Prevent commit if merge conflict markers or debuggers are in your changes

pre-commit

#!/bin/bash
#
# This pre-commit hook checks that there are no merge conflict markers
# or debuggers in your code before committing.
#
# To use this script copy it to .git/hooks/pre-commit and make it executable.

# Work out what to diff against, HEAD will work for any established repository.
if git rev-parse --verify HEAD >/dev/null 2>&1
then
    against=HEAD
else
    # hash for an empty tree object for all git repos
    against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

diffstr=`git diff --cached $against | grep -E '<<<<<<< HEAD|>>>>>>>|=======|debugger|binding.pry'`

if [[ -n "$diffstr" ]] ; then
    echo "|-------------------------------------------------------------|"
    echo "| You have left some merge conflict markers or                |"
    echo "| debuggers in your changes.                                  |"
    echo "| E.g '<<<<<<< HEAD' OR '>>>>>>>' OR '=======' OR             |"
    echo "|     'debugger' OR 'binding.pry'                             |"
    echo "| You can't commit until this has been resolved.              |"
    echo "| Resolve the conflict(s), remove the marker(s).              |"
    echo "| Add the files to git and commit again.                      |"
    echo "|-------------------------------------------------------------|"
    exit 1
fi