еще правки

api/src/core/exception_handlers.py

@@ -1,4 +1,5 @@
 from fastapi import FastAPI, HTTPException, status
+from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 from sqlalchemy.exc import IntegrityError, OperationalError, SQLAlchemyError, DBAPIError
 
@@ -94,7 +95,28 @@ def map_http_exception(exc: HTTPException) -> tuple[int, int, str, str]:
     return status_code, status_code, message, ""
 
 
+def map_request_validation_error(exc: RequestValidationError) -> tuple[int, int, str, str]:
+    status_code = status.HTTP_422_UNPROCESSABLE_ENTITY
+    errors = exc.errors()
+    if not errors:
+        return status_code, status_code, "Validation error", ""
+
+    first_error = errors[0]
+    message = str(first_error.get("msg") or "Validation error")
+    loc = first_error.get("loc") or ()
+    field = ".".join(str(part) for part in loc if part not in ("body", "query", "path", "header", "cookie"))
+    return status_code, status_code, message, field
+
+
 def register_exception_handlers(app: FastAPI) -> None:
+    @app.exception_handler(RequestValidationError)
+    async def request_validation_exception_handler(request, exc: RequestValidationError):
+        status_code, code, message, field = map_request_validation_error(exc)
+        return JSONResponse(
+            status_code=status_code,
+            content=_error_payload(code, message, field=field),
+        )
+
     @app.exception_handler(HTTPException)
     async def http_exception_handler(request, exc: HTTPException):
         status_code, code, message, field = map_http_exception(exc)

api/tests/unit/test_exception_handlers_http_shape.py

@@ -29,6 +29,10 @@ def _make_app() -> FastAPI:
         exc.orig = Exception("budget_form #99 не существует")
         raise exc
 
+    @app.get("/form/{form_id}")
+    async def form_by_id(form_id: int):
+        return {"form_id": form_id}
+
     return app
 
 
@@ -66,3 +70,15 @@ def test_sqlalchemy_exception_returns_structured_payload():
         "field": "",
         "message": "budget_form #99 не существует",
     }
+
+
+def test_request_validation_422_returns_structured_payload():
+    client = TestClient(_make_app())
+    response = client.get("/form/not-int")
+
+    assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+    assert response.json() == {
+        "code": status.HTTP_422_UNPROCESSABLE_ENTITY,
+        "field": "form_id",
+        "message": "Input should be a valid integer, unable to parse string as an integer",
+    }