MAGETWO-99500: Configurable options attribute position is not saved correctly via API

Author: Roman Lytvynenko

app/code/Magento/ConfigurableProduct/Test/Unit/Model/LinkManagementTest.php

@@ -158,7 +158,7 @@ public function testAddChild()
             ->getMock();
         $optionMock = $this->getMockBuilder(\Magento\ConfigurableProduct\Api\Data\Option::class)
             ->disableOriginalConstructor()
-            ->setMethods(['getProductAttribute', 'getAttributeId'])
+            ->setMethods(['getProductAttribute', 'getPosition', 'getAttributeId'])
             ->getMock();
         $productAttributeMock = $this->getMockBuilder(\Magento\Eav\Model\Entity\Attribute\AbstractAttribute::class)
             ->disableOriginalConstructor()
@@ -216,13 +216,15 @@ public function testAddChild()
         $productAttributeMock->expects($this->any())->method('getAttributeCode')->willReturn('color');
         $simple->expects($this->any())->method('getData')->willReturn('color');
         $optionMock->expects($this->any())->method('getAttributeId')->willReturn('1');
+        $optionMock->expects($this->any())->method('getPosition')->willReturn('0');
 
         $optionsFactoryMock->expects($this->any())->method('create')->willReturn([$optionMock]);
         $attributeFactoryMock->expects($this->any())->method('create')->willReturn($attributeMock);
         $attributeMock->expects($this->any())->method('getCollection')->willReturn($attributeCollectionMock);
         $attributeCollectionMock->expects($this->any())->method('addFieldToFilter')->willReturnSelf();
         $attributeCollectionMock->expects($this->any())->method('getItems')->willReturn([$attributeMock]);
 
+        $attributeMock->expects($this->any())->method('getId')->willReturn(1);
         $attributeMock->expects($this->any())->method('getOptions')->willReturn([$attributeOptionMock]);
 
         $extensionAttributesMock->expects($this->any())->method('setConfigurableProductOptions');

dev/tests/api-functional/testsuite/Magento/ConfigurableProduct/Api/LinkManagementTest.php

@@ -12,6 +12,9 @@
 use Magento\Framework\Webapi\Rest\Request;
 use Magento\TestFramework\TestCase\WebapiAbstract;
 
+/**
+ * Class LinkManagementTest for testing ConfigurableProduct to SimpleProduct link functionality
+ */
 class LinkManagementTest extends WebapiAbstract
 {
     const SERVICE_NAME = 'configurableProductLinkManagementV1';