Added config with ES2015-only rules

This commit adds an additional config, which should be used in
ES2015-based projects. It's available by adding
`extends: openstack/es2015` to project's .eslintrc file.

Change-Id: I5d54cdceb206db7a52ee396eafc513b290e38f86

.eslintrc-es2015

@@ -0,0 +1,28 @@
+# This file contains rules which should only be enabled in
+# ES2015-based projects.
+extends: openstack
+
+parserOptions:
+  ecmaVersion: 6
+  sourceType: module
+
+rules:
+  # disallow unnecessary .call() and .apply()
+  # http://eslint.org/docs/rules/no-useless-call
+  no-useless-call: 2
+
+  # require let or const instead of var
+  # http://eslint.org/docs/rules/no-var
+  no-var: 2
+
+  # suggest using arrow functions as callbacks
+  # http://eslint.org/docs/rules/prefer-arrow-callback
+  prefer-arrow-callback: 2
+
+  # suggest using the spread operator instead of .apply().
+  # http://eslint.org/docs/rules/prefer-spread
+  prefer-spread: 2
+
+  # suggest using the rest parameters instead of arguments
+  # http://eslint.org/docs/rules/prefer-rest-params
+  prefer-rest-params: 2

README.md

@@ -12,7 +12,8 @@ project to stay as close to the common guidelines as possible.
 To add these rules to your project, follow these steps.
 
 1. `npm install --save-dev eslint eslint-config-openstack`
-2. Add `extends: "openstack"` to your `.eslintrc` yaml file
+2. Add `extends: "openstack"` to your `.eslintrc` yaml file. If your project is using ES2015, add
+   `extends: "openstack/es2015"` instead.
 
 ## Approval Policies
 
@@ -29,11 +30,11 @@ Patches that upgrade eslint only require two core approvers to land. These patch
 upstream rules in a deactivated state, and delete any deprecated rules.
 
 #### Policy upgrades require all cores
-Updates to policies and governance on this project require +2 votes from all direct cores on the 
+Updates to policies and governance on this project require +2 votes from all direct cores on the
 project. Core votes from the parent OpenStack QA project are optional.
 
 #### Patches should be abandoned after a month of inactivity
 Cores should attempt to keep the list of extant patches small and managable. As such, they should
-talk to any author whose patch has failed to garner the necessary support, and has experienced 
-one month of inactivity. Reasonable notice should be given to the author before a patch is 
+talk to any author whose patch has failed to garner the necessary support, and has experienced
+one month of inactivity. Reasonable notice should be given to the author before a patch is
 abandoned.

es2015.js

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2016 Mirantis, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+**/
+
+/**
+ * The default module for this package simply reads in the .eslintrc-es2015 yaml file, and returns
+ * it as a module.
+ */
+
+module.exports = require('./load-config')('.eslintrc-es2015');

index.js

@@ -14,22 +14,9 @@
  * under the License.
  */
 
-/*eslint-disable strict*/
-'use strict';
-/*eslint-enable strict*/
-
 /**
  * The default module for this package simply reads in the .eslintrc yaml file, and returns it
  * as a module.
  */
 
-var yaml = require('js-yaml');
-var fs = require('fs');
-var path = require('path');
-
-/*eslint-disable no-sync */
-var rcPath = path.join(__dirname, '.eslintrc');
-var fileContent = fs.readFileSync(rcPath);
-/*eslint-enable no-sync */
-
-module.exports = yaml.safeLoad(fileContent);
+module.exports = require('./load-config')('.eslintrc');

load-config.js

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2015 Hewlett-Packard Development Company, L.P.
+ *
+ * Licensed under the Apache License, Version 2.0 (the 'License'); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * This is a helper module used to load and export YAML-based ESLint config
+ */
+
+var yaml = require('js-yaml');
+var fs = require('fs');
+var path = require('path');
+
+module.exports = function(filename) {
+  'use strict';
+
+  var rcPath = path.join(__dirname, filename);
+  var fileContent = fs.readFileSync(rcPath); // eslint-disable-line no-sync
+  return yaml.safeLoad(fileContent);
+};

package.json

@@ -5,7 +5,10 @@
   "main": "index.js",
   "files": [
     "index.js",
+    "es2015.js",
+    "load-config.js",
     ".eslintrc",
+    ".eslintrc-es2015",
     "LICENSE",
     "README.md"
   ],