Redefinition of Rails.env to support a hierarchy of environments, tested on 3.2.17

01_rails.rb

# Override Rails.env so we can have a env method that support this environment plus or minus other environments as true
# This initializer file is named 01_rails so it executes before any others
module Rails


  # Mini-helper class which subclasses String, duplicating the base of ActiveSupport::StringInquirer
  # Adds support for comparing hierarchy of environments, the method_name vs. current Rails.env
  #
  #   Rails.env # => "development"
  #   Rails.env.development? # => true
  #   Rails.env.production? # => false
  #   Rails.env.production?(:<) # => true (dev, test, qa, stage)
  #   Rails.env = "stage" # => "stage"
  #   Rails.env.stage?(:<) # => false (dev, test, qa)
  #   Rails.env.stage?(:>=) # => true (stage && production)
  class MyStringInquirer < String

    private
    def respond_to_missing?(method_name)
      method_name[-1] == '?'
    end

    def method_missing(method_name, arg=nil)
      envs = ["development", "test", "qa", "stage", "production"]
      comparators = [:>, :>=, :<, :<=, :==]

      if method_name[-1] == '?'
        name = method_name[0..-2]
        self_pos = envs.index(self)
        name_pos = envs.index(name)

        if arg.nil? || name_pos.nil? || self_pos.nil?
          self == name
        elsif comparators.include?(arg)
          self_pos.public_send(arg, name_pos)
        end
      else
        super
      end
    end
  end

  class << self
    def env
      @_env = nil if @_env.class.name == 'ActiveSupport::StringInquirer'
      @_env ||= MyStringInquirer.new(ENV["RAILS_ENV"] || ENV["RACK_ENV"] || "development")
    end
    def env=(environment)
      @_env = MyStringInquirer.new(environment)
    end
  end
end