Simplify toggle-nav-collapse JS

app/assets/javascripts/sidebar.js.coffee

@@ -3,12 +3,7 @@ $(document).on("click", '.toggle-nav-collapse', (e) ->
   collapsed = 'page-sidebar-collapsed'
   expanded = 'page-sidebar-expanded'
-  if $('.page-with-sidebar').hasClass(collapsed)
-    $('.page-with-sidebar').removeClass(collapsed).addClass(expanded)
-    $('.toggle-nav-collapse i').removeClass('fa-angle-right').addClass('fa-angle-left')
-    $.cookie("collapsed_nav", "false", { path: '/' })
-  else
-    $('.page-with-sidebar').removeClass(expanded).addClass(collapsed)
-    $('.toggle-nav-collapse i').removeClass('fa-angle-left').addClass('fa-angle-right')
-    $.cookie("collapsed_nav", "true", { path: '/' })
+  $('.page-with-sidebar').toggleClass("#{collapsed} #{expanded}")
+  $('.toggle-nav-collapse i').toggleClass("fa-angle-right fa-angle-left")
+  $.cookie("collapsed_nav", $('.page-with-sidebar').hasClass(collapsed), { path: '/' })
 )