Issue with Rails namespaces and STI - Spiced up with autoloading - ruby-on-rails

Question

I would need some help with restructuring a Rails application. Below you can find the extra details. The main questions:
I modified the code after #Nathan suggestions. Got one step further to heaven but still can smell some sulfur.
SOLVED: Why am I getting the error: "superclass mismatch for class Report"
SOLVED: Can I have some guidelines, how to structure complex namespacings, extensions and STI in Rails4?
After server restart, I get the error on the Spock main page: --"Unable to autoload constant Bridge, expected ...route goes here... app/models/spock/report/bridge.rb to define it"-- After refreshing the page, the error is gone. But still, indicates some problem. This is reproducible after every server restart. HINT: Possibly an autoload issue... Any idea is welcome.
Environment:
WEBrick 1.3.1
Rails 4.0.9
Ruby 2.1.5
Error details:
Unable to autoload constant Bridge, expected ...route goes here... bridge.rb to define it
app/views/spock/spock/index.html.erb:11:in `block in _app_views_spock_spock_index_html_erb___3895075684249237486_132397353980'
app/views/spock/spock/index.html.erb:6:in `map'
app/views/spock/spock/index.html.erb:6:in `_app_views_spock_spock_index_html_erb___3895075684249237486_132397353980'
File structure:
/app/controllers/spock/spock_controller.rb
/app/controllers/spock/marketplaces_controller.rb
/app/controllers/spock/reports_controller.rb
/app/modules/spock/spock_connector.rb
/app/modules/spock/report.rb
/app/modules/spock/report/bridge.rb
/app/modules/spock/report/metric.rb
Files:
# application.rb
...
config.autoload_paths += Dir[Rails.root.join('app', 'models', 'spock', '{**}')]
...
# routes.rb
namespace :spock do
get '/', :to => 'spock#index'
resources :marketplaces, only: [] do
resources :reports, only: [:show]
end
# spock_controller.rb
module Spock
class SpockController < ApplicationController
def index
#report_categories = Spock::Report.distinct.pluck(:category)
...
# marketplaces_controller
module Spock
class MarketplacesController < SpockController
end
end
# reports_controller
module Spock
class ReportsController < MarketplacesController
helper SpockHelper
...
# spock_connector.rb
module Spock
class SpockConnector < ::ActiveRecord::Base
self.abstract_class = true
establish_connection "spock_#{Rails.env}"
end
end
# report.rb
module Spock
class Report < SpockConnector
attr_accessor :legal_entity
end
end
# bridge.rb
module Spock
class Bridge < Report
...
# metric.rb
module Spock
class Metric < Report
...
Database:
/* reports table */
id, type, category,
1 Spock::Bridge Bridge
2 Spock::Metric Metric

Answer 1

You are opening/defining the Report class in 3 separate files.
In report.rb, you specify ::Spock::SpockConnector as the superclass for Report, but in bridge.rb and metric.rb, you are not specifying an explicit superclass, so Ruby uses Object as its superclass.
You cannot have both Object and ::Spock::SpockConnector as the immediate superclass of Report.
Solution:
In all 3 files you need to use class Report < ::Spock::SpockConnector
As soon as you fix that, you will encounter a similar error, because you are opening SpockConnector in several files, once with ::ActiveRecord::Base as the superclass, and other times with implicit Object as the superclass.
This is another contradiction, so in all files that open/define SpockConnector, you need to use ::ActiveRecord::Base as the superclass.
As for your namespacing question, that's opinion-based, but I will say that in Ruby there is no need to nest subclasses inside namespaces.
For example, you could keep Report, SpockConnector, Metric, and Bridge all at the same namespace level:
module Spock
class SpockConnector < ActiveRecord::Base
end
end
module Spock
class Report < SpockConnector
end
end
module Spock
class Metric < Report
end
end
module Spock
class Bridge < Report
end
end
The fully scoped names are then:
Spock::SpockConnector
Spock::Report
Spock::Bridge
Spock::Metric

Answer 2

OK. After a day of trial and error I found the cause of autoload issue.
If you find your self touching the autoload structure, that is a good sign on being on the wrong path.
So I removed the autoload path from the application.rb file.
And modified the STI classes a little bit, to match the Rails autoload logic;
# bridge.rb
module Spock
class Report
class Bridge < Report
...
# metric.rb
module Spock
class Report
class Metric < Report
...
Database:
/* reports table */
id, type, category,
1 Spock::Report::Bridge Bridge
2 Spock::Report::Metric Metric
Including the STI classes in the superclass makes them able to be autoloaded from the subfolder without including explicitly the folder in the application.rb file.
The downside is that the classes absolute paths gets longer...