NiftyBash: customize terminal prompt to show package.json version, git branch, and commit status (this is the end of my `.bashrc`)

.bashrc

COLOR_RED="\033[0;31m"
COLOR_YELLOW="\033[0;33m"
COLOR_GREEN="\033[0;32m"
COLOR_OCHRE="\033[38;5;95m"
COLOR_BLUE="\033[0;34m"
COLOR_WHITE="\033[0;37m"
COLOR_RESET="\033[0m"

function git_color() {
  local git_status="$(git status 2>/dev/null)"

  if [[ ! $git_status =~ "working directory clean" ]]; then
    echo -e $COLOR_GREEN
  elif [[ $git_status =~ "Your branch is ahead of" ]]; then
    echo -e $COLOR_YELLOW
  elif [[ $git_status =~ "nothing to commit" ]]; then
    echo -e $COLOR_GREEN
  else
    echo -e $COLOR_OCHRE
  fi
}

function git_branch() {
  local git_status="$(git status 2>/dev/null)"
  local on_branch="On branch ([^${IFS}]*)"
  local on_commit="HEAD detached at ([^${IFS}]*)"

  if [[ $git_status =~ $on_branch ]]; then
    local branch=${BASH_REMATCH[1]}
    echo "($branch)"
  elif [[ $git_status =~ $on_commit ]]; then
    local commit=${BASH_REMATCH[1]}
    echo "($commit)"
  fi
}

function npm_version() {
  if [ -f "package.json" ]; then
    # Version key/value should be on his own line
    PACKAGE_VERSION=$(cat package.json |
      grep version |
      head -1 |
      awk -F: '{ print $2 }' |
      sed 's/[",]//g' |
      tr -d '[[:space:]]')
    if [[ -n "$PACKAGE_VERSION" ]]; then
      # String exists
      echo "@$PACKAGE_VERSION"
    fi
  fi
}

PS1="${debian_chroot:+($debian_chroot)}"
PS1+="\[$COLOR_GREEN\]\u@\h\[$COLOR_WHITE\]:\[$COLOR_BLUE\]\w" # basename of pwd
PS1+="\[$COLOR_YELLOW\]\$(npm_version)"
PS1+="\[\$(git_color)\]" # colors git status
PS1+=" \$(git_branch)"   # prints current branch
PS1+="\n\[$COLOR_GREEN\]λ\[$COLOR_RESET\] "

# If this is an xterm set the title to user@host:dir (not really sure what this does)
case "$TERM" in
xterm* | rxvt*)
  PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
  ;;
*) ;;

esac

export PS1

README.md

Features

• NPM Package version
• Git status
• Git branch
• Cool lambda symbol

Screenshot

Instructions

Paste at the end of your .bashrc

Feel free to fork or request changes!