Helper in Laravel

composer and helper.json

 "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App\\": "app/"
        },
        "files":[
            "app/helpers.php" /* This line was added to load helper file. Then fire 'composer dump-autoload' command in terminal  */
        ]
    },

helpers.php

<?php
// FILE:: put this file here
// app/helpers.php
/*
 * Custom helpers functions for project by 
 * Shyam Makwana
 * 
 * Added By: Shyam Makwana
 * Date: 03rd May 2017
 * 
 */

use Illuminate\Support\Facades\Log;

/*
 * Check if string given is valid json or not 
 * 
 * @developer Shyam Makwana 
 * @param $str String given to check for valid json 
 * @return bool Returns true if json is valid or false
 */

function isJson($str) {
    $json = json_decode($str);
    return $json && $str != $json;
}

/*
 * Logs arguments in log file.
 * 
 * @developer Shyam Makwana 
 * @return void 
 */
function logInfo() {
     Log::info(func_get_args());
}