title: What is the current state of Unit testing support in the R language
body: <p><a href="http://en.wikipedia.org/wiki/R_%28programming_language%29" rel="noreferrer">R</a> is a statistics programming language.  Part of R is the use of Packages, which themselves are written in the R language.  Programming best practice includes the use of unit-testing to test the functions within these packages while they are being written and when they are used.</p>
  
  <p>I am aware of a few packages for unit testing within R, these being</p>
  
  <ul>
  <li><a href="http://cran.r-project.org/web/packages/RUnit/index.html" rel="noreferrer">RUnit</a></li>
  <li><a href="http://cran.r-project.org/web/packages/svUnit/index.html" rel="noreferrer">Svunit</a></li>
  <li><a href="http://cran.r-project.org/web/packages/testthat/index.html" rel="noreferrer">Testthat</a></li>
  </ul>
  
  <p>I'm interested to know;</p>
  
  <p>Are there any other packages out there ?
  Given peoples experience, do these packages excel at different things ?
  What's the current state of the art in unit testing for R ?</p>