MQE-2160: Extended data entity won't merge array items

Author: okolesnyk

dev/tests/functional/tests/MFTF/DevDocs/Data/MessageData.xml

@@ -17,4 +17,10 @@
             <item name="three">3</item>
         </array>
     </entity>
+
+    <entity name="ExtendedMessageData" extends="MessageData">
+        <array key="numbers">
+            <item name="TESTING CASE">TESTING CASE</item>
+        </array>
+    </entity>
 </entities>

dev/tests/functional/tests/MFTF/DevDocs/Test/DevDocsTest.xml

@@ -48,8 +48,8 @@
         </actionGroup>
 
         <assertEqualsCanonicalizing stepKey="assertMergedArray">
-            <actualResult type="array">{{MessageData.numbers}}</actualResult>
-            <expectedResult type="array">["Something New", "0", "1", "2", "3"]</expectedResult>
+            <actualResult type="array">{{ExtendedMessageData.numbers}}</actualResult>
+            <expectedResult type="array">["Something New", "0", "1", "2", "3", "TESTING CASE"]</expectedResult>
         </assertEqualsCanonicalizing>
     </test>
 </tests>

dev/tests/verification/Resources/ExtendedParameterArrayTest.txt

@@ -26,9 +26,9 @@ class ExtendParentDataTestCest
 	public function ExtendParentDataTest(AcceptanceTester $I)
 	{
 		$I->createEntity("simpleDataKey", "test", "extendParentData", [], []); // stepKey: simpleDataKey
-		$I->searchAndMultiSelectOption("#selector", ["otherName"]);
+		$I->searchAndMultiSelectOption("#selector", ["name", "otherName"]);
 		$I->searchAndMultiSelectOption("#selector", ["extendName"]);
-		$I->searchAndMultiSelectOption("#selector", ["item"]);
+		$I->searchAndMultiSelectOption("#selector", ["postname", "item"]);
 		$I->searchAndMultiSelectOption("#selector", [msq("extendParentData") . "prename"]);
 		$I->searchAndMultiSelectOption("#selector", ["postnameExtend" . msq("extendParentData")]);
 	}

src/Magento/FunctionalTestingFramework/DataGenerator/Util/DataExtensionUtil.php

@@ -62,7 +62,7 @@ public function extendEntity($entityObject)
 
         // Get all data for both parent and child and merge
         $referencedData = $parentEntity->getAllData();
-        $newData = array_merge($referencedData, $entityObject->getAllData());
+        $newData = array_merge_recursive($referencedData, $entityObject->getAllData());
 
         // Get all linked references for both parent and child and merge
         $referencedLinks = $parentEntity->getLinkedEntities();