How to remove the white space when in a no-git directory

[dss886]

When I am in a directory which is not a git repository, there is an white space shown at the end of the prompt.

I've tried to uncomment the if-statement in line 109 to line 128, not work.

Also tried the ternary expression as this article:

POWERLINE_GIT_INFO_LEFT=$(("$(git_prompt_info)"=""?1:0))

But end up with : zsh: bad math expression: illegal character: "

My temporary solution is add below lines to my ~/.zshrc:

function newCD(){
	cd $1;
	source "$ZSH/themes/$ZSH_THEME.zsh-theme"
}
alias cd="newCD"

But it seems to so ugly and unstable as I changed the behavior of the default command "cd", so does anyone have a better solution?