Showing git branch in fish shell prompt

config.fish

set fish_git_dirty_color red
set fish_git_not_dirty_color green

function parse_git_branch
  set -l branch (git branch 2> /dev/null | grep -e '\* ' | sed 's/^..\(.*\)/\1/')
  set -l git_diff (git diff)

  if test -n "$git_diff"
    echo (set_color $fish_git_dirty_color)$branch(set_color normal)
  else
    echo (set_color $fish_git_not_dirty_color)$branch(set_color normal)
  end
end

function fish_prompt
  if test -d .git
    printf '%s@%s %s%s%s:%s> ' (whoami) (hostname|cut -d . -f 1) (set_color $fish_color_cwd) (prompt_pwd) (set_color normal) (parse_git_branch)
  else
    printf '%s@%s %s%s%s> ' (whoami) (hostname|cut -d . -f 1) (set_color $fish_color_cwd) (prompt_pwd) (set_color normal)
  end
end

reference by http://zogovic.com/post/37906589287/showing-git-branch-in-fish-shell-prompt