How can I run a ruby class from rake file?

Hope that helps You're adding something called "Factories specs" (plural) to the STATS_DIRECTORIES array, but you call it "Factory specs" (singular) when you add it to TEST_TYPES array -- so when rake:stat hits your test/factories folder, it looks for "Factories specs" in TEST_TYPES, doesn't find it, and assumes it's code, not tests. You need to call it the same thing in both places:

::STATS_DIRECTORIES << %w(Factory\ specs test/factories) if File.exist?('test/factories')
::CodeStatistics::TEST_TYPES << "Factory specs" if File.exist?('test/factories')

will be helpful for those in need When you invoke Rake, you can pass the --trace flag to it. This should give you a backtrace, which I suspect is going to tell you the error is on the line not_flag = all_Active_Games > 0, because all_Active_Games is an ActiveRecord relation, but you're trying to compare it to the integer 0. Bascially, you have a type error. In a static language, this wouldn't even compile.
It would also be good to also fix your indentation, choose more descriptive variable names (x -> game)

seems to work fine As you can see, I've defined a function inside a rake file. No problem, that works fine. Problem is, when I declare def get_user_input in another rake file. In that case the function gets called from another .rake file Can you suggest anything? . , Moved the functions into a module and the problem gone.

namespace :backtest do

 Module MY
  def self.get_user_input
    if ENV['date_from'].present? && ENV['date_until'].present? 
      # get input...
    else
      abort 'Sample usage: blah blah...'
    end
  end
 end

 desc "Start backtest"
 task :start => :environment do
   My.get_user_input
   # rest of the code...
 end

end

hop of those help? Net::HTTP is part of the Ruby Standard Library, which is distributed with Ruby itself (not Rails). To use any of the standard libraries you must require them first.

it should still fix some issue When you see errors like "uninitialized constant" popping up and you're sure you've defined that constant in a file somewhere, make sure you're loading that code in before the method with the error runs.
It looks like in this case config/environment wasn't loaded before DB was referenced, so it can't complete.