change ErrorType from an enum to a type hint and replace the enum members use cases with constants.

This avoids triggering an exception when returning a yaml response since the yaml renderer used by drf-spectacular does not handle enums by default

fixes #98

Author: ghazi-git

docs/changelog.md

@@ -35,6 +35,19 @@ message:
     }
     ```
 - set minimum version of drf-spectacular to 0.27.1
+- `drf_standardized_errors.types.ErrorType` is now the following type hint
+    ```python
+    from typing import Literal
+    ErrorType = Literal["validation_error", "client_error", "server_error"]
+    ```
+    `ErrorType` was previously an enum. If you referenced its members in your code, make sure to replace their
+    use cases with the newly added constants:
+    ```
+    from drf_standardized_errors.types import VALIDATION_ERROR, CLIENT_ERROR, SERVER_ERROR
+    ErrorType.VALIDATION_ERROR --> VALIDATION_ERROR
+    ErrorType.CLIENT_ERROR --> CLIENT_ERROR
+    ErrorType.SERVER_ERROR --> SERVER_ERROR
+    ```
 
 ## [0.14.1] - 2024-08-10
 ### Added

drf_standardized_errors/formatter.py

@@ -5,7 +5,15 @@
 from rest_framework.status import is_client_error
 
 from .settings import package_settings
-from .types import Error, ErrorResponse, ErrorType, ExceptionHandlerContext
+from .types import (
+    CLIENT_ERROR,
+    SERVER_ERROR,
+    VALIDATION_ERROR,
+    Error,
+    ErrorResponse,
+    ErrorType,
+    ExceptionHandlerContext,
+)
 
 
 class ExceptionFormatter:
@@ -42,11 +50,11 @@ def run(self) -> Any:
 
     def get_error_type(self) -> ErrorType:
         if isinstance(self.exc, exceptions.ValidationError):
-            return ErrorType.VALIDATION_ERROR
+            return VALIDATION_ERROR
         elif is_client_error(self.exc.status_code):
-            return ErrorType.CLIENT_ERROR
+            return CLIENT_ERROR
         else:
-            return ErrorType.SERVER_ERROR
+            return SERVER_ERROR
 
     def get_errors(self) -> List[Error]:
         """

drf_standardized_errors/types.py

@@ -1,6 +1,5 @@
 from dataclasses import dataclass
-from enum import Enum
-from typing import List, Optional, TypedDict
+from typing import Final, List, Literal, Optional, TypedDict
 
 from rest_framework.request import Request
 from rest_framework.views import APIView
@@ -13,10 +12,10 @@ class ExceptionHandlerContext(TypedDict):
     request: Optional[Request]
 
 
-class ErrorType(str, Enum):
-    VALIDATION_ERROR = "validation_error"
-    CLIENT_ERROR = "client_error"
-    SERVER_ERROR = "server_error"
+VALIDATION_ERROR: Final = "validation_error"
+CLIENT_ERROR: Final = "client_error"
+SERVER_ERROR: Final = "server_error"
+ErrorType = Literal["validation_error", "client_error", "server_error"]
 
 
 @dataclass