title: What is "with_after_commit" and why can't I find anything about it?
body: <p>I helping out on a test suite that came from Rails 4 (which I am not so familiar with) and there were some tests that had "with_after_commit: true" in their declaration.</p>
  
  <p>After a bit of tinkering I removed it and the test suite ran a little bit faster.</p>
  
  <p>It was used in rails_helper.rb as well, much like this:
  <a href="https://stackoverflow.com/questions/10656942/why-after-commit-not-running-even-with-use-transactional-fixtures-false/26849392#26849392">Why after_commit not running even with use_transactional_fixtures = false</a></p>
  
  <p>The thing is: I can't find any information about it that would justify its use. I only find references to it in the thread above.</p>
  
  <p>Thanks!</p>