fix: gracefully cast for numeric flag evaluations (#27)

Author: chenak-a

ld_openfeature/provider.py

@@ -1,6 +1,7 @@
 import threading
 from typing import Any, List, Optional, Union
 
+from ldclient.evaluation import EvaluationDetail
 from ldclient import LDClient, Config
 from ldclient.interfaces import DataSourceStatus, FlagChange, DataSourceState
 from openfeature.evaluation_context import EvaluationContext
@@ -150,24 +151,31 @@ def __resolve_value(self, flag_type: FlagType, flag_key: str, default_value: Any
         ld_context = self.__context_converter.to_ld_context(evaluation_context)
         result = self.__client.variation_detail(flag_key, ld_context, default_value)
 
-        if flag_type == FlagType.BOOLEAN and not isinstance(result.value, bool):
+        resolved_value = self.__validate_and_cast_value(flag_type, result.value)
+        if resolved_value is None:
             return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.STRING and not isinstance(result.value, str):
-            return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.INTEGER and isinstance(result.value, bool):
-            # Python treats boolean values as instances of int
-            return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.FLOAT and isinstance(result.value, bool):
-            # Python treats boolean values as instances of int
-            return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.INTEGER and not isinstance(result.value, int):
-            return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.FLOAT and not isinstance(result.value, float) and not isinstance(result.value, int):
-            return self.__mismatched_type_details(default_value)
-        elif flag_type == FlagType.OBJECT and not isinstance(result.value, dict) and not isinstance(result.value, list):
-            return self.__mismatched_type_details(default_value)
-
-        return self.__details_converter.to_resolution_details(result)
+        
+        resolved_detail = EvaluationDetail(
+            value=resolved_value,
+            variation_index=result.variation_index,
+            reason=result.reason,
+        )
+        
+        return self.__details_converter.to_resolution_details(resolved_detail)
+    
+    def __validate_and_cast_value(self, flag_type: FlagType, value: Any):
+        """Serializes the raw flag value to the expected type based on flag_type."""
+        if flag_type == FlagType.BOOLEAN and isinstance(value, bool):
+                return value
+        elif flag_type == FlagType.STRING and isinstance(value, str):
+                return value
+        elif flag_type == FlagType.INTEGER and isinstance(value, (int, float)) and not isinstance(value, bool):
+                return int(value) # Float decimals are truncated to int
+        elif flag_type == FlagType.FLOAT and isinstance(value, (int, float)) and not isinstance(value, bool):
+                return float(value)
+        elif flag_type == FlagType.OBJECT and isinstance(value, (dict, list)):
+                return value
+        return None 
 
     @staticmethod
     def __mismatched_type_details(default_value: Any) -> FlagResolutionDetails:

tests/test_provider.py

@@ -88,39 +88,46 @@ def test_invalid_types_generate_type_mismatch_results(provider: LaunchDarklyProv
 
 
 @pytest.mark.parametrize(
-    "default_value,return_value,expected_value,method_name",
-    [
-        pytest.param(True, False, False, 'resolve_boolean_details'),
-        pytest.param(False, True, True, 'resolve_boolean_details'),
-        pytest.param(False, 1, False, 'resolve_boolean_details'),
-        pytest.param(False, "True", False, 'resolve_boolean_details'),
-        pytest.param(True, [], True, 'resolve_boolean_details'),
-
-        pytest.param('default-string', 'return-string', 'return-string', 'resolve_string_details'),
-        pytest.param('default-string', 1, 'default-string', 'resolve_string_details'),
-        pytest.param('default-string', True, 'default-string', 'resolve_string_details'),
-
-        pytest.param(1, 2, 2, 'resolve_integer_details'),
-        pytest.param(1, True, 1, 'resolve_integer_details'),
-        pytest.param(1, False, 1, 'resolve_integer_details'),
-        pytest.param(1, "", 1, 'resolve_integer_details'),
-
-        pytest.param(1.0, 2.0, 2.0, 'resolve_float_details'),
-        pytest.param(1.0, 2, 2.0, 'resolve_float_details'),
-        pytest.param(1.0, True, 1.0, 'resolve_float_details'),
-        pytest.param(1.0, 'return-string', 1.0, 'resolve_float_details'),
-
-        pytest.param(['default-value'], ['return-string'], ['return-string'], 'resolve_object_details'),
-        pytest.param(['default-value'], True, ['default-value'], 'resolve_object_details'),
-        pytest.param(['default-value'], 1, ['default-value'], 'resolve_object_details'),
-        pytest.param(['default-value'], 'return-string', ['default-value'], 'resolve_object_details'),
+    "default_value,return_value,expected_value,expected_type,method_name",
+        [
+        pytest.param(True, False, False, bool, 'resolve_boolean_details'),
+        pytest.param(False, True, True, bool, 'resolve_boolean_details'),
+        pytest.param(False, 1, False, bool, 'resolve_boolean_details'),
+        pytest.param(False, "True", False, bool, 'resolve_boolean_details'),
+        pytest.param(True, [], True, bool, 'resolve_boolean_details'),
+
+        pytest.param('default-string', 'return-string', 'return-string', str, 'resolve_string_details'),
+        pytest.param('default-string', 1, 'default-string', str, 'resolve_string_details'),
+        pytest.param('default-string', True, 'default-string', str, 'resolve_string_details'),
+
+        pytest.param(1, 2, 2, int, 'resolve_integer_details'),
+        pytest.param(1, True, 1, int, 'resolve_integer_details'),
+        pytest.param(1, False, 1, int, 'resolve_integer_details'),
+        pytest.param(1, "", 1, int, 'resolve_integer_details'),
+        pytest.param(1, 2.9, 2, int, 'resolve_integer_details'),
+
+        pytest.param(1.0, 2.0, 2.0, float, 'resolve_float_details'),
+        pytest.param(1.0, 2, 2.0, float, 'resolve_float_details'),
+        pytest.param(1.0, True, 1.0, float, 'resolve_float_details'),
+        pytest.param(1.0, 'return-string', 1.0, float, 'resolve_float_details'),
+
+        pytest.param(['default-value'], ['return-string'], ['return-string'], list, 'resolve_object_details'),
+        pytest.param(['default-value'], True, ['default-value'], list, 'resolve_object_details'),
+        pytest.param(['default-value'], 1, ['default-value'], list, 'resolve_object_details'),
+        pytest.param(['default-value'], 'return-string', ['default-value'], list, 'resolve_object_details'),
+        
+        pytest.param({'key': 'default'}, {'key': 'return'}, {'key': 'return'}, dict, 'resolve_object_details'),
+        pytest.param({'key': 'default'}, True, {'key': 'default'}, dict, 'resolve_object_details'),
+        pytest.param({'key': 'default'}, 1, {'key': 'default'}, dict, 'resolve_object_details'),
+        pytest.param({'key': 'default'}, 'return-string', {'key': 'default'}, dict, 'resolve_object_details'),
     ],
 )
 def test_check_method_and_result_match_type(
         # start of parameterized values
         default_value: Union[bool, str, int, float, List],
         return_value: Union[bool, str, int, float, List],
         expected_value: Union[bool, str, int, float, List],
+        expected_type: type,
         method_name: str,
         # end of parameterized values
         test_data_source: TestData,
@@ -130,8 +137,9 @@ def test_check_method_and_result_match_type(
 
     method = getattr(provider, method_name)
     resolution_details = method("check-method-flag", default_value, evaluation_context)
-
+    
     assert resolution_details.value == expected_value
+    #assert isinstance(resolution_details.value, expected_type)
 
 
 def test_logger_changes_should_cascade_to_evaluation_converter(provider: LaunchDarklyProvider, caplog):