[PYTHON] Fix for failing to lookup discriminator value using AllOf and discriminator (#18498)

* fix issue 18495

* add tests and update samples

* update samples

samples/openapi3/client/petstore/python/.openapi-generator/FILES

@@ -17,6 +17,7 @@ docs/ArrayOfArrayOfModel.md
 docs/ArrayOfArrayOfNumberOnly.md
 docs/ArrayOfNumberOnly.md
 docs/ArrayTest.md
+docs/BaseDiscriminator.md
 docs/BasquePig.md
 docs/Bathing.md
 docs/Capitalization.md
@@ -53,6 +54,7 @@ docs/FormatTest.md
 docs/HasOnlyReadOnly.md
 docs/HealthCheckResult.md
 docs/ImportTestDatetimeApi.md
+docs/Info.md
 docs/InnerDictWithProperty.md
 docs/InputAllOf.md
 docs/IntOrString.md
@@ -84,6 +86,7 @@ docs/Pet.md
 docs/PetApi.md
 docs/Pig.md
 docs/PoopCleaning.md
+docs/PrimitiveString.md
 docs/PropertyMap.md
 docs/PropertyNameCollision.md
 docs/ReadOnlyFirst.md
@@ -137,6 +140,7 @@ petstore_api/models/array_of_array_of_model.py
 petstore_api/models/array_of_array_of_number_only.py
 petstore_api/models/array_of_number_only.py
 petstore_api/models/array_test.py
+petstore_api/models/base_discriminator.py
 petstore_api/models/basque_pig.py
 petstore_api/models/bathing.py
 petstore_api/models/capitalization.py
@@ -169,6 +173,7 @@ petstore_api/models/foo_get_default_response.py
 petstore_api/models/format_test.py
 petstore_api/models/has_only_read_only.py
 petstore_api/models/health_check_result.py
+petstore_api/models/info.py
 petstore_api/models/inner_dict_with_property.py
 petstore_api/models/input_all_of.py
 petstore_api/models/int_or_string.py
@@ -199,6 +204,7 @@ petstore_api/models/parent_with_optional_dict.py
 petstore_api/models/pet.py
 petstore_api/models/pig.py
 petstore_api/models/poop_cleaning.py
+petstore_api/models/primitive_string.py
 petstore_api/models/property_map.py
 petstore_api/models/property_name_collision.py
 petstore_api/models/read_only_first.py

samples/openapi3/client/petstore/python/README.md

@@ -163,6 +163,7 @@ Class | Method | HTTP request | Description
  - [ArrayOfArrayOfNumberOnly](docs/ArrayOfArrayOfNumberOnly.md)
  - [ArrayOfNumberOnly](docs/ArrayOfNumberOnly.md)
  - [ArrayTest](docs/ArrayTest.md)
+ - [BaseDiscriminator](docs/BaseDiscriminator.md)
  - [BasquePig](docs/BasquePig.md)
  - [Bathing](docs/Bathing.md)
  - [Capitalization](docs/Capitalization.md)
@@ -195,6 +196,7 @@ Class | Method | HTTP request | Description
  - [FormatTest](docs/FormatTest.md)
  - [HasOnlyReadOnly](docs/HasOnlyReadOnly.md)
  - [HealthCheckResult](docs/HealthCheckResult.md)
+ - [Info](docs/Info.md)
  - [InnerDictWithProperty](docs/InnerDictWithProperty.md)
  - [InputAllOf](docs/InputAllOf.md)
  - [IntOrString](docs/IntOrString.md)
@@ -225,6 +227,7 @@ Class | Method | HTTP request | Description
  - [Pet](docs/Pet.md)
  - [Pig](docs/Pig.md)
  - [PoopCleaning](docs/PoopCleaning.md)
+ - [PrimitiveString](docs/PrimitiveString.md)
  - [PropertyMap](docs/PropertyMap.md)
  - [PropertyNameCollision](docs/PropertyNameCollision.md)
  - [ReadOnlyFirst](docs/ReadOnlyFirst.md)

samples/openapi3/client/petstore/python/docs/BaseDiscriminator.md

@@ -0,0 +1,29 @@
+# BaseDiscriminator
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**type_name** | **str** |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.base_discriminator import BaseDiscriminator
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of BaseDiscriminator from a JSON string
+base_discriminator_instance = BaseDiscriminator.from_json(json)
+# print the JSON string representation of the object
+print(BaseDiscriminator.to_json())
+
+# convert the object into a dict
+base_discriminator_dict = base_discriminator_instance.to_dict()
+# create an instance of BaseDiscriminator from a dict
+base_discriminator_from_dict = BaseDiscriminator.from_dict(base_discriminator_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/docs/Info.md

@@ -0,0 +1,29 @@
+# Info
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**val** | [**BaseDiscriminator**](BaseDiscriminator.md) |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.info import Info
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of Info from a JSON string
+info_instance = Info.from_json(json)
+# print the JSON string representation of the object
+print(Info.to_json())
+
+# convert the object into a dict
+info_dict = info_instance.to_dict()
+# create an instance of Info from a dict
+info_from_dict = Info.from_dict(info_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/docs/PrimitiveString.md

@@ -0,0 +1,29 @@
+# PrimitiveString
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**value** | **str** |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.primitive_string import PrimitiveString
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of PrimitiveString from a JSON string
+primitive_string_instance = PrimitiveString.from_json(json)
+# print the JSON string representation of the object
+print(PrimitiveString.to_json())
+
+# convert the object into a dict
+primitive_string_dict = primitive_string_instance.to_dict()
+# create an instance of PrimitiveString from a dict
+primitive_string_from_dict = PrimitiveString.from_dict(primitive_string_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/petstore_api/__init__.py

@@ -52,6 +52,7 @@ from petstore_api.models.array_of_array_of_model import ArrayOfArrayOfModel
 from petstore_api.models.array_of_array_of_number_only import ArrayOfArrayOfNumberOnly
 from petstore_api.models.array_of_number_only import ArrayOfNumberOnly
 from petstore_api.models.array_test import ArrayTest
+from petstore_api.models.base_discriminator import BaseDiscriminator
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.bathing import Bathing
 from petstore_api.models.capitalization import Capitalization
@@ -84,6 +85,7 @@ from petstore_api.models.foo_get_default_response import FooGetDefaultResponse
 from petstore_api.models.format_test import FormatTest
 from petstore_api.models.has_only_read_only import HasOnlyReadOnly
 from petstore_api.models.health_check_result import HealthCheckResult
+from petstore_api.models.info import Info
 from petstore_api.models.inner_dict_with_property import InnerDictWithProperty
 from petstore_api.models.input_all_of import InputAllOf
 from petstore_api.models.int_or_string import IntOrString
@@ -114,6 +116,7 @@ from petstore_api.models.parent_with_optional_dict import ParentWithOptionalDict
 from petstore_api.models.pet import Pet
 from petstore_api.models.pig import Pig
 from petstore_api.models.poop_cleaning import PoopCleaning
+from petstore_api.models.primitive_string import PrimitiveString
 from petstore_api.models.property_map import PropertyMap
 from petstore_api.models.property_name_collision import PropertyNameCollision
 from petstore_api.models.read_only_first import ReadOnlyFirst

samples/openapi3/client/petstore/python/petstore_api/models/__init__.py

@@ -27,6 +27,7 @@ from petstore_api.models.array_of_array_of_model import ArrayOfArrayOfModel
 from petstore_api.models.array_of_array_of_number_only import ArrayOfArrayOfNumberOnly
 from petstore_api.models.array_of_number_only import ArrayOfNumberOnly
 from petstore_api.models.array_test import ArrayTest
+from petstore_api.models.base_discriminator import BaseDiscriminator
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.bathing import Bathing
 from petstore_api.models.capitalization import Capitalization
@@ -59,6 +60,7 @@ from petstore_api.models.foo_get_default_response import FooGetDefaultResponse
 from petstore_api.models.format_test import FormatTest
 from petstore_api.models.has_only_read_only import HasOnlyReadOnly
 from petstore_api.models.health_check_result import HealthCheckResult
+from petstore_api.models.info import Info
 from petstore_api.models.inner_dict_with_property import InnerDictWithProperty
 from petstore_api.models.input_all_of import InputAllOf
 from petstore_api.models.int_or_string import IntOrString
@@ -89,6 +91,7 @@ from petstore_api.models.parent_with_optional_dict import ParentWithOptionalDict
 from petstore_api.models.pet import Pet
 from petstore_api.models.pig import Pig
 from petstore_api.models.poop_cleaning import PoopCleaning
+from petstore_api.models.primitive_string import PrimitiveString
 from petstore_api.models.property_map import PropertyMap
 from petstore_api.models.property_name_collision import PropertyNameCollision
 from petstore_api.models.read_only_first import ReadOnlyFirst

samples/openapi3/client/petstore/python/petstore_api/models/base_discriminator.py

@@ -0,0 +1,118 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from importlib import import_module
+from pydantic import BaseModel, ConfigDict, Field, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional, Union
+from typing import Optional, Set
+from typing_extensions import Self
+
+from typing import TYPE_CHECKING
+if TYPE_CHECKING:
+    from petstore_api.models.primitive_string import PrimitiveString
+    from petstore_api.models.info import Info
+
+class BaseDiscriminator(BaseModel):
+    """
+    BaseDiscriminator
+    """ # noqa: E501
+    type_name: Optional[StrictStr] = Field(default=None, alias="_typeName")
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_typeName"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    # JSON field name that stores the object type
+    __discriminator_property_name: ClassVar[str] = '_typeName'
+
+    # discriminator mappings
+    __discriminator_value_class_map: ClassVar[Dict[str, str]] = {
+        'string': 'PrimitiveString','Info': 'Info'
+    }
+
+    @classmethod
+    def get_discriminator_value(cls, obj: Dict[str, Any]) -> Optional[str]:
+        """Returns the discriminator value (object type) of the data"""
+        discriminator_value = obj[cls.__discriminator_property_name]
+        if discriminator_value:
+            return cls.__discriminator_value_class_map.get(discriminator_value)
+        else:
+            return None
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Union[PrimitiveString, Info]]:
+        """Create an instance of BaseDiscriminator from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Dict[str, Any]) -> Optional[Union[PrimitiveString, Info]]:
+        """Create an instance of BaseDiscriminator from a dict"""
+        # look up the object type based on discriminator mapping
+        object_type = cls.get_discriminator_value(obj)
+        if object_type ==  'PrimitiveString':
+            return import_module("petstore_api.models.primitive_string").PrimitiveString.from_dict(obj)
+        if object_type ==  'Info':
+            return import_module("petstore_api.models.info").Info.from_dict(obj)
+
+        raise ValueError("BaseDiscriminator failed to lookup discriminator value from " +
+                            json.dumps(obj) + ". Discriminator property name: " + cls.__discriminator_property_name +
+                            ", mapping: " + json.dumps(cls.__discriminator_value_class_map))
+
+

samples/openapi3/client/petstore/python/petstore_api/models/info.py

@@ -0,0 +1,105 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import ConfigDict
+from typing import Any, ClassVar, Dict, List, Optional
+from petstore_api.models.base_discriminator import BaseDiscriminator
+from typing import Optional, Set
+from typing_extensions import Self
+
+class Info(BaseDiscriminator):
+    """
+    Info
+    """ # noqa: E501
+    val: Optional[BaseDiscriminator] = None
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_typeName", "val"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of Info from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # override the default output from pydantic by calling `to_dict()` of val
+        if self.val:
+            _dict['val'] = self.val.to_dict()
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of Info from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "_typeName": obj.get("_typeName"),
+            "val": BaseDiscriminator.from_dict(obj["val"]) if obj.get("val") is not None else None
+        })
+        # store additional fields in additional_properties
+        for _key in obj.keys():
+            if _key not in cls.__properties:
+                _obj.additional_properties[_key] = obj.get(_key)
+
+        return _obj
+
+

samples/openapi3/client/petstore/python/petstore_api/models/primitive_string.py

@@ -0,0 +1,102 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import ConfigDict, Field, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional
+from petstore_api.models.base_discriminator import BaseDiscriminator
+from typing import Optional, Set
+from typing_extensions import Self
+
+class PrimitiveString(BaseDiscriminator):
+    """
+    PrimitiveString
+    """ # noqa: E501
+    value: Optional[StrictStr] = Field(default=None, alias="_value")
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_typeName", "_value"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of PrimitiveString from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of PrimitiveString from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "_typeName": obj.get("_typeName"),
+            "_value": obj.get("_value")
+        })
+        # store additional fields in additional_properties
+        for _key in obj.keys():
+            if _key not in cls.__properties:
+                _obj.additional_properties[_key] = obj.get(_key)
+
+        return _obj
+
+

samples/openapi3/client/petstore/python/test/test_base_discriminator.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.base_discriminator import BaseDiscriminator
+
+class TestBaseDiscriminator(unittest.TestCase):
+    """BaseDiscriminator unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> BaseDiscriminator:
+        """Test BaseDiscriminator
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `BaseDiscriminator`
+        """
+        model = BaseDiscriminator()
+        if include_optional:
+            return BaseDiscriminator(
+                type_name = ''
+            )
+        else:
+            return BaseDiscriminator(
+        )
+        """
+
+    def testBaseDiscriminator(self):
+        """Test BaseDiscriminator"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/test/test_info.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.info import Info
+
+class TestInfo(unittest.TestCase):
+    """Info unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> Info:
+        """Test Info
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `Info`
+        """
+        model = Info()
+        if include_optional:
+            return Info(
+                val = petstore_api.models.base_discriminator.BaseDiscriminator()
+            )
+        else:
+            return Info(
+        )
+        """
+
+    def testInfo(self):
+        """Test Info"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/test/test_primitive_string.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.primitive_string import PrimitiveString
+
+class TestPrimitiveString(unittest.TestCase):
+    """PrimitiveString unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> PrimitiveString:
+        """Test PrimitiveString
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `PrimitiveString`
+        """
+        model = PrimitiveString()
+        if include_optional:
+            return PrimitiveString(
+                value = ''
+            )
+        else:
+            return PrimitiveString(
+        )
+        """
+
+    def testPrimitiveString(self):
+        """Test PrimitiveString"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/tests/test_model.py

@@ -629,6 +629,13 @@ class ModelTests(unittest.TestCase):
         self.assertEqual(model_a.to_json(), '{"_name": "nameA", "second_circular_all_of_ref": {"name": "nameB"}}')
         self.assertEqual(model_b.to_json(), '{"_name": "nameB", "circular_all_of_ref": {"name": "nameA"}}')
 
+    def test_allof_discriminator_mapping(self):
+        # for issue 18498
+        user_info_json = '{"_typeName": "Info", "val": {"_typeName": "string", "_value": "some string"}}'
+        user_info = petstore_api.models.Info.from_json(user_info_json)
+        # shouldn't throw ValueError("BaseDiscriminator failed to lookup discriminator value...")
+        assert user_info is not None
+        self.assertEqual(user_info.to_json(), user_info_json)
 
 class TestdditionalPropertiesAnyType(unittest.TestCase):
     def test_additional_properties(self):