-1. formatting should be done by humans (with the help of tools) before committing. 

It should not be left to a robot to make automatic changes.

We already some pre-commit hooks which do basic checks. If anything more 

automated is desirable then enhancement to the pre-commit hooks could be the place to look for.

As far as I know, none of the core devs have expressed any complaints the pre-commit hooks.

-- 

Senthil