Update LabelManager to ES6.

app/assets/javascripts/LabelManager.js.es6

+((global) => {
+
+  class LabelManager {
+    constructor({ togglePriorityButton, prioritizedLabels, otherLabels } = {}) {
+      this.togglePriorityButton = togglePriorityButton || $('.js-toggle-priority');
+      this.prioritizedLabels = prioritizedLabels || $('.js-prioritized-labels');
+      this.otherLabels = otherLabels || $('.js-other-labels');
+      this.errorMessage = 'Unable to update label prioritization at this time';
+      this.prioritizedLabels.sortable({
+        items: 'li',
+        placeholder: 'list-placeholder',
+        axis: 'y',
+        update: this.onPrioritySortUpdate.bind(this)
+      });
+      this.bindEvents();
+    }
+
+    bindEvents() {
+      // TODO: Check if this is being bound correctly
+      return this.togglePriorityButton.on('click', this, this.onTogglePriorityClick);
+    }
+
+    onTogglePriorityClick(e) {
+      e.preventDefault();
+      const _this = e.data;
+      const $btn = $(e.currentTarget);
+      const $label = $(`#${$btn.data('domId')}`);
+      const action = $btn.parents('.js-prioritized-labels').length ? 'remove' : 'add';
+      const $tooltip = $(`#${$btn.find('.has-tooltip:visible').attr('aria-describedby')}`);
+      $tooltip.tooltip('destroy');
+      return _this.toggleLabelPriority($label, action);
+    }
+
+    toggleLabelPriority($label, action, persistState) {
+      if (persistState == null) {
+        persistState = true;
+      }
+      let xhr;
+      const _this = this;
+      const url = $label.find('.js-toggle-priority').data('url');
+      let $target = this.prioritizedLabels;
+      let $from = this.otherLabels;
+      if (action === 'remove') {
+        $target = this.otherLabels;
+        $from = this.prioritizedLabels;
+      }
+      if ($from.find('li').length === 1) {
+        $from.find('.empty-message').removeClass('hidden');
+      }
+      if (!$target.find('li').length) {
+        $target.find('.empty-message').addClass('hidden');
+      }
+      $label.detach().appendTo($target);
+      if (!persistState) {
+        return;
+      }
+      if (action === 'remove') {
+        xhr = $.ajax({
+          url,
+          type: 'DELETE'
+        });
+        if (!$from.find('li').length) {
+          $from.find('.empty-message').removeClass('hidden');
+        }
+      } else {
+        xhr = this.savePrioritySort($label, action);
+      }
+      return xhr.fail(this.rollbackLabelPosition.bind(this, $label, action));
+    }
+
+    onPrioritySortUpdate() {
+      const xhr = this.savePrioritySort();
+      return xhr.fail(function() {
+        return new Flash(this.errorMessage, 'alert');
+      });
+    }
+
+    savePrioritySort() {
+      return $.post({
+        url: this.prioritizedLabels.data('url'),
+        data: {
+          label_ids: this.getSortedLabelsIds()
+        }
+      });
+    }
+
+    rollbackLabelPosition($label, originalAction) {
+      const action = originalAction === 'remove' ? 'add' : 'remove';
+      this.toggleLabelPriority($label, action, false);
+      return new Flash(this.errorMessage, 'alert');
+    }
+
+    getSortedLabelsIds() {
+    // TODO: Check that this works how you expect
+     return this.prioritizedLabels.find('li').map(function(item) {
+        return $(item).data('id');
+      });
+    }
+  }
+
+  gl.LabelManager = LabelManager;
+
+})(window.gl || (window.gl = {}));
+

app/assets/javascripts/dispatcher.js

@@ -164,8 +164,9 @@
           new Labels();
           break;
         case 'projects:labels:index':
+          debugger;
           if ($('.prioritized-labels').length) {
-            new LabelManager();
+            new gl.LabelManager();
           }
           break;
         case 'projects:network:show':