A helper method to change the Rails environment within a block. I use this for testing isolated, environment-specific methods. Obviously, I wouldn’t suggest using this outside of test code. You could easily do something very stupid.

<code>
def with_rails_env(environment, &block)
  begin
    original_env = Rails.env
    Rails.instance_variable_set(:@_env, environment)
    yield if block_given?
  ensure
    Rails.instance_variable_set(:@_env, original_env)
  end
end
</code>