```ruby
module Jasmine
  module Dependencies

    class << self
      def rails3?
        safe_gem_check("rails", "~> 3") && running_rails3?
      end

      def rails4?
        safe_gem_check("rails", "~> 4.0.0.rc1") && running_rails4?
      end

      def rails?
        rails_available? && running_rails?
      end

      def rails_available?
        safe_gem_check("rails", '>= 3')
      end

      def legacy_rack?
        !defined?(Rack::Server)
      end

      def use_asset_pipeline?
        assets_pipeline_available = (rails3? || rails4?) && Rails.respond_to?(:application) && Rails.application.respond_to?(:assets)
        rails3_assets_enabled = rails3? && assets_pipeline_available && Rails.application.config.assets.enabled != false
        assets_pipeline_available && (rails4? || rails3_assets_enabled)
      end

      private

      def running_rails3?
        running_rails? && Rails.version.to_i == 3
      end

      def running_rails4?
        running_rails? && Rails.version.to_i == 4
      end

      def running_rails?
        defined?(Rails) && Rails.respond_to?(:version)
      end

      def safe_gem_check(gem_name, version_string)
        if Gem::Specification.respond_to?(:find_by_name)
          Gem::Specification.find_by_name(gem_name, version_string)
        elsif Gem.respond_to?(:available?)
          Gem.available?(gem_name, version_string)
        end
      rescue Gem::LoadError
        false
      end

    end
  end
end
```

Allow all versions of rails 4
user
```ruby
module Jasmine
  module Dependencies

    class << self
      def rails3?
        safe_gem_check("rails", "~> 3") && running_rails3?
      end

      def rails4?
        safe_gem_check("rails", "~> 4") && running_rails4?
      end

      def rails?
        rails_available? && running_rails?
      end

      def rails_available?
        safe_gem_check("rails", '>= 3')
      end

      def legacy_rack?
        !defined?(Rack::Server)
      end

      def use_asset_pipeline?
        assets_pipeline_available = (rails3? || rails4?) && Rails.respond_to?(:application) && Rails.application.respond_to?(:assets)
        rails3_assets_enabled = rails3? && assets_pipeline_available && Rails.application.config.assets.enabled != false
        assets_pipeline_available && (rails4? || rails3_assets_enabled)
      end

      private

      def running_rails3?
        running_rails? && Rails.version.to_i == 3
      end

      def running_rails4?
        running_rails? && Rails.version.to_i == 4
      end

      def running_rails?
        defined?(Rails) && Rails.respond_to?(:version)
      end

      def safe_gem_check(gem_name, version_string)
        if Gem::Specification.respond_to?(:find_by_name)
          Gem::Specification.find_by_name(gem_name, version_string)
        elsif Gem.respond_to?(:available?)
          Gem.available?(gem_name, version_string)
        end
      rescue Gem::LoadError
        false
      end

    end
  end
end
```
assistant