Laravel 5.4/5.5 auth by email or username

LoginController.php

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class LoginController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Login Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles authenticating users for the application and
    | redirecting them to your home screen. The controller uses a trait
    | to conveniently provide its functionality to your applications.
    |
    */

    use AuthenticatesUsers;

    /**
     * Where to redirect users after login.
     *
     * @var string
     */
    protected $redirectTo = '/';

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest')->except('logout');
    }

    // Changes for login by username (or email, by default)
    public function attemptLogin(Request $request)
    {
        $isEmail = filter_var($request->{$this->username()}, FILTER_VALIDATE_EMAIL);
        $loginField = $isEmail ? $this->username() : 'name'; // name - is username field in your db

        return Auth::attempt(
            [$loginField => $request->{$this->username()}, 'password' => $request->password],
            $request->has('remember')
        );
    }
}