JS / Ajax research for input suggestion

AjaxInputResearchController.php

<?php

class ClassController extends Controller
{
  public function list_professions(Request $request)
  {
    $em = $this->container->get('doctrine')->getManager();

    $type = $request->request->get('type');
    $profession_libelle = $request->request->get('profession_libelle');

    $liste_professions = '';

    $professions = $em->getRepository('App\Entity\Profession')->getProfessionByName($profession_libelle);
    if (!empty($professions)) {
      $liste_professions .= "<h5>Merci de sélectionner une profession :</h5><br><ul>";
      foreach ($professions as $profession) {
        $liste_professions .= "<li><a style='cursor:pointer;' class='a-suggest-profession' data-type='" . $type . "' data-profession='" . $profession['pro_libelleprofession'] . "'>" . $profession['pro_libelleprofession'] . "</a></li>";
      }
      $liste_professions .= "</ul>";
    } else {
      $liste_professions .= "<h5>Tapez une profession de votre choix</h5><br>";
    }

    return new Response($liste_professions);
  }
}

input_ajax_search.html

<div class="m-form__group form-group col-lg-2">
  <label for="conjoint_profession_libelle">Profession</label>
  <input class="form-control input m-input--solid profession_libelle" type="text" name="profession_libelle"
    data-type="conjoint" id="conjoint_profession_libelle" value="{{ conjoint.getProfessionLibelle() }}">
  <div id="div_suggestion_profession"></div>
</div>
<script>
  var time_localite = null;
  $(document).on("keyup", ".profession_libelle", function () {
    if (time_localite) clearTimeout(time_localite);
    var elem = $(this);
    time_localite = setTimeout(suggestProfession, 400, elem);
  });
  function suggestProfession(elem) {
    var type = $(elem).attr('data-type');
    var search = $(elem).val().trim();
    if (search.length >= 2) {
      $.ajax({
        type: "POST",
        async: false,
        url: "{{ path('list_professions') }}",
        data: { 'profession_libelle': search, 'type': type },
        success: function (data) {
          $("#div_suggestion_profession").show();
          $("#div_suggestion_profession").html(data);
        }
      });
    }
  }
</script>