Merged in update-old-version (pull request #6)

update-old-version: update code

Helper/Config.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * @author    JaJuMa GmbH <info@jajuma.de>
+ * @copyright Copyright (c) 2022-present JaJuMa GmbH <https://www.jajuma.de>. All rights reserved.
+ * @license   http://opensource.org/licenses/mit-license.php MIT License
+ */
+
+namespace Jajuma\DynamicShippingTax\Helper;
+
+use Magento\Framework\App\Helper\AbstractHelper;
+use Magento\Store\Model\ScopeInterface;
+
+class Config extends AbstractHelper
+{
+    public const CONFIG_PATH_DYNAMIC_SHIPPING_TAX_CLASS = 'tax/classes/dynamic_shipping_tax_class';
+
+    /**
+     * Get dynamic shipping tax class type
+     *
+     * @return mixed
+     */
+    public function getDynamicShippingTaxType()
+    {
+        return $this->scopeConfig->getValue(self::CONFIG_PATH_DYNAMIC_SHIPPING_TAX_CLASS);
+    }
+
+    /**
+     * Get default tax class
+     *
+     * @param mixed $store
+     * @return int
+     */
+    public function getDefaultTaxClass($store): int
+    {
+        return (int)$this->scopeConfig->getValue(
+            \Magento\Tax\Model\Config::CONFIG_XML_PATH_SHIPPING_TAX_CLASS,
+            ScopeInterface::SCOPE_STORE,
+            $store
+        );
+    }
+}

Model/Config.php

@@ -9,7 +9,9 @@
 
 class Config
 {
-    const SHIPPING_TAX_TYPE_DEFAULT = 0;
-    const SHIPPING_TAX_TYPE_HIGHEST_PRODUCT_TAX = 1;
-    const SHIPPING_TAX_TYPE_HIGHEST_PRODUCT_PRICE_AMOUNT = 2;
+    public const SHIPPING_TAX_TYPE_DEFAULT = 0;
+
+    public const SHIPPING_TAX_TYPE_HIGHEST_PRODUCT_TAX = 1;
+
+    public const SHIPPING_TAX_TYPE_HIGHEST_PRODUCT_PRICE_AMOUNT = 2;
 }

Model/System/Config/Source/Tax/Dynamic.php

@@ -14,20 +14,20 @@ class Dynamic implements \Magento\Framework\Option\ArrayInterface
     /**
      * @var array
      */
-    protected $options;
+    protected array $options = [];
 
     /**
      * Option Dynamic Shipping Tax
      *
      * @return array
      */
-    public function toOptionArray()
+    public function toOptionArray(): array
     {
         if (!$this->options) {
             $options = [
                 [
                     'value' => Config::SHIPPING_TAX_TYPE_DEFAULT,
-                    'label' => __('No dynamic shipping tax caluclation')
+                    'label' => __('No dynamic shipping tax calculation')
                 ],
                 [
                     'value' => Config::SHIPPING_TAX_TYPE_HIGHEST_PRODUCT_TAX,