Use ESM

Author: wooorm

.gitignore

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

.prettierignore

@@ -1,5 +1,2 @@
 coverage/
-unist-util-size.js
-unist-util-size.min.js
-*.json
 *.md

index.js

@@ -1,10 +1,6 @@
-'use strict'
+import {convert} from 'unist-util-is'
 
-var convert = require('unist-util-is/convert')
-
-module.exports = size
-
-function size(node, test) {
+export function size(node, test) {
   var is = convert(test)
   return fastSize(node)
 
@@ -13,7 +9,7 @@ function size(node, test) {
     var count = 0
     var index = -1
 
-    if (children && children.length) {
+    if (children && children.length > 0) {
       while (++index < children.length) {
         if (is(children[index], index, node)) count++
         count += fastSize(children[index])

package.json

@@ -22,37 +22,29 @@
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "dependencies": {
-    "unist-util-is": "^4.0.0"
+    "unist-util-is": "^5.0.0"
   },
   "devDependencies": {
-    "browserify": "^17.0.0",
+    "c8": "^7.0.0",
     "hastscript": "^6.0.0",
-    "nyc": "^15.0.0",
     "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"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
-    "build-bundle": "browserify . -s unistUtilSize -o unist-util-size.js",
-    "build-mangle": "browserify . -s unistUtilSize -o unist-util-size.min.js -p tinyify",
-    "build": "npm run build-bundle && npm run build-mangle",
-    "test-api": "node test",
-    "test-coverage": "nyc --reporter lcov tape test.js",
-    "test": "npm run format && npm run build && npm run test-coverage"
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+    "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": {
     "tabWidth": 2,
@@ -64,12 +56,9 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
-    "ignores": [
-      "unist-util-size.js"
-    ],
     "rules": {
-      "unicorn/explicit-length-check": "off"
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
     }
   },
   "remarkConfig": {

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
@@ -21,8 +24,8 @@ npm install unist-util-size
 ## Use
 
 ```js
-var h = require('hastscript')
-var size = require('unist-util-size')
+import {h} from 'hastscript'
+import {size} from 'unist-util-size'
 
 var tree = h('div', [
   h('p', [
@@ -41,6 +44,9 @@ console.log(size(tree, 'element')) // => 5
 
 ## API
 
+This package exports the following identifiers: `size`.
+There is no default export.
+
 ### `size(tree[, test])`
 
 Calculate the number of nodes in [`tree`][node].

test.js

@@ -1,8 +1,6 @@
-'use strict'
-
-var test = require('tape')
-var h = require('hastscript')
-var size = require('.')
+import test from 'tape'
+import h from 'hastscript'
+import {size} from './index.js'
 
 test('unist-util-size', function (t) {
   var tree = h('div', [