re-enable and autofix prefer-const rule

.eslintrc

@@ -2,6 +2,5 @@
 extends: '@elastic/kibana'
 rules:
   no-unused-vars: off
-  prefer-const: off
   no-extra-semi: off
   quotes: off

src/cli/cluster/worker.js

@@ -5,16 +5,16 @@ import { EventEmitter } from 'events';
 
 import { BinderFor, fromRoot } from '../../utils';
 
-let cliPath = fromRoot('src/cli');
-let baseArgs = _.difference(process.argv.slice(2), ['--no-watch']);
-let baseArgv = [process.execPath, cliPath].concat(baseArgs);
+const cliPath = fromRoot('src/cli');
+const baseArgs = _.difference(process.argv.slice(2), ['--no-watch']);
+const baseArgv = [process.execPath, cliPath].concat(baseArgs);
 
 cluster.setupMaster({
   exec: cliPath,
   silent: false
 });
 
-let dead = fork => {
+const dead = fork => {
   return fork.isDead() || fork.killed;
 };
 
@@ -40,7 +40,7 @@ module.exports = class Worker extends EventEmitter {
     this.clusterBinder = new BinderFor(cluster);
     this.processBinder = new BinderFor(process);
 
-    let argv = _.union(baseArgv, opts.argv || []);
+    const argv = _.union(baseArgv, opts.argv || []);
     this.env = {
       kbnWorkerType: this.type,
       kbnWorkerArgv: JSON.stringify(argv)
@@ -124,8 +124,8 @@ module.exports = class Worker extends EventEmitter {
   }
 
   flushChangeBuffer() {
-    let files = _.unique(this.changes.splice(0));
-    let prefix = files.length > 1 ? '\n - ' : '';
+    const files = _.unique(this.changes.splice(0));
+    const prefix = files.length > 1 ? '\n - ' : '';
     return files.reduce(function (list, file) {
       return `${list || ''}${prefix}"${file}"`;
     }, '');

src/cli/command.js

@@ -40,15 +40,15 @@ Command.prototype.unknownArgv = function (argv) {
  * @return {[type]} [description]
  */
 Command.prototype.collectUnknownOptions = function () {
-  let title = `Extra ${this._name} options`;
+  const title = `Extra ${this._name} options`;
 
   this.allowUnknownOption();
   this.getUnknownOptions = function () {
-    let opts = {};
-    let unknowns = this.unknownArgv();
+    const opts = {};
+    const unknowns = this.unknownArgv();
 
     while (unknowns.length) {
-      let opt = unknowns.shift().split('=');
+      const opt = unknowns.shift().split('=');
       if (opt[0].slice(0, 2) !== '--') {
         this.error(`${title} "${opt[0]}" must start with "--"`);
       }
@@ -75,14 +75,14 @@ Command.prototype.collectUnknownOptions = function () {
 };
 
 Command.prototype.parseOptions = _.wrap(Command.prototype.parseOptions, function (parse, argv) {
-  let opts = parse.call(this, argv);
+  const opts = parse.call(this, argv);
   this.unknownArgv(opts.unknown);
   return opts;
 });
 
 Command.prototype.action = _.wrap(Command.prototype.action, function (action, fn) {
   return action.call(this, function (...args) {
-    let ret = fn.apply(this, args);
+    const ret = fn.apply(this, args);
     if (ret && typeof ret.then === 'function') {
       ret.then(null, function (e) {
         console.log('FATAL CLI ERROR', e.stack);

src/cli/help.js

@@ -5,12 +5,12 @@ module.exports = function (command, spaces) {
     return command.outputHelp();
   }
 
-  let defCmd = _.find(command.commands, function (cmd) {
+  const defCmd = _.find(command.commands, function (cmd) {
     return cmd._name === 'serve';
   });
 
-  let desc = !command.description() ? '' : command.description();
-  let cmdDef = !defCmd ? '' : `=${defCmd._name}`;
+  const desc = !command.description() ? '' : command.description();
+  const cmdDef = !defCmd ? '' : `=${defCmd._name}`;
 
   return (
 `
@@ -31,11 +31,11 @@ function indent(str, n) {
 }
 
 function commandsSummary(program) {
-  let cmds = _.compact(program.commands.map(function (cmd) {
-    let name = cmd._name;
+  const cmds = _.compact(program.commands.map(function (cmd) {
+    const name = cmd._name;
     if (name === '*') return;
-    let opts = cmd.options.length ? ' [options]' : '';
-    let args = cmd._args.map(function (arg) {
+    const opts = cmd.options.length ? ' [options]' : '';
+    const args = cmd._args.map(function (arg) {
       return humanReadableArgName(arg);
     }).join(' ');
 
@@ -45,7 +45,7 @@ function commandsSummary(program) {
     ];
   }));
 
-  let cmdLColWidth = cmds.reduce(function (width, cmd) {
+  const cmdLColWidth = cmds.reduce(function (width, cmd) {
     return Math.max(width, cmd[0].length);
   }, 0);
 
@@ -69,6 +69,6 @@ ${indent(cmd.optionHelp(), 2)}
 }
 
 function humanReadableArgName(arg) {
-  let nameOutput = arg.name + (arg.variadic === true ? '...' : '');
+  const nameOutput = arg.name + (arg.variadic === true ? '...' : '');
   return arg.required ? '<' + nameOutput + '>' : '[' + nameOutput + ']';
 }

src/cli/log.js

@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import ansicolors from 'ansicolors';
 
-let log = _.restParam(function (color, label, rest1) {
+const log = _.restParam(function (color, label, rest1) {
   console.log.apply(console, [color(` ${_.trim(label)} `)].concat(rest1));
 });
 

src/cli_plugin/cli.js

@@ -5,8 +5,8 @@ import listCommand from './list';
 import installCommand from './install';
 import removeCommand from './remove';
 
-let argv = process.env.kbnWorkerArgv ? JSON.parse(process.env.kbnWorkerArgv) : process.argv.slice();
-let program = new Command('bin/kibana-plugin');
+const argv = process.env.kbnWorkerArgv ? JSON.parse(process.env.kbnWorkerArgv) : process.argv.slice();
+const program = new Command('bin/kibana-plugin');
 
 program
 .version(pkg.version)
@@ -23,7 +23,7 @@ program
 .command('help <command>')
 .description('get the help for a specific command')
 .action(function (cmdName) {
-  let cmd = _.find(program.commands, { _name: cmdName });
+  const cmd = _.find(program.commands, { _name: cmdName });
   if (!cmd) return program.error(`unknown command ${cmdName}`);
   cmd.help();
 });
@@ -35,7 +35,7 @@ program
 });
 
 // check for no command name
-let subCommand = argv[2] && !String(argv[2][0]).match(/^-|^\.|\//);
+const subCommand = argv[2] && !String(argv[2][0]).match(/^-|^\.|\//);
 if (!subCommand) {
   program.defaultHelp();
 }

src/cli_plugin/install/__tests__/index.js

@@ -8,7 +8,7 @@ describe('kibana cli', function () {
 
     describe('commander options', function () {
 
-      let program = {
+      const program = {
         command: function () { return program; },
         description: function () { return program; },
         option: function () { return program; },

src/cli_plugin/install/downloaders/file.js

@@ -3,7 +3,7 @@ import { createWriteStream, createReadStream, unlinkSync, statSync } from 'fs';
 
 function openSourceFile({ sourcePath }) {
   try {
-    let fileInfo = statSync(sourcePath);
+    const fileInfo = statSync(sourcePath);
 
     const readStream = createReadStream(sourcePath);
 

src/cli_plugin/install/downloaders/http.js

@@ -53,7 +53,7 @@ export default async function downloadUrl(logger, sourceUrl, targetPath, timeout
     const { req, resp } = await sendRequest({ sourceUrl, timeout });
 
     try {
-      let totalSize = parseFloat(resp.headers['content-length']) || 0;
+      const totalSize = parseFloat(resp.headers['content-length']) || 0;
       const progress = new Progress(logger);
       progress.init(totalSize);
 

src/core_plugins/elasticsearch/lib/__tests__/is_upgradeable.js

@@ -8,7 +8,7 @@ let version = pkg.version;
 
 describe('plugins/elasticsearch', function () {
   describe('lib/is_upgradeable', function () {
-    let server = {
+    const server = {
       config: _.constant({
         get: function (key) {
           switch (key) {
@@ -44,7 +44,7 @@ describe('plugins/elasticsearch', function () {
     upgradeDoc('5.0.0-alpha1', '5.0.0', false);
 
     it('should handle missing _id field', function () {
-      let doc = {
+      const doc = {
         '_index': '.kibana',
         '_type': 'config',
         '_score': 1,
@@ -58,7 +58,7 @@ describe('plugins/elasticsearch', function () {
     });
 
     it('should handle _id of @@version', function () {
-      let doc = {
+      const doc = {
         '_index': '.kibana',
         '_type': 'config',
         '_id': '@@version',

src/core_plugins/kbn_doc_views/public/views/table.js

@@ -26,7 +26,7 @@ docViewsRegistry.register(function () {
         };
 
         $scope.showArrayInObjectsWarning = function (row, field) {
-          let value = $scope.flattened[field];
+          const value = $scope.flattened[field];
           return _.isArray(value) && typeof value[0] === 'object';
         };
       }

src/core_plugins/kibana/index.js

@@ -30,7 +30,7 @@ module.exports = function (kibana) {
         ],
 
         injectVars: function (server, options) {
-          let config = server.config();
+          const config = server.config();
           return {
             kbnDefaultAppId: config.get('kibana.defaultAppId'),
             tilemap: config.get('tilemap')

src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/directives/output_preview.js

@@ -28,8 +28,8 @@ app.directive('outputPreview', function () {
       });
 
       $scope.updateUi = function () {
-        let left = $scope.oldObject;
-        let right = $scope.newObject;
+        const left = $scope.oldObject;
+        const right = $scope.newObject;
         let delta = $scope.diffpatch.diff(left, right);
         if (!delta || $scope.error) delta = {};
 

src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/__tests__/keys_deep.js

@@ -5,11 +5,11 @@ import keysDeep from '../keys_deep';
 describe('keys deep', function () {
 
   it('should list first level properties', function () {
-    let object = {
+    const object = {
       property1: 'value1',
       property2: 'value2'
     };
-    let expected = [
+    const expected = [
       'property1',
       'property2'
     ];
@@ -20,14 +20,14 @@ describe('keys deep', function () {
   });
 
   it('should list nested properties', function () {
-    let object = {
+    const object = {
       property1: 'value1',
       property2: 'value2',
       property3: {
         subProperty1: 'value1.1'
       }
     };
-    let expected = [
+    const expected = [
       'property1',
       'property2',
       'property3.subProperty1',
@@ -40,7 +40,7 @@ describe('keys deep', function () {
   });
 
   it('should recursivly list nested properties', function () {
-    let object = {
+    const object = {
       property1: 'value1',
       property2: 'value2',
       property3: {
@@ -52,7 +52,7 @@ describe('keys deep', function () {
         subProperty3: 'value1.3'
       }
     };
-    let expected = [
+    const expected = [
       'property1',
       'property2',
       'property3.subProperty1',
@@ -69,11 +69,11 @@ describe('keys deep', function () {
   });
 
   it('should list array properties, but not contents', function () {
-    let object = {
+    const object = {
       property1: 'value1',
       property2: [ 'item1', 'item2' ]
     };
-    let expected = [
+    const expected = [
       'property1',
       'property2'
     ];

src/core_plugins/kibana/public/management/sections/indices/add_data_steps/pipeline_setup/lib/keys_deep.js

@@ -2,10 +2,10 @@ import _ from 'lodash';
 
 export default function keysDeep(object, base) {
   let result = [];
-  let delimitedBase = base ? base + '.' : '';
+  const delimitedBase = base ? base + '.' : '';
 
   _.forEach(object, (value, key) => {
-    let fullKey = delimitedBase + key;
+    const fullKey = delimitedBase + key;
     if (_.isPlainObject(value)) {
       result = result.concat(keysDeep(value, fullKey));
     } else {

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();
 
-      let notify = new Notifier({
+      const notify = new Notifier({
         location: 'Add Data'
       });
 
-      let totalSteps = 4;
+      const totalSteps = 4;
       this.stepResults = {};
 
       this.setCurrentStep = (step) => {

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();
 
-        let notify = new Notifier({
+        const notify = new Notifier({
           location: 'Add Data'
         });
 
-        let totalSteps = 3;
+        const totalSteps = 3;
         this.stepResults = {};
 
         this.setCurrentStep = (step) => {

src/core_plugins/kibana/server/lib/__tests__/create_mappings_from_pattern_fields.js

@@ -36,7 +36,7 @@ describe('createMappingsFromPatternFields', function () {
   });
 
   it('should set the same default mapping for all non-strings', function () {
-    let mappings = createMappingsFromPatternFields(testFields);
+    const mappings = createMappingsFromPatternFields(testFields);
 
     _.forEach(mappings, function (mapping) {
       if (mapping.type !== 'text') {
@@ -50,7 +50,7 @@ describe('createMappingsFromPatternFields', function () {
   });
 
   it('should give strings a multi-field mapping with a "text" base type', function () {
-    let mappings = createMappingsFromPatternFields(testFields);
+    const mappings = createMappingsFromPatternFields(testFields);
 
     _.forEach(mappings, function (mapping) {
       if (mapping.type === 'text') {
@@ -61,7 +61,7 @@ describe('createMappingsFromPatternFields', function () {
 
   it('should handle nested fields', function () {
     testFields.push({name: 'geo.coordinates', type: 'geo_point'});
-    let mappings = createMappingsFromPatternFields(testFields);
+    const mappings = createMappingsFromPatternFields(testFields);
 
     expect(mappings).to.have.property('geo');
     expect(mappings.geo).to.have.property('properties');
@@ -74,7 +74,7 @@ describe('createMappingsFromPatternFields', function () {
   });
 
   it('should map all number fields as an ES double', function () {
-    let mappings = createMappingsFromPatternFields(testFields);
+    const mappings = createMappingsFromPatternFields(testFields);
 
     expect(mappings).to.have.property('bytes');
     expect(mappings.bytes).to.have.property('type', 'double');