`using_access_control` causes hangs on Rails 5.0

[samstickland]

Firstly, thanks for creating this gem, it's helping us out.

We our upgrading an old application to Rails 5.0 (5.0.7.2), and have switched to your gem (1.0.0) for this.

Including this DSL entry in a model using_access_control causes our tests to hang when these models are created (via FactoryBot).

I wonder if you could suggest some code that we can start digging into debugging purposes?

[samstickland]

Oh, I found the problem - an infinite loop - here:

[370, 379] in /Users/sam/.gem/ruby/2.6.9/gems/ae_declarative_authorization-1.0.0/lib/declarative_authorization/authorization.rb
   370:       raise AuthorizationUsageError, 'No context given or inferable from object' unless context
   371:       hierarchy = rev_priv_hierarchy
   372:
   373:       flattened_privileges = privileges.clone
   374:       flattened_privileges.each do |priv|
=> 375:         flattened_privileges.concat(hierarchy[[priv, nil]]) if hierarchy[[priv, nil]]
   376:         flattened_privileges.concat(hierarchy[[priv, context]]) if hierarchy[[priv, context]]
   377:       end
   378:       flattened_privileges.uniq
   379:     end
(byebug) flattened_privileges
[:create, :manage, :translate, :manage, :translate, :manage, :translate, :manage, :translate, :manage, :translate, :manage, :translate]
(byebug) privileges
[:create]
(byebug) hierarchy[[priv, nil]]
[:manage, :translate]

It loops over flatten_privileges but it's adding to flatten privileges as it goes, so the loop never finishes.

This is on Ruby 2.6.9 - perhaps the behaviour of each is different later versions of Ruby?

[samstickland]

Changing the each statement to:

privileges.each do |priv|

resolves this issue for us.

[dvicory]

@samstickland While this change seems fine, just to confirm - your test suite and everything after this change is good? We don't use using_access_control internally, so we don't have a baseline to compare with.

[samstickland]

Yes, this fixed the problem for us.