Update syntax

.eslintrc

@@ -1,6 +1,10 @@
 {
+  "parserOptions": {
+    "ecmaVersion": 6
+  },
   "env": {
-    "node": true
+    "node": true,
+    "es6": true
   },
   "rules": {
     "comma-dangle": [2, "always-multiline"],

lib/reporter.js

@@ -1,35 +1,33 @@
-var chalk = require('chalk');
-var _ = require('lodash');
 var defaultFormatter = require('./formatter');
+var chalk = require('chalk');
 var util = require('./util');
+var _ = require('lodash');
 
-module.exports = function(opts) {
-  var options = opts || {};
-
-  var formatter = options.formatter || defaultFormatter({
-    noIcon: options.noIcon,
-    noPlugin: options.noPlugin,
+module.exports = function(opts = {}) {
+  var formatter = opts.formatter || defaultFormatter({
+    noIcon: opts.noIcon,
+    noPlugin: opts.noPlugin,
   });
 
   var pluginFilter;
-  if (!options.plugins) {
+  if (!opts.plugins) {
     // Every plugin
     pluginFilter = function() { return true; };
-  } else if (options.plugins.every(function(plugin) { return plugin[0] === '!'; })) {
+  } else if (opts.plugins.every(function(plugin) { return plugin[0] === '!'; })) {
     // Blacklist
     pluginFilter = function(message) {
-      return options.plugins.indexOf('!' + message.plugin) === -1;
+      return opts.plugins.indexOf('!' + message.plugin) === -1;
     };
   } else {
     // Whitelist
     pluginFilter = function(message) {
-      return options.plugins.indexOf(message.plugin) !== -1;
+      return opts.plugins.indexOf(message.plugin) !== -1;
     };
   }
 
-  var messageFilter = options.filter || function(message) { return (message.type === 'warning'); };
+  var messageFilter = opts.filter || (message => message.type === 'warning');
 
-  return function(css, result) {
+  return (css, result) => {
     var messagesToLog = result.messages
       .filter(pluginFilter)
       .filter(messageFilter);
@@ -49,11 +47,11 @@ module.exports = function(opts) {
       });
     });
 
-    if (options.clearReportedMessages) {
+    if (opts.clearReportedMessages) {
       result.messages = _.difference(result.messages, messagesToLog);
     }
 
-    if (options.clearAllMessages) {
+    if (opts.clearAllMessages) {
       var messagesToClear = result.messages.filter(pluginFilter);
       result.messages = _.difference(result.messages, messagesToClear);
     }
@@ -63,14 +61,14 @@ module.exports = function(opts) {
 
     console.log(report);
 
-    if (options.throwError && shouldThrowError()) {
+    if (opts.throwError && shouldThrowError()) {
       throw new Error(chalk.red.bold('\n** postcss-reporter: warnings or errors were found **'));
     }
 
     function shouldThrowError() {
       return (
         messagesToLog.length
-        && messagesToLog.some(function(message) {
+        && messagesToLog.some(message => {
           return message.type === 'warning' || message.type === 'error';
         })
       );