Files for adding a new test in rails codebase

decimal_rounding_test.rb

# activerecord/test/cases/decimal_rounding_test.rb                                 
require "cases/helper"                                                             
require "models/thing"                                                             
                                                                                   
class DecimalRoundingTest < ActiveRecord::TestCase                                 
  ActiveRecord::Schema.define do                                                   
    create_table :things, force: true do |t|                                       
      t.decimal :price, precision: 4, scale: 4                                     
    end                                                                            
  end                                                                              
                                                                                   
  def test_decimal_rounding                                                        
    thing = Thing.create!                                                          
    thing.price = 0.00001                                                          
    assert_equal '0.00001', thing.price.to_s                                       
  end                                                                              
end  

thing.rb

# activerecord/test/models/thing.rb                                             
class Thing < ActiveRecord::Base                                                
end 

z_run.sh

# Script to run the above test 
bundle exec ruby -I activerecord/lib:activerecord/test activerecord/test/cases/decimal_rounding_test.rb