MAGETWO-99509: Download Option not working in Exports

- Added automated test script.

Author: Davit_Zakharyan

app/code/Magento/ImportExport/Test/Mftf/Section/AdminExportMainSection.xml

@@ -9,6 +9,7 @@
           xsi:noNamespaceSchemaLocation="urn:magento:mftf:Page/etc/SectionObject.xsd">
     <section name="AdminExportMainSection">
         <element name="entityType" type="select" selector="#entity"/>
+        <element name="exportFileFormat" type="select" selector="#file_format"/>
         <element name="entityAttributes" type="select" selector="#export_filter_form"/>
     </section>
 </sections>

app/code/Magento/ImportExport/Test/Mftf/Test/AdminCheckThatCSVCanBeExportedTest.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+
+<tests xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/testSchema.xsd">
+    <test name="AdminCheckThatCSVCanBeExportedTest">
+        <annotations>
+            <title value="Check that CSV can be exported"/>
+            <description value="Check that CSV can be exported"/>
+            <features value="ImportExport"/>
+            <severity value="CRITICAL"/>
+            <testCaseId value="MAGETWO-99457"/>
+            <useCaseId value="MAGETWO-98703"/>
+            <group value="importexport"/>
+        </annotations>
+        <before>
+            <!-- Create category and simple product, then log in -->
+            <comment userInput="Create category and simple product, then log in" stepKey="createDataAndLogIn"/>
+            <createData entity="ApiCategory" stepKey="createCategory"/>
+            <createData entity="ApiSimpleProduct" stepKey="createProduct">
+                <requiredEntity createDataKey="createCategory"/>
+            </createData>
+            <actionGroup ref="LoginAsAdmin" stepKey="loginAsAdmin"/>
+        </before>
+        <after>
+            <!-- Delete exported file, created data and log out -->
+            <comment userInput="Delete exported file, created data and log out" stepKey="deleteCreatedData"/>
+            <actionGroup ref="deleteExportedFile" stepKey="deleteExportedFile">
+                <argument name="rowIndex" value="0"/>
+            </actionGroup>
+            <deleteData createDataKey="createCategory" stepKey="deleteCategory"/>
+            <deleteData createDataKey="createProduct" stepKey="deleteProduct"/>
+            <actionGroup ref="logout" stepKey="logout"/>
+        </after>
+        <!-- Go to System -> Data Transfer -> Export page -->
+        <comment userInput="Go to System -> Data Transfer -> Export page" stepKey="goToAdminExportIndexPage"/>
+        <amOnPage url="{{AdminExportIndexPage.url}}" stepKey="navigateToAdminExportIndexPage"/>
+        <waitForPageLoad stepKey="waitPageToLoad"/>
+        <!-- Export all products -->
+        <comment userInput="Export all products" stepKey="exportAllProds"/>
+        <actionGroup ref="exportAllProducts" stepKey="exportAllProducts"/>
+        <!-- Run cron -->
+        <comment userInput="Run cron" stepKey="cronRun"/>
+        <magentoCLI command="cron:run" stepKey="runCron"/>
+        <!-- Download CSV file -->
+        <comment userInput="Download CSV file" stepKey="downloadCSVFile"/>
+        <actionGroup ref="downloadFileByRowIndex" stepKey="downloadCreatedProducts">
+            <argument name="rowIndex" value="0"/>
+        </actionGroup>
+    </test>
+</tests>