How do I force RAILS_ENV in a rake task?

Question

I have this little rake task:

namespace :db do 
  namespace :test do 
    task :reset do 
      ENV[\'RAILS_ENV\'] = \"test\" 
      Rake::Task[\'db:drop\']         


        

Answer 1

The cleanest and simplest solution would be to redefine RAILS_ENV (not ENV['RAILS_ENV'])

namespace :db do
  namespace :test do  
    task :reset do 
      RAILS_ENV = "test" 
      Rake::Task['db:drop'].invoke
      Rake::Task['db:create'].invoke
      Rake::Task['db:migrate'].invoke
    end
  end
end

During the boot process of a Rails application RAILS_ENV is initialized as follows

RAILS_ENV = (ENV['RAILS_ENV'] || 'development').dup unless defined?(RAILS_ENV)

The rest of Rails code uses RAILS_ENV directly.

However, as Michael has pointed out in a comment to his answer, switching RAILS_ENV on the fly can be risky. Another approach would be to switch the database connection, this solution is in fact used by the default db:test tasks

ActiveRecord::Base.establish_connection(:test)