Environment

• Ruby 2.5.8
• Rails 6.0.3.1
• Devise 4.7.1

Current behavior

class AuthenticatableUser < ActiveRecord::Base
  devise :database_authenticatable
end

pp AuthenticatableUser.first
=begin
#<AuthenticatableUser id: 1, name: "Greg Grimaldus", email: "greg@example.com", nested_field: 
=end

Additionally, the output is all one color in a REPL like Pry.

Expected behavior

class NonAuthenticatableUser < ActiveRecord::Base
end

pp NonAuthenticatableUser.first
=begin
#<NonAuthenticatableUser
 id: 1,
 name: "Greg Grimaldus",
 email: "greg@example.com",
 nested_field:
  #<NestedField:0x0ab88383223
   @nested_field_attr=1>,
 ...MANY_MORE_FIELDS...>
=end 

Additionally, in a REPL like Pry, each attribute has color highlighting based on the value type.

Cause

The reason this occurs is because Devise::Models::Authenticatable overrides inspect and if the method is overriden, then ActiveRecord::Core#pretty_print defers to super. This is probably PP::ObjectMixin#pretty_print, which doesn't have the niceties described in the "Expected behavior" section.