API Testing

<?php
class ApiClient
{
    const METHOD_GET = 'GET';
    const METHOD_PUT = 'PUT';
    const METHOD_POST = 'POST';
    const METHOD_DELETE = 'DELETE';
    protected $validMethods = [
        self::METHOD_GET,
        self::METHOD_PUT,
        self::METHOD_POST,
        self::METHOD_DELETE,
    ];
    protected $apiUrl;
    protected $cURL;
    protected $token;
 
    public function __construct($apiUrl, $username, $apiKey)
    {
        $this->apiUrl = rtrim($apiUrl, '/') . '/';
        $this->cURL = curl_init($this->apiUrl."rest/V1/integration/admin/token");
 
        $userData = array(
            'username' => $username,
            'password' => $apiKey          
        );
   
        curl_setopt($this->cURL, CURLOPT_CUSTOMREQUEST, "POST");
        curl_setopt($this->cURL, CURLOPT_POSTFIELDS, json_encode($userData));
        curl_setopt($this->cURL, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($this->cURL, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Content-Lenght: " . strlen(json_encode($userData))));
 
        $this->token = curl_exec($this->cURL);
    }
 
    public function call($url, $method = self::METHOD_GET, $data = [], $params = [])
    {
        if (!in_array($method, $this->validMethods)) {
            throw new Exception('Invalid HTTP-Methode: ' . $method);
        }
        $queryString = '';
        if (!empty($params)) {
            $queryString = http_build_query($params);
        }
        //$url = rtrim($url, '?') . '?';
        $url = $this->apiUrl . $url;// . $queryString;
        //$dataString = json_encode($data);
       
        $this->cURL = curl_init($url);
        curl_setopt($this->cURL, CURLOPT_CUSTOMREQUEST, $method);
        curl_setopt($this->cURL, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($this->cURL, CURLOPT_POSTFIELDS, json_encode($data));
        curl_setopt($this->cURL, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Authorization: Bearer " . json_decode($this->token)));
 
        $result = curl_exec($this->cURL);        
        $httpCode = curl_getinfo($this->cURL, CURLINFO_HTTP_CODE);
 
        return $this->prepareResponse($result, $httpCode);
    }
 
    public function get($url, $params = [])
    {
        return $this->call($url, self::METHOD_GET, [], $params);
    }
 
    public function post($url, $data = [], $params = [])
    {
        return $this->call($url, self::METHOD_POST, $data, $params);
    }
 
    public function put($url, $data = [], $params = [])
    {
        return $this->call($url, self::METHOD_PUT, $data, $params);
    }
 
    public function delete($url, $params = [])
    {
        return $this->call($url, self::METHOD_DELETE, [], $params);
    }
 
    protected function prepareResponse($result, $httpCode)
    {
        echo "<h2>HTTP: $httpCode</h2>";
        if (null === $decodedResult = json_decode($result, true)) {
            $jsonErrors = [
                JSON_ERROR_NONE => 'No error occurred',
                JSON_ERROR_DEPTH => 'The maximum stack depth has been reached',
                JSON_ERROR_CTRL_CHAR => 'Control character issue, maybe wrong encoded',
                JSON_ERROR_SYNTAX => 'Syntaxerror',
            ];
            echo '<h2>Could not decode json</h2>';
            echo 'json_last_error: ' . $jsonErrors[json_last_error()];
            echo '<br>Raw:<br>';
            echo '<pre>' . print_r($result, true) . '</pre>';
 
            return;
        }
        if (isset($decodedResult)) {
            echo '<pre>' . print_r($decodedResult, true) . '</pre>';
        }
 
        return $decodedResult;
    }
}
 
$client = new ApiClient('http://127.0.0.1/m2/','web','admin123');
 
//$client->get('rest/V1/orders/47'); //get Order
 
 
$userData = [
      "entity"=> [
        "order_id"=> 47,
        "parent_id"=> 47,
        //"entity_id"=> 47,
        "weight"=> 11,
        "qty"=> 1,
        "description"=> "Tracking code Descripton news test",
        "track_number"=> "1234567324654",
        "title"=> "Custom Tracking Code",
        "carrier_code"=> "fedex"
      ]
    ];
 
$entity =  $userData;
$client->post('rest/V1/shipment/track',$entity);