app/views/health_checks/create.js.erb
<% if !@server.down? %>
$("[data-behaviour~=perform-health-check]").removeClass("is-hidden");
$("[data-behaviour~=performing-health-check]").addClass("is-hidden");
<% else %>
$("[data-server-status~=down]").addClass("is-hidden");
$("[data-server-status~=up]").removeClass("is-hidden");
<% end %>