title: What is the difference between “assert”, “expect”, and “should” in Chai?
body: <p>What is the difference between <code>assert</code>, <code>expect</code>, and <code>should</code>? When to use what?</p>
  <pre class="lang-js prettyprint-override"><code>assert.equal(3, '3', '== coerces values to strings');
      
  var foo = 'bar';
      
  expect(foo).to.equal('bar');
      
  foo.should.equal('bar');
  </code></pre>