1994
Heckle
2123
2007-11-21T16:04:14Z
http://deepblue.springnote.com/pages/1994
2007-01-19T16:45:25Z
<h1>테스트를 테스트한다 - 루비 세디즘</h1>
<blockquote>
<p>"RSpec/Test::Unit is your safety belt. RCov is your airbag. Heckle is your helmet, neck brace and full fireproof suit."</p>
<p>"루비 프로그래밍을 하는데 RSpec이 안전벨트, RCov를 에어백이라고 한다면, Heckle은 헬멧과 목 보호대, 완벽한 방화복입니다." -- <a href="http://blog.aslakhellesoy.com/articles/2006/12/19/heckling-with-rspec">Aslak Hellesoy</a></p>
</blockquote>
<p> </p>
<p>Heckle은 Ruby2Ruby와 ParseTree를 이용해 루비 코드를 바꿉니다. 그렇다면, 테스트는 반드시 실패해야합니다. 만일 테스트가 성공한다면, 그 테스트에는 '빈틈'이 있는 것입니다. 이런 식의 코드 변형을 통한 테스트는 루비 코드를 특히나 테스트를 더욱 견고하게 해줍니다.</p>
<p> </p>
<h2>구구단 예제</h2>
<ul>
<li>gugu_spec.rb</li>
</ul>
<p> </p>
<ol class="code">
<li>context "구구단" do<br />
specify "5단을 잘 출력한다" do<br />
5.dan.to_a.should_be_eql [5,10,15,20,25,30,35,40,45]<br />
end<br />
end</li>
</ol>
<p> </p>
<ul>
<li>gugu.rb</li>
</ul>
<ol class="code">
<li>class Fixnum<br />
def dan<br />
raise if self < 2 || self > 9<br />
(1..9).map{|i| self*i}<br />
end<br />
end</li>
</ol>
<p> </p>
<p>실행 결과:</p>
<p> </p>
<ol class="code">
<li>[deepblue:ruby/test/heckle] deepblue% spec gugu_spec.rb --heckle Fixnum.dan . Finished in 0.000549 seconds 1 specification, 0 failures **********************************************************************<br />
*** Fixnum#dan loaded with 4 possible mutations<br />
********************************************************************** 4 mutations remaining...<br />
3 mutations remaining...<br />
2 mutations remaining...<br />
1 mutations remaining... The following mutations didn't cause test failures: def dan<br />
raise if ((self < -5) or (self > 9))<br />
(1..9).map do |i|<br />
(self * i)<br />
end<br />
end def dan<br />
raise if ((self < 2) or (self > 14))<br />
(1..9).map do |i|<br />
(self * i)<br />
end<br />
end</li>
</ol>
<p> </p>
<p>테스트가 부족함을 알 수 있다. 테스트를 보강하자.</p>
<p> </p>
<ol class="code">
<li>context "구구단" do<br />
specify "5단을 잘 출력한다" do<br />
5.dan.to_a.should_be_eql [5,10,15,20,25,30,35,40,45]<br />
end<br />
<br />
specify "우리나라 구구단은 2단부터 9단까지뿐이다" do<br />
lambda{ 1.dan }.should_raise<br />
lambda{ 10.dan }.should_raise<br />
end<br />
end</li>
</ol>
<p> </p>
<ol class="code">
<li>[deepblue:ruby/test/heckle] deepblue% spec gugu_spec.rb --heckle Fixnum.dan .. Finished in 0.000841 seconds 2 specifications, 0 failures **********************************************************************<br />
*** Fixnum#dan loaded with 4 possible mutations<br />
********************************************************************** 4 mutations remaining...<br />
3 mutations remaining...<br />
2 mutations remaining...<br />
1 mutations remaining... The following mutations didn't cause test failures: def dan<br />
raise if ((self < 2) or (self > 6))<br />
(1..9).map do |i|<br />
(self * i)<br />
end<br />
end</li>
</ol>
<p> </p>
<p>아직도 부족하다</p>
<p> </p>
<ol class="code">
<li>context "구구단" do<br />
specify "5단을 잘 출력한다" do<br />
5.dan.to_a.should_be_eql [5,10,15,20,25,30,35,40,45]<br />
end<br />
<br />
specify "우리나라 구구단은 2단부터 9단까지뿐이다" do<br />
lambda{ 1.dan }.should_raise<br />
lambda{ 10.dan }.should_raise (2..9).each do |i|<br />
lambda{ i.dan }.should_not_raise<br />
end<br />
end<br />
end</li>
</ol>
<p> </p>
<ol class="code">
<li>[deepblue:ruby/test/heckle] deepblue% spec gugu_spec.rb --heckle Fixnum.dan .. Finished in 0.000974 seconds 2 specifications, 0 failures **********************************************************************<br />
*** Fixnum#dan loaded with 4 possible mutations<br />
********************************************************************** 4 mutations remaining...<br />
3 mutations remaining...<br />
2 mutations remaining...<br />
1 mutations remaining...<br />
No mutants survived. Cool!</li>
</ol>
<p> </p>
<p>드디어 성공했다!</p>
<p> </p>
<h2>참고 자료</h2>
<ul>
<li><a href="http://jester.sourceforge.net/">http://jester.sourceforge.net/</a></li>
<li><a href="http://del.icio.us/byblue/heckle">http://del.icio.us/byblue/heckle</a></li>
</ul>
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