fix(phpstan): code improvements and resolve warnings

Reviewed code and made several improvements which provide better error handling, code quality, and resolved warnings. The changes include:

• Syntax modifications for better readability,
• Ensured variable type checks before using methods,
• Resolved warning instances in phpstan,
• Adapted code to comply with modern PHP nullable type indicator.

Alongside, made version update in phive/phars.xml. Also, unnecessary comments or instances are removed for a cleaner code.

Related: #16 (closed)

bin/backend/classes/CouponCodes.js

@@ -13,7 +13,7 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
 ], function (QUIAjax) {
     "use strict";
 
-    var pkg = 'quiqqer/coupons';
+    const pkg = 'quiqqer/coupons';
 
     return new Class({
 
@@ -28,9 +28,9 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
         create: function (Attributes) {
             return new Promise(function (resolve, reject) {
                 QUIAjax.post('package_quiqqer_coupons_ajax_create', resolve, {
-                    'package' : pkg,
+                    'package': pkg,
                     attributes: JSON.encode(Attributes),
-                    onError   : reject
+                    onError: reject
                 });
             });
         },
@@ -45,10 +45,10 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
         edit: function (id, Attributes) {
             return new Promise(function (resolve, reject) {
                 QUIAjax.post('package_quiqqer_coupons_ajax_edit', resolve, {
-                    'package' : pkg,
-                    id        : id,
+                    'package': pkg,
+                    id: id,
                     attributes: JSON.encode(Attributes),
-                    onError   : reject
+                    onError: reject
                 });
             });
         },
@@ -63,8 +63,8 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
             return new Promise(function (resolve, reject) {
                 QUIAjax.post('package_quiqqer_coupons_ajax_delete', resolve, {
                     'package': pkg,
-                    ids      : JSON.encode(ids),
-                    onError  : reject
+                    ids: JSON.encode(ids),
+                    onError: reject
                 });
             });
         },
@@ -78,9 +78,9 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
         getList: function (SearchParams) {
             return new Promise(function (resolve, reject) {
                 QUIAjax.get('package_quiqqer_coupons_ajax_getList', resolve, {
-                    'package'   : pkg,
+                    'package': pkg,
                     searchParams: JSON.encode(SearchParams),
-                    onError     : reject
+                    onError: reject
                 });
             });
         },
@@ -96,9 +96,9 @@ define('package/quiqqer/coupons/bin/backend/classes/CouponCodes', [
             return new Promise(function (resolve, reject) {
                 QUIAjax.post('package_quiqqer_coupons_ajax_sendMail', resolve, {
                     'package': pkg,
-                    ids      : JSON.encode(ids),
-                    resend   : resend ? 1 : 0,
-                    onError  : reject
+                    ids: JSON.encode(ids),
+                    resend: resend ? 1 : 0,
+                    onError: reject
                 });
             });
         }