spec_helper.rb

##
# rSpec Hash additions.
#
# From 
#   * http://wincent.com/knowledge-base/Fixtures_considered_harmful%3F
#   * Neil Rahilly

class Hash

  ##
  # Filter keys out of a Hash.
  #
  #   { :a => 1, :b => 2, :c => 3 }.except(:a)
  #   => { :b => 2, :c => 3 }

  def except(*keys)
    self.reject { |k,v| keys.include?(k || k.to_sym) }
  end

  ##
  # Override some keys.
  #
  #   { :a => 1, :b => 2, :c => 3 }.with(:a => 4)
  #   => { :a => 4, :b => 2, :c => 3 }
  
  def with(overrides = {})
    self.merge overrides
  end

  ##
  # Returns a Hash with only the pairs identified by +keys+.
  #
  #   { :a => 1, :b => 2, :c => 3 }.only(:a)
  #   => { :a => 1 }
  
  def only(*keys)
    self.reject { |k,v| !keys.include?(k || k.to_sym) }
  end

end