
+        elif isinstance(_not_required_nullable_model, Unset):
+            not_required_nullable_model = UNSET
+        else:
             not_required_nullable_model = ModelWithUnionProperty.from_dict(_not_required_nullable_model)
 
         a_model = cls(

end_to_end_tests/golden-record/my_test_api_client/models/model_with_any_json_properties.py

@@ -46,7 +46,6 @@ def _parse_additional_property(
                 data: object,
             ) -> Union[List[str], ModelWithAnyJsonPropertiesAdditionalPropertyType0, bool, float, int, str]:
                 try:
-                    additional_property_type_0: ModelWithAnyJsonPropertiesAdditionalPropertyType0
                     if not isinstance(data, dict):
                         raise TypeError()
                     additional_property_type_0 = ModelWithAnyJsonPropertiesAdditionalPropertyType0.from_dict(data)
@@ -55,7 +54,6 @@ def _parse_additional_property(
                 except:  # noqa: E722
                     pass
                 try:
-                    additional_property_type_1: List[str]
                     if not isinstance(data, list):
                         raise TypeError()
                     additional_property_type_1 = cast(List[str], data)

end_to_end_tests/golden-record/my_test_api_client/models/model_with_primitive_additional_properties.py

@@ -33,9 +33,11 @@ def to_dict(self) -> Dict[str, Any]:
     @classmethod
     def from_dict(cls: Type[T], src_dict: Dict[str, Any]) -> T:
         d = src_dict.copy()
-        a_date_holder: Union[Unset, ModelWithPrimitiveAdditionalPropertiesADateHolder] = UNSET
         _a_date_holder = d.pop("a_date_holder", UNSET)
-        if not isinstance(_a_date_holder, Unset):
+        a_date_holder: Union[Unset, ModelWithPrimitiveAdditionalPropertiesADateHolder]
+        if isinstance(_a_date_holder, Unset):
+            a_date_holder = UNSET
+        else:
             a_date_holder = ModelWithPrimitiveAdditionalPropertiesADateHolder.from_dict(_a_date_holder)
 
         model_with_primitive_additional_properties = cls(

end_to_end_tests/golden-record/my_test_api_client/models/model_with_property_ref.py

@@ -31,9 +31,11 @@ def to_dict(self) -> Dict[str, Any]:
     @classmethod
     def from_dict(cls: Type[T], src_dict: Dict[str, Any]) -> T:
         d = src_dict.copy()
-        inner: Union[Unset, ModelName] = UNSET
         _inner = d.pop("inner", UNSET)
-        if not isinstance(_inner, Unset):
+        inner: Union[Unset, ModelName]
+        if isinstance(_inner, Unset):
+            inner = UNSET
+        else:
             inner = ModelName.from_dict(_inner)
 
         model_with_property_ref = cls(

end_to_end_tests/golden-record/my_test_api_client/models/model_with_union_property.py

@@ -44,23 +44,25 @@ def _parse_a_property(data: object) -> Union[AnEnum, AnIntEnum, Unset]:
             if isinstance(data, Unset):
                 return data
             try:
-                a_property_type_0: Union[Unset, AnEnum]
                 if not isinstance(data, str):
                     raise TypeError()
-                a_property_type_0 = UNSET
                 _a_property_type_0 = data
-                if not isinstance(_a_property_type_0, Unset):
+                a_property_type_0: Union[Unset, AnEnum]
+                if isinstance(_a_property_type_0, Unset):
+                    a_property_type_0 = UNSET
+                else:
                     a_property_type_0 = AnEnum(_a_property_type_0)
 
                 return a_property_type_0
             except:  # noqa: E722
                 pass
             if not isinstance(data, int):
                 raise TypeError()
-            a_property_type_1: Union[Unset, AnIntEnum]
-            a_property_type_1 = UNSET
             _a_property_type_1 = data
-            if not isinstance(_a_property_type_1, Unset):
+            a_property_type_1: Union[Unset, AnIntEnum]
+            if isinstance(_a_property_type_1, Unset):
+                a_property_type_1 = UNSET
+            else:
                 a_property_type_1 = AnIntEnum(_a_property_type_1)
 
             return a_property_type_1

end_to_end_tests/golden-record/my_test_api_client/models/model_with_union_property_inlined.py

@@ -46,23 +46,25 @@ def _parse_fruit(
             if isinstance(data, Unset):
                 return data
             try:
-                fruit_type_0: Union[Unset, ModelWithUnionPropertyInlinedFruitType0]
                 if not isinstance(data, dict):
                     raise TypeError()
-                fruit_type_0 = UNSET
                 _fruit_type_0 = data
-                if not isinstance(_fruit_type_0, Unset):
+                fruit_type_0: Union[Unset, ModelWithUnionPropertyInlinedFruitType0]
+                if isinstance(_fruit_type_0, Unset):
+                    fruit_type_0 = UNSET
+                else:
                     fruit_type_0 = ModelWithUnionPropertyInlinedFruitType0.from_dict(_fruit_type_0)
 
                 return fruit_type_0
             except:  # noqa: E722
                 pass
             if not isinstance(data, dict):
                 raise TypeError()
-            fruit_type_1: Union[Unset, ModelWithUnionPropertyInlinedFruitType1]
-            fruit_type_1 = UNSET
             _fruit_type_1 = data
-            if not isinstance(_fruit_type_1, Unset):
+            fruit_type_1: Union[Unset, ModelWithUnionPropertyInlinedFruitType1]
+            if isinstance(_fruit_type_1, Unset):
+                fruit_type_1 = UNSET
+            else:
                 fruit_type_1 = ModelWithUnionPropertyInlinedFruitType1.from_dict(_fruit_type_1)
 
             return fruit_type_1

openapi_python_client/templates/property_templates/property_macros.py.jinja

@@ -1,16 +1,20 @@
 {% macro construct_template(construct_function, property, source, initial_value=None) %}
 {% if property.required and not property.nullable %}
 {{ property.python_name }} = {{ construct_function(property, source) }}
-{% else %}
-{% if initial_value != None %}
-{{ property.python_name }} = {{ initial_value }}
-{% elif property.nullable %}
-{{ property.python_name }} = None
-{% else %}
-{{ property.python_name }}: {{ property.get_type_string() }} = UNSET
-{% endif %}
+{% else %}{# Must be nullable OR non-required #}
 _{{ property.python_name }} = {{ source }}
-if {% if property.nullable %}_{{ property.python_name }} is not None{% endif %}{% if property.nullable and not property.required %} and {% endif %}{% if not property.required %}not isinstance(_{{ property.python_name }},  Unset){% endif %}:
+{{ property.python_name }}: {{ property.get_type_string() }}
+    {% if property.nullable %}
+if _{{ property.python_name }} is None:
+    {{ property.python_name }} = {% if initial_value != None %}{{ initial_value }}{% else %}None{% endif %}
+
+    {% endif %}
+    {% if not property.required %}
+{% if property.nullable %}elif{% else %}if{% endif %} isinstance(_{{ property.python_name }},  Unset):
+    {{ property.python_name }} = {% if initial_value != None %}{{ initial_value }}{% else %}UNSET{% endif %}
+
+    {% endif %}
+else:
     {{ property.python_name }} = {{ construct_function(property, "_" + property.python_name) }}
 {% endif %}
 {% endmacro %}

openapi_python_client/templates/property_templates/union_property.py.jinja

@@ -11,7 +11,6 @@ def _parse_{{ property.python_name }}(data: object) -> {{ property.get_type_stri
     {% for inner_property in property.inner_properties_with_template() %}
     {% if not loop.last or property.has_properties_without_templates %}
     try:
-        {{ inner_property.python_name }}: {{ inner_property.get_type_string() }}
     {% from "property_templates/" + inner_property.template import construct, check_type_for_construct %}
         if not {{ check_type_for_construct(inner_property, "data") }}:
             raise TypeError()
@@ -23,7 +22,6 @@ def _parse_{{ property.python_name }}(data: object) -> {{ property.get_type_stri
     {% from "property_templates/" + inner_property.template import construct, check_type_for_construct %}
     if not {{ check_type_for_construct(inner_property, "data") }}:
         raise TypeError()
-    {{ inner_property.python_name }}: {{ inner_property.get_type_string() }}
     {{ construct(inner_property, "data", initial_value="UNSET") | indent(4) }}
     return {{ inner_property.python_name }}
     {% endif %}

tests/test_templates/test_property_templates/test_date_property/optional_nullable.py

@@ -7,9 +7,13 @@
 if not isinstance(some_source, Unset):
     some_destination = some_source.isoformat() if some_source else None
 
-a_prop = None
 _a_prop = some_destination
-if _a_prop is not None and not isinstance(_a_prop,  Unset):
+a_prop: Union[Unset, None, datetime.date]
+if _a_prop is None:
+    a_prop = None
+elif isinstance(_a_prop,  Unset):
+    a_prop = UNSET
+else:
     a_prop = isoparse(_a_prop).date()
 
 

tests/test_templates/test_property_templates/test_date_property/required_nullable.py

@@ -4,9 +4,11 @@
 from dateutil.parser import isoparse
 some_source = date(2020, 10, 12)
 some_destination = some_source.isoformat() if some_source else None 
-a_prop = None
 _a_prop = some_destination
-if _a_prop is not None:
+a_prop: Optional[datetime.date]
+if _a_prop is None:
+    a_prop = None
+else:
     a_prop = isoparse(_a_prop).date()