JSFiddle - React, Tailwind, and code Playground

HTML

<button class="tvshow">Test</button>

<ul class="container__list-of-shows">
      <li>
        <a href="#" class="btn icon-close  js-remove-item" title="Remove this"></a>

        <img src="../images/poster_126.42.jpg" alt="show" />
        <div class="container__list-of-shows__info">
          <span class="container__list-of-shows__info__title">something</span>
        </div>
      </li>
</ul>

JavaScript

var selectedTVshow = 'something';
$('.tvshow').on('click', function() {
  checkIfDuplicate(selectedTVshow);
})

function checkIfDuplicate(show) {
  $('.container__list-of-shows li').each(function() {
    var tvShowTitle = $(this).find('.container__list-of-shows__info__title').text;
    console.log(tvShowTitle);
    if (tvShowTitle === show)
        $('body').append('<p>true</p>');
      // return false
  })
}