unixorn/git-extra-commands

#!/usr/bin/env bash
#
# Fetch PR branches by refspec from one of a repository's remotes.
#
# Copyright 2020-2022, Joe Block <jpb@unixorn.net>

set -o pipefail

DEFAULT_REMOTE=${DEFAULT_REMOTE:-"origin"}

function debug() {
  if [[ -n "$DEBUG" ]]; then
    echo "$@"
  fi
}

function usage() {
  local myname
  myname=$(basename "$0")
  echo "$myname [remote]"
  echo
  echo "Pulls all the PR branches from one of your remotes. If remote is not specified, defaults to $DEFAULT_REMOTE."
}

function fail() {
  printf '%s\n' "$1" >&2  ## Send message to stderr. Exclude >&2 if you don't want it that way.
  exit "${2-1}"  ## Return a code specified by $2 or 1 by default.
}

function has() {
  # Check if a command is in $PATH
  which "$@" > /dev/null 2>&1
}

if [[ "$1" == '--help' ]]; then
  usage
  exit 0
fi

debug "DEFAULT_REMOTE: $DEFAULT_REMOTE"

if ! has git; then
  fail "Couldn't find git in your PATH"
fi

if [ -z "$1" ]; then
  echo "Remote not specified, using $DEFAULT_REMOTE."
  git_remote="$DEFAULT_REMOTE"
else
  git_remote="$1"
fi

# Get all Pull Request branches as local remote branches by refspec.
# shellcheck disable=SC2086
exec git fetch "$git_remote" +refs/heads/\*:refs/remotes/$git_remote/\* +refs/pull/\*/head:refs/remotes/$git_remote/pr/\*