diff --git a/.eslintrc b/.eslintrc
index 1904222b3cfa9..76c42539c061c 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -2,7 +2,6 @@
 extends: '@elastic/kibana'
 rules:
   no-unused-vars: off
-  no-var: off
   prefer-const: off
   no-extra-semi: off
   quotes: off
diff --git a/src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/keys_deep.js b/src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/keys_deep.js
index 6485f55344d81..5b5976583f132 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/keys_deep.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/keys_deep.js
@@ -5,7 +5,7 @@ export default function keysDeep(object, base) {
   let delimitedBase = base ? base + '.' : '';
 
   _.forEach(object, (value, key) => {
-    var fullKey = delimitedBase + key;
+    let fullKey = delimitedBase + key;
     if (_.isPlainObject(value)) {
       result = result.concat(keysDeep(value, fullKey));
     } else {
diff --git a/src/core_plugins/kibana/public/management/sections/indices/filebeat/directives/filebeat_wizard.js b/src/core_plugins/kibana/public/management/sections/indices/filebeat/directives/filebeat_wizard.js
index a454cd8d88349..fa2967f8cebc3 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/filebeat/directives/filebeat_wizard.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/filebeat/directives/filebeat_wizard.js
@@ -20,11 +20,11 @@ modules.get('apps/management')
       const ingest = Private(IngestProvider);
       const $state = this.state = new AppState();
 
-      var notify = new Notifier({
+      let notify = new Notifier({
         location: 'Add Data'
       });
 
-      var totalSteps = 4;
+      let totalSteps = 4;
       this.stepResults = {};
 
       this.setCurrentStep = (step) => {
diff --git a/src/core_plugins/kibana/public/management/sections/indices/upload/directives/upload_wizard.js b/src/core_plugins/kibana/public/management/sections/indices/upload/directives/upload_wizard.js
index ec455e8eb2dff..92c79fe01d152 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/upload/directives/upload_wizard.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/upload/directives/upload_wizard.js
@@ -19,11 +19,11 @@ modules.get('apps/management')
         const ingest = Private(IngestProvider);
         const $state = this.state = new AppState();
 
-        var notify = new Notifier({
+        let notify = new Notifier({
           location: 'Add Data'
         });
 
-        var totalSteps = 3;
+        let totalSteps = 3;
         this.stepResults = {};
 
         this.setCurrentStep = (step) => {
diff --git a/src/core_plugins/table_vis/public/table_vis_controller.js b/src/core_plugins/table_vis/public/table_vis_controller.js
index 1d7af7d3c1b7e..15e1cc40ed0b1 100644
--- a/src/core_plugins/table_vis/public/table_vis_controller.js
+++ b/src/core_plugins/table_vis/public/table_vis_controller.js
@@ -11,7 +11,7 @@ const module = uiModules.get('kibana/table_vis', ['kibana']);
 module.controller('KbnTableVisController', function ($scope, Private) {
   const tabifyAggResponse = Private(AggResponseTabifyTabifyProvider);
 
-  var uiStateSort = ($scope.uiState) ? $scope.uiState.get('vis.params.sort') : {};
+  let uiStateSort = ($scope.uiState) ? $scope.uiState.get('vis.params.sort') : {};
   assign($scope.vis.params.sort, uiStateSort);
 
   $scope.sort = $scope.vis.params.sort;
diff --git a/src/fixtures/mock_ui_state.js b/src/fixtures/mock_ui_state.js
index 50d913ae337e8..5f5b90e38eb3d 100644
--- a/src/fixtures/mock_ui_state.js
+++ b/src/fixtures/mock_ui_state.js
@@ -10,4 +10,4 @@ export default {
   },
   on: _.noop,
   off: _.noop
-}
+};
diff --git a/src/ui/public/directives/__tests__/paginated_selectable_list.js b/src/ui/public/directives/__tests__/paginated_selectable_list.js
index eb18304b478ff..a066d470b4497 100644
--- a/src/ui/public/directives/__tests__/paginated_selectable_list.js
+++ b/src/ui/public/directives/__tests__/paginated_selectable_list.js
@@ -21,9 +21,9 @@ let stringList = [
 
 let lists = [objectList, stringList, []];
 
-var $scope;
-var $element;
-var $isolatedScope;
+let $scope;
+let $element;
+let $isolatedScope;
 
 lists.forEach(function (list) {
   let isArrayOfObjects = list.every((item) => {
diff --git a/src/ui/public/kbn_top_nav/__tests__/kbn_top_nav_controller.js b/src/ui/public/kbn_top_nav/__tests__/kbn_top_nav_controller.js
index 36614f1e9b7e9..bdb9759052e0d 100644
--- a/src/ui/public/kbn_top_nav/__tests__/kbn_top_nav_controller.js
+++ b/src/ui/public/kbn_top_nav/__tests__/kbn_top_nav_controller.js
@@ -303,7 +303,7 @@ describe('KbnTopNavController', function () {
         expect(controller.menuItems).to.have.length(4);
 
         // check that the items were added
-        var matches = controller.menuItems.reduce((acc, item) => {
+        let matches = controller.menuItems.reduce((acc, item) => {
           if (item.key === 'green' || item.key === 'red') {
             acc[item.key] = item;
           }
@@ -324,7 +324,7 @@ describe('KbnTopNavController', function () {
         expect(controller.menuItems).to.have.length(3);
 
         // check that the items were added
-        var match = controller.menuItems.filter((item) => {
+        let match = controller.menuItems.filter((item) => {
           return item.key === 'green';
         });
         expect(match[0]).to.have.property('run');
diff --git a/src/ui/public/paginated_table/__tests__/index.js b/src/ui/public/paginated_table/__tests__/index.js
index 34eea5692ab8c..945118d794a70 100644
--- a/src/ui/public/paginated_table/__tests__/index.js
+++ b/src/ui/public/paginated_table/__tests__/index.js
@@ -165,7 +165,7 @@ describe('paginated table', function () {
       paginatedTable.sortColumn(1);
       $scope.$digest();
 
-      var tableRows = $el.find('tbody tr');
+      let tableRows = $el.find('tbody tr');
       expect(tableRows.eq(2).find('td').eq(1).text()).to.be('cccc');
       expect(tableRows.eq(1).find('td').eq(1).text()).to.be('bbbb');
       expect(tableRows.eq(0).find('td').eq(1).text()).to.be('aaaa');
@@ -175,7 +175,7 @@ describe('paginated table', function () {
       paginatedTable.sortColumn(1, 'desc');
       $scope.$digest();
 
-      var tableRows = $el.find('tbody tr');
+      let tableRows = $el.find('tbody tr');
       expect(tableRows.eq(0).find('td').eq(1).text()).to.be('zzzz');
       expect(tableRows.eq(1).find('td').eq(1).text()).to.be('cccc');
       expect(tableRows.eq(2).find('td').eq(1).text()).to.be('bbbb');
diff --git a/src/ui/public/pattern_checker/pattern_checker.js b/src/ui/public/pattern_checker/pattern_checker.js
index 5ac8834d8a8e8..134bfce760f61 100644
--- a/src/ui/public/pattern_checker/pattern_checker.js
+++ b/src/ui/public/pattern_checker/pattern_checker.js
@@ -17,7 +17,7 @@ module.directive('patternChecker', function () {
     controller: function (Notifier, $scope, $timeout, $http) {
       let validationTimeout;
 
-      var notify = new Notifier({
+      let notify = new Notifier({
         location: 'Add Data'
       });
 
diff --git a/src/ui/public/vislib/__tests__/lib/layout/splits/column_chart/splits.js b/src/ui/public/vislib/__tests__/lib/layout/splits/column_chart/splits.js
index ce07621a41d93..2ec53d8c8e990 100644
--- a/src/ui/public/vislib/__tests__/lib/layout/splits/column_chart/splits.js
+++ b/src/ui/public/vislib/__tests__/lib/layout/splits/column_chart/splits.js
@@ -173,9 +173,9 @@ describe('Vislib Split Function Test Suite', function () {
     });
 
     describe('chart title split function', function () {
-      var visEl;
-      var newEl;
-      var fixture;
+      let visEl;
+      let newEl;
+      let fixture;
 
       beforeEach(ngMock.inject(function () {
         visEl = el.append('div').attr('class', 'vis-wrapper');
diff --git a/tasks/build/babel_options.js b/tasks/build/babel_options.js
index 586e3cedd0e3a..9c8db68e28310 100644
--- a/tasks/build/babel_options.js
+++ b/tasks/build/babel_options.js
@@ -1,9 +1,9 @@
 module.exports = function (grunt) {
 
-  var srcFile = 'build/kibana/src/optimize/babel_options.js';
-  var buildFile = 'build/kibana/src/optimize/babel_options.build.js';
-  var rename = require('fs').renameSync;
-  var unlink = require('fs').unlinkSync;
+  let srcFile = 'build/kibana/src/optimize/babel_options.js';
+  let buildFile = 'build/kibana/src/optimize/babel_options.build.js';
+  let rename = require('fs').renameSync;
+  let unlink = require('fs').unlinkSync;
 
   grunt.registerTask('_build:babelOptions', function () {
     unlink(srcFile);
diff --git a/tasks/build/download_node_builds.js b/tasks/build/download_node_builds.js
index cb74b55cec446..e74e2e8db3551 100644
--- a/tasks/build/download_node_builds.js
+++ b/tasks/build/download_node_builds.js
@@ -65,8 +65,8 @@ module.exports = function (grunt) {
 
     activeDownloads.push(platform);
 
-    var bytes = parseInt(resp.headers['content-length'], 10) || 'unknown number of';
-    var mb = ((bytes / 1024) / 1024).toFixed(2);
+    let bytes = parseInt(resp.headers['content-length'], 10) || 'unknown number of';
+    let mb = ((bytes / 1024) / 1024).toFixed(2);
     grunt.log.ok(`downloading ${platform.name} - ${mb} mb`);
   };
 
diff --git a/tasks/build/install_npm_deps.js b/tasks/build/install_npm_deps.js
index e7198706f5c58..efebb5e5ac34b 100644
--- a/tasks/build/install_npm_deps.js
+++ b/tasks/build/install_npm_deps.js
@@ -1,6 +1,6 @@
 module.exports = function (grunt) {
-  var { exec } = require('child_process');
-  var { resolve } = require('path');
+  let { exec } = require('child_process');
+  let { resolve } = require('path');
 
   grunt.registerTask('_build:installNpmDeps', function () {
     grunt.file.mkdir('build/kibana/node_modules');
diff --git a/tasks/build/shasums.js b/tasks/build/shasums.js
index cb0b405c2ad2c..f6bc6a6ba8100 100644
--- a/tasks/build/shasums.js
+++ b/tasks/build/shasums.js
@@ -1,12 +1,12 @@
-var { promisify } = require('bluebird');
-var readdir = promisify(require('fs').readdir);
-var exec = promisify(require('child_process').exec);
-var platform = require('os').platform();
-var cmd = /^win/.test(platform) ? 'sha1sum ' : 'shasum ';
+let { promisify } = require('bluebird');
+let readdir = promisify(require('fs').readdir);
+let exec = promisify(require('child_process').exec);
+let platform = require('os').platform();
+let cmd = /^win/.test(platform) ? 'sha1sum ' : 'shasum ';
 
 module.exports = function (grunt) {
   grunt.registerTask('_build:shasums', function () {
-    var targetDir = grunt.config.get('target');
+    let targetDir = grunt.config.get('target');
 
     // for when shasums is run but archives and ospackages was not
     grunt.file.mkdir(targetDir);
diff --git a/tasks/config/eslint.js b/tasks/config/eslint.js
index d302a59299387..7314928335a45 100644
--- a/tasks/config/eslint.js
+++ b/tasks/config/eslint.js
@@ -1,4 +1,4 @@
-var resolve = require('path').resolve;
+let resolve = require('path').resolve;
 
 module.exports = function (grunt) {
   return {
diff --git a/tasks/config/esvm.js b/tasks/config/esvm.js
index 91ebfb7b40b0e..52600ae78c941 100644
--- a/tasks/config/esvm.js
+++ b/tasks/config/esvm.js
@@ -1,8 +1,8 @@
 module.exports = function (grunt) {
-  var resolve = require('path').resolve;
-  var directory = resolve(__dirname, '../../esvm');
-  var dataDir = resolve(directory, 'data_dir');
-  var serverConfig = require('../../test/server_config');
+  let resolve = require('path').resolve;
+  let directory = resolve(__dirname, '../../esvm');
+  let dataDir = resolve(directory, 'data_dir');
+  let serverConfig = require('../../test/server_config');
 
   return {
     options: {
diff --git a/tasks/config/intern.js b/tasks/config/intern.js
index 75d9567b364c1..8fc678855251e 100644
--- a/tasks/config/intern.js
+++ b/tasks/config/intern.js
@@ -1,4 +1,4 @@
-var path = require('path');
+let path = require('path');
 
 
 module.exports = function (grunt) {
diff --git a/tasks/config/s3.js b/tasks/config/s3.js
index 19a1491412e2c..c9c1ff0e1a68b 100644
--- a/tasks/config/s3.js
+++ b/tasks/config/s3.js
@@ -1,5 +1,5 @@
 module.exports = function (grunt) {
-  var { config } = grunt;
+  let { config } = grunt;
 
   return {
     release: {
diff --git a/tasks/lint_staged_files.js b/tasks/lint_staged_files.js
index e7c2f95752d13..07d13efca4889 100644
--- a/tasks/lint_staged_files.js
+++ b/tasks/lint_staged_files.js
@@ -8,7 +8,7 @@ export default function (grunt) {
     grunt.task.requires('collectFilesToCommit');
 
     // match these patterns
-    var patterns = grunt.config.get('eslint.source.files.src');
+    let patterns = grunt.config.get('eslint.source.files.src');
     if (!patterns) grunt.fail.warn('eslint file pattern is not defined');
 
     const files = grunt.config
diff --git a/tasks/release_packages.js b/tasks/release_packages.js
index 23701a91589fa..87accb94fd524 100644
--- a/tasks/release_packages.js
+++ b/tasks/release_packages.js
@@ -59,7 +59,7 @@ export default (grunt) => {
       grunt.fail.fatal('Aborting publish');
     }
 
-    var rl = readline.createInterface({
+    let rl = readline.createInterface({
       input: process.stdin,
       output: process.stdout
     });
diff --git a/tasks/sterilize.js b/tasks/sterilize.js
index 11b827e5bbe62..7e194d440e9df 100644
--- a/tasks/sterilize.js
+++ b/tasks/sterilize.js
@@ -26,7 +26,7 @@ export default function (grunt) {
 
     rl.on('close', this.async());
     rl.question(`\n${danger} Do you really want to delete all of the above files?, [N/y] `, function (resp) {
-      var yes = resp.toLowerCase().trim()[0] === 'y';
+      let yes = resp.toLowerCase().trim()[0] === 'y';
       rl.close();
 
       if (yes) {
diff --git a/tasks/utils/install_or_update_repo.js b/tasks/utils/install_or_update_repo.js
index 588d43b63fd8f..f803cf33d5801 100644
--- a/tasks/utils/install_or_update_repo.js
+++ b/tasks/utils/install_or_update_repo.js
@@ -1,12 +1,12 @@
-var Promise = require('bluebird');
-var spawn = require('./spawn');
-var grunt = require('grunt');
+let Promise = require('bluebird');
+let spawn = require('./spawn');
+let grunt = require('grunt');
 
 module.exports = function (repo, dir) {
   // store the previous and new hash from the repo
   // to know if there was an update from fetch
-  var prevHash;
-  var newHash;
+  let prevHash;
+  let newHash;
 
   return Promise.resolve()
   .then(function () {
diff --git a/tasks/utils/update_version.js b/tasks/utils/update_version.js
index 5180069ae2b96..e38436ab08cf2 100644
--- a/tasks/utils/update_version.js
+++ b/tasks/utils/update_version.js
@@ -1,8 +1,8 @@
-var _ = require('lodash');
+let _ = require('lodash');
 
 module.exports = updateVersion;
 
-var versions = [
+let versions = [
   'major',
   'minor',
   'patch',
@@ -44,7 +44,7 @@ var versions = [
 function updateVersion(version, expr) {
   expr = String(expr).split('=');
 
-  var change = {
+  let change = {
     name: expr[0],
     val: expr[1] || null
   };
@@ -58,7 +58,7 @@ function updateVersion(version, expr) {
   }
 
   // parse the current version
-  var parts = _.chain(version.split('.'))
+  let parts = _.chain(version.split('.'))
 
   // ensure that their are three pieces, either x.x.x or x.x.x-y
   .tap(function (versionNumbers) {
@@ -70,7 +70,7 @@ function updateVersion(version, expr) {
   // describe all of the version parts with a name, parse
   // the numbers, and extract tag from patch
   .transform(function (parts, v, i) {
-    var name = versions[i];
+    let name = versions[i];
 
     if (name !== 'patch') {
       parts[name] = _.parseInt(v);
@@ -86,7 +86,7 @@ function updateVersion(version, expr) {
   // sanity check
   .tap(function (parts) {
 
-    var valid = true;
+    let valid = true;
     valid = valid && _.isNumber(parts.major);
     valid = valid && _.isNumber(parts.minor);
     valid = valid && _.isNumber(parts.patch);
@@ -121,7 +121,7 @@ function updateVersion(version, expr) {
     }
 
     // properties that are zero-d by the previous update
-    var emptyUpdates = versions.slice(versions.indexOf(change.name) + 1);
+    let emptyUpdates = versions.slice(versions.indexOf(change.name) + 1);
     while (emptyUpdates.length) {
       parts[emptyUpdates.shift()] = '';
     }
diff --git a/test/fixtures/__tests__/scenario_manager.js b/test/fixtures/__tests__/scenario_manager.js
index 144f6c1cfaa80..fd271a388d6f8 100644
--- a/test/fixtures/__tests__/scenario_manager.js
+++ b/test/fixtures/__tests__/scenario_manager.js
@@ -1,18 +1,18 @@
-var expect = require('expect.js');
-var sinon = require('sinon');
-var Promise = require('bluebird');
+let expect = require('expect.js');
+let sinon = require('sinon');
+let Promise = require('bluebird');
 
-var ScenarioManager = require('../scenario_manager');
+let ScenarioManager = require('../scenario_manager');
 
 describe('scenario manager', function () {
-  var manager = new ScenarioManager('http://localhost:9200');
+  let manager = new ScenarioManager('http://localhost:9200');
 
   describe('loading and unloading', function () {
     this.timeout(60000);
 
-    var bulk;
-    var create;
-    var indicesDelete;
+    let bulk;
+    let create;
+    let indicesDelete;
     beforeEach(function () {
       bulk = sinon.stub(manager.client, 'bulk', Promise.resolve);
       create = sinon.stub(manager.client.indices, 'create', Promise.resolve);
@@ -43,9 +43,9 @@ describe('scenario manager', function () {
     });
 
     it('should be able to reload a scenario', function () {
-      var load = sinon.stub(manager, 'load', Promise.resolve);
-      var unload = sinon.stub(manager, 'unload', Promise.resolve);
-      var id = 'makelogs';
+      let load = sinon.stub(manager, 'load', Promise.resolve);
+      let unload = sinon.stub(manager, 'unload', Promise.resolve);
+      let id = 'makelogs';
       return manager.reload(id).then(function () {
         expect(load.calledWith(id)).to.be(true);
         expect(unload.calledWith(id)).to.be(true);
@@ -56,9 +56,9 @@ describe('scenario manager', function () {
     });
 
     it('should load if the index does not exist', function () {
-      var load = sinon.stub(manager, 'load', Promise.resolve);
-      var throwError = sinon.stub(manager.client, 'count', Promise.reject);
-      var id = 'makelogs';
+      let load = sinon.stub(manager, 'load', Promise.resolve);
+      let throwError = sinon.stub(manager.client, 'count', Promise.reject);
+      let id = 'makelogs';
       return manager.loadIfEmpty(id).then(function () {
         expect(load.calledWith(id)).to.be(true);
 
@@ -68,13 +68,13 @@ describe('scenario manager', function () {
     });
 
     it('should load if the index is empty', function () {
-      var load = sinon.stub(manager, 'load', Promise.resolve);
-      var returnZero = sinon.stub(manager.client, 'count', function () {
+      let load = sinon.stub(manager, 'load', Promise.resolve);
+      let returnZero = sinon.stub(manager.client, 'count', function () {
         return Promise.resolve({
           'count': 0
         });
       });
-      var id = 'makelogs';
+      let id = 'makelogs';
       return manager.loadIfEmpty(id).then(function () {
         expect(load.calledWith(id)).to.be(true);
 
@@ -85,13 +85,13 @@ describe('scenario manager', function () {
 
 
     it('should not load if the index is not empty', function () {
-      var load = sinon.stub(manager, 'load', Promise.resolve);
-      var returnOne = sinon.stub(manager.client, 'count', function () {
+      let load = sinon.stub(manager, 'load', Promise.resolve);
+      let returnOne = sinon.stub(manager.client, 'count', function () {
         return Promise.resolve({
           'count': 1
         });
       });
-      var id = 'makelogs';
+      let id = 'makelogs';
       return manager.loadIfEmpty(id).then(function () {
         expect(load.called).to.be(false);
 
diff --git a/test/fixtures/config.js b/test/fixtures/config.js
index b9acf71b8e1cc..911d6caa74dcd 100644
--- a/test/fixtures/config.js
+++ b/test/fixtures/config.js
@@ -1,5 +1,5 @@
-var path = require('path');
-var rootDir = path.join(__dirname, 'scenarios');
+let path = require('path');
+let rootDir = path.join(__dirname, 'scenarios');
 
 module.exports = {
   scenarios: {
diff --git a/test/fixtures/scenario_manager.js b/test/fixtures/scenario_manager.js
index d4f071358d369..24965de1b2b29 100644
--- a/test/fixtures/scenario_manager.js
+++ b/test/fixtures/scenario_manager.js
@@ -1,7 +1,7 @@
-var path = require('path');
-var elasticsearch = require('elasticsearch');
-var Promise = require('bluebird');
-var config = require('./config').scenarios;
+let path = require('path');
+let elasticsearch = require('elasticsearch');
+let Promise = require('bluebird');
+let config = require('./config').scenarios;
 
 function ScenarioManager(server) {
   if (!server) throw new Error('No server defined');
@@ -23,14 +23,14 @@ function ScenarioManager(server) {
 * @return {Promise} A promise that is resolved when elasticsearch has a response
 */
 ScenarioManager.prototype.load = function (id) {
-  var self = this;
-  var scenario = config[id];
+  let self = this;
+  let scenario = config[id];
   if (!scenario) return Promise.reject('No scenario found for ' + id);
 
   return Promise.all(scenario.bulk.map(function mapBulk(bulk) {
-    var loadIndexDefinition;
+    let loadIndexDefinition;
     if (bulk.indexDefinition) {
-      var body = require(path.join(scenario.baseDir, bulk.indexDefinition));
+      let body = require(path.join(scenario.baseDir, bulk.indexDefinition));
       loadIndexDefinition = self.client.indices.create({
         index: bulk.indexName,
         body: body
@@ -41,7 +41,7 @@ ScenarioManager.prototype.load = function (id) {
 
     return loadIndexDefinition
     .then(function bulkRequest() {
-      var body = require(path.join(scenario.baseDir, bulk.source));
+      let body = require(path.join(scenario.baseDir, bulk.source));
       return self.client.bulk({
         body: body
       });
@@ -71,10 +71,10 @@ ScenarioManager.prototype.load = function (id) {
 * @return {Promise} A promise that is resolved when elasticsearch has a response
 */
 ScenarioManager.prototype.unload = function (id) {
-  var scenario = config[id];
+  let scenario = config[id];
   if (!scenario) return Promise.reject('No scenario found for ' + id);
 
-  var indices = scenario.bulk.map(function mapBulk(bulk) {
+  let indices = scenario.bulk.map(function mapBulk(bulk) {
     return bulk.indexName;
   });
 
@@ -96,7 +96,7 @@ ScenarioManager.prototype.unload = function (id) {
 * @return {Promise} A promise that is resolved when elasticsearch has a response
 */
 ScenarioManager.prototype.reload = function (id) {
-  var self = this;
+  let self = this;
 
   return self.unload(id)
   .then(function load() {
@@ -120,12 +120,12 @@ ScenarioManager.prototype.deleteAll = function () {
  * @return {Promise} A promise that is resolved when elasticsearch has a response
  */
 ScenarioManager.prototype.loadIfEmpty = function (id) {
-  var self = this;
-  var scenario = config[id];
+  let self = this;
+  let scenario = config[id];
   if (!scenario) throw new Error('No scenario found for ' + id);
 
   return Promise.all(scenario.bulk.map(function mapBulk(bulk) {
-    var loadIndexDefinition;
+    let loadIndexDefinition;
 
     return self.client.count({
       index: bulk.indexName
diff --git a/test/functional/apps/console/_console.js b/test/functional/apps/console/_console.js
index 32881b4ebf3b8..69259c7cf947b 100644
--- a/test/functional/apps/console/_console.js
+++ b/test/functional/apps/console/_console.js
@@ -15,7 +15,7 @@ bdd.describe('console app', function describeIndexTests() {
   });
 
   bdd.it('should show the default request', function () {
-    var expectedRequest = [
+    let expectedRequest = [
       'GET _search',
       '{',
       '  "query": {',
@@ -39,7 +39,7 @@ bdd.describe('console app', function describeIndexTests() {
   });
 
   bdd.it('default request response should contain .kibana' , function () {
-    var expectedResponseContains = '"_index": ".kibana",';
+    let expectedResponseContains = '"_index": ".kibana",';
     return PageObjects.console.clickPlay()
     .then(function () {
       PageObjects.common.saveScreenshot('Console-default-request');
diff --git a/test/functional/apps/dashboard/_dashboard.js b/test/functional/apps/dashboard/_dashboard.js
index 2009a7be42717..523b84dafebe6 100644
--- a/test/functional/apps/dashboard/_dashboard.js
+++ b/test/functional/apps/dashboard/_dashboard.js
@@ -13,7 +13,7 @@ import PageObjects from '../../../support/page_objects';
 bdd.describe('dashboard tab', function describeIndexTests() {
   bdd.before(function () {
     PageObjects.common.debug('Starting dashboard before method');
-    var logstash = scenarioManager.loadIfEmpty('logstashFunctional');
+    let logstash = scenarioManager.loadIfEmpty('logstashFunctional');
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
     // and load a set of makelogs data
@@ -32,7 +32,7 @@ bdd.describe('dashboard tab', function describeIndexTests() {
   });
 
   bdd.describe('add visualizations to dashboard', function dashboardTest() {
-    var visualizations = ['Visualization漢字 AreaChart',
+    let visualizations = ['Visualization漢字 AreaChart',
       'Visualization☺漢字 DataTable',
       'Visualization漢字 LineChart',
       'Visualization PieChart',
@@ -61,8 +61,8 @@ bdd.describe('dashboard tab', function describeIndexTests() {
     });
 
     bdd.it('set the timepicker time to that which contains our test data', function setTimepicker() {
-      var fromTime = '2015-09-19 06:31:44.000';
-      var toTime = '2015-09-23 18:31:44.000';
+      let fromTime = '2015-09-19 06:31:44.000';
+      let toTime = '2015-09-23 18:31:44.000';
 
       // .then(function () {
       PageObjects.common.debug('Set absolute time range from \"' + fromTime + '\" to \"' + toTime + '\"');
@@ -111,7 +111,7 @@ bdd.describe('dashboard tab', function describeIndexTests() {
     });
 
     bdd.it('should have all the expected initial sizes', function checkVisualizationSizes() {
-      var visObjects = [ { dataCol: '1', dataRow: '1', dataSizeX: '3', dataSizeY: '2', title: 'Visualization漢字 AreaChart' },
+      let visObjects = [ { dataCol: '1', dataRow: '1', dataSizeX: '3', dataSizeY: '2', title: 'Visualization漢字 AreaChart' },
         { dataCol: '4', dataRow: '1', dataSizeX: '3', dataSizeY: '2', title: 'Visualization☺漢字 DataTable' },
         { dataCol: '7', dataRow: '1', dataSizeX: '3', dataSizeY: '2', title: 'Visualization漢字 LineChart' },
         { dataCol: '10', dataRow: '1', dataSizeX: '3', dataSizeY: '2', title: 'Visualization PieChart' },
diff --git a/test/functional/apps/discover/_collapse_expand.js b/test/functional/apps/discover/_collapse_expand.js
index 1f44f0bd10845..91b9f7253c2be 100644
--- a/test/functional/apps/discover/_collapse_expand.js
+++ b/test/functional/apps/discover/_collapse_expand.js
@@ -12,8 +12,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('discover tab', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
diff --git a/test/functional/apps/discover/_discover.js b/test/functional/apps/discover/_discover.js
index d81d7aa73a743..9e0fefa43fce6 100644
--- a/test/functional/apps/discover/_discover.js
+++ b/test/functional/apps/discover/_discover.js
@@ -12,8 +12,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('discover app', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
@@ -37,12 +37,12 @@ bdd.describe('discover app', function describeIndexTests() {
 
 
   bdd.describe('query', function () {
-    var queryName1 = 'Query # 1';
-    var fromTimeString = 'September 19th 2015, 06:31:44.000';
-    var toTimeString = 'September 23rd 2015, 18:31:44.000';
+    let queryName1 = 'Query # 1';
+    let fromTimeString = 'September 19th 2015, 06:31:44.000';
+    let toTimeString = 'September 23rd 2015, 18:31:44.000';
 
     bdd.it('should show correct time range string by timepicker', function () {
-      var expectedTimeRangeString = fromTimeString + ' to ' + toTimeString;
+      let expectedTimeRangeString = fromTimeString + ' to ' + toTimeString;
       return PageObjects.discover.getTimespanText()
       .then(function (actualTimeString) {
         expect(actualTimeString).to.be(expectedTimeRangeString);
@@ -50,7 +50,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('save query should show toast message and display query name', function () {
-      var expectedSavedQueryMessage = 'Discover: Saved Data Source "' + queryName1 + '"';
+      let expectedSavedQueryMessage = 'Discover: Saved Data Source "' + queryName1 + '"';
       return PageObjects.discover.saveSearch(queryName1)
       .then(function () {
         return PageObjects.header.getToastMessage();
@@ -85,7 +85,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show the correct hit count', function () {
-      var expectedHitCount = '14,004';
+      let expectedHitCount = '14,004';
       return PageObjects.common.try(function tryingForTime() {
         return PageObjects.discover.getHitCount()
         .then(function compareData(hitCount) {
@@ -95,7 +95,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show the correct bar chart', function () {
-      var expectedBarChartData = [ '3.237',
+      let expectedBarChartData = [ '3.237',
         '17.674', '64.75', '125.737', '119.962', '65.712', '16.449',
         '2.712', '3.675', '17.674', '59.762', '119.087', '123.812',
         '61.862', '15.487', '2.362', '2.800', '15.312', '61.862', '123.2',
@@ -108,7 +108,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct time range string in chart', function () {
-      var expectedTimeRangeString = fromTimeString + ' - ' + toTimeString;
+      let expectedTimeRangeString = fromTimeString + ' - ' + toTimeString;
       return PageObjects.discover.getChartTimespan()
       .then(function (actualTimeString) {
         expect(actualTimeString).to.be(expectedTimeRangeString);
@@ -116,7 +116,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct initial chart interval of 3 hours', function () {
-      var expectedChartInterval = 'by 3 hours';
+      let expectedChartInterval = 'by 3 hours';
       return PageObjects.discover.getChartInterval()
       .then(function (actualInterval) {
         expect(actualInterval).to.be(expectedChartInterval);
@@ -124,8 +124,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Hourly', function () {
-      var chartInterval = 'Hourly';
-      var expectedBarChartData = [ '1.527', '2.290',
+      let chartInterval = 'Hourly';
+      let expectedBarChartData = [ '1.527', '2.290',
         '5.599', '7.890', '13.236', '30.290', '46.072', '55.490', '86.8',
         '112', '122.181', '131.6', '132.872', '113.527', '102.581',
         '81.709', '65.672', '43.781', '24.181', '14', '9.672', '6.109',
@@ -148,8 +148,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Daily', function () {
-      var chartInterval = 'Daily';
-      var expectedBarChartData = [
+      let chartInterval = 'Daily';
+      let expectedBarChartData = [
         '133.196', '129.192', '129.724'
       ];
       return PageObjects.discover.setChartInterval(chartInterval)
@@ -162,8 +162,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Weekly', function () {
-      var chartInterval = 'Weekly';
-      var expectedBarChartData = [ '66.598', '129.458'];
+      let chartInterval = 'Weekly';
+      let expectedBarChartData = [ '66.598', '129.458'];
       return PageObjects.discover.setChartInterval(chartInterval)
       .then(function () {
         return PageObjects.common.sleep(2000);
@@ -174,8 +174,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('browser back button should show previous interval Daily', function () {
-      var expectedChartInterval = 'Daily';
-      var expectedBarChartData = [
+      let expectedChartInterval = 'Daily';
+      let expectedBarChartData = [
         '133.196', '129.192', '129.724'
       ];
       return this.remote.goBack()
@@ -193,8 +193,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Monthly', function () {
-      var chartInterval = 'Monthly';
-      var expectedBarChartData = [ '122.535'];
+      let chartInterval = 'Monthly';
+      let expectedBarChartData = [ '122.535'];
       return PageObjects.discover.setChartInterval(chartInterval)
       .then(function () {
         return PageObjects.common.sleep(2000);
@@ -205,8 +205,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Yearly', function () {
-      var chartInterval = 'Yearly';
-      var expectedBarChartData = [ '122.535'];
+      let chartInterval = 'Yearly';
+      let expectedBarChartData = [ '122.535'];
       return PageObjects.discover.setChartInterval(chartInterval)
       .then(function () {
         return PageObjects.common.sleep(2000);
@@ -217,8 +217,8 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data for chart interval Auto', function () {
-      var chartInterval = 'Auto';
-      var expectedBarChartData = [ '3.237',
+      let chartInterval = 'Auto';
+      let expectedBarChartData = [ '3.237',
         '17.674', '64.75', '125.737', '119.962', '65.712', '16.449',
         '2.712', '3.675', '17.674', '59.762', '119.087', '123.812',
         '61.862', '15.487', '2.362', '2.800', '15.312', '61.862', '123.2',
@@ -234,7 +234,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('should show Auto chart interval of 3 hours', function () {
-      var expectedChartInterval = 'by 3 hours';
+      let expectedChartInterval = 'by 3 hours';
       return PageObjects.discover.getChartInterval()
       .then(function (actualInterval) {
         expect(actualInterval).to.be(expectedChartInterval);
@@ -252,10 +252,10 @@ bdd.describe('discover app', function describeIndexTests() {
         return PageObjects.discover.getBarChartData()
         .then(function compareData(paths) {
           // the largest bars are over 100 pixels high so this is less than 1% tolerance
-          var barHeightTolerance = 1;
-          var stringResults = '';
-          var hasFailure = false;
-          for (var y = 0; y < expectedBarChartData.length; y++) {
+          let barHeightTolerance = 1;
+          let stringResults = '';
+          let hasFailure = false;
+          for (let y = 0; y < expectedBarChartData.length; y++) {
             stringResults += y + ': expected = ' + expectedBarChartData[y] + ', actual = ' + paths[y] +
              ', Pass = ' + (Math.abs(expectedBarChartData[y] - paths[y]) < barHeightTolerance) + '\n';
             if ((Math.abs(expectedBarChartData[y] - paths[y]) > barHeightTolerance)) {
@@ -266,7 +266,7 @@ bdd.describe('discover app', function describeIndexTests() {
             PageObjects.common.log(stringResults);
             PageObjects.common.log(paths);
           }
-          for (var x = 0; x < expectedBarChartData.length; x++) {
+          for (let x = 0; x < expectedBarChartData.length; x++) {
             expect(Math.abs(expectedBarChartData[x] - paths[x]) < barHeightTolerance).to.be.ok();
           }
         });
@@ -277,8 +277,8 @@ bdd.describe('discover app', function describeIndexTests() {
   });
 
   bdd.describe('query #2, which has an empty time range', function () {
-    var fromTime = '1999-06-11 09:22:11.000';
-    var toTime = '1999-06-12 11:21:04.000';
+    let fromTime = '1999-06-11 09:22:11.000';
+    let toTime = '1999-06-12 11:21:04.000';
 
     bdd.before(() => {
       PageObjects.common.debug('setAbsoluteRangeForAnotherQuery');
diff --git a/test/functional/apps/discover/_field_data.js b/test/functional/apps/discover/_field_data.js
index 5123a54178cc8..35a33bdd331b3 100644
--- a/test/functional/apps/discover/_field_data.js
+++ b/test/functional/apps/discover/_field_data.js
@@ -12,8 +12,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('discover app', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
@@ -37,12 +37,12 @@ bdd.describe('discover app', function describeIndexTests() {
 
 
   bdd.describe('field data', function () {
-    var queryName1 = 'Query # 1';
-    var fromTimeString = 'September 19th 2015, 06:31:44.000';
-    var toTimeString = 'September 23rd 2015, 18:31:44.000';
+    let queryName1 = 'Query # 1';
+    let fromTimeString = 'September 19th 2015, 06:31:44.000';
+    let toTimeString = 'September 23rd 2015, 18:31:44.000';
 
     bdd.it('search php should show the correct hit count', function () {
-      var expectedHitCount = '445';
+      let expectedHitCount = '445';
       return PageObjects.discover.query('php')
       .then(function () {
         return PageObjects.common.try(function tryingForTime() {
@@ -65,7 +65,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('search _type:apache should show the correct hit count', function () {
-      var expectedHitCount = '11,156';
+      let expectedHitCount = '11,156';
       return PageObjects.discover.query('_type:apache')
       .then(function () {
         return PageObjects.common.try(function tryingForTime() {
@@ -78,7 +78,7 @@ bdd.describe('discover app', function describeIndexTests() {
     });
 
     bdd.it('doc view should show Time and _source columns', function () {
-      var expectedHeader = 'Time _source';
+      let expectedHeader = 'Time _source';
       return PageObjects.discover.getDocHeader()
       .then(function (header) {
         expect(header).to.be(expectedHeader);
@@ -87,7 +87,7 @@ bdd.describe('discover app', function describeIndexTests() {
 
     bdd.it('doc view should show oldest time first', function () {
       // Note: Could just check the timestamp, but might as well check that the whole doc is as expected.
-      var ExpectedDoc =
+      let ExpectedDoc =
         'September 22nd 2015, 23:50:13.253 index:logstash-2015.09.22 @timestamp:September 22nd 2015, 23:50:13.253'
         + ' ip:238.171.34.42 extension:jpg response:200 geo.coordinates:{ "lat": 38.66494528, "lon": -88.45299556'
         + ' } geo.src:FR geo.dest:KH geo.srcdest:FR:KH @tags:success, info utc_time:September 22nd 2015,'
@@ -138,7 +138,7 @@ bdd.describe('discover app', function describeIndexTests() {
 
     bdd.it('doc view should sort ascending', function () {
       // Note: Could just check the timestamp, but might as well check that the whole doc is as expected.
-      var ExpectedDoc =
+      let ExpectedDoc =
         'September 20th 2015, 00:00:00.000 index:logstash-2015.09.20 @timestamp:September 20th 2015, 00:00:00.000'
         + ' ip:143.84.142.7 extension:jpg response:200 geo.coordinates:{ "lat": 38.68407028, "lon": -120.9871642 }'
         + ' geo.src:ES geo.dest:US geo.srcdest:ES:US @tags:error, info utc_time:September 20th 2015, 00:00:00.000'
@@ -230,8 +230,8 @@ bdd.describe('discover app', function describeIndexTests() {
 
 
     bdd.it('a bad syntax query should show an error message', function () {
-      var expectedHitCount = '1011,156';
-      var expectedError = 'Discover: Failed to parse query [xxx(yyy]';
+      let expectedHitCount = '1011,156';
+      let expectedError = 'Discover: Failed to parse query [xxx(yyy]';
       return PageObjects.discover.query('xxx(yyy')
       .then(function () {
         return PageObjects.header.getToastMessage();
diff --git a/test/functional/apps/discover/_shared_links.js b/test/functional/apps/discover/_shared_links.js
index 6e3fc4e886fbe..1f54f5b722058 100644
--- a/test/functional/apps/discover/_shared_links.js
+++ b/test/functional/apps/discover/_shared_links.js
@@ -11,18 +11,18 @@ import {
 import PageObjects from '../../../support/page_objects';
 
 bdd.describe('shared links', function describeIndexTests() {
-  var baseUrl;
+  let baseUrl;
   // The message changes for Firefox < 41 and Firefox >= 41
   // var expectedToastMessage = 'Share search: URL selected. Press Ctrl+C to copy.';
   // var expectedToastMessage = 'Share search: URL copied to clipboard.';
   // Pass either one.
-  var expectedToastMessage = /Share search: URL (selected\. Press Ctrl\+C to copy\.|copied to clipboard\.)/;
+  let expectedToastMessage = /Share search: URL (selected\. Press Ctrl\+C to copy\.|copied to clipboard\.)/;
 
   bdd.before(function () {
     baseUrl = PageObjects.common.getHostPort();
 
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
@@ -52,7 +52,7 @@ bdd.describe('shared links', function describeIndexTests() {
 
   bdd.describe('shared link', function () {
     bdd.it('should show "Share a link" caption', function () {
-      var expectedCaption = 'Share a link';
+      let expectedCaption = 'Share a link';
       return PageObjects.discover.clickShare()
       .then(function () {
         PageObjects.common.saveScreenshot('Discover-share-link');
@@ -64,7 +64,7 @@ bdd.describe('shared links', function describeIndexTests() {
     });
 
     bdd.it('should show the correct formatted URL', function () {
-      var expectedUrl = baseUrl
+      let expectedUrl = baseUrl
         + '/app/kibana?_t=1453775307251#'
         + '/discover?_g=(refreshInterval:(display:Off,pause:!f,value:0),time'
         + ':(from:\'2015-09-19T06:31:44.000Z\',mode:absolute,to:\'2015-09'
@@ -95,7 +95,7 @@ bdd.describe('shared links', function describeIndexTests() {
 
     // TODO: verify clipboard contents
     bdd.it('shorten URL button should produce a short URL', function () {
-      var re = new RegExp(baseUrl + '/goto/[0-9a-f]{32}$');
+      let re = new RegExp(baseUrl + '/goto/[0-9a-f]{32}$');
       return PageObjects.discover.clickShortenUrl()
       .then(function () {
         return PageObjects.common.try(function tryingForTime() {
diff --git a/test/functional/apps/management/_creation_form_changes.js b/test/functional/apps/management/_creation_form_changes.js
index d774268b40524..6920447acf111 100644
--- a/test/functional/apps/management/_creation_form_changes.js
+++ b/test/functional/apps/management/_creation_form_changes.js
@@ -22,7 +22,7 @@ bdd.describe('user input reactions', function () {
   });
 
   bdd.it('should hide time-based index pattern when time-based option is unchecked', function () {
-    var self = this;
+    let self = this;
     return PageObjects.settings.getTimeBasedEventsCheckbox()
     .then(function (selected) {
       // uncheck the 'time-based events' checkbox
@@ -30,14 +30,14 @@ bdd.describe('user input reactions', function () {
     })
     // try to find the checkbox (this shouldn fail)
     .then(function () {
-      var waitTime = 10000;
+      let waitTime = 10000;
       return PageObjects.settings.getTimeBasedIndexPatternCheckbox(waitTime);
     })
     .then(function () {
       PageObjects.common.saveScreenshot('Settings-indices-hide-time-based-index-pattern');
       // we expect the promise above to fail
-      var handler = PageObjects.common.createErrorHandler(self);
-      var msg = 'Found time based index pattern checkbox';
+      let handler = PageObjects.common.createErrorHandler(self);
+      let msg = 'Found time based index pattern checkbox';
       handler(msg);
     })
     .catch(function () {
diff --git a/test/functional/apps/management/_index_pattern_create_delete.js b/test/functional/apps/management/_index_pattern_create_delete.js
index fa272902a0a22..bcb08b23308ba 100644
--- a/test/functional/apps/management/_index_pattern_create_delete.js
+++ b/test/functional/apps/management/_index_pattern_create_delete.js
@@ -48,7 +48,7 @@ bdd.describe('creating and deleting default index', function describeIndexTests(
       return PageObjects.settings.getTableHeader()
       .then(function (headers) {
         PageObjects.common.debug('header.length = ' + headers.length);
-        var expectedHeaders = [
+        let expectedHeaders = [
           'name',
           'type',
           'format',
@@ -60,7 +60,7 @@ bdd.describe('creating and deleting default index', function describeIndexTests(
         // 6 name   type  format  analyzed  indexed   controls
         expect(headers.length).to.be(expectedHeaders.length);
 
-        var comparedHeaders = headers.map(function compareHead(header, i) {
+        let comparedHeaders = headers.map(function compareHead(header, i) {
           return header.getVisibleText()
           .then(function (text) {
             expect(text).to.be(expectedHeaders[i]);
@@ -74,7 +74,7 @@ bdd.describe('creating and deleting default index', function describeIndexTests(
 
   bdd.describe('index pattern deletion', function indexDelete() {
     bdd.before(function () {
-      var expectedAlertText = 'Are you sure you want to remove this index pattern?';
+      let expectedAlertText = 'Are you sure you want to remove this index pattern?';
       return PageObjects.settings.removeIndexPattern()
       .then(function (alertText) {
         PageObjects.common.saveScreenshot('Settings-indices-confirm-remove-index-pattern');
diff --git a/test/functional/apps/management/_index_pattern_popularity.js b/test/functional/apps/management/_index_pattern_popularity.js
index 220fa32abd870..6e8b09581b6c7 100644
--- a/test/functional/apps/management/_index_pattern_popularity.js
+++ b/test/functional/apps/management/_index_pattern_popularity.js
@@ -27,7 +27,7 @@ bdd.describe('index result popularity', function describeIndexTests() {
   });
 
   bdd.describe('change popularity', function indexPatternCreation() {
-    var fieldName = 'geo.coordinates';
+    let fieldName = 'geo.coordinates';
 
     // set the page size to All again, https://github.com/elastic/kibana/issues/5030
     // TODO: remove this after issue #5030 is closed
diff --git a/test/functional/apps/management/_index_pattern_results_sort.js b/test/functional/apps/management/_index_pattern_results_sort.js
index 9eeba547be3ea..f84dada2e2008 100644
--- a/test/functional/apps/management/_index_pattern_results_sort.js
+++ b/test/functional/apps/management/_index_pattern_results_sort.js
@@ -16,7 +16,7 @@ bdd.describe('index result field sort', function describeIndexTests() {
     return esClient.deleteAndUpdateConfigDoc();
   });
 
-  var columns = [{
+  let columns = [{
     heading: 'name',
     first: '@message',
     last: 'xss.raw',
@@ -77,10 +77,10 @@ bdd.describe('index result field sort', function describeIndexTests() {
   });
 
   bdd.describe('field list pagination', function () {
-    var expectedDefaultPageSize = 25;
-    var expectedFieldCount = 85;
-    var expectedLastPageCount = 10;
-    var pages = [1, 2, 3, 4];
+    let expectedDefaultPageSize = 25;
+    let expectedFieldCount = 85;
+    let expectedLastPageCount = 10;
+    let pages = [1, 2, 3, 4];
 
     bdd.before(function () {
       return PageObjects.settings.navigateTo()
@@ -110,8 +110,8 @@ bdd.describe('index result field sort', function describeIndexTests() {
     });
 
     bdd.it('should have the correct number of rows per page', function () {
-      var pageCount = Math.ceil(expectedFieldCount / expectedDefaultPageSize);
-      var chain = pages.reduce(function (chain, val) {
+      let pageCount = Math.ceil(expectedFieldCount / expectedDefaultPageSize);
+      let chain = pages.reduce(function (chain, val) {
         return chain.then(function () {
           return PageObjects.settings.goToPage(val)
           .then(function () {
@@ -122,7 +122,7 @@ bdd.describe('index result field sort', function describeIndexTests() {
           })
           .then(function (pageCount) {
             PageObjects.common.saveScreenshot('Settings-indices-paged');
-            var expectedSize = (val < 4) ? expectedDefaultPageSize : expectedLastPageCount;
+            let expectedSize = (val < 4) ? expectedDefaultPageSize : expectedLastPageCount;
             expect(pageCount.length).to.be(expectedSize);
           });
         });
diff --git a/test/functional/apps/management/_initial_state.js b/test/functional/apps/management/_initial_state.js
index df889f5247eae..e8d6258b85eec 100644
--- a/test/functional/apps/management/_initial_state.js
+++ b/test/functional/apps/management/_initial_state.js
@@ -37,7 +37,7 @@ bdd.describe('initial state', function () {
   });
 
   bdd.it('should contain default index pattern', function () {
-    var defaultPattern = 'logstash-*';
+    let defaultPattern = 'logstash-*';
 
     return PageObjects.settings.getIndexPatternField().getProperty('value')
     .then(function (pattern) {
diff --git a/test/functional/apps/visualize/_area_chart.js b/test/functional/apps/visualize/_area_chart.js
index 8176333202185..a6c257eb16ae3 100644
--- a/test/functional/apps/visualize/_area_chart.js
+++ b/test/functional/apps/visualize/_area_chart.js
@@ -10,8 +10,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     PageObjects.common.debug('navigateToApp visualize');
     return PageObjects.common.navigateToApp('visualize')
@@ -60,7 +60,7 @@ bdd.describe('visualize app', function describeIndexTests() {
   });
 
   bdd.describe('area charts', function indexPatternCreation() {
-    var vizName1 = 'Visualization AreaChart';
+    let vizName1 = 'Visualization AreaChart';
 
     bdd.it('should save and load with special characters', function pageHeader() {
       const vizNamewithSpecialChars = vizName1 + '/?&=%';
@@ -99,12 +99,12 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show correct chart, take screenshot', function pageHeader() {
-      var chartHeight = 0;
-      var xAxisLabels = [ '2015-09-20 00:00', '2015-09-21 00:00',
+      let chartHeight = 0;
+      let xAxisLabels = [ '2015-09-20 00:00', '2015-09-21 00:00',
         '2015-09-22 00:00', '2015-09-23 00:00'
       ];
-      var yAxisLabels = ['0','200','400','600','800','1,000','1,200','1,400','1,600'];
-      var expectedAreaChartData = [37, 202, 740, 1437, 1371, 751, 188, 31, 42, 202,
+      let yAxisLabels = ['0','200','400','600','800','1,000','1,200','1,400','1,600'];
+      let expectedAreaChartData = [37, 202, 740, 1437, 1371, 751, 188, 31, 42, 202,
         683, 1361, 1415, 707, 177, 27, 32, 175, 707, 1408, 1355, 726, 201, 29
       ];
 
@@ -134,7 +134,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data', function pageHeader() {
-      var expectedTableData = [ 'September 20th 2015, 00:00:00.000 37',
+      let expectedTableData = [ 'September 20th 2015, 00:00:00.000 37',
         'September 20th 2015, 03:00:00.000 202',
         'September 20th 2015, 06:00:00.000 740',
         'September 20th 2015, 09:00:00.000 1,437',
diff --git a/test/functional/apps/visualize/_chart_types.js b/test/functional/apps/visualize/_chart_types.js
index 42191bdb65aab..2f3bee327fb21 100644
--- a/test/functional/apps/visualize/_chart_types.js
+++ b/test/functional/apps/visualize/_chart_types.js
@@ -17,7 +17,7 @@ bdd.describe('visualize app', function describeIndexTests() {
 
   bdd.describe('chart types', function indexPatternCreation() {
     bdd.it('should show the correct chart types', function pageHeader() {
-      var expectedChartTypes = [
+      let expectedChartTypes = [
         'Area chart', 'Data table', 'Line chart', 'Markdown widget',
         'Metric', 'Pie chart', 'Tile map', 'Vertical bar chart'
       ];
diff --git a/test/functional/apps/visualize/_data_table.js b/test/functional/apps/visualize/_data_table.js
index d49bd7b2cb090..ad241f01b60a8 100644
--- a/test/functional/apps/visualize/_data_table.js
+++ b/test/functional/apps/visualize/_data_table.js
@@ -9,8 +9,8 @@ import {
 import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
-  var fromTime = '2015-09-19 06:31:44.000';
-  var toTime = '2015-09-23 18:31:44.000';
+  let fromTime = '2015-09-19 06:31:44.000';
+  let toTime = '2015-09-23 18:31:44.000';
 
   bdd.before(function () {
     PageObjects.common.debug('navigateToApp visualize');
@@ -52,7 +52,7 @@ bdd.describe('visualize app', function describeIndexTests() {
   });
 
   bdd.describe('data table', function indexPatternCreation() {
-    var vizName1 = 'Visualization DataTable';
+    let vizName1 = 'Visualization DataTable';
 
     bdd.it('should be able to save and load', function pageHeader() {
       return PageObjects.visualize.saveVisualization(vizName1)
@@ -72,8 +72,8 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data, take screenshot', function pageHeader() {
-      var chartHeight = 0;
-      var expectedChartData = [ '0 2,088', '2,000 2,748', '4,000 2,707', '6,000 2,876',
+      let chartHeight = 0;
+      let expectedChartData = [ '0 2,088', '2,000 2,748', '4,000 2,707', '6,000 2,876',
       '8,000 2,863', '10,000 147', '12,000 148', '14,000 129', '16,000 161', '18,000 137'
       ];
 
diff --git a/test/functional/apps/visualize/_line_chart.js b/test/functional/apps/visualize/_line_chart.js
index e3f11e38aedcc..53fc12f760930 100644
--- a/test/functional/apps/visualize/_line_chart.js
+++ b/test/functional/apps/visualize/_line_chart.js
@@ -10,8 +10,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     PageObjects.common.debug('navigateToApp visualize');
     return PageObjects.common.navigateToApp('visualize')
@@ -51,10 +51,10 @@ bdd.describe('visualize app', function describeIndexTests() {
   });
 
   bdd.describe('line charts', function indexPatternCreation() {
-    var vizName1 = 'Visualization LineChart';
+    let vizName1 = 'Visualization LineChart';
 
     bdd.it('should be able to save and load', function pageHeader() {
-      var remote = this.remote;
+      let remote = this.remote;
 
       return PageObjects.visualize.saveVisualization(vizName1)
       .then(function (message) {
@@ -75,11 +75,11 @@ bdd.describe('visualize app', function describeIndexTests() {
 
     bdd.it('should show correct chart, take screenshot', function pageHeader() {
 
-      var remote = this.remote;
+      let remote = this.remote;
 
       // this test only verifies the numerical part of this data
       // it could also check the legend to verify the extensions
-      var expectedChartData = ['jpg 9,109', 'css 2,159', 'png 1,373', 'gif 918', 'php 445'];
+      let expectedChartData = ['jpg 9,109', 'css 2,159', 'png 1,373', 'gif 918', 'php 445'];
 
       // sleep a bit before trying to get the chart data
       return PageObjects.common.sleep(3000)
@@ -87,8 +87,8 @@ bdd.describe('visualize app', function describeIndexTests() {
         return PageObjects.visualize.getLineChartData('fill="#57c17b"')
         .then(function showData(data) {
           PageObjects.common.saveScreenshot('Visualize-line-chart');
-          var tolerance = 10; // the y-axis scale is 10000 so 10 is 0.1%
-          for (var x = 0; x < data.length; x++) {
+          let tolerance = 10; // the y-axis scale is 10000 so 10 is 0.1%
+          for (let x = 0; x < data.length; x++) {
             PageObjects.common.debug('x=' + x + ' expectedChartData[x].split(\' \')[1] = ' +
               (expectedChartData[x].split(' ')[1]).replace(',', '') + '  data[x]=' + data[x] +
               ' diff=' + Math.abs(expectedChartData[x].split(' ')[1].replace(',', '') - data[x]));
@@ -101,8 +101,8 @@ bdd.describe('visualize app', function describeIndexTests() {
 
     bdd.it('should show correct data', function pageHeader() {
 
-      var remote = this.remote;
-      var expectedChartData = ['jpg 9,109', 'css 2,159', 'png 1,373', 'gif 918', 'php 445'];
+      let remote = this.remote;
+      let expectedChartData = ['jpg 9,109', 'css 2,159', 'png 1,373', 'gif 918', 'php 445'];
 
       return PageObjects.visualize.collapseChart()
       .then(function getDataTableData() {
diff --git a/test/functional/apps/visualize/_metric_chart.js b/test/functional/apps/visualize/_metric_chart.js
index bdadd31fb8b04..341335b4b5217 100644
--- a/test/functional/apps/visualize/_metric_chart.js
+++ b/test/functional/apps/visualize/_metric_chart.js
@@ -9,8 +9,8 @@ import {
 import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
-  var fromTime = '2015-09-19 06:31:44.000';
-  var toTime = '2015-09-23 18:31:44.000';
+  let fromTime = '2015-09-19 06:31:44.000';
+  let toTime = '2015-09-23 18:31:44.000';
 
   bdd.before(function () {
     PageObjects.common.debug('navigateToApp visualize');
@@ -31,7 +31,7 @@ bdd.describe('visualize app', function describeIndexTests() {
   bdd.describe('metric chart', function indexPatternCreation() {
 
     bdd.it('should show Count', function pageHeader() {
-      var expectedCount = ['14,004', 'Count'];
+      let expectedCount = ['14,004', 'Count'];
 
       // initial metric of "Count" is selected by default
       return PageObjects.common.try(function tryingForTime() {
@@ -44,7 +44,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Average', function pageHeader() {
-      var avgMachineRam = ['13,104,036,080.615', 'Average machine.ram'];
+      let avgMachineRam = ['13,104,036,080.615', 'Average machine.ram'];
       return PageObjects.visualize.clickMetricEditor()
       .then(function () {
         PageObjects.common.debug('Aggregation = Average');
@@ -68,7 +68,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Sum', function pageHeader() {
-      var sumPhpMemory = ['85,865,880', 'Sum of phpmemory'];
+      let sumPhpMemory = ['85,865,880', 'Sum of phpmemory'];
       PageObjects.common.debug('Aggregation = Sum');
       return PageObjects.visualize.selectAggregation('Sum')
       .then(function selectField() {
@@ -89,7 +89,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Median', function pageHeader() {
-      var medianBytes = ['5,565.263', '50th percentile of bytes'];
+      let medianBytes = ['5,565.263', '50th percentile of bytes'];
       //  For now, only comparing the text label part of the metric
       PageObjects.common.debug('Aggregation = Median');
       return PageObjects.visualize.selectAggregation('Median')
@@ -112,7 +112,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Min', function pageHeader() {
-      var minTimestamp = ['September 20th 2015, 00:00:00.000', 'Min @timestamp'];
+      let minTimestamp = ['September 20th 2015, 00:00:00.000', 'Min @timestamp'];
       PageObjects.common.debug('Aggregation = Min');
       return PageObjects.visualize.selectAggregation('Min')
       .then(function selectField() {
@@ -133,7 +133,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Max', function pageHeader() {
-      var maxRelatedContentArticleModifiedTime = ['April 4th 2015, 00:54:41.000', 'Max relatedContent.article:modified_time'];
+      let maxRelatedContentArticleModifiedTime = ['April 4th 2015, 00:54:41.000', 'Max relatedContent.article:modified_time'];
       PageObjects.common.debug('Aggregation = Max');
       return PageObjects.visualize.selectAggregation('Max')
       .then(function selectField() {
@@ -154,7 +154,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Standard Deviation', function pageHeader() {
-      var standardDeviationBytes = [
+      let standardDeviationBytes = [
         '-1,435.138', 'Lower Standard Deviation of bytes',
         '12,889.766', 'Upper Standard Deviation of bytes'
       ];
@@ -178,7 +178,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Unique Count', function pageHeader() {
-      var uniqueCountClientip = ['1,000', 'Unique count of clientip'];
+      let uniqueCountClientip = ['1,000', 'Unique count of clientip'];
       PageObjects.common.debug('Aggregation = Unique Count');
       return PageObjects.visualize.selectAggregation('Unique Count')
       .then(function selectField() {
@@ -206,7 +206,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Percentiles', function pageHeader() {
-      var percentileMachineRam = [
+      let percentileMachineRam = [
         '2,147,483,648', '1st percentile of machine.ram',
         '3,221,225,472', '5th percentile of machine.ram',
         '7,516,192,768', '25th percentile of machine.ram',
@@ -236,7 +236,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show Percentile Ranks', function pageHeader() {
-      var percentileRankBytes = [ '2.036%', 'Percentile rank 99 of "memory"'];
+      let percentileRankBytes = [ '2.036%', 'Percentile rank 99 of "memory"'];
       PageObjects.common.debug('Aggregation = Percentile Ranks');
       return PageObjects.visualize.selectAggregation('Percentile Ranks')
       .then(function selectField() {
diff --git a/test/functional/apps/visualize/_pie_chart.js b/test/functional/apps/visualize/_pie_chart.js
index 4629067fac949..38fd7e1977156 100644
--- a/test/functional/apps/visualize/_pie_chart.js
+++ b/test/functional/apps/visualize/_pie_chart.js
@@ -10,8 +10,8 @@ import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
   bdd.before(function () {
-    var fromTime = '2015-09-19 06:31:44.000';
-    var toTime = '2015-09-23 18:31:44.000';
+    let fromTime = '2015-09-19 06:31:44.000';
+    let toTime = '2015-09-23 18:31:44.000';
 
     PageObjects.common.debug('navigateToApp visualize');
     return PageObjects.common.navigateToApp('visualize')
@@ -59,10 +59,10 @@ bdd.describe('visualize app', function describeIndexTests() {
 
 
   bdd.describe('pie chart', function indexPatternCreation() {
-    var vizName1 = 'Visualization PieChart';
+    let vizName1 = 'Visualization PieChart';
 
     bdd.it('should save and load', function pageHeader() {
-      var remote = this.remote;
+      let remote = this.remote;
 
       return PageObjects.visualize.saveVisualization(vizName1)
       .then(function (message) {
@@ -85,12 +85,12 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show 10 slices in pie chart, take screenshot', function pageHeader() {
-      var remote = this.remote;
-      var expectedPieChartSliceCount = 10;
+      let remote = this.remote;
+      let expectedPieChartSliceCount = 10;
 
       return PageObjects.visualize.getPieChartData()
       .then(function (pieData) {
-        var barHeightTolerance = 1;
+        let barHeightTolerance = 1;
         PageObjects.common.debug('pieData.length = ' + pieData.length);
         PageObjects.common.saveScreenshot('Visualize-pie-chart');
         expect(pieData.length).to.be(expectedPieChartSliceCount);
@@ -98,8 +98,8 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show correct data', function pageHeader() {
-      var remote = this.remote;
-      var expectedTableData =  [ '0 55', '40,000 50', '80,000 41', '120,000 43',
+      let remote = this.remote;
+      let expectedTableData =  [ '0 55', '40,000 50', '80,000 41', '120,000 43',
         '160,000 44', '200,000 40', '240,000 46', '280,000 39', '320,000 40', '360,000 47'
       ];
 
diff --git a/test/functional/apps/visualize/_tile_map.js b/test/functional/apps/visualize/_tile_map.js
index 6381ec32a393a..1e34697c5aa95 100644
--- a/test/functional/apps/visualize/_tile_map.js
+++ b/test/functional/apps/visualize/_tile_map.js
@@ -9,8 +9,8 @@ import {
 import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
-  var fromTime = '2015-09-19 06:31:44.000';
-  var toTime = '2015-09-23 18:31:44.000';
+  let fromTime = '2015-09-19 06:31:44.000';
+  let toTime = '2015-09-23 18:31:44.000';
 
   bdd.before(function () {
 
@@ -52,7 +52,7 @@ bdd.describe('visualize app', function describeIndexTests() {
   bdd.describe('tile map chart', function indexPatternCreation() {
 
     bdd.it('should show correct tile map data on default zoom level', function pageHeader() {
-      var expectedTableData = [ 'dn 1,429', 'dp 1,418', '9y 1,215', '9z 1,099', 'dr 1,076',
+      let expectedTableData = [ 'dn 1,429', 'dp 1,418', '9y 1,215', '9z 1,099', 'dr 1,076',
         'dj 982', '9v 938', '9q 722', '9w 475', 'cb 457', 'c2 453', '9x 420', 'dq 399',
         '9r 396', '9t 274', 'c8 271', 'dh 214', 'b6 207', 'bd 206', 'b7 167', 'f0 141',
         'be 128', '9m 126', 'bf 85', 'de 73', 'bg 71', '9p 71', 'c1 57', 'c4 50', '9u 48',
@@ -75,7 +75,7 @@ bdd.describe('visualize app', function describeIndexTests() {
 
 
     bdd.it('should zoom out to level 1 from default level 2', function pageHeader() {
-      var expectedPrecision2Circles =  [ { color: '#750000', radius: 48 },
+      let expectedPrecision2Circles =  [ { color: '#750000', radius: 48 },
         { color: '#750000', radius: 48 },
         { color: '#750000', radius: 44 },
         { color: '#a40000', radius: 42 },
@@ -143,7 +143,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('"Fit data bounds" should zoom to level 3', function pageHeader() {
-      var expectedPrecision2ZoomCircles =   [ { color: '#750000', radius: 192 },
+      let expectedPrecision2ZoomCircles =   [ { color: '#750000', radius: 192 },
         { color: '#750000', radius: 191 },
         { color: '#750000', radius: 177 },
         { color: '#a40000', radius: 168 },
@@ -206,12 +206,12 @@ bdd.describe('visualize app', function describeIndexTests() {
     ** changed, then open the saved viz and check that it's back to the original data.
     */
     bdd.it('should save with zoom level and load, take screenshot', function pageHeader() {
-      var vizName1 = 'Visualization TileMap';
-      var expectedTableData =  [ 'dr4 127', 'dr7 92', '9q5 91', '9qc 89', 'drk 87',
+      let vizName1 = 'Visualization TileMap';
+      let expectedTableData =  [ 'dr4 127', 'dr7 92', '9q5 91', '9qc 89', 'drk 87',
         'dps 82', 'dph 82', 'dp3 79', 'dpe 78', 'dp8 77'
       ];
 
-      var expectedTableDataZoomed = [ 'dr5r 21', 'dps8 20', '9q5b 19', 'b6uc 17',
+      let expectedTableDataZoomed = [ 'dr5r 21', 'dps8 20', '9q5b 19', 'b6uc 17',
         '9y63 17', 'c20g 16', 'dqfz 15', 'dr8h 14', 'dp8p 14', 'dp3k 14'
       ];
 
diff --git a/test/functional/apps/visualize/_vertical_bar_chart.js b/test/functional/apps/visualize/_vertical_bar_chart.js
index b8c8dea03f65a..1161a7d8daa31 100644
--- a/test/functional/apps/visualize/_vertical_bar_chart.js
+++ b/test/functional/apps/visualize/_vertical_bar_chart.js
@@ -9,8 +9,8 @@ import {
 import PageObjects from '../../../support/page_objects';
 
 bdd.describe('visualize app', function describeIndexTests() {
-  var fromTime = '2015-09-19 06:31:44.000';
-  var toTime = '2015-09-23 18:31:44.000';
+  let fromTime = '2015-09-19 06:31:44.000';
+  let toTime = '2015-09-23 18:31:44.000';
 
   bdd.before(function () {
     PageObjects.common.debug('navigateToApp visualize');
@@ -51,7 +51,7 @@ bdd.describe('visualize app', function describeIndexTests() {
   });
 
   bdd.describe('vertical bar chart', function indexPatternCreation() {
-    var vizName1 = 'Visualization VerticalBarChart';
+    let vizName1 = 'Visualization VerticalBarChart';
 
     bdd.it('should save and load', function pageHeader() {
       return PageObjects.visualize.saveVisualization(vizName1)
@@ -74,7 +74,7 @@ bdd.describe('visualize app', function describeIndexTests() {
     });
 
     bdd.it('should show correct chart, take screenshot', function pageHeader() {
-      var expectedChartValues = [37, 202, 740, 1437, 1371, 751, 188, 31, 42, 202, 683,
+      let expectedChartValues = [37, 202, 740, 1437, 1371, 751, 188, 31, 42, 202, 683,
         1361, 1415, 707, 177, 27, 32, 175, 707, 1408, 1355, 726, 201, 29
       ];
 
@@ -96,7 +96,7 @@ bdd.describe('visualize app', function describeIndexTests() {
 
     bdd.it('should show correct data', function pageHeader() {
       // this is only the first page of the tabular data.
-      var expectedChartData =  [ 'September 20th 2015, 00:00:00.000 37',
+      let expectedChartData =  [ 'September 20th 2015, 00:00:00.000 37',
         'September 20th 2015, 03:00:00.000 202',
         'September 20th 2015, 06:00:00.000 740',
         'September 20th 2015, 09:00:00.000 1,437',
diff --git a/test/functional/apps/visualize/index.js b/test/functional/apps/visualize/index.js
index 9ae80a96a4235..2ad3ec18c6441 100644
--- a/test/functional/apps/visualize/index.js
+++ b/test/functional/apps/visualize/index.js
@@ -16,11 +16,11 @@ bdd.describe('visualize app', function () {
   this.timeout = defaultTimeout;
 
   bdd.before(function () {
-    var self = this;
+    let self = this;
     remote.setWindowSize(1200,800);
 
     PageObjects.common.debug('Starting visualize before method');
-    var logstash = scenarioManager.loadIfEmpty('logstashFunctional');
+    let logstash = scenarioManager.loadIfEmpty('logstashFunctional');
     // delete .kibana index and update configDoc
     return esClient.deleteAndUpdateConfigDoc({'dateFormat:tz':'UTC', 'defaultIndex':'logstash-*'})
     .then(function loadkibanaIndexPattern() {
diff --git a/test/functional/status_page/index.js b/test/functional/status_page/index.js
index afe34c9a947b2..d1f6f0b37c5ae 100644
--- a/test/functional/status_page/index.js
+++ b/test/functional/status_page/index.js
@@ -4,7 +4,7 @@ import {
 
 import PageObjects from '../../support/page_objects';
 
-var expect = require('expect.js');
+let expect = require('expect.js');
 
 bdd.describe('status page', function () {
   bdd.before(function () {
@@ -12,7 +12,7 @@ bdd.describe('status page', function () {
   });
 
   bdd.it('should show the kibana plugin as ready', function () {
-    var self = this;
+    let self = this;
 
     return PageObjects.common.tryForTime(6000, function () {
       return PageObjects.common.findTestSubject('statusBreakdown')
diff --git a/test/mocha_setup.js b/test/mocha_setup.js
index ea24360a11832..24acc31cefd35 100644
--- a/test/mocha_setup.js
+++ b/test/mocha_setup.js
@@ -1,5 +1,5 @@
-var sinon = require('sinon');
-var autoRelease = require('auto-release-sinon');
+let sinon = require('sinon');
+let autoRelease = require('auto-release-sinon');
 
 require('babel/register')(require('../src/optimize/babel_options').node);
 
@@ -13,7 +13,7 @@ require('babel/register')(require('../src/optimize/babel_options').node);
 // The global "afterEach" variable is also tracked, and once it is assigned by mocha
 // the variable global is reconfigured to point directly to the new value (from mocha)
 // and all of the queued invocations are executed.
-var queuedAfterEachArgs = [];
+let queuedAfterEachArgs = [];
 Object.defineProperty(global, 'afterEach', {
   configurable: true,
   get() { return undefined; },
diff --git a/test/server_config.js b/test/server_config.js
index a462a525685b9..ee82cbe035196 100644
--- a/test/server_config.js
+++ b/test/server_config.js
@@ -1,6 +1,6 @@
-var shield = require('./shield');
+let shield = require('./shield');
 
-var kibanaURL = '/app/kibana';
+let kibanaURL = '/app/kibana';
 
 module.exports = {
   servers: {
diff --git a/test/support/env_setup.js b/test/support/env_setup.js
index 0ced6024f85bb..25683e344da0d 100644
--- a/test/support/env_setup.js
+++ b/test/support/env_setup.js
@@ -1,4 +1,4 @@
-var defaults = require('lodash').defaults;
+let defaults = require('lodash').defaults;
 const babelOptions = require('../../src/optimize/babel_options');
 
 require('source-map-support').install();
diff --git a/test/support/page_objects/common.js b/test/support/page_objects/common.js
index 661ff8f865d35..e7e3731b49a03 100644
--- a/test/support/page_objects/common.js
+++ b/test/support/page_objects/common.js
@@ -35,7 +35,7 @@ export default class Common {
 
   init(remote) {
     function injectTimestampQuery(func, url) {
-      var formatted = modifyQueryString(url, function (parsed) {
+      let formatted = modifyQueryString(url, function (parsed) {
         parsed.query._t = Date.now();
       });
       return func.call(this, formatted);
@@ -51,7 +51,7 @@ export default class Common {
     }
 
     function modifyQueryString(url, func) {
-      var parsed = parse(url, true);
+      let parsed = parse(url, true);
       if (parsed.query === null) {
         parsed.query = {};
       }
@@ -76,8 +76,8 @@ export default class Common {
   }
 
   navigateToApp(appName, testStatusPage) {
-    var self = this;
-    var appUrl = getUrl.noAuth(config.servers.kibana, config.apps[appName]);
+    let self = this;
+    let appUrl = getUrl.noAuth(config.servers.kibana, config.apps[appName]);
     self.debug('navigating to ' + appName + ' url: ' + appUrl);
 
     function navigateTo(url) {
@@ -100,7 +100,7 @@ export default class Common {
             .then(function (kibanaLoaded) {
               self.debug('kibanaLoaded = ' + kibanaLoaded);
               if (!kibanaLoaded) {
-                var msg = 'Kibana is not loaded, retrying';
+                let msg = 'Kibana is not loaded, retrying';
                 self.debug(msg);
                 throw new Error(msg);
               }
@@ -111,7 +111,7 @@ export default class Common {
           return self.remote.getCurrentUrl();
         })
         .then(function (currentUrl) {
-          var loginPage = new RegExp('login').test(currentUrl);
+          let loginPage = new RegExp('login').test(currentUrl);
           if (loginPage) {
             self.debug('Found loginPage = ' + loginPage + ', username = '
               + config.servers.kibana.shield.username);
@@ -126,7 +126,7 @@ export default class Common {
         })
         .then(function (currentUrl) {
           currentUrl = currentUrl.replace(/\/\/\w+:\w+@/, '//');
-          var maxAdditionalLengthOnNavUrl = 230;
+          let maxAdditionalLengthOnNavUrl = 230;
           // On several test failures at the end of the TileMap test we try to navigate back to
           // Visualize so we can create the next Vertical Bar Chart, but we can see from the
           // logging and the screenshot that it's still on the TileMap page. Why didn't the "get"
@@ -137,11 +137,11 @@ export default class Common {
           // Navigating to Settings when there is a default index pattern has a URL length of 196
           // (from debug output). Some other tabs may also be long. But a rather simple configured
           // visualization is about 1000 chars long. So at least we catch that case.
-          var navSuccessful = new RegExp(appUrl + '.{0,' + maxAdditionalLengthOnNavUrl + '}$')
+          let navSuccessful = new RegExp(appUrl + '.{0,' + maxAdditionalLengthOnNavUrl + '}$')
           .test(currentUrl);
 
           if (!navSuccessful) {
-            var msg = 'App failed to load: ' + appName +
+            let msg = 'App failed to load: ' + appName +
             ' in ' + defaultFindTimeout + 'ms' +
             ' appUrl = ' + appUrl +
             ' currentUrl = ' + currentUrl;
@@ -156,7 +156,7 @@ export default class Common {
 
     return navigateTo(appUrl)
     .then(function (currentUrl) {
-      var lastUrl = currentUrl;
+      let lastUrl = currentUrl;
       return self.try(function () {
         // give the app time to update the URL
         return self.sleep(501)
@@ -175,7 +175,7 @@ export default class Common {
   }
 
   runScript(fn, timeout) {
-    var self = this;
+    let self = this;
     // by default, give the app 10 seconds to load
     timeout = timeout || 10000;
 
@@ -183,9 +183,9 @@ export default class Common {
     return self.remote
     .setExecuteAsyncTimeout(timeout)
     .executeAsync(function (done) {
-      var interval = setInterval(function () {
-        var ready = (document.readyState === 'complete');
-        var hasJQuery = !!window.$;
+      let interval = setInterval(function () {
+        let ready = (document.readyState === 'complete');
+        let hasJQuery = !!window.$;
 
         if (ready && hasJQuery) {
           console.log('doc ready, jquery loaded');
@@ -199,25 +199,25 @@ export default class Common {
   }
 
   getApp() {
-    var self = this;
+    let self = this;
 
     return self.remote.setFindTimeout(defaultFindTimeout)
     .findByCssSelector('.app-wrapper .application')
     .then(function () {
       return self.runScript(function () {
-        var $ = window.$;
-        var $scope = $('.app-wrapper .application').scope();
+        let $ = window.$;
+        let $scope = $('.app-wrapper .application').scope();
         return $scope ? $scope.chrome.getApp() : {};
       });
     });
   }
 
   checkForKibanaApp() {
-    var self = this;
+    let self = this;
 
     return self.getApp()
     .then(function (app) {
-      var appId = app.id;
+      let appId = app.id;
       self.debug('current application: ' + appId);
       return appId === 'kibana';
     })
@@ -246,7 +246,7 @@ export default class Common {
   }
 
   sleep(sleepMilliseconds) {
-    var self = this;
+    let self = this;
     self.debug('... sleep(' + sleepMilliseconds + ') start');
 
     return bluebird.resolve().delay(sleepMilliseconds)
diff --git a/test/support/page_objects/console_page.js b/test/support/page_objects/console_page.js
index f896eebade953..a18668b4eaac7 100644
--- a/test/support/page_objects/console_page.js
+++ b/test/support/page_objects/console_page.js
@@ -32,7 +32,7 @@ export default class ConsolePage {
         return line.getVisibleText();
       }
 
-      var getEditorDataPromises = editorData.map(getEditorData);
+      let getEditorDataPromises = editorData.map(getEditorData);
       return Promise.all(getEditorDataPromises);
     });
   }
diff --git a/test/support/page_objects/dashboard_page.js b/test/support/page_objects/dashboard_page.js
index 3b15bec5b955f..bac3c80d49c93 100644
--- a/test/support/page_objects/dashboard_page.js
+++ b/test/support/page_objects/dashboard_page.js
@@ -124,7 +124,7 @@ export default class DashboardPage {
   // use the search filter box to narrow the results down to a single
   // entry, or at least to a single page of results
   loadSavedDashboard(dashName) {
-    var self = this;
+    let self = this;
     return this.findTimeout
     .findByCssSelector('button.ng-scope[aria-label="Load Saved Dashboard"]')
     .click()
@@ -160,7 +160,7 @@ export default class DashboardPage {
         return chart.getAttribute('title');
       }
 
-      var getTitlePromises = titleObjects.map(getTitles);
+      let getTitlePromises = titleObjects.map(getTitles);
       return Promise.all(getTitlePromises);
     });
   }
@@ -172,7 +172,7 @@ export default class DashboardPage {
     .then(function (titleObjects) {
 
       function getTitles(chart) {
-        var obj = {};
+        let obj = {};
         return chart.getAttribute('data-col')
         .then(theData => {
           obj = {dataCol:theData};
@@ -211,7 +211,7 @@ export default class DashboardPage {
         });
       }
 
-      var getTitlePromises = titleObjects.map(getTitles);
+      let getTitlePromises = titleObjects.map(getTitles);
       return Promise.all(getTitlePromises);
     });
   }
diff --git a/test/support/page_objects/discover_page.js b/test/support/page_objects/discover_page.js
index 0ffe20ed99257..d03fd696cde03 100644
--- a/test/support/page_objects/discover_page.js
+++ b/test/support/page_objects/discover_page.js
@@ -88,7 +88,7 @@ export default class DiscoverPage {
         .getAttribute('height');
       }
 
-      var getChartDataPromises = chartData.map(getChartData);
+      let getChartDataPromises = chartData.map(getChartData);
       return Promise.all(getChartDataPromises);
     })
     .then(function (bars) {
diff --git a/test/support/page_objects/header_page.js b/test/support/page_objects/header_page.js
index 9312895531a62..05db918f09e2d 100644
--- a/test/support/page_objects/header_page.js
+++ b/test/support/page_objects/header_page.js
@@ -73,7 +73,7 @@ export default class HeaderPage {
   }
 
   clickGoButton() {
-    var self = this;
+    let self = this;
     return this.remote.setFindTimeout(defaultFindTimeout)
     .findByClassName('kbn-timepicker-go')
     .click()
diff --git a/test/support/page_objects/settings_page.js b/test/support/page_objects/settings_page.js
index 4209ac1cabe6e..c9982943c9be2 100644
--- a/test/support/page_objects/settings_page.js
+++ b/test/support/page_objects/settings_page.js
@@ -41,7 +41,7 @@ export default class SettingsPage {
   }
 
   setAdvancedSettings(propertyName, propertyValue) {
-    var self = this;
+    let self = this;
 
     return PageObjects.common.findTestSubject('advancedSetting&' + propertyName + ' editButton')
     .click()
@@ -69,7 +69,7 @@ export default class SettingsPage {
   }
 
   getAdvancedSettings(propertyName) {
-    var self = this;
+    let self = this;
     PageObjects.common.debug('in setAdvancedSettings');
     return PageObjects.common.findTestSubject('advancedSetting&' + propertyName + ' currentValue')
     .getVisibleText();
@@ -177,7 +177,7 @@ export default class SettingsPage {
         });
       }
 
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Bluebird.all(getChartTypesPromises);
     });
   }
@@ -192,8 +192,8 @@ export default class SettingsPage {
   }
 
   getFieldsTabCount() {
-    var self = this;
-    var selector = 'li.kbn-management-tab.active a small';
+    let self = this;
+    let selector = 'li.kbn-management-tab.active a small';
 
     return PageObjects.common.try(function () {
       return self.remote.setFindTimeout(defaultFindTimeout / 10)
@@ -206,12 +206,12 @@ export default class SettingsPage {
   }
 
   getPageSize() {
-    var selectedItemLabel = '';
+    let selectedItemLabel = '';
     return this.remote.setFindTimeout(defaultFindTimeout)
     .findAllByCssSelector('select.ng-pristine.ng-valid.ng-untouched option')
     .then(function (chartTypes) {
       function getChartType(chart) {
-        var thisChart = chart;
+        let thisChart = chart;
         return chart.isSelected()
         .then(function (isSelected) {
           if (isSelected === true) {
@@ -223,7 +223,7 @@ export default class SettingsPage {
         });
       }
 
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Bluebird.all(getChartTypesPromises);
     })
     .then(() => {
@@ -336,7 +336,7 @@ export default class SettingsPage {
   }
 
   removeIndexPattern() {
-    var alertText;
+    let alertText;
 
     return PageObjects.common.try(() => {
       PageObjects.common.debug('click delete index pattern button');
diff --git a/test/support/page_objects/shield_page.js b/test/support/page_objects/shield_page.js
index 5840169cdba02..529ef9c59ade0 100644
--- a/test/support/page_objects/shield_page.js
+++ b/test/support/page_objects/shield_page.js
@@ -10,7 +10,7 @@ export default class ShieldPage {
   }
 
   login(user, pwd) {
-    var remote = this.remote;
+    let remote = this.remote;
     return remote.setFindTimeout(defaultFindTimeout)
     .findById('username')
     .type(user)
diff --git a/test/support/page_objects/visualize_page.js b/test/support/page_objects/visualize_page.js
index 094d7e2e010a2..092592f6910f1 100644
--- a/test/support/page_objects/visualize_page.js
+++ b/test/support/page_objects/visualize_page.js
@@ -75,7 +75,7 @@ export default class VisualizePage {
   }
 
   getChartTypes() {
-    var types = [];
+    let types = [];
     return this.remote
     .setFindTimeout(defaultFindTimeout)
     .findAllByCssSelector('.wizard-type-heading h4')
@@ -83,7 +83,7 @@ export default class VisualizePage {
       function getChartType(chart) {
         return chart.getVisibleText();
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     })
     .then(function (texts) {
@@ -208,7 +208,7 @@ export default class VisualizePage {
           }
         });
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     });
   }
@@ -228,7 +228,7 @@ export default class VisualizePage {
   }
 
   selectField(fieldValue) {
-    var self = this;
+    let self = this;
     return PageObjects.common.try(function tryingForTime() {
       return self.remote
       .setFindTimeout(defaultFindTimeout)
@@ -350,7 +350,7 @@ export default class VisualizePage {
   }
 
   clickVisualizationByLinkText(vizName) {
-    var self = this;
+    let self = this;
     PageObjects.common.debug('clickVisualizationByLinkText(' + vizName + ')');
 
     return PageObjects.common.try(function tryingForTime() {
@@ -364,7 +364,7 @@ export default class VisualizePage {
   // this starts by clicking the Load Saved Viz button, not from the
   // bottom half of the "Create a new visualization      Step 1" page
   loadSavedVisualization(vizName) {
-    var self = this;
+    let self = this;
     return this.clickLoadSavedVisButton()
     .then(function filterVisualization() {
       return self.openSavedVisualization(vizName);
@@ -374,7 +374,7 @@ export default class VisualizePage {
   // this is for starting on the
   // bottom half of the "Create a new visualization      Step 1" page
   openSavedVisualization(vizName) {
-    var self = this;
+    let self = this;
     return self.filterVisByName(vizName)
     .then(() => {
       return PageObjects.common.sleep(1000);
@@ -393,7 +393,7 @@ export default class VisualizePage {
         return chart
         .getVisibleText();
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     })
     .then(texts => {
@@ -412,7 +412,7 @@ export default class VisualizePage {
         return chart
         .getVisibleText();
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     })
     .then(texts => {
@@ -428,14 +428,14 @@ export default class VisualizePage {
    */
   getAreaChartData(aggregateName) {
 
-    var self = this.remote;
-    var chartData = [];
-    var tempArray = [];
-    var chartSections = 0;
-    var chartMap = {};
-    var height = 0;
-    var yAxisLabel = 0;
-    var yAxisHeight = 0;
+    let self = this.remote;
+    let chartData = [];
+    let tempArray = [];
+    let chartSections = 0;
+    let chartMap = {};
+    let height = 0;
+    let yAxisLabel = 0;
+    let yAxisHeight = 0;
 
     // 1). get the maximim chart Y-Axis marker value
     return this.remote
@@ -474,7 +474,7 @@ export default class VisualizePage {
       tempArray = data.replace('M','').split('L');
       chartSections = tempArray.length / 2;
       PageObjects.common.debug('chartSections = ' + chartSections + ' height = ' + yAxisHeight + ' yAxisLabel = ' + yAxisLabel);
-      for (var i = 0; i < chartSections; i++) {
+      for (let i = 0; i < chartSections; i++) {
         chartData[i] = Math.round((yAxisHeight - tempArray[i].split(',')[1]) / yAxisHeight * yAxisLabel);
         PageObjects.common.debug('chartData[i] =' + chartData[i]);
       }
@@ -485,9 +485,9 @@ export default class VisualizePage {
 
   // The current test shows dots, not a line.  This function gets the dots and normalizes their height.
   getLineChartData(cssPart) {
-    var self = this.remote;
-    var yAxisLabel = 0;
-    var yAxisHeight;
+    let self = this.remote;
+    let yAxisLabel = 0;
+    let yAxisHeight;
 
     // 1). get the maximim chart Y-Axis marker value
     return this.remote
@@ -535,7 +535,7 @@ export default class VisualizePage {
           }
 
           // 4). pass the chartTypes to the getChartType function
-          var getChartTypesPromises = chartTypes.map(getChartType);
+          let getChartTypesPromises = chartTypes.map(getChartType);
           return Promise.all(getChartTypesPromises);
         });
       })
@@ -548,9 +548,9 @@ export default class VisualizePage {
 
   // this is ALMOST identical to DiscoverPage.getBarChartData
   getBarChartData() {
-    var self = this.remote;
-    var yAxisLabel = 0;
-    var yAxisHeight;
+    let self = this.remote;
+    let yAxisLabel = 0;
+    let yAxisHeight;
 
     // 1). get the maximim chart Y-Axis marker value
     return this.remote
@@ -601,7 +601,7 @@ export default class VisualizePage {
             }
           });
         }
-        var getChartTypesPromises = chartTypes.map(getChartType);
+        let getChartTypesPromises = chartTypes.map(getChartType);
         return Promise.all(getChartTypesPromises);
       })
       .then(function (bars) {
@@ -611,7 +611,7 @@ export default class VisualizePage {
   }
 
   getPieChartData() {
-    var self = this.remote;
+    let self = this.remote;
 
     // 1). get the maximim chart Y-Axis marker value
     return this.remote
@@ -626,7 +626,7 @@ export default class VisualizePage {
           return slice;
         });
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     })
     .then(function (slices) {
@@ -670,7 +670,7 @@ export default class VisualizePage {
   }
 
   waitForToastMessageGone() {
-    var self = this;
+    let self = this;
     return PageObjects.common.try(function tryingForTime() {
       return self.remote
       .setFindTimeout(100)
@@ -742,8 +742,8 @@ export default class VisualizePage {
     .then((chartTypes) => {
 
       function getChartType(chart) {
-        var color;
-        var radius;
+        let color;
+        let radius;
         return chart.getAttribute('stroke')
         .then((stroke) => {
           color = stroke;
@@ -760,7 +760,7 @@ export default class VisualizePage {
           return {color: color, radius: radius};
         });
       }
-      var getChartTypesPromises = chartTypes.map(getChartType);
+      let getChartTypesPromises = chartTypes.map(getChartType);
       return Promise.all(getChartTypesPromises);
     })
     .then((circles) => {
diff --git a/test/support/utils/elastic_dump.js b/test/support/utils/elastic_dump.js
index e019a4497e717..cb1f167523547 100644
--- a/test/support/utils/elastic_dump.js
+++ b/test/support/utils/elastic_dump.js
@@ -4,11 +4,11 @@ import {
 } from './';
 
 export default (function () {
-  var util = require('util');
-  var path = require('path');
-  var url = require('url');
-  var resolve = require('path').resolve;
-  var Elasticdump = require('elasticdump').elasticdump;
+  let util = require('util');
+  let path = require('path');
+  let url = require('url');
+  let resolve = require('path').resolve;
+  let Elasticdump = require('elasticdump').elasticdump;
 
   function ElasticDump() {
   }
@@ -22,7 +22,7 @@ export default (function () {
     */
     elasticdumpModule: function elasticdumpModule(myinput, myoutput, index, mytype) {
 
-      var options = {
+      let options = {
         limit:           100,
         offset:          0,
         debug:           false,
@@ -46,12 +46,12 @@ export default (function () {
         skip:            null,
         toLog:           null,
       };
-      var dumper = new Elasticdump(options.input, options.output, options);
+      let dumper = new Elasticdump(options.input, options.output, options);
 
       dumper.on('log',   function (message) { Log.debug(message); });
       dumper.on('error', function (error)   { Log.debug('error', 'Error Emitted => ' + (error.message || JSON.stringify(error))); });
 
-      var promise = new Promise(function (resolve, reject) {
+      let promise = new Promise(function (resolve, reject) {
         dumper.dump(function (error, totalWrites) {
           if (error) {
             Log.debug('THERE WAS AN ERROR :-(');
@@ -72,7 +72,7 @@ export default (function () {
     ** Fails if the files already exist, so consider appending a timestamp to filename.
     */
     elasticDump: function elasticDump(index, file) {
-      var self = this;
+      let self = this;
       Log.debug('Dumping mapping from ' + url.format(config.servers.elasticsearch) + '/' + index
         + ' to (' + file + '.mapping.json)');
       return this.elasticdumpModule(url.format(config.servers.elasticsearch),
@@ -94,7 +94,7 @@ export default (function () {
     elasticLoad: function elasticLoad(file, index) {
       // TODO: should we have a flag to delete the index first?
       // or use scenarioManager.unload(index) ? <<- currently this
-      var self = this;
+      let self = this;
       Log.debug('Loading mapping (test/fixtures/dump_data/' + file + '.mapping.json) into '
         + url.format(config.servers.elasticsearch) + '/' + index);
       return this.elasticdumpModule('test/fixtures/dump_data/' + file + '.mapping.json',
diff --git a/test/support/utils/es_client.js b/test/support/utils/es_client.js
index 10a85f9fcec39..1235bb3bb7247 100644
--- a/test/support/utils/es_client.js
+++ b/test/support/utils/es_client.js
@@ -6,8 +6,8 @@ import {
 
 export default (function () {
 
-  var elasticsearch = require('elasticsearch');
-  var Promise = require('bluebird');
+  let elasticsearch = require('elasticsearch');
+  let Promise = require('bluebird');
 
   function EsClient(server) {
     if (!server) throw new Error('No server defined');
@@ -50,7 +50,7 @@ export default (function () {
     ** Also used after deleting .kibana index to know Kibana has recreated it.
     */
     getConfigId: function () {
-      var configId;
+      let configId;
 
       return this.client.search({
         index: '.kibana',
@@ -81,9 +81,9 @@ export default (function () {
     */
     updateConfigDoc: function (docMap) {
       // first we need to get the config doc's id so we can use it in our _update call
-      var self = this;
-      var configId;
-      var docMapString = JSON.stringify(docMap);
+      let self = this;
+      let configId;
+      let docMapString = JSON.stringify(docMap);
 
       return this.getConfigId()
       // now that we have the id, we can update
@@ -110,8 +110,8 @@ export default (function () {
     * @return {Promise} A promise that is resolved when elasticsearch has a response
     */
     deleteAndUpdateConfigDoc: function (docMap) {
-      var self = this;
-      var configId;
+      let self = this;
+      let configId;
 
       return this.delete('.kibana')
       .then(function () {
@@ -120,7 +120,7 @@ export default (function () {
             return self.getConfigId();
           });
         } else {
-          var docMapString = JSON.stringify(docMap);
+          let docMapString = JSON.stringify(docMap);
           return Try.try(function () {
             return self.updateConfigDoc(docMap);
           });
diff --git a/test/support/utils/try.js b/test/support/utils/try.js
index 1735e3e7f82d3..58ef7a57ef5eb 100644
--- a/test/support/utils/try.js
+++ b/test/support/utils/try.js
@@ -10,11 +10,11 @@ import Log from './log.js';
 class Try {
 
   tryForTime(timeout, block) {
-    var self = this;
-    var start = Date.now();
-    var retryDelay = 502;
-    var lastTry = 0;
-    var tempMessage;
+    let self = this;
+    let start = Date.now();
+    let retryDelay = 502;
+    let lastTry = 0;
+    let tempMessage;
 
     function attempt() {
       lastTry = Date.now();
diff --git a/test/unit/api/ingest/_data.js b/test/unit/api/ingest/_data.js
index 4d2a4e5249f18..8daffc34eb2f3 100644
--- a/test/unit/api/ingest/_data.js
+++ b/test/unit/api/ingest/_data.js
@@ -1,9 +1,9 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
-  var fakeNamesIndexTemplate = require('intern/dojo/node!../../fixtures/fake_names_index_template.json');
-  var fs = require('intern/dojo/node!fs');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
+  let fakeNamesIndexTemplate = require('intern/dojo/node!../../fixtures/fake_names_index_template.json');
+  let fs = require('intern/dojo/node!fs');
 
   return function (bdd, scenarioManager, request) {
     const es = scenarioManager.client;
@@ -33,7 +33,7 @@ define(function (require) {
       });
 
       bdd.it('should also accept the raw csv data in the payload body', function () {
-        var csvData = fs.readFileSync('test/unit/fixtures/fake_names_big.csv', {encoding: 'utf8'});
+        let csvData = fs.readFileSync('test/unit/fixtures/fake_names_big.csv', {encoding: 'utf8'});
 
         return request.post('/kibana/names/_data')
         .send(csvData)
diff --git a/test/unit/api/ingest/_del.js b/test/unit/api/ingest/_del.js
index 3d174c45feeec..b310dc0df2944 100644
--- a/test/unit/api/ingest/_del.js
+++ b/test/unit/api/ingest/_del.js
@@ -1,8 +1,8 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
 
   return function (bdd, scenarioManager, request) {
diff --git a/test/unit/api/ingest/_post.js b/test/unit/api/ingest/_post.js
index 732c9499a70fe..0b70c35ddeaea 100644
--- a/test/unit/api/ingest/_post.js
+++ b/test/unit/api/ingest/_post.js
@@ -1,8 +1,8 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   return function (bdd, scenarioManager, request) {
     bdd.describe('POST ingest', function postIngest() {
@@ -101,7 +101,7 @@ define(function (require) {
               id: 'logstash-*'
             })
             .then(function (res) {
-              var fields = JSON.parse(res._source.fields);
+              let fields = JSON.parse(res._source.fields);
               // @timestamp was created with only name and type, all other fields should be set as defaults by API
               expect(res._source.title).to.be('logstash-*');
               expect(fields[1].name).to.be('@timestamp');
@@ -142,7 +142,7 @@ define(function (require) {
           .then(function () {
             return scenarioManager.client.indices.getTemplate({name: 'kibana-logstash-*'})
             .then(function (template) {
-              var mappings = template['kibana-logstash-*'].mappings._default_.properties;
+              let mappings = template['kibana-logstash-*'].mappings._default_.properties;
               expect(mappings).to.be.ok();
               expect(_.isEqual(mappings.ip, {index: true, type: 'ip', doc_values: true})).to.be.ok();
               expect(_.isEqual(mappings['@timestamp'], {index: true, type: 'date', doc_values: true})).to.be.ok();
@@ -220,7 +220,7 @@ define(function (require) {
 
       bdd.it('should return 409 conflict when the pattern matches existing indices',
         function existingIndicesConflict() {
-          var ingestConfig = createTestData();
+          let ingestConfig = createTestData();
           ingestConfig.index_pattern.id = ingestConfig.index_pattern.title = '.kib*';
 
           return request.post('/kibana/ingest')
@@ -229,7 +229,7 @@ define(function (require) {
         });
 
       bdd.it('should enforce snake_case in the request body', function () {
-        var ingestConfig = createTestData();
+        let ingestConfig = createTestData();
         ingestConfig.index_pattern = _.mapKeys(ingestConfig.index_pattern, function (value, key) {
           return _.camelCase(key);
         });
diff --git a/test/unit/api/ingest/_processors.js b/test/unit/api/ingest/_processors.js
index ecb0c43d7b688..3e1cb7d01e84b 100644
--- a/test/unit/api/ingest/_processors.js
+++ b/test/unit/api/ingest/_processors.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   return function (bdd, scenarioManager, request) {
     bdd.describe('processors', () => {
diff --git a/test/unit/api/ingest/_simulate.js b/test/unit/api/ingest/_simulate.js
index 7b8daf3c0fe7c..61a1e0e1ef312 100644
--- a/test/unit/api/ingest/_simulate.js
+++ b/test/unit/api/ingest/_simulate.js
@@ -1,8 +1,8 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let createTestData = require('intern/dojo/node!../../../unit/api/ingest/data');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/index.js b/test/unit/api/ingest/index.js
index d83140c7dc9e6..e0a40193c94b2 100644
--- a/test/unit/api/ingest/index.js
+++ b/test/unit/api/ingest/index.js
@@ -1,20 +1,20 @@
 define(function (require) {
-  var bdd = require('intern!bdd');
-  var serverConfig = require('intern/dojo/node!../../../server_config');
-  var ScenarioManager = require('intern/dojo/node!../../../fixtures/scenario_manager');
-  var request = require('intern/dojo/node!supertest-as-promised');
-  var url = require('intern/dojo/node!url');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
-  var post = require('./_post');
-  var del = require('./_del');
-  var data = require('./_data');
-  var simulate = require('./_simulate');
-  var processors = require('./_processors');
-  var processorTypes = require('./processors/index');
+  let bdd = require('intern!bdd');
+  let serverConfig = require('intern/dojo/node!../../../server_config');
+  let ScenarioManager = require('intern/dojo/node!../../../fixtures/scenario_manager');
+  let request = require('intern/dojo/node!supertest-as-promised');
+  let url = require('intern/dojo/node!url');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
+  let post = require('./_post');
+  let del = require('./_del');
+  let data = require('./_data');
+  let simulate = require('./_simulate');
+  let processors = require('./_processors');
+  let processorTypes = require('./processors/index');
 
   bdd.describe('ingest API', function () {
-    var scenarioManager = new ScenarioManager(url.format(serverConfig.servers.elasticsearch));
+    let scenarioManager = new ScenarioManager(url.format(serverConfig.servers.elasticsearch));
     request = request(url.format(serverConfig.servers.kibana) + '/api');
 
     bdd.before(function () {
diff --git a/test/unit/api/ingest/processors/_append.js b/test/unit/api/ingest/processors/_append.js
index 238cac6b9ee24..7fc214870d7a9 100644
--- a/test/unit/api/ingest/processors/_append.js
+++ b/test/unit/api/ingest/processors/_append.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_convert.js b/test/unit/api/ingest/processors/_convert.js
index 38a07d3507766..f96a936081f2b 100644
--- a/test/unit/api/ingest/processors/_convert.js
+++ b/test/unit/api/ingest/processors/_convert.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_date.js b/test/unit/api/ingest/processors/_date.js
index a3e018e4bd885..df21a8ef07383 100644
--- a/test/unit/api/ingest/processors/_date.js
+++ b/test/unit/api/ingest/processors/_date.js
@@ -1,8 +1,8 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
-  var moment = require('intern/dojo/node!moment');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
+  let moment = require('intern/dojo/node!moment');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_geoip.js b/test/unit/api/ingest/processors/_geoip.js
index 452c3e5d8416c..9131a143c6d9f 100644
--- a/test/unit/api/ingest/processors/_geoip.js
+++ b/test/unit/api/ingest/processors/_geoip.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_grok.js b/test/unit/api/ingest/processors/_grok.js
index b1ee7d4e2de25..ffb9584e3a706 100644
--- a/test/unit/api/ingest/processors/_grok.js
+++ b/test/unit/api/ingest/processors/_grok.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_gsub.js b/test/unit/api/ingest/processors/_gsub.js
index 2d97067a911f1..cd9afe53b2004 100644
--- a/test/unit/api/ingest/processors/_gsub.js
+++ b/test/unit/api/ingest/processors/_gsub.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_join.js b/test/unit/api/ingest/processors/_join.js
index 7e98650fc47c1..18f9896b291ba 100644
--- a/test/unit/api/ingest/processors/_join.js
+++ b/test/unit/api/ingest/processors/_join.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_lowercase.js b/test/unit/api/ingest/processors/_lowercase.js
index 747dfb003b6c6..df5c0b206afff 100644
--- a/test/unit/api/ingest/processors/_lowercase.js
+++ b/test/unit/api/ingest/processors/_lowercase.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_remove.js b/test/unit/api/ingest/processors/_remove.js
index f454b79ff936b..6c08025f4457c 100644
--- a/test/unit/api/ingest/processors/_remove.js
+++ b/test/unit/api/ingest/processors/_remove.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_rename.js b/test/unit/api/ingest/processors/_rename.js
index 3370ba6f48b45..a11249eb74c38 100644
--- a/test/unit/api/ingest/processors/_rename.js
+++ b/test/unit/api/ingest/processors/_rename.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_set.js b/test/unit/api/ingest/processors/_set.js
index 395a29a80d5b2..9f247ae044fa7 100644
--- a/test/unit/api/ingest/processors/_set.js
+++ b/test/unit/api/ingest/processors/_set.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_split.js b/test/unit/api/ingest/processors/_split.js
index 9e6900b0f822e..df0473f016a31 100644
--- a/test/unit/api/ingest/processors/_split.js
+++ b/test/unit/api/ingest/processors/_split.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_trim.js b/test/unit/api/ingest/processors/_trim.js
index 1f08d5c1eb167..da33e3d3be840 100644
--- a/test/unit/api/ingest/processors/_trim.js
+++ b/test/unit/api/ingest/processors/_trim.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/_uppercase.js b/test/unit/api/ingest/processors/_uppercase.js
index c2cd5cf1b7256..751e695526a57 100644
--- a/test/unit/api/ingest/processors/_uppercase.js
+++ b/test/unit/api/ingest/processors/_uppercase.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   const testPipeline = {
     processors: [{
diff --git a/test/unit/api/ingest/processors/index.js b/test/unit/api/ingest/processors/index.js
index 3420996767864..b5d25061c25b8 100644
--- a/test/unit/api/ingest/processors/index.js
+++ b/test/unit/api/ingest/processors/index.js
@@ -1,18 +1,18 @@
 define(function (require) {
-  var append = require('./_append');
-  var convert = require('./_convert');
-  var date = require('./_date');
-  var geoip = require('./_geoip');
-  var grok = require('./_grok');
-  var gsub = require('./_gsub');
-  var join = require('./_join');
-  var lowercase = require('./_lowercase');
-  var remove = require('./_remove');
-  var rename = require('./_rename');
-  var set = require('./_set');
-  var split = require('./_split');
-  var trim = require('./_trim');
-  var uppercase = require('./_uppercase');
+  let append = require('./_append');
+  let convert = require('./_convert');
+  let date = require('./_date');
+  let geoip = require('./_geoip');
+  let grok = require('./_grok');
+  let gsub = require('./_gsub');
+  let join = require('./_join');
+  let lowercase = require('./_lowercase');
+  let remove = require('./_remove');
+  let rename = require('./_rename');
+  let set = require('./_set');
+  let split = require('./_split');
+  let trim = require('./_trim');
+  let uppercase = require('./_uppercase');
 
   return function processors(bdd, scenarioManager, request) {
     append(bdd, scenarioManager, request);
diff --git a/test/unit/api/search/_count.js b/test/unit/api/search/_count.js
index 239a936cfd1ed..235f0b9002358 100644
--- a/test/unit/api/search/_count.js
+++ b/test/unit/api/search/_count.js
@@ -1,7 +1,7 @@
 define(function (require) {
-  var Promise = require('bluebird');
-  var _ = require('intern/dojo/node!lodash');
-  var expect = require('intern/dojo/node!expect.js');
+  let Promise = require('bluebird');
+  let _ = require('intern/dojo/node!lodash');
+  let expect = require('intern/dojo/node!expect.js');
 
   return function (bdd, scenarioManager, request) {
     bdd.describe('Count API', function postIngest() {
diff --git a/test/unit/api/search/index.js b/test/unit/api/search/index.js
index 85fd81bc12253..111f6d837bf92 100644
--- a/test/unit/api/search/index.js
+++ b/test/unit/api/search/index.js
@@ -1,13 +1,13 @@
 define(function (require) {
-  var bdd = require('intern!bdd');
-  var serverConfig = require('intern/dojo/node!../../../server_config');
-  var ScenarioManager = require('intern/dojo/node!../../../fixtures/scenario_manager');
-  var request = require('intern/dojo/node!supertest-as-promised');
-  var url = require('intern/dojo/node!url');
-  var count = require('./_count');
+  let bdd = require('intern!bdd');
+  let serverConfig = require('intern/dojo/node!../../../server_config');
+  let ScenarioManager = require('intern/dojo/node!../../../fixtures/scenario_manager');
+  let request = require('intern/dojo/node!supertest-as-promised');
+  let url = require('intern/dojo/node!url');
+  let count = require('./_count');
 
   bdd.describe('search API', function () {
-    var scenarioManager = new ScenarioManager(url.format(serverConfig.servers.elasticsearch));
+    let scenarioManager = new ScenarioManager(url.format(serverConfig.servers.elasticsearch));
     request = request(url.format(serverConfig.servers.kibana) + '/api');
 
     bdd.before(function () {
diff --git a/test/utils/__tests__/get_page.js b/test/utils/__tests__/get_page.js
index d46f23c77359e..ac61ad2760ff3 100644
--- a/test/utils/__tests__/get_page.js
+++ b/test/utils/__tests__/get_page.js
@@ -1,9 +1,9 @@
-var expect = require('expect.js');
-var getUrl = require('../get_url');
+let expect = require('expect.js');
+let getUrl = require('../get_url');
 
 describe('getUrl', function () {
   it('should convert to a url', function () {
-    var url = getUrl({
+    let url = getUrl({
       protocol: 'http',
       hostname: 'localhost',
     }, {
@@ -14,7 +14,7 @@ describe('getUrl', function () {
   });
 
   it('should convert to a url with port', function () {
-    var url = getUrl({
+    let url = getUrl({
       protocol: 'http',
       hostname: 'localhost',
       port: 9220
diff --git a/test/utils/get_url.js b/test/utils/get_url.js
index 8dd676d98b627..cff9f6c5cb6a1 100644
--- a/test/utils/get_url.js
+++ b/test/utils/get_url.js
@@ -1,5 +1,5 @@
-var _ = require('lodash');
-var url = require('url');
+let _ = require('lodash');
+let url = require('url');
 
 /**
 * Converts a config and a pathname to a url
diff --git a/test/visual_regression/home/_loading.js b/test/visual_regression/home/_loading.js
index a3d77860f34f8..97aa0b81088ff 100644
--- a/test/visual_regression/home/_loading.js
+++ b/test/visual_regression/home/_loading.js
@@ -5,7 +5,7 @@ import {
   consolePage
 } from '../../support';
 
-var expect = require('expect.js');
+let expect = require('expect.js');
 
 bdd.describe('Loading', function coverLoadingUi() {
   bdd.it('should show loading feebdack', async function () {