From a9f59822fc63e0f19999d584642f2982a4f777c6 Mon Sep 17 00:00:00 2001
From: dtomlinson <dtomlinson@williamhill.co.uk>
Date: Fri, 3 Jan 2020 17:31:13 +0000
Subject: [PATCH] updating config library.py

---
 .../read-from-config/library.py               | 39 +++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/python/module-packages/read-from-config/library.py b/python/module-packages/read-from-config/library.py
index 253919c..ebc50c3 100644
--- a/python/module-packages/read-from-config/library.py
+++ b/python/module-packages/read-from-config/library.py
@@ -1,7 +1,8 @@
 # Change MYMODULE
 from __future__ import annotations
 import sys
-from typing import Any, TypeVar, Type, TYPE_CHECKING
+from typing import Any, TypeVar, Type, TYPE_CHECKING, Union, List
+import ast
 
 if TYPE_CHECKING:
     import logging
@@ -24,22 +25,54 @@ def set_config(
     key: str,
     default: str = None,
     cast: Any = None,
+    check: Union[None, List] = None,
 ) -> None:
     """Sets the config variable on the instance of a class.
 
     Parameters
     ----------
     config_inst : Type[config_inst_t]
-        Instance of the :class:`~MYMODULE.config.Config` class.
+        Instance of the :class:`~netacea_slackbot.config.Config` class.
     key : str
         The key referencing the config variable.
     default : str, optional
         The default value.
     cast : Any, optional
         The type of the variable.
+    check : Union[None, List], optional
+        Type of object to check against. This is useful if you want to use TOML
+        to define a list, but want to make sure that a string representation
+        of a list will be loaded properly if it set as an environment variable.
+
+        Example:
+
+        `config.toml` has the following attribute set:
+            [package.users]
+            auth = ['user1', 'user2']
+
+        If set as an environment variable you can pass this list as a string
+        and set check=list:
+
+        Environment variable:
+        PACKAGE_USERS_AUTH = "['user1', 'user2']"
+
+        Usage in code:
+        ```python
+        set_config(CONFIG, 'users.auth', check=list)
+        ```
     """
     config_var = key.lower().replace('.', '_')
-    setattr(config_inst, config_var, config_inst.get(key, default, cast))
+    if check is None:
+        setattr(config_inst, config_var, config_inst.get(key, default, cast))
+    else:
+        if type(config_inst.get(key, default, cast)) is not check:
+            if check is list:
+                var = ast.literal_eval(config_inst.get(key, default, cast))
+                setattr(config_inst, config_var, var)
+        else:
+            setattr(
+                config_inst, config_var, config_inst.get(key, default, cast)
+            )
 
 
 # Create function to print cached logged messages and reset