MAGETWO-36484: Unit test code coverage in MLS10

Author: Maksym Savich

app/code/Magento/Config/Test/Unit/Block/System/Config/Form/Field/FileTest.php

@@ -13,11 +13,6 @@
 
 class FileTest extends \PHPUnit_Framework_TestCase
 {
-    /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $_objectManagerMock;
-
     /**
      * @var \Magento\Config\Block\System\Config\Form\Field\File
      */

app/code/Magento/Config/Test/Unit/Block/System/Config/Form/Field/HeadingTest.php

@@ -0,0 +1,53 @@
+<?php
+/**
+ * Copyright © 2015 Magento. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+/**
+ * Tests for \Magento\Framework\Data\Form\Element\File
+ */
+namespace Magento\Config\Test\Unit\Block\System\Config\Form\Field;
+
+class HeadingTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var \PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $_objectManagerMock;
+
+    /**
+     * @var \Magento\Config\Block\System\Config\Form\Field\File
+     */
+    protected $file;
+
+    public function testRender()
+    {
+        $htmlId = 'test_HTML_id';
+        $label = 'test_label';
+
+        $elementMock = $this->getMockBuilder('Magento\Framework\Data\Form\Element\AbstractElement')
+            ->disableOriginalConstructor()
+                ->setMethods(['getHtmlId', 'getLabel'])
+            ->getMock();
+        $elementMock->expects($this->any())->method('getHtmlId')->willReturn($htmlId);
+        $elementMock->expects($this->any())->method('getLabel')->willReturn($label);
+
+        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+
+        $heading = $objectManager->getObject('\Magento\Config\Block\System\Config\Form\Field\Heading', []);
+
+        $html = $heading->render($elementMock);
+
+        $this->assertEquals(
+            '<tr class="system-fieldset-sub-head" id="row_' . $htmlId . '">' .
+                '<td colspan="5">' .
+                    '<h4 id="' . $htmlId . '">' . $label . '</h4>' .
+                '</td>' .
+            '</tr>',
+            $html
+        );
+    }
+}