MC-40148: Create automated test for: "Set decimal Qty increment"

Author: romadjelf

dev/tests/integration/testsuite/Magento/CatalogInventory/Model/System/Config/Backend/QtyincrementsTest.php

@@ -0,0 +1,56 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogInventory\Model\System\Config\Backend;
+
+use Magento\CatalogInventory\Model\Configuration;
+use Magento\Config\Model\Config\BackendFactory;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\ObjectManagerInterface;
+use Magento\TestFramework\Helper\Bootstrap;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Checks that the qty increments config backend model is working correctly
+ */
+class QtyincrementsTest extends TestCase
+{
+    /** @var ObjectManagerInterface */
+    private $objectManager;
+
+    /** @var Qtyincrements */
+    private $qtyIncrements;
+
+    /** @var BackendFactory */
+    private $backendFactory;
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp(): void
+    {
+        $this->objectManager = Bootstrap::getObjectManager();
+        $this->backendFactory = $this->objectManager->create(BackendFactory::class);
+        $this->qtyIncrements = $this->backendFactory->create(Qtyincrements::class, [
+            'data' => [
+                'path' => Configuration::XML_PATH_QTY_INCREMENTS,
+            ]
+        ]);
+    }
+
+    /**
+     * @return void
+     */
+    public function testAfterSaveWithDecimals(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage((string)__("Quantity increments can't use decimals. Enter a new increment and try again."));
+        $value = 10.5;
+        $this->qtyIncrements->setValue((string)$value);
+        $this->qtyIncrements->beforeSave();
+    }
+}