Git stack

git-stack

#!/bin/sh
#
# git-stack: Push this commit to a branch specified in its
# commit description.
#
# -- IMPORTANT -- this script is for macOS (using BSD sed)
# 
# Taken from https://wchargin.github.io/posts/managing-dependent-pull-requests/
# Copyright (c) 2017 William Chargin. Released under the MIT license.

set -eu

DIRECTIVE='stacked-branch'  # any regex metacharacters should be escaped
BRANCH_PREFIX="${USER}/stacked/"

target_branch() {
    directive="$( \
        git show --pretty='%B' \
        | sed -n -E 's/^'"${DIRECTIVE}"': ([A-Za-z0-9_.-]+)$/\1/p' \
        ; )"
    if [ -z "${directive}" ]; then
        printf >&2 'error: missing "%s" directive\n' "${DIRECTIVE}"
        return 1
    fi
    if [ "$(printf '%s\n' "${directive}" | wc -l)" -gt 1 ]; then
        printf >&2 'error: multiple "%s" directives\n' "${DIRECTIVE}"
        return 1
    fi
    printf '%s%s\n' "${BRANCH_PREFIX}" "${directive}"
}

main() {
    if [ "${1:-}" = "--query" ]; then
        target_branch
        return
    fi
    remote="${1:-origin}"
    branch="$(target_branch)"
    set -x
    git push --force-with-lease "${remote}" HEAD:refs/heads/"${branch}"
}

main "$@"

Script needs to be marked executable and placed somewhere on the PATH