ENH(transformers): added better logic for converting to bool

src/caoscrawler/transformer_functions.py

@@ -127,11 +127,20 @@ def cast_to_bool(in_value: Any, params: dict) -> bool:
     """
     Cast the `in_value` to bool.
 
+    This is done by comparing `in_value` to "True".
+    Only "true", "True", "False" and "false" are accepted as possible values.
+    All other input values raise an error.
+
     Parameters
     ==========
     No parameters.
     """
-    return bool(in_value)
+    val = str(in_value).lower()
+    if val == "true":
+        return True
+    if val == "false":
+        return False
+    raise ValueError("Invalid value for type cast to bool: {}".format(in_value))
 
 
 def cast_to_str(in_value: Any, params: dict) -> str: