Incorrect return value from Product Attribute Repository

[samtay]

To adhere to Magento\Catalog\Api\ProductAttributeRepositoryInterface (extends Magento\Framework\Api\MetadataServiceInterface), the

Magento\Catalog\Model\Product\Attribute\Repository::getCustomAttributesMetadata

implementation should return Magento\Framework\Api\MetadataObjectInterface[], however it instead returns Magento\Catalog\Api\Data\ProductAttributeInterface[].

The ProductAttributeInterface does declare the two methods declared in MetadataObjectInterface , however they are not related by PHP extend.

[andimov]

@samtay, to allow us research the issue, please, provide the used version and description according to the template.

[samtay]

The issue exists on all versions, on CE develop branch. The description is in the initial comment. I don't see what more information you need? This isn't a huge deal, I'm just letting you know there is a disconnect in the hierarchy of the interfaces. The documentation is incorrect -- which the framework can be very finicky about sometimes when generating code or parsing objects in the webapi. Something for you to be aware of.

[vkublytskyi]

@samtay, thank you for reporting this issue. To fix this issue we will add declaration that Magento\Eav\Api\Data\AttributeInterface extends Magento\Framework\Api\MetadataObjectInterface.
Internal ticket MAGETWO-55438.