Phase 1 of AUDIT-2026-Q3.md item P1.10 wiring.
Previously _register_apperror did:
try:
from app.core.errors import AppError
@app.exception_handler(AppError)
async def _app_error(...): ...
except Exception as exc:
log.info("error_handler_skipped name=AppError err=%s", exc)
That meant: if AppError was missing (it was — see previous commit), the
import silently failed and the app booted with ZERO typed-error handling.
All 2,532 except Exception: blocks would surface to clients as opaque 500s.
This change:
- Imports AppError (+ 4 commonly-raised subclasses) at module top so a
missing class is a hard ImportError at import time.
- Drops the try/except wrapper around _register_apperror.
- Renames the inner handlers to handle_app_error / handle_generic_exception
for clarity.
- handle_app_error returns exc.to_dict() (code, message, context) +
path + type, status_code = exc.status_code. The old code referenced
exc.message which would AttributeError since AppError stores message
via super().__init__, not as a self attribute.
- Drops the no-op try/except/pass in _register_validation (was a stub;
Phase 3 of the audit will wire RequestValidationError -> RMI ValidationError).
Verified via FastAPI TestClient:
GET /a AuthError -> 401 {code: auth.unauthorized, ...}
GET /r RateLimitError -> 429 {code: ratelimit.exceeded, ...}
GET /v ValidationError -> 400 {code: validation.failed, ...}
GET /n NotFoundError -> 404 {code: not_found, ...}
GET /u UpstreamError -> 502 {code: upstream.failed, ...}
GET /x RuntimeError -> 500 {error: internal_error, ...} (generic handler)
GET /404 -> 404 {error: not_found, hint, ...} (404 handler)
Refs AUDIT-2026-Q3.md P1.10.
