title: Should unit tests use logging?
body: <p>There seems to be two trends on this topic:</p>
  
  <ol>
  <li>Some answers (such as <a href="https://stackoverflow.com/questions/3820290/is-there-any-simple-pattern-of-slf4j-usage-in-unit-tests/3820378#3820378">this one</a>) suggest unit tests should not log anything.</li>
  <li>Some questions and answers (such as <a href="https://stackoverflow.com/questions/3820290/is-there-any-simple-pattern-of-slf4j-usage-in-unit-tests">this one</a>) suggest different logging techniques and formats used in unit tests.</li>
  </ol>
  
  <p>Should unit tests log what they do? Would those additional informations be helpful in the unit test reports? Or should unit tests be silent as long as they don't fail?</p>
  
  <p>My question targets Java unit tests, but input from programmers in other languages could be interesting as well.</p>