ruby on rails - how to include module for MiniTest -

i have class company include growthrate.

models/company.rb

class company < activerecord::base   include growthrate end 

in growth_rate.rb, add methods array.

models/company/growth_rate.rb

module company::growthrate   extend activesupport::concern end  module company::growthrate::array   def growth_rate     # calculate growth rate   end end  class array   include company::growthrate::array end 

and want test method of array minitest.

test/models/company/growth_rate_test.rb

require 'test_helper'  class companytest < activesupport::testcase   include company::growthrate   test 'test adjusted_growth_rate'     array = [1, 0.9]     array.stub :growth_rate, 1       # assert_equal     end   end end 

but test ends name error.

nameerror: undefined method `growth_rate' `company::growthrate::array' 

how can include method minitest?

test/test_helper.rb

env['rails_env'] ||= 'test' require file.expand_path('../../config/environment', __file__) require 'rails/test_help' require 'minitest/mock' class activesupport::testcase   # setup fixtures in test/fixtures/*.yml tests in alphabetical order.   fixtures :all end 

i think have move models/company/growth_rate.rb app/model/concerns folder filename = 'growth_rate.rb'

then don't use company class prevent conflict class name

module growthrate   extend activesupport::concern    # ... end 

now can include company model

then create array.rb file in config/initializers folder contains

class array   def growth_rate     # calculate growth rate   end end 

this file loaded once rails, it's adding custom method array class if want to

now can remove include company::growthrate test/models/company/growth_rate_test.rb