undefined method 'define_dynamic_method' during rake db:migrate

[ndbroadbent]

I wanted to create a migration to move my admin boolean flags into Roles. My migration looks like this:

class MigrateRolesToRolify < ActiveRecord::Migration[5.0]
  def up
    User.all.each do |user|
      if user.admin?
        user.add_role :admin
      end
    end
  end
end

When I run rake db:migrate, I get the following error:

== 20170630154905 MigrateRolesToRolify: migrating =============================
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

undefined method `define_dynamic_method' for #<Class:0x007fbdc4f94eb0>
Did you mean?  define_method
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/dynamic_matchers.rb:21:in `method_missing'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/rolify-5.1.0/lib/rolify/role.rb:18:in `add_role'
/Users/ndbroadbent/code/my_app/db/migrate/20170630154905_migrate_roles_to_rolify.rb:6:in `block in up'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/relation/delegation.rb:38:in `each'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/relation/delegation.rb:38:in `each'
/Users/ndbroadbent/code/my_app/db/migrate/20170630154905_migrate_roles_to_rolify.rb:3:in `up'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/migration.rb:792:in `exec_migration'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/migration.rb:773:in `block (2 levels) in migrate'
/Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/activerecord-5.0.2/lib/active_record/migration.rb:772:in `block in migrate'

Any idea why this might be happening?

(FYI, it works fine if I run user.add_role :admin in the Rails console.)

NOTE: In my logs you can see that I was testing on Rails 5.0.2. I just updated to Rails 5.1.2 and am seeing the same error.

[ndbroadbent]

Update - Actually it does crash in the Rails console if I run:

User.all.each do |user|
  if user.admin?
    user.add_role :admin
  end
end

[ndbroadbent]

Ah, I think there's a bug in Rolify. Rolify.dynamic_shortcuts is not true when the app is first loading, but it is set to true later on. So the Dynamic module is not being extended.

I added a debugger statement to lib/rolify.rb to show how that is happening:

[12, 21] in /Users/ndbroadbent/.rvm/gems/ruby-2.3.3/gems/rolify-5.1.0/lib/rolify.rb
   12:   @@resource_types = []
   13:
   14:   def rolify(options = {})
   15:     include Role
   16:     debugger
=> 17:     extend Dynamic if Rolify.dynamic_shortcuts
   18:
   19:     options.reverse_merge!({:role_cname => 'Role'})
   20:     self.role_cname = options[:role_cname]
   21:     self.role_table_name = self.role_cname.tableize.gsub(/\//, "_")
(byebug) Rolify.dynamic_shortcuts
false
(byebug) c

Running via Spring preloader in process 75374
Loading development environment (Rails 5.1.2)
irb: warn: can't alias context from irb_context.
2.3.3 :001 >   Rolify.dynamic_shortcuts
 => true
2.3.3 :002 >

[ndbroadbent]

Argh, I figured out why my User model was being loaded before Rolify was configured.

I'm using the simple_token_authentication gem, so I added this line to my ApplicationController:

acts_as_token_authentication_handler_for User

And my ApplicationController was being loaded at the bottom of my pundit initializer:

ApplicationController.send :include, PunditHelper

I added an underscore to move the rolify initializer to the top (config/initializers/rolify.rb => config/initializers/_rolify.rb), and this fixed the error.

[texpert]

Have you added rolify to User model?

Also, to not load all the users, it is better to do it like this:

User.where(admin: true).each do |user|
  user.add_role :admin
end