Describe the bug
When using @storybook/addons-backgrounds in a react project with a custom Decorator, the initial/default background value is not passed to the context.globals.

I have a project performing text contrast logic where I need the initial value to pass to javascript.

To Reproduce

1. Pull down and run this re

Current behavior

I think there's a mismatch of environment variables being read by babel (JSX config) and Styleguidist, causing some issues deeper down.

(I've noticed this was raised before but was closed)

• build.js sets the env to be production here: https://github.com/styleguidist/react-styleguidist/blob/master/src/s

hello, i just found a text mentioning a basePxFontSize configuration which is not documented anywhere inside the doc. This is really useful to use inside custom transforms and it should be documented.

Rule request

We need to forbid code like raise exc from exc, because it does not make much sense and works the same way:

>>> e = Exception('m')
>>> raise e
Traceback (most recent call last):
  File "ex.py", line 1, in <module>
    e = Exception("m"); raise e
Exception: m

And with from:

>>> e = Exception('m')
>>> raise e from e
Traceback (most rec