Filter the empty params. #402

src/Payment/API.php

@@ -383,6 +383,7 @@ protected function request($api, array $params, $method = 'post', array $options
         $params['mch_id'] = $this->merchant->merchant_id;
         $params['device_info'] = $this->merchant->device_info;
         $params['nonce_str'] = uniqid();
+        $params = array_filter($params);
         $params['sign'] = generate_sign($params, $this->merchant->key, 'md5');
 
         $options = array_merge([

src/Payment/LuckyMoney/API.php

@@ -181,6 +181,7 @@ public function getMerchant()
      */
     protected function request($api, array $params, $method = 'post')
     {
+        $params = array_filter($params);
         $params['mch_id'] = $this->merchant->merchant_id;
         $params['nonce_str'] = uniqid();
         $params['sign'] = \EasyWeChat\Payment\generate_sign($params, $this->merchant->key, 'md5');

src/Payment/MerchantPay/API.php

@@ -121,6 +121,7 @@ public function getMerchant()
      */
     protected function request($api, array $params, $method = 'post')
     {
+        $params = array_filter($params);
         $params['nonce_str'] = uniqid();
         $params['sign'] = \EasyWeChat\Payment\generate_sign($params, $this->merchant->key, 'md5');