fix(robot-server): fix typing_extensions bug

robot-server/robot_server/service/models/json_api/__init__.py

@@ -0,0 +1,8 @@
+from enum import Enum
+
+
+# TODO(isk: 3/24/20): remove this enum and replace with typing.Literal
+# after migration to python 3.8
+class ResourceTypes(str, Enum):
+    """Resource object types"""
+    item = "item"

robot-server/robot_server/service/models/json_api/factory.py

@@ -2,17 +2,18 @@
 
 from .request import json_api_request, RequestModel
 from .response import json_api_response, ResponseModel
+from . import ResourceTypes
 
 
 def generate_json_api_models(
-    type_string: str,
+    resource_type: ResourceTypes,
     attributes_model: Any,
     *,
     list_response: bool = False
 ) -> Tuple[Type[RequestModel], Type[ResponseModel]]:
     return (
-        json_api_request(type_string, attributes_model),
+        json_api_request(resource_type, attributes_model),
         json_api_response(
-            type_string, attributes_model, use_list=list_response
+            resource_type, attributes_model, use_list=list_response
         ),
     )

robot-server/robot_server/service/models/json_api/request.py

@@ -1,13 +1,13 @@
 from typing import Generic, TypeVar, Optional, Any, Type
-from typing_extensions import Literal
 from pydantic import Field
 from pydantic.generics import GenericModel
 
-TypeT = TypeVar('TypeT')
+from . import ResourceTypes
+
 AttributesT = TypeVar('AttributesT')
 
 
-class RequestDataModel(GenericModel, Generic[TypeT, AttributesT]):
+class RequestDataModel(GenericModel, Generic[AttributesT]):
     """
     """
     id: Optional[str] = \
@@ -16,7 +16,7 @@ class RequestDataModel(GenericModel, Generic[TypeT, AttributesT]):
                           " required when the resource object originates at"
                           " the client and represents a new resource to be"
                           " created on the server.")
-    type: TypeT = \
+    type: ResourceTypes = \
         Field(...,
               description="type member is used to describe resource objects"
                           " that share common attributes.")
@@ -42,13 +42,11 @@ def attributes(self):
 
 # Note(isk: 3/13/20): formats and returns request model
 def json_api_request(
-    type_string: str,
+    resource_type: ResourceTypes,
     attributes_model: Any
 ) -> Type[RequestModel]:
-    request_data_model = RequestDataModel[
-        Literal[type_string],    # type: ignore
-        attributes_model,    # type: ignore
-    ]
+    type_string = resource_type.value
+    request_data_model = RequestDataModel[attributes_model]    # type: ignore
     request_data_model.__name__ = f'RequestData[{type_string}]'
     request_model = RequestModel[request_data_model]
     request_model.__name__ = f'Request[{type_string}]'

robot-server/robot_server/service/models/json_api/response.py

@@ -1,22 +1,22 @@
 from typing import Generic, TypeVar, Optional, List, \
     Dict, Any, Type, get_type_hints
-from typing_extensions import Literal
 from pydantic import Field
 from pydantic.generics import GenericModel
 
 from .resource_links import ResourceLinks
+from . import ResourceTypes
+
 
-TypeT = TypeVar('TypeT', bound=str)
 AttributesT = TypeVar('AttributesT')
 
 
-class ResponseDataModel(GenericModel, Generic[TypeT, AttributesT]):
+class ResponseDataModel(GenericModel, Generic[AttributesT]):
     """
     """
     id: str = \
         Field(...,
               description="id member represents a resource object.")
-    type: TypeT = \
+    type: ResourceTypes = \
         Field(...,
               description="type member is used to describe resource objects"
                           " that share common attributes.")
@@ -64,9 +64,9 @@ def resource_object(
         # a list, if not return None.
         if getattr(data_type, '__origin__', None) is list:
             data_type = data_type.__args__[0]
-        # Note(isk: 3/13/20): get type name from data object
-        # using get_type_hints
-        typename = get_type_hints(data_type)['type'].__args__[0]
+        # Note(isk: 3/24/20): get type name from _resource_type private
+        # variable set in json_api_response
+        typename = cls._resource_type     # type: ignore
         return data_type(
             id=id,
             type=typename,
@@ -77,23 +77,23 @@ def resource_object(
 # Note(isk: 3/13/20): returns response based on whether
 # the data object is a list or not
 def json_api_response(
-    type_string: str,
+    resource_type: ResourceTypes,
     attributes_model: Any,
     *,
     use_list: bool = False
 ) -> Type[ResponseModel]:
-    response_data_model = ResponseDataModel[
-        Literal[type_string],    # type: ignore
-        attributes_model,    # type: ignore
-    ]
+    type_string = resource_type.value
+    response_data_model = ResponseDataModel[attributes_model]    # type: ignore
     if use_list:
         response_data_model = List[response_data_model]    # type: ignore
         response_data_model.__name__ = f'ListResponseData[{type_string}]'
         response_model_list = ResponseModel[response_data_model]
         response_model_list.__name__ = f'ListResponse[{type_string}]'
+        response_model_list._resource_type = type_string     # type: ignore
         return response_model_list
     else:
         response_data_model.__name__ = f'ResponseData[{type_string}]'
         response_model = ResponseModel[response_data_model]
         response_model.__name__ = f'Response[{type_string}]'
+        response_model._resource_type = type_string     # type: ignore
         return response_model

robot-server/robot_server/service/routers/item.py

@@ -5,14 +5,16 @@
 from robot_server.service.models.json_api.factory import \
     generate_json_api_models
 from robot_server.service.models.json_api.errors import ErrorResponse
+from robot_server.service.models.json_api import ResourceTypes
+
 # https://github.com/encode/starlette/blob/master/starlette/status.py
 from starlette.status import HTTP_400_BAD_REQUEST, \
     HTTP_422_UNPROCESSABLE_ENTITY
 
 router = APIRouter()
 
-ITEM_TYPE_NAME = "item"
-ItemRequest, ItemResponse = generate_json_api_models(ITEM_TYPE_NAME, Item)
+ITEM_TYPE = ResourceTypes.item
+ItemRequest, ItemResponse = generate_json_api_models(ITEM_TYPE, Item)
 
 
 @router.get("/items/{item_id}",

robot-server/tests/service/helpers.py

@@ -3,6 +3,7 @@
 from uuid import uuid4
 
 from robot_server.service.models.json_api.request import json_api_request
+from robot_server.service.models.json_api import ResourceTypes
 
 
 @dataclass
@@ -19,5 +20,5 @@ class ItemModel(BaseModel):
     price: float
 
 
-item_type_name = 'item'
-ItemRequest = json_api_request(item_type_name, ItemModel)
+item_type = ResourceTypes.item
+ItemRequest = json_api_request(item_type, ItemModel)

robot-server/tests/service/models/json_api/test_errors.py

@@ -66,11 +66,12 @@ def test_transform_validation_error_to_json_api_errors():
         'errors': [
             {
                 'status': str(HTTP_422_UNPROCESSABLE_ENTITY),
-                'detail': "unexpected value; permitted: 'item'",
+                'detail': "value is not a valid enumeration member; permitted:"
+                          " 'item'",
                 'source': {
                     'pointer': '/data/type'
                 },
-                'title': 'value_error.const'
+                'title': 'type_error.enum'
             },
             {
                 'status': str(HTTP_422_UNPROCESSABLE_ENTITY),

robot-server/tests/service/models/json_api/test_factory.py

@@ -1,34 +1,36 @@
 from typing import List
-from typing_extensions import Literal
 
 from robot_server.service.models.json_api.factory import \
     generate_json_api_models
 from robot_server.service.models.json_api.request import RequestModel, \
     RequestDataModel
 from robot_server.service.models.json_api.response import ResponseModel, \
     ResponseDataModel
+from robot_server.service.models.json_api import ResourceTypes
 from tests.service.helpers import ItemModel
 
+ITEM_TYPE = ResourceTypes.item
+
 
 def test_json_api_model():
-    ItemRequest, ItemResponse = generate_json_api_models('item', ItemModel)
+    ItemRequest, ItemResponse = generate_json_api_models(ITEM_TYPE, ItemModel)
     assert ItemRequest == RequestModel[
-        RequestDataModel[Literal['item'], ItemModel]
+        RequestDataModel[ItemModel]
     ]
     assert ItemResponse == ResponseModel[
-        ResponseDataModel[Literal['item'], ItemModel]
+        ResponseDataModel[ItemModel]
     ]
 
 
 def test_json_api_model__list_response():
     ItemRequest, ItemResponse = generate_json_api_models(
-        'item',
+        ITEM_TYPE,
         ItemModel,
         list_response=True
     )
     assert ItemRequest == RequestModel[
-        RequestDataModel[Literal['item'], ItemModel]
+        RequestDataModel[ItemModel]
     ]
     assert ItemResponse == ResponseModel[
-        List[ResponseDataModel[Literal['item'], ItemModel]]
+        List[ResponseDataModel[ItemModel]]
     ]

robot-server/tests/service/models/json_api/test_request.py

@@ -3,11 +3,15 @@
 from pydantic import ValidationError
 
 from robot_server.service.models.json_api.request import json_api_request
+from robot_server.service.models.json_api import ResourceTypes
 from tests.service.helpers import ItemModel
 
 
+ITEM_TYPE = ResourceTypes.item
+
+
 def test_attributes_as_dict():
-    DictRequest = json_api_request('item', dict)
+    DictRequest = json_api_request(ITEM_TYPE, dict)
     obj_to_validate = {
         'data': {'type': 'item', 'attributes': {}}
     }
@@ -22,7 +26,7 @@ def test_attributes_as_dict():
 
 
 def test_attributes_as_item_model():
-    ItemRequest = json_api_request('item', ItemModel)
+    ItemRequest = json_api_request(ITEM_TYPE, ItemModel)
     obj_to_validate = {
         'data': {
             'type': 'item',
@@ -39,7 +43,7 @@ def test_attributes_as_item_model():
 
 
 def test_attributes_as_item_model__empty_dict():
-    ItemRequest = json_api_request('item', ItemModel)
+    ItemRequest = json_api_request(ITEM_TYPE, ItemModel)
     obj_to_validate = {
         'data': {
             'type': 'item',
@@ -67,7 +71,7 @@ def test_attributes_as_item_model__empty_dict():
 
 
 def test_type_invalid_string():
-    MyRequest = json_api_request('item', dict)
+    MyRequest = json_api_request(ITEM_TYPE, dict)
     obj_to_validate = {
         'data': {'type': 'not_an_item', 'attributes': {}}
     }
@@ -77,15 +81,16 @@ def test_type_invalid_string():
     assert e.value.errors() == [
         {
             'loc': ('data', 'type'),
-            'msg': "unexpected value; permitted: 'item'",
-            'type': 'value_error.const',
-            'ctx': {'given': 'not_an_item', 'permitted': ('item',)},
+            'msg': "value is not a valid enumeration member;"
+                   " permitted: 'item'",
+            'type': 'type_error.enum',
+            'ctx': {'enum_values': [ITEM_TYPE]},
         },
     ]
 
 
 def test_attributes_required():
-    MyRequest = json_api_request('item', dict)
+    MyRequest = json_api_request(ITEM_TYPE, dict)
     obj_to_validate = {
         'data': {'type': 'item', 'attributes': None}
     }
@@ -102,7 +107,7 @@ def test_attributes_required():
 
 
 def test_data_required():
-    MyRequest = json_api_request('item', dict)
+    MyRequest = json_api_request(ITEM_TYPE, dict)
     obj_to_validate = {
         'data': None
     }
@@ -119,7 +124,7 @@ def test_data_required():
 
 
 def test_request_with_id():
-    MyRequest = json_api_request('item', dict)
+    MyRequest = json_api_request(ITEM_TYPE, dict)
     obj_to_validate = {
         'data': {
             'type': 'item',