Use ESM

Author: wooorm

.gitignore

@@ -1,6 +1,5 @@
 .DS_Store
 *.log
-.nyc_output/
 coverage/
 node_modules/
 yarn.lock

.prettierignore

@@ -1,3 +1,2 @@
 coverage/
-*.json
 *.md

index.js

@@ -1,19 +1,11 @@
-module.exports = toString
-
-function toString(node) {
+export function toString(node) {
   // A root or an element
-  if ('children' in node) {
-    return all(node)
-  }
-
+  if ('children' in node) return all(node)
   return 'value' in node ? node.value : ''
 }
 
 function one(node) {
-  if (node.type === 'text') {
-    return node.value
-  }
-
+  if (node.type === 'text') return node.value
   // Ignore things like comments, instruction, cdata.
   return node.children ? all(node) : ''
 }

package.json

@@ -24,30 +24,27 @@
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "devDependencies": {
-    "nyc": "^15.0.0",
+    "c8": "^7.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "unist-builder": "^2.0.0",
-    "xo": "^0.38.0"
+    "unist-builder": "^3.0.0",
+    "xo": "^0.39.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . --write --loglevel warn && xo --fix",
-    "test-api": "node test",
-    "test-coverage": "nyc --reporter lcov tape test.js",
+    "test-api": "node test.js",
+    "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test.js",
     "test": "npm run format && npm run test-coverage"
   },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
-  },
   "prettier": {
     "tabWidth": 2,
     "useTabs": false,
@@ -58,7 +55,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false
+    "rules": {
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    }
   },
   "remarkConfig": {
     "plugins": [

readme.md

@@ -15,6 +15,9 @@ The resulting text is returned.
 
 ## 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
@@ -24,8 +27,8 @@ npm install xast-util-to-string
 ## Use
 
 ```js
-var x = require('xastscript')
-var toString = require('xast-util-to-string')
+import {x} from 'xastscript'
+import {toString} from 'xast-util-to-string'
 
 var tree = x(
   'ncx',
@@ -50,6 +53,9 @@ A Christmas CarolCharles Dickens
 
 ## API
 
+This package exports the following identifiers: `toString`.
+There is no default export.
+
 ### `toString(node)`
 
 Utility to get the plain text value of a [*node*][node].

test.js

@@ -1,8 +1,6 @@
-'use strict'
-
-var test = require('tape')
-var u = require('unist-builder')
-var toString = require('.')
+import test from 'tape'
+import {u} from 'unist-builder'
+import {toString} from './index.js'
 
 test('xast-util-to-string', function (t) {
   t.deepEqual(