title: Nice way to get rid of no-unused-expressions linter error with chai
body: <p>In my Chai tests I often find myself wanting to use their assertions that are something like <code>.to.be.empty</code>, <code>.to.be.true</code> e.t.c., because I find them to be cleaner to read than <code>.to.be.length(1)</code> or <code>.to.be.equal(true)</code>. However, this breaks my linter (I'm using default Airbnb linting). </p>
  
  <p>I could use the <code>// disable-eslint-line</code> syntax, but then I'd have to add it to every single line that reads like that and that seems tedious. </p>
  
  <p>I've also read about the <a href="https://github.com/prodatakey/dirty-chai" rel="noreferrer">DirtyChai</a> library, but that would require me to go back through my entire testing library adding brackets to them all which seems like something I shouldn't have to do simply to get my linter to pass something it should probably be OK with in the first place. </p>
  
  <p>Does anyone know a nicer way to handle this than the ways I've outlined above?</p>