utils: added decorator to simplify common error handling

- we add a simple decorator which allows arguments for the exceptions to catch and also
for the exception to later reraise from the caught exception
- this simplifies the code within the version manager when we deal with versions that could be integer strings

karapace/utils.py

@@ -19,6 +19,7 @@
 from types import MappingProxyType
 from typing import AnyStr, cast, IO, Literal, NoReturn, overload, TypeVar
 
+import functools
 import importlib
 import kafka.client_async
 import logging
@@ -214,6 +215,23 @@ def convert_to_int(object_: dict, key: str, content_type: str) -> None:
         )
 
 
+def catch_and_raise_error(to_catch: tuple[Exception], to_raise: Exception):
+    def wrapper(f):
+        @functools.wraps(f)
+        def catcher(*args, **kwargs):
+            try:
+                value = f(*args, **kwargs)
+                if not value:
+                    raise to_raise
+                return value
+            except to_catch as exc:
+                raise to_raise from exc
+
+        return catcher
+
+    return wrapper
+
+
 class KarapaceKafkaClient(KafkaClient):
     def __init__(self, **configs):
         kafka.client_async.BrokerConnection = KarapaceBrokerConnection

tests/unit/test_utils.py

@@ -0,0 +1,29 @@
+"""
+karapace - Test utils
+
+Copyright (c) 2024 Aiven Ltd
+See LICENSE for details
+"""
+
+from karapace.utils import catch_and_raise_error
+
+import pytest
+
+
+def test_catch_and_raise_error():
+    class RaiseMe(Exception):
+        pass
+
+    @catch_and_raise_error(to_catch=(ValueError,), to_raise=RaiseMe)
+    def v():
+        int("not a number")
+
+    with pytest.raises(RaiseMe):
+        v()
+
+    @catch_and_raise_error(to_catch=(ZeroDivisionError,), to_raise=RaiseMe)
+    def z():
+        _ = 100 / 0
+
+    with pytest.raises(RaiseMe):
+        z()