TEST008 - Error Handling Middleware Testing (#88)

Author: s223503101

database/Validation/TEST008-Error-Handling-Middleware-Testing.md

@@ -0,0 +1,70 @@
+# TEST008 - Error Handling Middleware Testing
+
+This document records the testing evidence and result for ticket **TEST008**.
+
+## Ticket intent
+
+- Trigger API errors.
+- Check response format.
+- Confirm consistent error responses.
+- Confirm proper status codes.
+
+## Scope
+
+Validated backend error handling behavior implemented in:
+
+- `database/logging_system/request_middleware.py`
+- `database/logging_system/exception_handler.py`
+
+Automated tests added in:
+
+- `test/test_t1008_error_handling_middleware.py`
+
+## Test cases implemented
+
+1. **Success path includes request traceability**
+   - Call `GET /ok`.
+   - Expect HTTP `200`.
+   - Expect body: `{"ok": true}`.
+   - Expect `X-Request-ID` response header is present.
+
+2. **Error path returns consistent format and status**
+   - Call `GET /explode` (forced runtime exception).
+   - Expect HTTP `500`.
+   - Expect body includes:
+     - `message` = `"Internal server error"`
+     - `request_id` (non-empty)
+   - Expect `X-Request-ID` header equals body `request_id`.
+
+## Fix applied during testing
+
+While executing TEST008, one assertion failed because error responses did not include the `X-Request-ID` header.  
+To align success and error behavior, `global_exception_handler` was updated to set:
+
+- `headers={"X-Request-ID": request_id}`
+
+in the returned `JSONResponse`.
+
+## Execution evidence
+
+Command run from repository root:
+
+```bash
+python -m pytest test/test_t1008_error_handling_middleware.py -q
+```
+
+Observed result:
+
+```text
+..                                                                       [100%]
+2 passed in 0.30s
+```
+
+## Final result
+
+TEST008 acceptance criteria are satisfied by automated tests:
+
+- API errors are triggered and validated.
+- Error response format is consistent.
+- Proper status codes are returned (`200` success, `500` unhandled error).
+- `request_id` tracing is consistent in both payload and response header.

database/logging_system/exception_handler.py

@@ -38,4 +38,5 @@ async def global_exception_handler(request: Request, exc: Exception) -> JSONResp
             "message": "Internal server error",
             "request_id": request_id,
         },
+        headers={"X-Request-ID": request_id},
     )

test/test_t1008_error_handling_middleware.py

@@ -0,0 +1,50 @@
+import pytest
+
+fastapi = pytest.importorskip("fastapi")
+pytest.importorskip("starlette")
+
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+from database.logging_system.exception_handler import global_exception_handler
+from database.logging_system.request_middleware import RequestLoggingMiddleware
+
+
+def _build_test_app() -> FastAPI:
+    app = FastAPI()
+    app.add_middleware(RequestLoggingMiddleware)
+    app.add_exception_handler(Exception, global_exception_handler)
+
+    @app.get("/ok")
+    async def ok_route():
+        return {"ok": True}
+
+    @app.get("/explode")
+    async def explode_route():
+        raise RuntimeError("TEST008 forced failure")
+
+    return app
+
+
+def test_t1008_success_request_has_request_id_header():
+    client = TestClient(_build_test_app())
+
+    response = client.get("/ok")
+
+    assert response.status_code == 200
+    assert response.json() == {"ok": True}
+    assert "X-Request-ID" in response.headers
+    assert response.headers["X-Request-ID"]
+
+
+def test_t1008_error_response_has_consistent_shape_and_status_code():
+    client = TestClient(_build_test_app(), raise_server_exceptions=False)
+
+    response = client.get("/explode")
+
+    assert response.status_code == 500
+    payload = response.json()
+    assert payload["message"] == "Internal server error"
+    assert "request_id" in payload
+    assert payload["request_id"]
+    assert response.headers["X-Request-ID"] == payload["request_id"]