Stache binding within attribute

I have bindings such as <div class="other-class {{test}}" />". This seems to still be working but there is a warning in the console: can-stache/expressions/helper.js: Unable to find helper \"test\".

I have created an example. The div contains the correct output but there is still the warning. Should I implement this in some other way? Perhaps an attribute on the model that returns the composed values?

This is fine. The warning is a bug. Can you create an issue?

Thanks for the feedback Justin. I have created an issue.