ZSH: show current git branch on enter

.zshrc

# This prints the current git branch when you submit an empty
# line (i.e. press enter) in zsh
#
# Less distracting than adding it to your prompt, but still
# very easy to run.

git-status-on-enter () {
    if [ ${#${(z)BUFFER}} -eq 0 ]; then
        if git rev-parse --git-dir > /dev/null 2>&1 ; then
            echo
            printf "%s" "$(git -c color.status=always status -sb)"
        fi
    fi
    zle accept-line
}
zle -N git-status-on-enter
bindkey '^M' git-status-on-enter