Enforce a consistent ES6 coding style

Replace the old (and broken) jshint + jscsrc by eslint and configure
it to support some of the ES6 features.

The command `eslint` currently has one error which is a bug that was
discovered by its static analysis and should be fixed (usage of a
dead object).

client/components/cards/labels.js

@@ -1,136 +1,136 @@
-
-var labelColors;
-Meteor.startup(function() {
+let labelColors;
+Meteor.startup(() => {
   labelColors = Boards.simpleSchema()._schema['labels.$.color'].allowedValues;
 });
 
 BlazeComponent.extendComponent({
-  template: function() {
+  template() {
     return 'formLabel';
   },
 
-  onCreated: function() {
+  onCreated() {
     this.currentColor = new ReactiveVar(this.data().color);
   },
 
-  labels: function() {
-    return _.map(labelColors, function(color) {
-      return { color: color, name: '' };
+  labels() {
+    return _.map(labelColors, (color) => {
+      return { color, name: '' };
     });
   },
 
-  isSelected: function(color) {
+  isSelected(color) {
     return this.currentColor.get() === color;
   },
 
-  events: function() {
+  events() {
     return [{
-      'click .js-palette-color': function() {
+      'click .js-palette-color'() {
         this.currentColor.set(this.currentData().color);
-      }
+      },
     }];
-  }
+  },
 }).register('formLabel');
 
 Template.createLabelPopup.helpers({
   // This is the default color for a new label. We search the first color that
   // is not already used in the board (although it's not a problem if two
   // labels have the same color).
-  defaultColor: function() {
-    var labels = Boards.findOne(Session.get('currentBoard')).labels;
-    var usedColors = _.pluck(labels, 'color');
-    var availableColors = _.difference(labelColors, usedColors);
+  defaultColor() {
+    const labels = Boards.findOne(Session.get('currentBoard')).labels;
+    const usedColors = _.pluck(labels, 'color');
+    const availableColors = _.difference(labelColors, usedColors);
     return availableColors.length > 1 ? availableColors[0] : labelColors[0];
-  }
+  },
 });
 
 Template.cardLabelsPopup.events({
-  'click .js-select-label': function(evt) {
-    var cardId = Template.parentData(2).data._id;
-    var labelId = this._id;
-    var operation;
+  'click .js-select-label'(evt) {
+    const cardId = Template.parentData(2).data._id;
+    const labelId = this._id;
+    let operation;
     if (Cards.find({ _id: cardId, labelIds: labelId}).count() === 0)
       operation = '$addToSet';
     else
       operation = '$pull';
 
-    var query = {};
-    query[operation] = {
-      labelIds: labelId
-    };
-    Cards.update(cardId, query);
+    Cards.update(cardId, {
+      [operation]: {
+        labelIds: labelId,
+      },
+    });
     evt.preventDefault();
   },
   'click .js-edit-label': Popup.open('editLabel'),
-  'click .js-add-label': Popup.open('createLabel')
+  'click .js-add-label': Popup.open('createLabel'),
 });
 
 Template.formLabel.events({
-  'click .js-palette-color': function(evt) {
-    var $this = $(evt.currentTarget);
+  'click .js-palette-color'(evt) {
+    const $this = $(evt.currentTarget);
 
     // hide selected ll colors
     $('.js-palette-select').addClass('hide');
 
     // show select color
     $this.find('.js-palette-select').removeClass('hide');
-  }
+  },
 });
 
 Template.createLabelPopup.events({
   // Create the new label
-  'submit .create-label': function(evt, tpl) {
-    var name = tpl.$('#labelName').val().trim();
-    var boardId = Session.get('currentBoard');
-    var color = Blaze.getData(tpl.find('.fa-check')).color;
+  'submit .create-label'(evt, tpl) {
+    const name = tpl.$('#labelName').val().trim();
+    const boardId = Session.get('currentBoard');
+    const color = Blaze.getData(tpl.find('.fa-check')).color;
 
     Boards.update(boardId, {
       $push: {
         labels: {
+          name,
+          color,
           _id: Random.id(6),
-          name: name,
-          color: color
-        }
-      }
+        },
+      },
     });
 
     Popup.back();
     evt.preventDefault();
-  }
+  },
 });
 
 Template.editLabelPopup.events({
   'click .js-delete-label': Popup.afterConfirm('deleteLabel', function() {
-    var boardId = Session.get('currentBoard');
+    const boardId = Session.get('currentBoard');
     Boards.update(boardId, {
       $pull: {
         labels: {
-          _id: this._id
-        }
-      }
+          _id: this._id,
+        },
+      },
     });
 
     Popup.back(2);
   }),
-  'submit .edit-label': function(evt, tpl) {
+  'submit .edit-label'(evt, tpl) {
     evt.preventDefault();
-    var name = tpl.$('#labelName').val().trim();
-    var boardId = Session.get('currentBoard');
-    var getLabel = Utils.getLabelIndex(boardId, this._id);
-    var color = Blaze.getData(tpl.find('.fa-check')).color;
+    const name = tpl.$('#labelName').val().trim();
+    const boardId = Session.get('currentBoard');
+    const getLabel = Utils.getLabelIndex(boardId, this._id);
+    const color = Blaze.getData(tpl.find('.fa-check')).color;
 
-    var $set = {};
-    $set[getLabel.key('name')] = name;
-    $set[getLabel.key('color')] = color;
-
-    Boards.update(boardId, { $set: $set });
+    Boards.update(boardId, {
+      $set: {
+        [getLabel.key('name')]: name,
+        [getLabel.key('color')]: color,
+      },
+    });
 
     Popup.back();
-  }
+  },
 });
 
 Template.cardLabelsPopup.helpers({
-  isLabelSelected: function(cardId) {
+  isLabelSelected(cardId) {
     return _.contains(Cards.findOne(cardId).labelIds, this._id);
-  }
+  },
 });