Ruby's Hash deep search

hash.rb

class Hash
  def deep_has_key?(key)
    self.has_key?(key) || any? {|k, v| v.deep_has_key?(key) if v.is_a? Hash}
  end
  alias :deep_include? :deep_has_key?
  alias :deep_key? :deep_has_key?
  alias :deep_member? :deep_has_key?
  
  def deep_has_value?(value)
    self.has_value?(value) || any? {|k,v| v.deep_has_value?(value) if v.is_a? Hash}
  end
  alias :deep_value? :deep_has_value?
end

hash_test.rb

require 'test/unit'

class HashDeepHasKeyTest < Test::Unit::TestCase
  def returns_true_on_first_level_search
    assert({:a => 'a'}.deep_has_key?(:a))
  end
  
  def returns_false_on_first_level_search
    assert_false({:a => 'a'}.deep_has_key?(:b))
  end
  
  def returns_true_on_second_level_search
    assert({:a => {:b => 'b'}}.deep_has_key?(:b))
  end
  
  def returns_false_on_second_level_search
    assert_false({:a => {:b => 'b'}}.deep_has_key?(:c))
  end
  
  def returns_true_on_second_level_and_last_element_search
    assert({:a => {:c => 'c'}, :b =>{:d => 'd'}}.deep_has_key?(:d))
  end
  
  def returns_false_on_second_level_and_last_element_search
    assert_false({:a => {:c => 'c'}, :b =>{:d => 'd'}}.deep_has_key?(:e))
  end
  
  def returns_true_on_third_level_and_last_element_search
    assert({:a => {:c => 'c'}, :b =>{:d => {:e => 'e'}}}.deep_has_key?(:e))
  end
  
  def returns_true_on_deepest_level
    assert({:a => {:b => {:c => {:d => {:e => {:f => {:g => {:h => {:i => {:j => {:k => {:l => 'luca'}}}}}}}}}}}}.deep_has_key?(:l))
  end
end

class HashDeepHasValueTest < Test::Unit::TestCase
  def returns_true_on_first_level_search
    assert({:a => 'a'}.deep_has_value?('a'))
  end
  
  def returns_false_on_first_level_search
    assert_false({:a => 'a'}.deep_has_value?('b'))
  end
  
  def returns_true_on_second_level_search
    assert({:a => {:b => 'b'}}.deep_has_value?('b'))
  end
  
  def returns_false_on_second_level_search
    assert_false({:a => {:b => 'b'}}.deep_has_value?('c'))
  end
  
  def returns_true_on_second_level_and_last_element_search
    assert({:a => {:c => 'c'}, :b =>{:d => 'd'}}.deep_has_value?('d'))
  end
  
  def returns_false_on_second_level_and_last_element_search
    assert_false({:a => {:c => 'c'}, :b =>{:d => 'd'}}.deep_has_value?('e'))
  end
  
  def returns_true_on_third_level_and_last_element_search
    assert({:a => {:c => 'c'}, :b =>{:d => {:e => 'e'}}}.deep_has_value?('e'))
  end
  
  def returns_true_on_deepest_level
    assert({:a => {:b => {:c => {:d => {:e => {:f => {:g => {:h => {:i => {:j => {:k => {:l => 'luca'}}}}}}}}}}}}.deep_has_value?('luca'))
  end
end