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

@@ -1,9 +1,5 @@
-'use strict'
-
-module.exports = headingRank
-
 // Rank of a heading: H1 -> 1, H2 -> 2, etc.
-function headingRank(node) {
+export function headingRank(node) {
   var name =
     (node && node.type === 'element' && node.tagName.toLowerCase()) || ''
   var code =

package.json

@@ -25,22 +25,25 @@
   "contributors": [
     "Titus Wormer <[email protected]> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "devDependencies": {
-    "hastscript": "^6.0.0",
-    "nyc": "^15.0.0",
+    "c8": "^7.0.0",
+    "hastscript": "^7.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "xo": "^0.38.0"
+    "xo": "^0.39.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --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"
   },
   "prettier": {
@@ -53,13 +56,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+    "rules": {
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    }
   },
   "remarkConfig": {
     "plugins": [

readme.md

@@ -12,6 +12,9 @@
 
 ## 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
@@ -30,6 +33,9 @@ rank(h('h5', 'Alpha')) //=> 5
 
 ## API
 
+This package exports the following identifiers: `headingRank`.
+There is no default export.
+
 ### `headingRank(node)`
 
 Get the rank (`1` to `6`) of headings (`h1` to `h6`).

test.js

@@ -1,21 +1,19 @@
-'use strict'
+import test from 'tape'
+import {h} from 'hastscript'
+import {headingRank} from './index.js'
 
-var test = require('tape')
-var h = require('hastscript')
-var rank = require('.')
-
-test('rank', function (t) {
-  t.equal(rank(), null, 'should return null for non-nodes')
+test('headingRank', function (t) {
+  t.equal(headingRank(), null, 'should return null for non-nodes')
 
   t.equal(
-    rank({type: 'text', value: '!'}),
+    headingRank({type: 'text', value: '!'}),
     null,
     'should return null for non-elements'
   )
 
-  t.equal(rank(h('p', '!')), null, 'should return null for non-headings')
+  t.equal(headingRank(h('p', '!')), null, 'should return null for non-headings')
 
-  t.equal(rank(h('h5', '!')), 5, 'should return the rank of a heading')
+  t.equal(headingRank(h('h5', '!')), 5, 'should return the rank of a heading')
 
   t.end()
 })