git-branch-backup.zsh

#! /usr/bin/env zsh

function latest_backup_id() {
    local branch="${1}"
    [[ "${branch}" == "" ]] && return 1

    local prefix="${b}.backup"
    git branch --list --color=never "${prefix}*" \
        | sed "s/^..${prefix}//" \
        | sort -nr \
        | head -n1 \
}

function new_backup_id() {
    local branch="${1}"
    latest=$(latest_backup_id "${branch}") || return 1
    echo $(( $latest + 1 ))
}

main() {
    local b id
    b=$(git rev-parse --abbrev-ref HEAD) || return 1
    id=$(new_backup_id "${b}") || return 1

    git checkout -b "${b}.backup${id}" || return 1
    git checkout "${b}" || return 1
}

main