MC-18701: API Attribute Option update creates same value multiple times

Author: dyushkin

app/code/Magento/Eav/Model/Entity/Attribute/OptionManagement.php

@@ -41,7 +41,16 @@ public function __construct(
     }
 
     /**
-     * @inheritdoc
+     * Add option to attribute.
+     *
+     * @param int $entityType
+     * @param string $attributeCode
+     * @param \Magento\Eav\Api\Data\AttributeOptionInterface $option
+     * @return string
+     * @throws InputException
+     * @throws NoSuchEntityException
+     * @throws StateException
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      */
     public function add($entityType, $attributeCode, $option)
     {
@@ -148,7 +157,7 @@ public function getItems($entityType, $attributeCode)
      * @param EavAttributeInterface $attribute
      * @param int $optionId
      * @return void
-     *@throws NoSuchEntityException
+     * @throws NoSuchEntityException
      */
     protected function validateOption($attribute, $optionId)
     {

dev/tests/integration/testsuite/Magento/Swatches/Model/SwatchAttributeOptionAddTest.php

@@ -36,7 +36,7 @@ public function testSwatchOptionAdd()
         $attribute = $this->objectManager
             ->create(\Magento\Catalog\Model\ResourceModel\Eav\Attribute::class)
             ->load('color_swatch', 'attribute_code');
-        $optionsPerAttribute = 3;
+        $optionsPerAttribute = 4;
 
         $data['options']['option'] = array_reduce(
             range(10, $optionsPerAttribute),