git checkout remote pull request to local branch and track it with FZF-TMUX

checkout-pr.zsh

# git checkout remote pull request to local branch and track it with FZF-TMUX
# Requirements:
# - hub : https://github.com/github/hub
# - fzf-tmux : https://github.com/junegunn/fzf#fzf-tmux-script
pr() {
  local pr_list pr_id origin branch_name
  pr_list=$(cat /dev/null | hub pr list -f "%pC%>(8)%i%Creset %t @%au %l%n")
  result=$?
  if [[ $pr_list == *"github.com username:"* ]]; then
    echo "Please run 'hub pr list' to login GitHub"
    return
  fi

  if [ $result -ne 0 ]; then
    return
  fi

  pr_id=$(
    echo $pr_list |
    fzf-tmux -d 15 --no-hscroll |
    sed 's/[^#]*#\([^ ]*\).*/\1/') || return

  branch_name=pr.$pr_id
  # check the branch exists
  if [ $(git branch | grep $branch_name | wc -l) -eq  1 ]; then
    git checkout $branch_name
  else
    origin='origin'
    if git remote | grep -qE '^upstream$'; then
      origin='upstream'
    fi
    [[ "$pr_id" =~ ^[0-9]+$ ]] && hub pr checkout $pr_id $branch_name
  fi
}