fix: return false when object contains invalid regex (#18)

* fix: return false when object contains invalid regex

* style: format python code (pep8)

* Update condition_test.py

Co-authored-by: MatthewLENG2002 <MatthewLENG2002@users.noreply.github.com>

Author: matthew-leng

featureprobe/model/condition.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import logging
+import re
 import time
 from typing import List, Dict, Union, Optional, TYPE_CHECKING
 
@@ -81,7 +82,11 @@ def _match_string_condition(self, user: "User", **_) -> bool:
         subject_val = user[self._subject]
         if empty_str(subject_val):
             return False
-        return self._predicate.matcher(subject_val, self._objects)
+        try:
+            return self._predicate.matcher(subject_val, self._objects)
+        except re.error as e:
+            self._logger.error('Invalid regular expression', exc_info=e)
+            return False
 
     def _match_segment_condition(
             self, user: "User", segments: Dict[str, "Segment"], **_) -> bool:

tests/condition_test.py

@@ -99,6 +99,17 @@ def test_string_matches_regex():
     assert not condition.match_objects(user, segments)
 
 
+def test_string_invalid_regex():
+    condition.objects = ['\\\\\\']
+    user['userId'] = '13797347245'
+
+    condition.predicate = fp.StringPredicate.MATCHES_REGEX
+    assert not condition.match_objects(user, segments)
+
+    condition.predicate = fp.StringPredicate.DOES_NOT_MATCH_REGEX
+    assert not condition.match_objects(user, segments)
+
+
 def test_string_is_not_any_of():
     condition.objects = ['12345', '987654', '665544']
     condition.predicate = fp.StringPredicate.IS_NOT_ANY_OF