title: How to add custom message to Jest expect?
body: <p>Image following test case:</p>
  
  <pre><code>it('valid emails checks', () =&gt; {
    ['abc@y.com', 'a@b.nz'/*, ...*/].map(mail =&gt; {
      expect(isValid(mail)).toBe(true);
    });
  });
  </code></pre>
  
  <p>I would like to add auto-generated message for each email like <code>Email 'f@f.com' should be valid</code> so that it's easy to find failing test cases.</p>
  
  <p>Something like:</p>
  
  <pre><code>// .map(email =&gt;
  expect(isValid(email), `Email ${email} should be valid`).toBe(true);
  </code></pre>
  
  <p>Is it possible in <strong>Jest</strong> ?</p>
  
  <p>In Chai it was possible to do with second parameter like <code>expect(value, 'custom fail message').to.be...</code> and in Jasmine seems like it's done with <code>.because</code> clause. But cannot find solution in Jest.</p>