Can policyfiles require other files?

I think the answer is no, based on what I found here:
https://www.chef.io/blog/2015/10/05/policyfiles-why-what-and-how/
and here:
https://feedback.chef.io/forums/301644-chef-product-feedback/suggestions/9999225-chef-policies-policyfiles-should-be-able-to-incl

I want to add a line like:

require 'common_attributes'

in my policyfilies. Tried a few variations and none worked when I run chef update.

Sadly this is a result of using instance_eval. If this was all just classes and modules, you could do what you want to do, but the price you pay is that the “pretty”, simple interface is replaced with plain Ruby. This is something I would prefer but most people apparently do not.

If you want to implement this yourself right now, you can do eval(IO.read(“filename”))

We definitely plan to implement this kind of functionality, though we are looking at the use cases we expect various kinds of organizations to have to see exactly what the feature set needs to be.