FatalThrowableError in Call to a member function get_one() on null

i have some laravel code like this

public function update_password(Request $request)
    {
        $data = array(
            'password_current' => $request->input('password_current'), 
            'password_new' => $request->input('password_new'),
            'password_new_confirmation' => $request->input('password_new_confirmation'), 
            );

        $rules = [
            'password_current' => 'required',
            'password_new' => 'required|confirmed',
            'password_new_confirmation' => 'required',
        ];

        $validator = Validator::make($data, $rules);
        if ($validator->fails()) {   
            return redirect()->action('Editor\ProfileController@edit_password')->withInput()->withErrors(['New password confirmation failed!']);
        } else {
            
            $user = $this->UserRepository->get_one(Auth::user()->id);
            
            if(Hash::check($request->input('password_current'), $user->password))
            {
                $this->UserRepository->change_password(Auth::user()->id, $request->input('password_new'));

                return redirect()->action('Editor\ProfileController@show');
            } else {
                return redirect()->action('Editor\ProfileController@edit_password')->withInput()->withErrors(['Current password mismatch!']);
            }
        }
    }

but when i run the program, the program notification is FatalThrowableError, Call to a member function get_one() on null. i change with other script in google but no one is work.

$user = $this->UserRepository->get_one(Auth::user()->id);

anyone ever had this problem?

I try to change script like

use Auth;
$user_id = Auth::user()->id;

and still not work.

via Chebli Mohamed