business-rules extension updates

Author: jerryvig

business_rules/engine.py

@@ -58,13 +58,16 @@ def check_condition(condition, defined_variables):
     """
     name, op, value, other_name = condition['name'], condition['operator'], condition.get('value'), condition.get('other_name')
     operator_type = _get_variable_value(defined_variables, name)
-    if other_name:
+    if other_name is not None:
         other_operator_type = _get_variable_value(defined_variables, other_name)
         if other_operator_type != operator_type:
-            raise ValueError("Both variables in a comparison must be of the same type")
+            raise ValueError("Both variables in a dual variable comparison must be of the same type")
         return _do_operator_comparison(operator_type, op, other_operator_type)
-    else:
+    elif value is not None:
         return _do_operator_comparison(operator_type, op, value)
+    else:
+        raise ValueError("Condition must have a 'value' or 'other_name' key")
+
 
 def _get_variable_value(defined_variables, name):
     """ Call the function provided on the defined_variables object with the

tests/test_engine_logic.py

@@ -237,3 +237,28 @@ def test_do_with_invalid_action() -> None:
     err_string = "Action fakeone is not defined in class BaseActions"
     with pytest.raises(AssertionError, match=err_string):
         engine.do_actions(actions, BaseActions())
+
+
+@pytest.mark.parametrize(("variable_value", "expected"), [
+    ("test_value", True),
+    ("test_value2", False),
+])
+def test_check_condition_with_value(variable_value, expected) -> None:
+    """
+    DOCUMENT ME.
+    """
+    condition = {"name": "name", "operator": "equal_to", "value": "test_value"}
+    with patch.object(engine, "_get_variable_value", return_value=StringType(variable_value)):
+        assert engine.check_condition(condition, BaseVariables()) is expected
+
+
+def test_check_condition_raises_if_both_value_and_other_name_missing() -> None:
+    """
+    DOCUMENT ME.
+    """
+    condition = {"name": "name", "operator": "operator",}
+    with (
+        patch.object(engine, "_get_variable_value", return_value=StringType("test_value")),
+        pytest.raises(ValueError, match="Condition must have a 'value' or 'other_name' key"),
+    ):
+        engine.check_condition(condition, BaseVariables())