ENGCOM-6629: Unit Test for Magento\Sitemap\Model\Config\Backend\Priority #26430

 - Merge Pull Request #26430 from karyna-tsymbal-atwix/magento2:unit-test-magento-sitemap-model-priority
 - Merged commits:
   1. 74ad5dd
   2. fd3fc0e
   3. 1df8216

Author: magento-engcom-team

app/code/Magento/Sitemap/Test/Unit/Model/Config/Backend/PriorityTest.php

@@ -0,0 +1,89 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Sitemap\Test\Unit\Model\Config\Backend;
+
+use Magento\Sitemap\Model\Config\Backend\Priority;
+use PHPUnit\Framework\MockObject\MockObject;
+
+/**
+ * Tests for @see Priority
+ */
+class PriorityTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var Priority|MockObject
+     */
+    private $priorityMock;
+
+    /**
+     * @inheritDoc
+     */
+    protected function setUp()
+    {
+        $this->priorityMock = $this->getMockBuilder(Priority::class)
+            ->disableOriginalConstructor()
+            ->setMethods(['getValue'])
+            ->getMock();
+    }
+
+    /**
+     * Verify before save in chainable
+     *
+     * @param string $value
+     * @dataProvider dataProviderTestBeforeSaveValueCorrect
+     */
+    public function testBeforeSaveIsChainable($value)
+    {
+        $this->priorityMock->expects($this->once())
+            ->method('getValue')
+            ->willReturn($value);
+
+        $this->assertSame($this->priorityMock, $this->priorityMock->beforeSave());
+    }
+
+    /**
+     * Verify before save value out of range
+     *
+     * @param string $value
+     * @dataProvider dataProviderTestBeforeSaveValueOutOfRange
+     */
+    public function testBeforeSaveValueOutOfRange($value)
+    {
+        $this->priorityMock->expects($this->once())
+            ->method('getValue')
+            ->willReturn($value);
+
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('The priority must be between 0 and 1.');
+
+        $this->priorityMock->beforeSave();
+    }
+
+    /**
+     * Data provider
+     *
+     * @return array
+     */
+    public function dataProviderTestBeforeSaveValueCorrect()
+    {
+        return [
+            ['0'], ['0.0'], ['0.5'], ['1']
+        ];
+    }
+
+    /**
+     * Data provider
+     *
+     * @return array
+     */
+    public function dataProviderTestBeforeSaveValueOutOfRange()
+    {
+        return [
+            ['-1'], ['2'], ['nan']
+        ];
+    }
+}