Deprecated. Use https://github.com/henriquemoody/duloc/blob/master/home/bin/git-fixup instead.

git-fixup

#!/usr/bin/env bash
# Usage: {script} PATH
# Construct a commit message for use with rebase --autosquash.
#
# The commit message will be the subject line from the specified commit with a
# prefix of "fixup! " and will contain the changes on the PATH.
#
#   --help, -h   Displays this help
#
# Report bugs to Henrique Moody <henriquemoody@gmail.com>
#

set -eo pipefail

declare -a HASH_LIST=()
declare -i HASH_INDEX=1
declare -i HASH_CHOSEN=0
declare -r PATHNAME=${1:-}

help()
{
  sed -E 's/^#\s?(.*)/\1/g' "${0}" |
    sed -nE '/^Usage/,/^Report/p' |
    sed "s/{script}/$(basename "${0}")/g"
}

git-log()
{
  local -r format=$'%H\t%h\t%s'

  if [[ ! -z "${PATHNAME}" ]]; then
    git log origin/HEAD...HEAD --format="${format}" "${PATHNAME}" 2> /dev/null ||
      git log --max-count 10 --format="${format}" "${PATHNAME}"
    return
  fi

  git log origin/HEAD...HEAD --format="${format}" 2> /dev/null ||
    git log --max-count 10 --format="${format}"
}

git-commit()
{
  if [[ ! -z "${PATHNAME}" ]]; then
    set -x
    git commit --fixup="${HASH_LIST[HASH_CHOSEN]}" "${PATHNAME}"
  fi

  set -x
  git commit --fixup="${HASH_LIST[HASH_CHOSEN]}"
}

if [[ "${1:-}" = "--help" ]] || [[ "${1:-}" = "-h" ]]; then
  help
  exit
fi

while IFS=$'\t' read -r commit_hash abbreviated_commit_hash subject; do
  if [[ "${subject}" =~ "fixup!" ]]; then
    continue
  fi

  echo "${HASH_INDEX}: ${abbreviated_commit_hash} -> ${subject}"

  HASH_LIST[HASH_INDEX]=${commit_hash}
  HASH_INDEX=$[HASH_INDEX + 1]
done < <(git-log)

if [[ ${#HASH_LIST[@]} -eq 1 ]]; then
  HASH_CHOSEN=1
fi

echo

while [[ ${HASH_CHOSEN} -eq 0 ]]; do
  echo -n "> Which commit would you like to fixup? "
  read user_input

  if [[ ! -v "HASH_LIST[user_input]" ]]; then
    echo "'${user_input}' is not a valid option." 1>&2
    continue
  fi

  HASH_CHOSEN=${user_input}
done

echo

git-commit

I had to add a default value on https://gist.github.com/henriquemoody/050d81f0f57df02bdd42dcb14f9fafd0#file-gfixup-L48 to make it work on bash 5.0.18:

- while [[ -z "${HASH_LIST[HASH_CHOSEN]}" ]]; do
+ while [[ -z "${HASH_LIST[HASH_CHOSEN]:-}" ]]; do

Thanks! I do recommend you using this one, though: https://github.com/henriquemoody/duloc/blob/master/home/bin/git-fixup

I've made quite a few updates that I didn't update before.