Bash git script to revert n pull requests from a git repo. The command will squash each of the reverts into a single commit to keep the history cleaner. A commit message must also be supplied as an argument.

git-revert-merges

#!/bin/bash
usage="$(basename "$0") [-h] <n> <commit-message> -- revert back n pull requests

where:
    -h  show this help text"

while getopts ':h:' option; do
  case "$option" in
    h) echo "$usage"
       exit
       ;;
    :) printf "missing argument for -%s\n" "$OPTARG" >&2
       echo "$usage" >&2
       exit 1
       ;;
   \?) printf "illegal option: -%s\n" "$OPTARG" >&2
       echo "$usage" >&2
       exit 1
       ;;
  esac
done

#check if the user is being silly
if [ $# -ne 2 ]
  then
    echo "Command requires at exactly two arguments"
    echo "$usage" >&2
    exit 1
fi

#check if we have valid number
if echo $1 | grep -E '^[0-9]+$' > /dev/null
  then
  output="$(git rev-list --merges --max-count=$1 HEAD)"
else
  echo "Argument must be a positive integer."
  echo "$usage" >&2
  exit 1
fi

#convert list of merge hashes to array
read -a commits <<< $output

#Revert each o the changes
for commit in "${commits[@]}"; do
  echo Reverting merge: $commit
  git revert -m 1 --no-edit $commit
done

#Squash the reverts into a single commit for cleaner history
git reset --soft HEAD~$1
message="The following merge commits were reverted: ${commits[@]}"
git commit -m "$2" -m "$message"