unixorn/git-extra-commands

#!/usr/bin/env bash
# Usage: git where-pr [--print] <ref>
#
# Opens the Pull Request on GitHub where the commit originated.
# https://github.com/mislav/dotfiles/blob/master/bin/git-where-pr
set -e

mode=open

case "$1" in
-h | --help )
  sed -ne '/^#/!q;s/.\{1,2\}//;1d;p' < "$0"
  exit 0
  ;;
--print )
  mode=echo
  shift 1
  ;;
esac

ref="$1"
if [ -z "$ref" ]; then
  "$0" --help >&2
  exit 1
fi

pull_id="$(git log --merges --ancestry-path --oneline "${ref}.." | awk '
  /Merge pull request #/ { sub("#", "", $5); print $5 }
' | tail -1)"

if [ -n "$pull_id" ]; then
  url="$(git remote -v | awk '
    /^origin\t/ { print $2 }
  ' | head -1 | sed -E 's!(git@github\.com:|git://github\.com/)!https://github.com/!')"
  url="${url%.git}"
  $mode "${url}/pull/${pull_id}"
else
  echo "Could not find pull request" >&2
  exit 1
fi