Validation change for Text type EAV attributes

[tim-reynolds]

The call on Mage_Eav_Model_Attribute_Data_Text:67 to empty returns true of a value of "0" is entered, as specified in the PHP spec. This prevents the entry of zero on the backend admin for fields. Zero should be a valid value, as it was in our case.

Unit test added. I apologize for not including that initially. I closed the other pull request.

[magento-team]

@tim-reynolds-briteskies
Thank you for the valuable contribution.
Proposed changes have been incorporated into the internal repository with the following deviations:

• Mage::helper() calls have been replaced with the dependency injection to avoid dealing with the global registry in tests
• Attribute mock is created based on Mage_Eav_Model_Entity_Attribute_Abstract class, so that Mage_Eav_Model_Attribute_Data_Abstract::setAttribute() can be utilized in tests instead of mocking getAttribute() method, which allows to not mock tested class at all
• fixed name of the data provider to correspond to the convention <testedMethodName>DataProvider
• converted comments to the data sets into data set names

Changes will be available on the GitHub with one of the nearest code publications from the internal repository.

Closing the ticket as complete. Thank you.

[tim-reynolds]

Thank you for the detailed write up. This was my first attempt at unit testing Magento2 so I was pretty sure what I did could have been done better. I look forward to seeing the final result.

Thanks!