From fae89bd452af16775e253389d302d2c2d5d93147 Mon Sep 17 00:00:00 2001
From: Arthur Meyre <arthur.meyre@zama.ai>
Date: Thu, 4 Nov 2021 15:16:27 +0100
Subject: [PATCH] refactor: add python generic helpers

- move catch and update_and_return_dict there
---
 concrete/common/helpers/__init__.py           |  2 +-
 concrete/common/helpers/python_helpers.py     | 35 +++++++++++++++++++
 .../common/representation/intermediate.py     | 12 +------
 tests/common/helpers/test_python_helpers.py   | 24 +++++++++++++
 4 files changed, 61 insertions(+), 12 deletions(-)
 create mode 100644 concrete/common/helpers/python_helpers.py
 create mode 100644 tests/common/helpers/test_python_helpers.py

diff --git a/concrete/common/helpers/__init__.py b/concrete/common/helpers/__init__.py
index 908c72ca0..8680796ce 100644
--- a/concrete/common/helpers/__init__.py
+++ b/concrete/common/helpers/__init__.py
@@ -1,3 +1,3 @@
 """Helpers for all kinds of tasks."""
 
-from . import indexing_helpers
+from . import indexing_helpers, python_helpers
diff --git a/concrete/common/helpers/python_helpers.py b/concrete/common/helpers/python_helpers.py
new file mode 100644
index 000000000..e7c7bbed2
--- /dev/null
+++ b/concrete/common/helpers/python_helpers.py
@@ -0,0 +1,35 @@
+"""Common python helpers."""
+
+from typing import Any, Callable, Iterable, Mapping, Tuple, Union
+
+
+def update_and_return_dict(
+    dict_to_update: dict, update_values: Union[Mapping, Iterable[Tuple[Any, Any]]]
+) -> dict:
+    """Update a dictionary and return the ref to the dictionary that was updated.
+
+    Args:
+        dict_to_update (dict): the dict to update
+        update_values (Union[Mapping, Iterable[Tuple[Any, Any]]]): the values to update the dict
+            with
+
+    Returns:
+        dict: the dict that was just updated.
+    """
+    dict_to_update.update(update_values)
+    return dict_to_update
+
+
+def catch(func: Callable, *args, **kwargs) -> Union[Any, None]:
+    """Execute func by passing args and kwargs. Catch exceptions and return None in case of failure.
+
+    Args:
+        func (Callable): function to execute and catch exceptions from
+
+    Returns:
+        Union[Any, None]: the function result if there was no exception, None otherwise.
+    """
+    try:
+        return func(*args, **kwargs)
+    except Exception:  # pylint: disable=broad-except
+        return None
diff --git a/concrete/common/representation/intermediate.py b/concrete/common/representation/intermediate.py
index 445ec6e27..fd0bdeffb 100644
--- a/concrete/common/representation/intermediate.py
+++ b/concrete/common/representation/intermediate.py
@@ -16,6 +16,7 @@ from ..data_types.dtypes_helpers import (
 from ..data_types.integers import Integer
 from ..debugging.custom_assert import assert_true
 from ..helpers import indexing_helpers
+from ..helpers.python_helpers import catch, update_and_return_dict
 from ..values import (
     BaseValue,
     ClearScalar,
@@ -390,22 +391,11 @@ class GenericFunction(IntermediateNode):
         min_input_range = variable_input_dtype.min_value()
         max_input_range = variable_input_dtype.max_value() + 1
 
-        def catch(func, *args, **kwargs):
-            try:
-                return func(*args, **kwargs)
-            # We currently cannot trigger exceptions in the code during evaluation
-            except Exception:  # pragma: no cover # pylint: disable=broad-except
-                return None
-
         template_input_dict = {
             idx: node.evaluate({}) if isinstance(node, Constant) else None
             for idx, node in enumerate(ordered_preds)
         }
 
-        def update_and_return_dict(dict_to_update: dict, update_values):
-            dict_to_update.update(update_values)
-            return dict_to_update
-
         table = [
             catch(
                 self.evaluate,
diff --git a/tests/common/helpers/test_python_helpers.py b/tests/common/helpers/test_python_helpers.py
new file mode 100644
index 000000000..2b219b9b6
--- /dev/null
+++ b/tests/common/helpers/test_python_helpers.py
@@ -0,0 +1,24 @@
+"""Test file for common python helpers"""
+
+from concrete.common.helpers.python_helpers import catch
+
+
+def test_catch_failure():
+    """Test case for when the function called with catch raises an exception."""
+
+    def f_fail():
+        return 1 / 0
+
+    assert catch(f_fail) is None
+
+
+def test_catch():
+    """Test case for catch"""
+
+    def f(*args, **kwargs):
+        return *args, dict(**kwargs)
+
+    assert catch(f, (1, 2, 3,), **{"one": 1, "two": 2, "three": 3}) == (
+        (1, 2, 3),
+        {"one": 1, "two": 2, "three": 3},
+    )