Add support for custom HTTP exception classes

Author: zmievsa

CHANGELOG.md

@@ -5,6 +5,12 @@ Please follow [the Keep a Changelog standard](https://keepachangelog.com/en/1.0.
 
 ## [Unreleased]
 
+## [5.1.4]
+
+### Fixed
+
+* Fixed a bug where a custom HTTP exception was not being copied correctly so its unique properties are ignored
+
 ## [5.1.3]
 
 ### Fixed

cadwyn/structure/versions.py

@@ -1,5 +1,6 @@
 import email.message
 import functools
+import http
 import inspect
 import json
 from collections import defaultdict
@@ -8,7 +9,7 @@
 from contextvars import ContextVar
 from datetime import date
 from enum import Enum
-from typing import TYPE_CHECKING, ClassVar, Union
+from typing import TYPE_CHECKING, ClassVar, Union, cast
 
 from fastapi import BackgroundTasks, HTTPException, params
 from fastapi import Request as FastapiRequest
@@ -616,12 +617,13 @@ async def _convert_endpoint_response_to_version(  # noqa: C901
                     detail = response_info.body["detail"]
                 else:
                     detail = response_info.body
+                if detail is None:
+                    detail = http.HTTPStatus(response_info.status_code).phrase
+                raised_exception.detail = cast(str, detail)
+                raised_exception.headers = dict(response_info.headers)
+                raised_exception.status_code = response_info.status_code
 
-                raise HTTPException(
-                    status_code=response_info.status_code,
-                    detail=detail,
-                    headers=dict(response_info.headers),
-                )
+                raise raised_exception
             return response_info._response
         return response_info.body
 

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "cadwyn"
-version = "5.1.3"
+version = "5.1.4"
 description = "Production-ready community-driven modern Stripe-like API versioning in FastAPI"
 authors = [{ name = "Stanislav Zmiev", email = "zmievsa@gmail.com" }]
 license = "MIT"

tests/test_data_migrations.py

@@ -3,14 +3,15 @@
 from collections.abc import Callable, Coroutine
 from contextvars import ContextVar
 from io import StringIO
-from typing import Any, Literal, Union
+from typing import Any, Literal, Optional, Union
 
 import fastapi
 import pytest
 from dirty_equals import IsPartialDict, IsStr
 from fastapi import APIRouter, Body, Cookie, File, Header, HTTPException, Query, Request, Response, UploadFile
 from fastapi.responses import JSONResponse
 from fastapi.routing import APIRoute
+from fastapi.testclient import TestClient
 from pydantic import BaseModel, Field, RootModel
 from starlette.responses import StreamingResponse
 
@@ -32,6 +33,7 @@
 from cadwyn.structure.schemas import schema
 from cadwyn.structure.versions import Version, VersionBundle
 from tests.conftest import (
+    CreateVersionedApp,
     CreateVersionedClients,
     client,
     version_change,
@@ -1226,3 +1228,41 @@ def response_converter(response: ResponseInfo):
         resp_2001 = client_2001.post(f"/{endpoint}", json={"i": ["original_request"]})
         assert resp_2001.status_code == 200
         assert resp_2001.json() == {"i": ["original_request", endpoint]}
+
+
+def test__response_migrations__with_custom_http_exception(
+    create_versioned_app: CreateVersionedApp,
+    router: VersionedAPIRouter,
+) -> None:
+    class CustomHTTPException(HTTPException):
+        error_code: Optional[str] = None
+
+        def __init__(self, detail: str, error_code: Optional[str] = None):
+            self.error_code = error_code
+            super().__init__(status_code=400, detail=detail)
+
+    def http_exception_handler(request, exc):
+        # Check if the exception has an error_code attribute
+        error_code = exc.error_code if hasattr(exc, "error_code") else "generic_error"
+
+        return JSONResponse(
+            status_code=exc.status_code,
+            content={"code": error_code, "message": exc.detail},
+        )
+
+    # Register exception handler for Cadwyn
+
+    @router.post("/test")
+    async def endpoint():
+        raise CustomHTTPException("Cadwyn error occurred", error_code="cadwyn_error")
+
+    app = create_versioned_app(version_change())
+    app.add_exception_handler(HTTPException, http_exception_handler)
+    with TestClient(app) as client:
+        resp = client.post("/test", headers={"X-API-VERSION": "2000-01-01"})
+        assert resp.status_code == 400
+        assert resp.json() == {"code": "cadwyn_error", "message": "Cadwyn error occurred"}
+
+        resp_2001 = client.post("/test", headers={"X-API-VERSION": "2001-01-01"})
+        assert resp_2001.status_code == 400
+        assert resp_2001.json() == {"code": "cadwyn_error", "message": "Cadwyn error occurred"}