Over the weekend, I wanted to implement something that acted as both a class and function decorator, but could also be used as a context manager. I needed this flexibility for overriding configuration values making it easier to write tests. I wanted to use it in the following ways:

1. as a function decorator:

   @config_override(DEBUG='False')
   def test_something():
       ...
   

2. as a class decorator that would decorate all methods that start with test_:

   @config_override(DEBUG='False')
   class TestSomething:
       def test_something(self):
           ...
   

3. as a context manager that allowed for multiple layer of overriding:

   def test_something():
       with config_override(DEBUG='False'):
           with config_override(SOMETHING_ELSE='ou812'):
               ...
   

This kind of need comes up periodically, but infrequently enough that I forget how I wrote it the last time around.

This post walks through how I structured it.

Read more… (3 mins to read)