# Refactoring a function name across several patches with git rebase

git rebase is one of my favorite git commands. It allows to update a set of local patches against another git branch and also to rework, trough the -i flag some previous patches.

The problem I had to deal with was quite simple, rename a function called notProperPythonCode to proper_python that was defined in the first patch and be sure that all other patches are using the correct name. The –exec flag allows to run a custom script after each patch is applied, so that I could run sed to process the Python files and replace the old function name with the new one. The process is quite simple, except that such changes would trigger a lot of merge conflicts, trivial to solve but quite annoying.
Fortunately git rebase allows to choose what merge strategy must be adopted for solving conflicts, the theirs strategy in case of a conflict, will take the previous version of the patch and silently use it. That is fine for this simple substitution case, where we process each file ending by *.py in the repository.

In the end, the final command looked like this:

git rebase -X theirs -i \
--exec "sh -c \"git ls-files *.py \
| xargs sed --follow-symlinks -i -e \
's|notProperPythonCode|proper_python|g'\" \
&& git commit --amend -a -C HEAD" origin/master