Update to es6+.

Remove support for node 8.

Update dependencies.

Update eslint config.

.eslintrc.json

@@ -6,6 +6,18 @@
   },
   "globals": {},
   "extends": "eslint:recommended",
+
+  // Stop ESLint from looking for a configuration file in parent folders
+  "root": true,
+
+  "parser": "babel-eslint",
+  "parserOptions": {
+    "ecmaVersion": 8,
+    "sourceType": "script",
+    "ecmaFeatures": {
+      "experimentalObjectRestSpread": true
+    }
+  },
   "rules": {
     "block-scoped-var": 2,
     "complexity": [
@@ -43,11 +55,6 @@
       "never"
     ],
 
-    "strict": [
-      2,
-      "global"
-    ],
-
     "no-shadow": 2,
     "no-use-before-define": 2,
 
@@ -125,9 +132,10 @@
     ],
     "new-cap": 2,
     "new-parens": 2,
-    "newline-after-var": [
-      1,
-      "always"
+    "padding-line-between-statements": [
+        "error",
+        { "blankLine": "always", "prev": ["const", "let", "var"], "next": "*"},
+        { "blankLine": "any",    "prev": ["const", "let", "var"], "next": ["const", "let", "var"]}
     ],
     "no-array-constructor": 2,
     "no-bitwise": 1,
@@ -141,7 +149,6 @@
       1,
       "always"
     ],
-    "one-var": 1,
     "operator-assignment": [
       1,
       "always"

.travis.yml

@@ -2,7 +2,6 @@ language: node_js
 node_js:
   - '12'
   - '10'
-  - '8'
 before_script:
   - npm install -g gulp
   - gulp lint

gulpfile.js

@@ -1,26 +1,21 @@
 /* eslint-disable */
-'use strict';
+const gulp = require('gulp');
+const mocha = require('gulp-mocha');
+const eslint = require('gulp-eslint');
 
-var gulp = require('gulp'),
-    mocha = require('gulp-mocha'),
-    eslint = require('gulp-eslint'),
-    paths = {
-        scripts: ['./*.js', './lib/*.js', '!./gulpfile.js']
-    };
+const paths = {
+    scripts: ['./*.js', './lib/*.js', '!./gulpfile.js']
+};
 
-gulp.task('lint', function () {
-    return gulp.src(paths.scripts)
-        .pipe(eslint())
-        .pipe(eslint.format())
-        .pipe(eslint.failAfterError());
-});
+gulp.task('lint', () => gulp.src(paths.scripts)
+    .pipe(eslint({fix: true}))
+    .pipe(eslint.format())
+    .pipe(eslint.failAfterError()));
 
-gulp.task('test', function () {
-    return gulp.src('./test/*.js')
-        .pipe(mocha({ reporter: 'spec' }));
-});
+gulp.task('test', () => gulp.src('./test/*.js')
+    .pipe(mocha({ reporter: 'spec' })));
 
-gulp.task('watch', function () {
+gulp.task('watch', () => {
     gulp.watch(paths.scripts, gulp.parallel('lint', 'test'));
 });
 

index.js

@@ -1,38 +1,34 @@
-'use strict';
+const extend = require('extend');
+const inlineContent = require('./lib/inlineContent');
 
-var extend = require('extend'),
-    inlineContent = require('./lib/inlineContent');
+module.exports = (html, options) => new Promise((resolve, reject) => {
+    const opt = extend(true, {
+        extraCss: '',
+        applyStyleTags: true,
+        removeStyleTags: true,
+        applyLinkTags: true,
+        removeLinkTags: true,
+        preserveMediaQueries: false,
+        removeHtmlSelectors: false,
+        applyWidthAttributes: false,
+        applyTableAttributes: false,
+        codeBlocks: {
+            EJS: { start: '<%', end: '%>' },
+            HBS: { start: '{{', end: '}}' }
+        },
+        xmlMode: false,
+        decodeEntities: false,
+        lowerCaseTags: true,
+        lowerCaseAttributeNames: false,
+        recognizeCDATA: false,
+        recognizeSelfClosing: false
+    }, options);
 
-module.exports = function (html, options) {
-    return new Promise(function (resolve, reject) {
-        var opt = extend(true, {
-            extraCss: '',
-            applyStyleTags: true,
-            removeStyleTags: true,
-            applyLinkTags: true,
-            removeLinkTags: true,
-            preserveMediaQueries: false,
-            removeHtmlSelectors: false,
-            applyWidthAttributes: false,
-            applyTableAttributes: false,
-            codeBlocks: {
-                EJS: { start: '<%', end: '%>' },
-                HBS: { start: '{{', end: '}}' }
-            },
-            xmlMode: false,
-            decodeEntities: false,
-            lowerCaseTags: true,
-            lowerCaseAttributeNames: false,
-            recognizeCDATA: false,
-            recognizeSelfClosing: false
-        }, options);
-
-        inlineContent(String(html), opt)
-            .then(function (data) {
-                resolve(data);
-            })
-            .catch(function (err) {
-                reject(err);
-            });
-    });
-};
+    inlineContent(String(html), opt)
+        .then(data => {
+            resolve(data);
+        })
+        .catch(err => {
+            reject(err);
+        });
+});

lib/addProps.js

@@ -1,38 +1,36 @@
-'use strict';
-
-var cssSelector = require('./styleSelector'),
-    importantSelector = cssSelector('<!important>', [ 2, 0, 0, 0 ]),
-    property = require('./cssProperty');
+const cssSelector = require('./styleSelector');
+const importantSelector = cssSelector('<!important>', [ 2, 0, 0, 0 ]);
+const property = require('./cssProperty');
 
 function getProperty(style, name, selector) {
-    var value = style[name],
-        sel = style._importants[name] ? importantSelector : selector;
+    const value = style[name];
+    const sel = style._importants[name] ? importantSelector : selector;
 
     return property(name, value, sel);
 }
 
 // go through the properties
-module.exports = function (el, style, selector) {
-    var i,
-        l = style.length,
-        name,
-        prop,
-        existing,
-        winner;
+module.exports = ({ styleProps }, style, selector) => {
+    let i;
+    const l = style.length;
+    let name;
+    let prop;
+    let existing;
+    let winner;
 
     for (i = 0; i < l; i++) {
         name = style[i];
         prop = getProperty(style, name, selector);
-        existing = el.styleProps[name];
+        existing = styleProps[name];
 
         if (existing) {
             winner = existing.compare(prop);
 
             if (winner === prop) {
-                el.styleProps[name] = prop;
+                styleProps[name] = prop;
             }
         } else {
-            el.styleProps[name] = prop;
+            styleProps[name] = prop;
         }
     }
 };

lib/cssProperty.js

@@ -1,5 +1,3 @@
-'use strict';
-
 /**
  * Compares two specificity vectors, returning the winning one.
  *
@@ -10,7 +8,7 @@
  */
 
 function compareSpecificity(a, b) {
-    var i;
+    let i;
 
     for (i = 0; i < 4; i++) {
         if (a[i] === b[i]) {
@@ -34,31 +32,31 @@ function compareSpecificity(a, b) {
  * @api public
  */
 
-module.exports = function (prop, value, selector) {
-    var o = {},
+module.exports = (prop, value, selector) => {
+    let o = {};
 
-        /**
-         * Compares with another Property based on Selector#specificity.
-         *
-         * @api public
-         */
+    /**
+     * Compares with another Property based on Selector#specificity.
+     *
+     * @api public
+     */
 
-        compare = function (property) {
-            var a = selector.specificity(),
-                b = property.selector.specificity(),
-                winner = compareSpecificity(a, b);
+    const compare = property => {
+        const a = selector.specificity();
+        const b = property.selector.specificity();
+        const winner = compareSpecificity(a, b);
 
-            if (winner === a && a !== b) {
-                return o;
-            }
-            return property;
-        };
+        if (winner === a && a !== b) {
+            return o;
+        }
+        return property;
+    };
 
     o = {
-        prop: prop,
-        value: value,
-        selector: selector,
-        compare: compare
+        prop,
+        value,
+        selector,
+        compare
     };
 
     return o;

lib/handleRule.js

@@ -1,25 +1,23 @@
-'use strict';
+const cssSelector = require('./styleSelector');
+const parseCSS = require('css-rules');
+const styleSelector = cssSelector('<style attribute>', [ 1, 0, 0, 0 ]);
+const addProps = require('./addProps');
 
-var cssSelector = require('./styleSelector'),
-    parseCSS = require('css-rules'),
-    styleSelector = cssSelector('<style attribute>', [ 1, 0, 0, 0 ]),
-    addProps = require('./addProps');
+module.exports = (rule, $) => {
+    const sel = rule[0];
+    const style = rule[1];
+    const selector = cssSelector(sel);
+    const editedElements = [];
 
-module.exports = function (rule, $) {
-    var sel = rule[0],
-        style = rule[1],
-        selector = cssSelector(sel),
-        editedElements = [];
-
-    $(sel).each(function (index, el) {
-        var cssText;
+    $(sel).each((index, el) => {
+        let cssText;
 
         if (!el.styleProps) {
             el.styleProps = {};
 
             // if the element has inline styles, fake selector with topmost specificity
             if ($(el).attr('style')) {
-                cssText = '* { ' + $(el).attr('style') + ' } ';
+                cssText = `* { ${$(el).attr('style')} } `;
 
                 addProps(el, parseCSS(cssText)[0][1], styleSelector);
             }