Use const, let.

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

.eslintrc.js

@@ -1,11 +1,14 @@
 module.exports = {
     "env": {
       "browser": false,
-      "es6": false,
+      "es6": true,
       "mocha": true,
       "node": true
     },
-    "extends": "google",
+    "extends": [
+      "google",
+      "eslint:recommended"
+    ],
     "rules": {
       "block-spacing": [2, "always"],
       "brace-style": [2, "1tbs", { "allowSingleLine": true }],
@@ -14,6 +17,8 @@ module.exports = {
       "curly": 0,
       "key-spacing": [2, {align: "value"}],
       "max-len": [1, 120],
+      "no-console": 1,
+      "no-empty": [2, { "allowEmptyCatch": true }],
       "no-eval": 1, // we use it on purpose
       "no-loop-func": 1,
       "no-multi-spaces": 0,

lib/cache.js

@@ -4,28 +4,27 @@ var path = require('path');
 
 var h = require('./helper');
 
-var cache = {};
+const cache = {};
 
 cache.init = function() {
   h.mkdir(h.getCacheDir());
 };
 
 cache.get = function(k) {
-  var fullpath = h.getCacheFile(k);
+  const fullpath = h.getCacheFile(k);
   if (!fs.existsSync(fullpath)) return null;
 
-  var v = JSON.parse(fs.readFileSync(fullpath));
-  return v;
+  return JSON.parse(fs.readFileSync(fullpath));
 };
 
 cache.set = function(k, v) {
-  var fullpath = h.getCacheFile(k);
+  const fullpath = h.getCacheFile(k);
   fs.writeFileSync(fullpath, JSON.stringify(v));
   return true;
 };
 
 cache.del = function(k) {
-  var fullpath = h.getCacheFile(k);
+  const fullpath = h.getCacheFile(k);
   if (!fs.existsSync(fullpath)) return false;
 
   fs.unlinkSync(fullpath);
@@ -38,8 +37,8 @@ cache.list = function() {
       return path.extname(filename) === '.json';
     })
     .map(function(filename) {
-      var k = path.basename(filename, '.json');
-      var stat = fs.statSync(h.getCacheFile(k));
+      const k = path.basename(filename, '.json');
+      const stat = fs.statSync(h.getCacheFile(k));
       return {
         name:  k,
         size:  stat.size,

lib/chalk.js

@@ -3,17 +3,17 @@ var _ = require('underscore');
 var style = require('ansi-styles');
 var supportsColor = require('supports-color');
 
-var chalk = {
+const chalk = {
   enabled: supportsColor.stdout,
   use256:  supportsColor.stdout && supportsColor.stdout.has256,
   themes:  {},
   theme:   {}
 };
 
-var pres = [];
-var posts = [];
+const pres = [];
+const posts = [];
 
-var DEFAULT = {
+const DEFAULT = {
   black:   '#000000',
   blue:    '#0000ff',
   cyan:    '#00ffff',
@@ -26,12 +26,12 @@ var DEFAULT = {
 };
 
 chalk.setTheme = function(name) {
-  var theme = this.themes[name] || this.themes.default || {};
+  const theme = this.themes[name] || this.themes.default || {};
   this.theme = _.extendOwn(DEFAULT, theme);
 };
 
 chalk.sprint = function(s, hex) {
-  var color = chalk.use256 ? style.color.ansi256.hex(hex) : style.color.ansi.hex(hex);
+  const color = chalk.use256 ? style.color.ansi256.hex(hex) : style.color.ansi.hex(hex);
   return color + s + style.color.close;
 };
 
@@ -44,9 +44,7 @@ chalk.print = function(s) {
 chalk.wrap = function(pre, post) {
   pres.push(pre);
   posts.unshift(post);
-  var f = function(s) {
-    return chalk.print(s);
-  };
+  const f = function(s) { return chalk.print(s); };
   Object.setPrototypeOf(f, chalk);
   return f;
 };
@@ -55,11 +53,11 @@ function bgName(s) { return 'bg' + s[0].toUpperCase() + s.substr(1); }
 
 chalk.init = function() {
   require('./helper').getCodeDirData('colors').forEach(function(f) {
-    var o = {};
+    const o = {};
     _.pairs(f.data).forEach(function(x) {
-      var k = x[0];
-      var v = x[1];
-      var bgK = bgName(k);
+      const k = x[0];
+      const v = x[1];
+      const bgK = bgName(k);
 
       if (chalk.use256) {
         o[k] = style.color.ansi256.hex(v);
@@ -80,7 +78,7 @@ chalk.init = function() {
       },
       configurable: true
     });
-    var bgcolor = bgName(color);
+    const bgcolor = bgName(color);
     Object.defineProperty(chalk, bgcolor, {
       get: function() {
         return chalk.wrap(chalk.theme[bgcolor], style.bgColor.close);

lib/cli.js

@@ -27,24 +27,22 @@ function initIcon() {
 function initLogLevel() {
   log.init();
 
-  var level = 'INFO';
+  let level = 'INFO';
   if (process.argv.indexOf('-v') >= 0) level = 'DEBUG';
   if (process.argv.indexOf('-vv') >= 0) level = 'TRACE';
 
   // print HTTP details in TRACE
   if (level === 'TRACE') {
-    var request = require('request');
+    const request = require('request');
     request.debug = true;
 
     console.error = _.wrap(console.error, function(func) {
-      var args = _.toArray(arguments);
+      let args = _.toArray(arguments);
       args.shift();
 
       // FIXME: hack HTTP request log, hope no one else use it...
       if (args.length > 0 && args[0].indexOf('REQUEST ') === 0) {
-        args = args.map(function(arg) {
-          return h.printSafeHTTP(arg);
-        });
+        args = args.map(function(arg) { return h.printSafeHTTP(arg); });
         log.trace.apply(log, args);
       } else {
         log.info.apply(log, args);

lib/commands/cache.js

@@ -7,7 +7,7 @@ var log = require('../log');
 var cache = require('../cache');
 var session = require('../session');
 
-var cmd = {
+const cmd = {
   command: 'cache [keyword]',
   desc:    'Manage local cache',
   builder: function(yargs) {
@@ -33,7 +33,7 @@ var cmd = {
 cmd.handler = function(argv) {
   session.argv = argv;
 
-  var caches = cache.list()
+  const caches = cache.list()
     .filter(function(f) {
       return argv.keyword.length === 0 || f.name.startsWith(argv.keyword + '.');
     });
@@ -42,7 +42,7 @@ cmd.handler = function(argv) {
     caches.forEach(function(f) { cache.del(f.name); });
   } else {
     _.sortBy(caches, function(f) {
-      var x = parseInt(f.name.split('.')[0], 10);
+      let x = parseInt(f.name.split('.')[0], 10);
       if (Number.isNaN(x)) x = 0;
       return x;
     })

lib/commands/config.js

@@ -8,7 +8,7 @@ var config = require('../config');
 var log = require('../log');
 var session = require('../session');
 
-var cmd = {
+const cmd = {
   command: 'config [key] [value]',
   aliases: ['conf', 'cfg', 'setting'],
   desc:    'Manage user configs',
@@ -49,7 +49,7 @@ function prettyConfig(cfg) {
 }
 
 function loadConfig(showall) {
-  var cfg = showall ? config.getAll(true) : nconf.get();
+  const cfg = showall ? config.getAll(true) : nconf.get();
   return _.omit(cfg, 'type');
 }
 
@@ -65,7 +65,7 @@ cmd.handler = function(argv) {
   if (argv.key.length === 0)
     return log.info(prettyConfig(loadConfig(argv.all)));
 
-  var v = nconf.get(argv.key);
+  const v = nconf.get(argv.key);
 
   // delete
   if (argv.delete) {

lib/commands/list.js

@@ -9,7 +9,7 @@ var log = require('../log');
 var core = require('../core');
 var session = require('../session');
 
-var cmd = {
+const cmd = {
   command: 'list [keyword]',
   aliases: ['ls'],
   desc:    'List questions',
@@ -47,7 +47,7 @@ cmd.handler = function(argv) {
   core.filterProblems(argv, function(e, problems) {
     if (e) return log.fail(e);
 
-    var word = argv.keyword.toLowerCase();
+    const word = argv.keyword.toLowerCase();
     if (word) {
       if (word.endsWith(word.substr(-1).repeat(6))) {
         log.warn('Hmmm...you might need a new keyboard?');
@@ -57,8 +57,8 @@ cmd.handler = function(argv) {
       });
     }
 
-    var stat = {};
-    var KEYS = ['locked', 'starred', 'ac', 'notac', 'None', 'Easy', 'Medium', 'Hard'];
+    const stat = {};
+    const KEYS = ['locked', 'starred', 'ac', 'notac', 'None', 'Easy', 'Medium', 'Hard'];
     KEYS.forEach(function(x) { stat[x] = 0; });
 
     problems = _.sortBy(problems, function(x) { return -x.id; });
@@ -78,12 +78,12 @@ cmd.handler = function(argv) {
           problem.percent);
 
       if (argv.extra) {
-        var badges = [problem.category];
+        let badges = [problem.category];
         badges = badges.concat(problem.companies || []);
         badges = badges.concat(problem.tags || []);
 
-        var buf = [];
-        var len = 0;
+        let buf = [];
+        let len = 0;
         badges.forEach(function(x) {
           if (len + x.length + 3 >= 60) {
             log.printf('%12s%s', ' ', chalk.dim(buf.join(' | ')));

lib/commands/plugin.js

@@ -8,7 +8,7 @@ var log = require('../log');
 var Plugin = require('../plugin');
 var session = require('../session');
 
-var cmd = {
+const cmd = {
   command: 'plugin [name]',
   aliases: ['extension', 'ext'],
   desc:    'Manage plugins',
@@ -62,7 +62,7 @@ var cmd = {
 cmd.handler = function(argv) {
   session.argv = argv;
 
-  var name = argv.name;
+  const name = argv.name;
   if (argv.install) {
     Plugin.install(name, function(e, plugin) {
       if (e) return log.error(e);
@@ -71,28 +71,27 @@ cmd.handler = function(argv) {
     return;
   }
 
-  var plugins = Plugin.plugins;
+  let plugins = Plugin.plugins;
   if (name) {
     plugins = plugins.filter(function(p) {
       return p.name === name;
     });
   }
   if (plugins.length === 0) return log.error('Plugin not found!');
 
-  var plugin = plugins[0];
-  var fullpath = h.getPluginFile(plugin.file);
-  var newname;
+  const plugin = plugins[0];
+  const fullpath = h.getPluginFile(plugin.file);
 
   if (argv.enable) {
     if (plugin.enabled) return;
-    newname = h.getPluginFile(plugin.file.substr(1));
+    const newname = h.getPluginFile(plugin.file.substr(1));
 
     fs.rename(fullpath, newname, function(e) {
       if (e) log.error(e.message);
     });
   } else if (argv.disable) {
     if (!plugin.enabled) return;
-    newname = h.getPluginFile('.' + plugin.file);
+    const newname = h.getPluginFile('.' + plugin.file);
 
     fs.rename(fullpath, newname, function(e) {
       if (e) log.error(e.message);