If an interface definition is missing the "value" attribute, the resulting error message is inscrutable

[bemasc]

Specifically, the error message is "Message discarded for not matching declared type!", with no indication of which module or message triggered the error.

Presumably something more specific would be better ... ideally at build time!

[willscott]

This is a dup. of #23, and is a long-standing issue with how we handle the declarative interfaces.

The first step is probably to update https://github.com/freedomjs/freedom/blob/master/src/consumer.js#L329 such that it returns a promise, and rejections can be caught up the chain where information about the context where the error occured can be included with the error itself.