MAGETWO-89261: Template file 'header.html' is not found.

Author: ameysar

app/code/Magento/Theme/Model/Design/Config/Validator.php

@@ -114,6 +114,7 @@ private function getTemplateText($templateId, DesignConfigInterface $designConfi
         if (is_numeric($templateId)) {
             $template->load($templateId);
         } else {
+            $template->setForcedArea($templateId);
             $template->loadDefault($templateId);
         }
         $text = $template->getTemplateText();

app/code/Magento/Theme/Test/Unit/Model/Design/Config/ValidatorTest.php

@@ -0,0 +1,124 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Theme\Test\Unit\Model\Design\Config;
+
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Theme\Model\Design\Config\Validator;
+
+/**
+ * Unit tests for Magento\Theme\Test\Unit\Model\Design\Config\Validator.
+ */
+class ValidatorTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var \Magento\Framework\Mail\TemplateInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $templateFactory;
+
+    /**
+     * @var \Magento\Framework\Mail\TemplateInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $template;
+
+    /**
+     * @var \Magento\Theme\Api\Data\DesignConfigInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $designConfig;
+
+    /**
+     * @var ObjectManager
+     */
+    private $objectManager;
+
+    /**
+     * @inheritdoc
+     */
+    public function setUp()
+    {
+        $this->objectManager = new ObjectManager($this);
+        $this->templateFactory = $this->getMockBuilder(\Magento\Framework\Mail\TemplateInterfaceFactory::class)
+            ->disableOriginalConstructor()
+            ->setMethods(['create'])
+            ->getMockForAbstractClass();
+        $this->template = $this->getMockBuilder(\Magento\Framework\Mail\TemplateInterface::class)
+            ->disableOriginalConstructor()
+            ->setMethods(
+                [
+                    'emulateDesign',
+                    'setForcedArea',
+                    'loadDefault',
+                    'getTemplateText',
+                    'revertDesign',
+                ]
+            )
+            ->getMockForAbstractClass();
+        $this->templateFactory->expects($this->any())->method('create')->willReturn($this->template);
+        $this->designConfig = $this->getMockBuilder(\Magento\Theme\Api\Data\DesignConfigInterface::class)
+            ->disableOriginalConstructor()
+            ->setMethods(['getExtensionAttributes'])
+            ->getMockForAbstractClass();
+    }
+
+    /**
+     * @return void
+     */
+    public function testGetDefaultTemplateTextDefaultScope()
+    {
+        $templateId = 'email_template';
+        $designData = [
+            'field_config' => ['field' => 'fieldValue'],
+            'value' => $templateId,
+        ];
+
+        $this->templateFactory->expects($this->once())->method('create');
+        $this->designConfig->expects($this->any())->method('getScope')->willReturn('default');
+        $this->template->expects($this->once())->method('emulateDesign');
+        $this->template->expects($this->once())->method('setForcedArea')->with($templateId);
+        $this->template->expects($this->once())->method('loadDefault')->with($templateId);
+        $this->template->expects($this->once())->method('getTemplateText');
+        $this->template->expects($this->once())->method('revertDesign');
+
+        $extensionAttributes = $this->getMockBuilder(\Magento\Theme\Api\Data\DesignConfigExtensionInterface::class)
+            ->disableOriginalConstructor()
+            ->setMethods(['getDesignConfigData'])
+            ->getMockForAbstractClass();
+
+        $extensionAttributes->expects($this->any())->method('getDesignConfigData')->willReturn(
+            [
+                $this->getDesignConfigData($designData),
+            ]
+        );
+
+        $this->designConfig->expects($this->any())->method('getExtensionAttributes')->willReturn($extensionAttributes);
+
+        /** @var Validator $validator */
+        $validator = $this->objectManager->getObject(
+            Validator::class,
+            [
+                'templateFactory' => $this->templateFactory,
+                'fields' => ['field' => 'fieldValue'],
+            ]
+        );
+        $validator->validate($this->designConfig);
+    }
+
+    /**
+     * Returns design config data object.
+     *
+     * @param array $data
+     * @return \Magento\Theme\Model\Data\Design\Config\Data
+     */
+    private function getDesignConfigData(array $data = [])
+    {
+        return $this->objectManager->getObject(
+            \Magento\Theme\Model\Data\Design\Config\Data::class,
+            [
+                'data' => $data,
+            ]
+        );
+    }
+}