_unit.haml

- content_for :item_title do
  = link_to unit.name, unit
= content_for :actions do
  = edit_button(unit)
  = destroy_button(unit)
  = link_to replicate_unit_path(unit), remote: true, class: 'btn btn-default replicate-unit' do
    %i.fa.fa-copy
= label_group 'Issues' do
  - if unit.alerts?
    .tag.tag-danger
      %i.fa.fa-exclamation-triangle
      = unit.alerts.count
  - else
    .tag.tag-success
      %i.fa.fa-check
      0

replicate.js.erb

<% if @unit_replica.valid? %>
  $('ul').append("<%= j render 'unit', locals: {unit: @unit_replica} %>");
<% end %>

units.js

$(function(){
  $("link").click(function(event){
    $.ajax({
      type:'get',
      url: "replicate.js"
    });
 });
});

units_controller.rb

def replicate
    authorize @unit
    @unit_replica = @unit.replicate_unit
    authorize @unit_replica
    # redirect_to account_units_path
    respond_to do |format|
      format.html { redirect_to referer, notice: 'Unit copied' }
      # format.js {}
      format.js
    end
    # render nothing: true, status: 200, content_type: 'text/html'
  end