Use ESM

core.js

@@ -1,11 +1,7 @@
-'use strict'
+import toText from 'hast-util-to-text'
+import visit from 'unist-util-visit'
 
-var toText = require('hast-util-to-text')
-var visit = require('unist-util-visit')
-
-module.exports = createPlugin
-
-function createPlugin(lowlight) {
+export function createPlugin(lowlight) {
   return function (options) {
     var settings = options || {}
     var name = 'hljs'
@@ -17,7 +13,7 @@ function createPlugin(lowlight) {
 
     if (settings.languages) {
       // eslint-disable-next-line guard-for-in
-      for (let name in settings.languages) {
+      for (const name in settings.languages) {
         lowlight.registerLanguage(name, settings.languages[name])
       }
     }

index.js

@@ -1,5 +1,4 @@
-'use strict'
-var lowlight = require('lowlight')
-var createPlugin = require('./core')
+import lowlight from 'lowlight'
+import {createPlugin} from './core.js'
 
-module.exports = createPlugin(lowlight)
+export default createPlugin(lowlight)

light.js

@@ -1,5 +1,4 @@
-'use strict'
-var lowlight = require('lowlight/lib/core')
-var createPlugin = require('./core')
+import lowlight from 'lowlight/lib/core.js'
+import {createPlugin} from './core.js'
 
-module.exports = createPlugin(lowlight)
+export default createPlugin(lowlight)

package.json

@@ -24,6 +24,9 @@
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "core.js",
     "index.js",
@@ -41,7 +44,7 @@
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "xo": "^0.37.0"
+    "xo": "^0.39.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
@@ -59,8 +62,9 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
     "rules": {
+      "no-var": "off",
+      "prefer-arrow-callback": "off",
       "unicorn/prefer-includes": "off"
     }
   },

test.js

@@ -1,12 +1,10 @@
-'use strict'
-
-var test = require('tape')
-var rehype = require('rehype')
-var highlight = require('.')
-var light = require('./light')
-var js = require('highlight.js/lib/languages/javascript')
-var as = require('highlight.js/lib/languages/applescript')
-var cp = require('highlight.js/lib/languages/cpp')
+import test from 'tape'
+import rehype from 'rehype'
+import highlight from './index.js'
+import light from './light.js'
+import js from 'highlight.js/lib/languages/javascript.js'
+import as from 'highlight.js/lib/languages/applescript.js'
+import cp from 'highlight.js/lib/languages/cpp.js'
 
 test('highlight()', function (t) {
   t.equal(
@@ -414,7 +412,7 @@ test('highlight()', function (t) {
       .data('settings', {fragment: true})
       .use(highlight, {
         languages: {
-          test: function () {
+          test() {
             return {
               aliases: ['test'],
               keywords: {keyword: 'test'}