Google has added article structured data support to the rich results test tool. So that is one less thing you need to rely on the structured data testing tool for and I am sure more and more is coming.
Google announced the structured data testing tool will go away eventually, which upset many SEOs. Google then said it will continue to expand the rich result test tool and added license structured data support and now this, article structured data support.
Google said on Twitter “We are happy to announce support for Article structured data in the Rich Results Test tool.” With that, Lizzi Harvey from Google said she updated the article structured data developer docs “to show how that will look (there’s a different search appearance & schema requirements for AMP vs non-AMP).” A clarification was made that there are different Article requirements for AMP and non-AMP pages. Added an example of a non-AMP page with Article structured data.
Forum discussion at Twitter.