_flash_bs.html.erb

<% heading ||= '' %>
<% dismissible ||= false %>

<% flash.each do |type, msg| %>
  <div class="alert alert-<%= type %> alert-dismissible" role="alert">
    <% if heading.present? %>
      <h4 class="alert-heading"><%= heading %></h4>
    <% end %>
    <div><%= msg %></div>
    <% if dismissible %>
       <button class="close" type="button" data-dismiss="alert" aria-label="Close">
          <span aria-hidden="true">×</span>
      </button>
    <% end %>
  </div>
<% end %>

_flash_bulma.html.erb

<% flash.each do |type, msg| %>
  <div class="<%= class_names(['notification', { 'is-info' => (type == 'notice'), 'is-warning' => (type == 'warning'), 'is-danger' => (type == 'alert') }])%>">
    <button type="button" class="delete"></button>
     <%= msg %>
  </div>
<% end %>