[internal] Remove all variable redeclarations

Redeclaring variables causes ambiguity and serves no purpose. It
actually causes a runtime error when you do it with `let`, and we can
enforce not doing it via a linter rule.

src/ui/public/agg_types/buckets/range.js

@@ -30,7 +30,7 @@ export default function RangeAggDefinition(Private) {
 
       var id = RangeKey.idBucket(bucket);
 
-      var key = keys.get(id);
+      key = keys.get(id);
       if (!key) {
         key = new RangeKey(bucket);
         keys.set(id, key);

src/ui/public/visualize/visualize_legend.js

@@ -90,7 +90,7 @@ uiModules.get('kibana')
       // Most of these functions were moved directly from the old Legend class. Not a fan of this.
       function getLabels(data, type) {
         if (!data) return [];
-        var data = data.columns || data.rows || [data];
+        data = data.columns || data.rows || [data];
         if (type === 'pie') return Data.prototype.pieNames(data);
         return getSeriesLabels(data);
       };

test/fixtures/scenario_manager.js

@@ -123,7 +123,6 @@ ScenarioManager.prototype.loadIfEmpty = function (id) {
   var scenario = config[id];
   if (!scenario) throw new Error('No scenario found for ' + id);
 
-  var self = this;
   return Promise.all(scenario.bulk.map(function mapBulk(bulk) {
     var loadIndexDefinition;
 

test/functional/apps/discover/index.js

@@ -9,7 +9,6 @@ define(function (require) {
   var collapseExpand = require('./_collapse_expand');
 
   bdd.describe('discover app', function () {
-    var scenarioManager;
     var remote;
     var scenarioManager = new ScenarioManager(url.format(config.servers.elasticsearch));
     this.timeout = config.timeouts.default;

test/functional/apps/visualize/index.js

@@ -20,7 +20,6 @@ define(function (require) {
 
   bdd.describe('visualize app', function () {
     var common;
-    var scenarioManager;
     var remote;
     var headerPage;
     var settingsPage;

test/support/pages/common.js

@@ -91,7 +91,7 @@ define(function (require) {
             return self.remote.getCurrentUrl();
           })
           .then(function (currentUrl) {
-            var currentUrl = currentUrl.replace(/\/\/\w+:\w+@/, '//');
+            currentUrl = currentUrl.replace(/\/\/\w+:\w+@/, '//');
             var navSuccessful = new RegExp(appUrl).test(currentUrl);
             if (!navSuccessful) {
               var msg = 'App failed to load: ' + appName +