Use ESM

.gitignore

@@ -1,8 +1,5 @@
 .DS_Store
 *.log
-.nyc_output/
 coverage/
 node_modules/
-hast-util-to-parse5.js
-hast-util-to-parse5.min.js
 yarn.lock

.prettierignore

@@ -1,5 +1,2 @@
 coverage/
-hast-util-to-parse5.js
-hast-util-to-parse5.min.js
-*.json
 *.md

index.js

@@ -1,27 +1,14 @@
-'use strict'
-
-var xtend = require('xtend')
-var html = require('property-information/html')
-var svg = require('property-information/svg')
-var find = require('property-information/find')
-var toH = require('hast-to-hyperscript')
-var ns = require('web-namespaces')
-var zwitch = require('zwitch')
-
-module.exports = toParse5
-
-var one = zwitch('type', {
-  handlers: {
-    root: root,
-    element: element,
-    text: text,
-    comment: comment,
-    doctype: doctype
-  }
-})
+import {html, svg, find} from 'property-information'
+import {toH} from 'hast-to-hyperscript'
+import {webNamespaces} from 'web-namespaces'
+import {zwitch} from 'zwitch'
+
+var own = {}.hasOwnProperty
+
+var one = zwitch('type', {handlers: {root, element, text, comment, doctype}})
 
 // Transform a tree from hast to Parse5’s AST.
-function toParse5(tree, space) {
+export function toParse5(tree, space) {
   return one(tree, space === 'svg' ? svg : html)
 }
 
@@ -62,7 +49,7 @@ function comment(node, schema) {
 }
 
 function element(node, schema) {
-  return toH(h, xtend(node, {children: []}), {space: schema.space})
+  return toH(h, Object.assign({}, node, {children: []}), {space: schema.space})
 
   function h(name, attrs) {
     var values = []
@@ -73,9 +60,13 @@ function element(node, schema) {
     var p5
 
     for (key in attrs) {
+      if (!own.call(attrs, key) || attrs[key] === false) {
+        continue
+      }
+
       info = find(schema, key)
 
-      if (attrs[key] === false || (info.boolean && !attrs[key])) {
+      if (info.boolean && !attrs[key]) {
         continue
       }
 
@@ -91,7 +82,7 @@ function element(node, schema) {
           value.prefix = key.slice(0, index)
         }
 
-        value.namespace = ns[info.space]
+        value.namespace = webNamespaces[info.space]
       }
 
       values.push(value)
@@ -115,7 +106,7 @@ function patch(node, p5, parentSchema) {
 
   if (node.type === 'element') {
     if (schema.space === 'html' && node.tagName === 'svg') schema = svg
-    p5.namespaceURI = ns[schema.space]
+    p5.namespaceURI = webNamespaces[schema.space]
   }
 
   if (node.type === 'element' || node.type === 'root') {

package.json

@@ -24,36 +24,33 @@
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "dependencies": {
-    "hast-to-hyperscript": "^9.0.0",
-    "property-information": "^5.0.0",
-    "web-namespaces": "^1.0.0",
-    "xtend": "^4.0.0",
-    "zwitch": "^1.0.0"
+    "hast-to-hyperscript": "^10.0.0",
+    "property-information": "^6.0.0",
+    "web-namespaces": "^2.0.0",
+    "zwitch": "^2.0.0"
   },
   "devDependencies": {
-    "browserify": "^17.0.0",
+    "c8": "^7.0.0",
     "json-stringify-safe": "^5.0.0",
-    "nyc": "^15.0.0",
     "parse5": "^6.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "tinyify": "^3.0.0",
-    "xo": "^0.38.0"
+    "xo": "^0.39.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
-    "build-bundle": "browserify . -s hastUtilToParse5 -o hast-util-to-parse5.js",
-    "build-mangle": "browserify . -s hastUtilToParse5 -o hast-util-to-parse5.min.js -p tinyify",
-    "build": "npm run build-bundle && npm run build-mangle",
-    "test-api": "node test",
-    "test-coverage": "nyc --reporter lcov tape test",
-    "test": "npm run format && npm run build && npm run test-coverage"
+    "test-api": "node test/index.js",
+    "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test/index.js",
+    "test": "npm run format && npm run test-coverage"
   },
   "prettier": {
     "tabWidth": 2,
@@ -65,20 +62,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
     "rules": {
-      "unicorn/prefer-includes": "off",
-      "guard-for-in": "off"
-    },
-    "ignores": [
-      "hast-util-to-parse5.js"
-    ]
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    }
   },
   "remarkConfig": {
     "plugins": [

readme.md

@@ -15,6 +15,9 @@
 
 ## Install
 
+This package is [ESM only](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c):
+Node 12+ is needed to use it and it must be `import`ed instead of `require`d.
+
 [npm][]:
 
 ```sh
@@ -24,7 +27,7 @@ npm install hast-util-to-parse5
 ## Use
 
 ```js
-var toParse5 = require('hast-util-to-parse5')
+import {toParse5} from 'hast-util-to-parse5'
 
 var ast = toParse5({
   type: 'element',
@@ -48,6 +51,9 @@ Yields:
 
 ## API
 
+This package exports the following identifiers: `toParse5`.
+There is no default export.
+
 ### `toParse5(tree[, space])`
 
 Transform a [**hast**][hast] [*tree*][tree] to [Parse5’s AST][ast].

test/comment.js

@@ -1,8 +1,6 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {toParse5} from '../index.js'
 
 test('comment', function (t) {
   var actual = toParse5({type: 'comment', value: 'Alpha'})

test/doctype.js

@@ -1,8 +1,6 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {toParse5} from '../index.js'
 
 test('doctype', function (t) {
   t.test('should transform a doctype (legacy)', function (st) {

test/element.js

@@ -1,9 +1,7 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var json = require('./json')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {json} from './json.js'
+import {toParse5} from '../index.js'
 
 test('element', function (t) {
   t.test('should transform elements', function (st) {

test/index.js

@@ -2,12 +2,12 @@
 
 /* eslint-disable import/no-unassigned-import */
 
-require('./root')
-require('./doctype')
-require('./text')
-require('./comment')
-require('./element')
-require('./position')
-require('./svg')
+import './root.js'
+import './doctype.js'
+import './text.js'
+import './comment.js'
+import './element.js'
+import './position.js'
+import './svg.js'
 
 /* eslint-enable import/no-unassigned-import */

test/json.js

@@ -1,9 +1,5 @@
-'use strict'
+import stringify from 'json-stringify-safe'
 
-var stringify = require('json-stringify-safe')
-
-module.exports = json
-
-function json(value) {
+export function json(value) {
   return JSON.parse(stringify(value))
 }

test/position.js

@@ -1,9 +1,7 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var json = require('./json')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {json} from './json.js'
+import {toParse5} from '../index.js'
 
 test('position', function (t) {
   var actual = toParse5({

test/root.js

@@ -1,9 +1,7 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var json = require('./json')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {json} from './json.js'
+import {toParse5} from '../index.js'
 
 test('root', function (t) {
   t.test('should transform a root (quirks)', function (st) {

test/svg.js

@@ -1,9 +1,7 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var json = require('./json')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {json} from './json.js'
+import {toParse5} from '../index.js'
 
 test('svg', function (t) {
   t.test('should transform SVG in HTML', function (st) {

test/text.js

@@ -1,8 +1,6 @@
-'use strict'
-
-var test = require('tape')
-var parse5 = require('parse5')
-var toParse5 = require('..')
+import test from 'tape'
+import parse5 from 'parse5'
+import {toParse5} from '../index.js'
 
 test('text', function (t) {
   var expected = parse5.parseFragment('Alpha').childNodes[0]