gitx.sh

gitx() {
  local gitdir gitdirtx=false
  local worktree worktreetx=false
  gitdir=$(git rev-parse --git-dir) || return $?
  worktree=$(git rev-parse --show-toplevel) || return $?
  case $gitdir   in *.git/worktrees/tx) gitdirtx=true;;   esac
  case $worktree in *.git/tx)           worktreetx=true;; esac
  case ${1-} in
  begin)
    test "$gitdirtx:$worktreetx" = "false:false" || {
      echo "gitx: already in a transaction" >&2
      return 1
    }
    git worktree add "${gitdir}/tx" --detach || return $?
    cd "${gitdir}/tx" || return $?
    gitdir=$(git rev-parse --git-dir) || return $?
    printf "%s\n" "$OLDPWD" > "$gitdir/tx-source"
    ;;
  commit)
    test "$gitdirtx:$worktreetx" = "true:true" || {
      echo "gitx: not in a transaction" >&2
      return 1
    }
    { git diff-files --quiet --ignore-submodules &&
      git diff-index --quiet --cached --ignore-submodules HEAD; } || {
      echo "gitx: worktree contains uncommitted changes" >&2
      return 1
    }
    local hash branch
    hash=$(git rev-parse HEAD) || return $?
    worktree=$(cat -- "$gitdir/tx-source") || return $?
    if branch=$(git -C "$worktree" symbolic-ref --quiet HEAD)
    then
      case $branch in
      refs/heads/*) branch=${branch#refs/heads/} ;;
      *)            echo "cannot determine branch name" >&2
                    return 1 ;;
      esac
    else unset branch
    fi
    gitdir=$(git -C "$worktree" rev-parse --git-dir) || return $?
    git -C "$worktree" checkout ${branch+-B "$branch"} $hash || return $?
    cd -- "${worktree}" || return $?
    git worktree remove "${gitdir}/tx" || return $?
    ;;
  rollback)
    test "$gitdirtx:$worktreetx" = "true:true" || {
      echo "gitx: not in a transaction" >&2
      return 1
    }
    worktree=$(cat -- "$gitdir/tx-source") || return $?
    gitdir=$(git -C "$worktree" rev-parse --git-dir) || return $?
    cd -- "${worktree}" || return $?
    git worktree remove -f "${gitdir}/tx" || return $?
    ;;
  *)
    echo "usage: gitx begin|commit|rollback" >&2
    return 1
    ;;
  esac
}