add a linter and use it

.eslintrc.js

@@ -0,0 +1,284 @@
+/*
+ * Copyright IBM Corp. 2015-2018
+ *
+ * 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.
+ */
+
+// Configuration for eslint.
+// See: https://eslint.org/docs/rules/
+
+module.exports = {
+    "env": {
+        "es6": true,
+        "node": true,
+        "mocha": true
+    },
+    "parserOptions": {
+        "ecmaVersion": 8
+    },
+    "plugins": [
+        "chai-friendly"
+    ],
+    "extends": "eslint:recommended",
+    "rules": {
+        "accessor-pairs": "error",
+        "array-bracket-newline": "error",
+        "array-bracket-spacing": "off",
+        "array-callback-return": "error",
+        "array-element-newline": "off",
+        "arrow-body-style": "error",
+        "arrow-parens": "off",
+        "arrow-spacing": [
+            "error",
+            {
+                "after": true,
+                "before": true
+            }
+        ],
+        "block-scoped-var": "error",
+        "block-spacing": "off",
+        "brace-style": [
+            "error",
+            "1tbs",
+            {
+                "allowSingleLine": true
+            }
+        ],
+        "callback-return": "error",
+        "camelcase": "off",
+        "capitalized-comments": "off",
+        "class-methods-use-this": "off",
+        "comma-dangle": "error",
+        "comma-spacing": "off",
+        "comma-style": [
+            "error",
+            "last"
+        ],
+        "complexity": "error",
+        "computed-property-spacing": [
+            "error",
+            "never"
+        ],
+        "consistent-return": "off",
+        "consistent-this": "error",
+        "curly": "off",
+        "default-case": "error",
+        "dot-location": [
+            "error",
+            "property"
+        ],
+        "dot-notation": [
+            "error",
+            {
+                "allowKeywords": true
+            }
+        ],
+        "eol-last": "off",
+        "eqeqeq": "off",
+        "for-direction": "error",
+        "func-call-spacing": "off",
+        "func-name-matching": "off",
+        "func-names": "off",
+        "func-style": "off",
+        "generator-star-spacing": "error",
+        "global-require": "off",
+        "guard-for-in": "error",
+        "handle-callback-err": "off",
+        "id-blacklist": "error",
+        "id-length": "off",
+        "id-match": "error",
+        "indent": ["error", 2],
+        "indent-legacy": "off",
+        "init-declarations": "off",
+        "jsx-quotes": "error",
+        "key-spacing": "off",
+        "keyword-spacing": "off",
+        "line-comment-position": "off",
+        "linebreak-style": "off",
+        "lines-around-comment": "off",
+        "lines-around-directive": "off",
+        "max-depth": "error",
+        "max-len": "off",
+        "max-lines": "off",
+        "max-nested-callbacks": "error",
+        "max-params": "error",
+        "max-statements": "off",
+        "max-statements-per-line": "off",
+        "multiline-ternary": [
+            "error",
+            "never"
+        ],
+        "new-parens": "error",
+        "newline-after-var": "off",
+        "newline-before-return": "off",
+        "newline-per-chained-call": "error",
+        "no-alert": "error",
+        "no-array-constructor": "error",
+        "no-await-in-loop": "error",
+        "no-bitwise": "error",
+        "no-buffer-constructor": "off",
+        "no-caller": "error",
+        "no-catch-shadow": "error",
+        "no-confusing-arrow": "error",
+        "no-continue": "off",
+        "no-console": "off",
+        "no-div-regex": "error",
+        "no-duplicate-imports": "error",
+        "no-else-return": "off",
+        "no-empty-function": "error",
+        "no-eq-null": "error",
+        "no-eval": "error",
+        "no-extend-native": "error",
+        "no-extra-bind": "error",
+        "no-extra-label": "error",
+        "no-extra-parens": "off",
+        "no-floating-decimal": "error",
+        "no-implicit-coercion": "error",
+        "no-implicit-globals": "off",
+        "no-implied-eval": "error",
+        "no-inline-comments": "off",
+        "no-inner-declarations": [
+            "error",
+            "functions"
+        ],
+        "no-invalid-this": "error",
+        "no-iterator": "error",
+        "no-label-var": "error",
+        "no-labels": "error",
+        "no-lone-blocks": "error",
+        "no-lonely-if": "off",
+        "no-loop-func": "error",
+        "no-magic-numbers": "off",
+        "no-mixed-operators": "error",
+        "no-mixed-requires": "error",
+        "no-multi-assign": "off",
+        "no-multi-spaces": "off",
+        "no-multi-str": "error",
+        "no-multiple-empty-lines": "error",
+        "no-native-reassign": "error",
+        "no-negated-condition": "off",
+        "no-negated-in-lhs": "error",
+        "no-nested-ternary": "error",
+        "no-new": "error",
+        "no-new-func": "error",
+        "no-new-object": "error",
+        "no-new-require": "error",
+        "no-new-wrappers": "error",
+        "no-octal-escape": "error",
+        "no-param-reassign": "off",
+        "no-path-concat": "error",
+        "no-plusplus": "off",
+        "no-process-env": "off",
+        "no-process-exit": "off",
+        "no-proto": "error",
+        "no-prototype-builtins": "off",
+        "no-restricted-globals": "error",
+        "no-restricted-imports": "error",
+        "no-restricted-modules": "error",
+        "no-restricted-properties": "error",
+        "no-restricted-syntax": "error",
+        "no-return-assign": "error",
+        "no-return-await": "error",
+        "no-script-url": "error",
+        "no-self-compare": "error",
+        "no-sequences": "error",
+        "no-shadow": "off",
+        "no-shadow-restricted-names": "error",
+        "no-spaced-func": "off",
+        "no-sync": "error",
+        "no-tabs": "error",
+        "no-template-curly-in-string": "error",
+        "no-ternary": "off",
+        "no-throw-literal": "error",
+        "no-trailing-spaces": "error",
+        "no-undef-init": "off",
+        "no-undefined": "off",
+        "no-underscore-dangle": "off",
+        "no-unmodified-loop-condition": "error",
+        "no-unneeded-ternary": "error",
+        "no-unused-expressions": "off",
+        "no-use-before-define": "off",
+        "no-useless-call": "error",
+        "no-useless-computed-key": "error",
+        "no-useless-concat": "error",
+        "no-useless-constructor": "error",
+        "no-useless-rename": "error",
+        "no-useless-return": "error",
+        "no-var": "error",
+        "no-void": "error",
+        "no-warning-comments": "off",
+        "no-whitespace-before-property": "error",
+        "no-with": "error",
+        "nonblock-statement-body-position": [
+            "error",
+            "any"
+        ],
+        "object-curly-newline": "off",
+        "object-curly-spacing": "off",
+        "object-property-newline": "off",
+        "object-shorthand": "off",
+        "one-var": "off",
+        "one-var-declaration-per-line": "error",
+        "operator-assignment": "error",
+        "operator-linebreak": "off",
+        "padded-blocks": "off",
+        "padding-line-between-statements": "error",
+        "prefer-arrow-callback": "off",
+        "prefer-const": "error",
+        "prefer-numeric-literals": "error",
+        "prefer-promise-reject-errors": "off",
+        "prefer-reflect": "off",
+        "prefer-rest-params": "off",
+        "prefer-spread": "error",
+        "prefer-template": "off",
+        "quote-props": "off",
+        "quotes": "off",
+        "radix": "error",
+        "require-await": "error",
+        "require-jsdoc": "off",
+        "rest-spread-spacing": "error",
+        "semi": "off",
+        "semi-spacing": "off",
+        "semi-style": [
+            "error",
+            "last"
+        ],
+        "sort-imports": "error",
+        "sort-keys": "off",
+        "sort-vars": "error",
+        "space-before-blocks": "off",
+        "space-before-function-paren": "off",
+        "space-in-parens": "off",
+        "space-infix-ops": "off",
+        "space-unary-ops": "off",
+        "spaced-comment": "off",
+        "strict": "off",
+        "switch-colon-spacing": "error",
+        "symbol-description": "error",
+        "template-curly-spacing": "error",
+        "template-tag-spacing": "error",
+        "unicode-bom": [
+            "error",
+            "never"
+        ],
+        "valid-jsdoc": "off",
+        "vars-on-top": "off",
+        "wrap-iife": "error",
+        "wrap-regex": "error",
+        "yield-star-spacing": "error",
+        "yoda": [
+            "error",
+            "never"
+        ]
+    }
+};

.travis.yml

@@ -1,11 +1,12 @@
 language: node_js
 node_js:
-- '5'
 - '6'
+- '8'
+- '10'
 script:
 - "npm install"
 - "curl $GP_FAKE_BROKER > local-credentials.json"
-- if [[ $TRAVIS_NODE_VERSION == '5' ]];
+- if [[ $TRAVIS_NODE_VERSION == '8' ]];
   then nyc npm test && nyc report --reporter=text-lcov | coveralls;
   else npm test;
   fi

index.js

@@ -1,5 +1,5 @@
-/*	
- * Copyright IBM Corp. 2015,2017
+/*
+ * Copyright IBM Corp. 2015,2018
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.