gistfile2.txt

Error:

[dfr@beta trunk]$ ruby test/unit/has_attribute_based_equality_test.rb -n test_is_equal_by
Loaded suite test/unit/has_attribute_based_equality_test
Started
E
Finished in 0.005169 seconds.

  1) Error:
test_is_equal_by(HasAttributeBasedEqualityTest):
LocalJumpError: unexpected return
    /home/dfr/webitects/trunk/lib/has_attribute_based_equality.rb:7:in `eql?'
    /home/dfr/webitects/trunk/lib/has_attribute_based_equality.rb:5:in `each'
    /home/dfr/webitects/trunk/lib/has_attribute_based_equality.rb:5:in `eql?'
    /home/dfr/webitects/trunk/lib/has_attribute_based_equality.rb:15:in `=='
    test/unit/has_attribute_based_equality_test.rb:29:in `should_be_not_equal'
    test/unit/has_attribute_based_equality_test.rb:16:in `test_is_equal_by'
    /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/testing/default.rb:7:in `run'

1 tests, 5 assertions, 0 failures, 1 errors
[dfr@beta trunk]$ 

has_attribute_based_equality.rb

module HasAttributeBasedEquality
  def is_equal_by *attributes
    include(Module.new do
      define_method :eql? do |other|
        attributes.each do |attr|
          unless self.send(attr) == other.send(attr)
            return false
          end
        end
        true
      end
      define_method :hash do
        attributes.map { |attr| send(attr) }.hash
      end
      def == other; eql?(other) end
    end)
  end
end
# includes the is_equal_by hook into all objects without enabling the functionality by default
Class.class_eval { include HasAttributeBasedEquality }

test_has_attribute_based_equality.rb

class HasAttributeBasedEqualityTest < ActiveSupport::TestCase
  def test_truth
    assert true
  end

  def test_is_equal_by
    foo_class = Class.new
    foo_class.class_eval do
      attr_accessor :a, :b, :c
      def initialize *args; @a, @b, @c = args end
      is_equal_by :a, :b
    end
    should_be_equal foo_class.new("1", "2", "3"), foo_class.new("1", "2", "5")
    should_be_not_equal foo_class.new("1", "2", "3"), foo_class.new("1", "3", "2")
  end

  private
  
  def should_be_equal foo, bar
    assert_equal foo, bar
    assert foo.eql?(bar), "#{foo.inspect} should be eql? to #{bar.inspect}."
    assert_equal foo.hash, bar.hash, "#{foo.inspect} should have same hash code as #{bar.inspect}."
    assert (foo == bar), "#{foo.inspect} should be == #{bar.inspect}."
  end

  def should_be_not_equal foo, bar
    assert_not_equal foo, bar
    assert !foo.eql?(bar), "#{foo.inspect} should not be eql? to #{bar.inspect}."
    assert_not_equal foo.hash, bar.hash, "#{foo.inspect} should not have same hash code as #{bar.inspect}."
    assert (foo != bar), "#{foo.inspect} should be != #{bar.inspect}."
  end
end