Assert that a DOM node list contains elements satisfying a given specification.

See to contain for more details.

var element = createElement(`
  <section>
    <h1>Numbers</h1>
    <hr>
    <ol data-test-id="numbers">
      <li class="number">One</li>
      <li class="number">Two</li>
      <li class="number">Three</li>
    </ol>
  </section>
`);
 
expect(element, 'queried for', 'li', 'to contain', '<li>One</li>');
 
expect(element, 'to contain', { textContent: 'Three' });
 
expect(element, 'to contain', { name: 'li', textContent: /One|Two|Tree/ });

In case of a failing expectation you get the following output:

expect(
  element,
  'queried for',
  'li',
  'to contain',
  '<li class="count">Three</li>'
);

expected
<section>
  
<h1>Numbers</h1>
  
<hr>
  
<ol data-test-id="numbers">
  
<li class="number">...</li>
  
<li class="number">...</li>
  
<li class="number">...</li>
</ol>
</section>
queried for li to contain '<li class="count">Three</li>'
  
expected
NodeList[
  
<li class="number">One</li>,
  
<li class="number">Two</li>,
  
<li class="number">Three</li>
]
to contain <li class="count">Three</li>
 
<li
  
class="number" 
//
 
expected [ 'number' ] to contain 'count'
>Three</li>

You can also assert that the element has no descendant elements satisfying the given specification:

expect(
  element,
  'queried for',
  'li',
  'not to contain',
  '<li class="count">Three</li>'
);