Use ESM

Author: wooorm

.gitignore

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

.prettierignore

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

index.js

@@ -1,15 +1,11 @@
-'use strict'
+import {headingRank} from 'hast-util-heading-rank'
+import {visit} from 'unist-util-visit'
 
-var headingRank = require('hast-util-heading-rank')
-var visit = require('unist-util-visit')
-
-module.exports = shiftHeading
-
-function shiftHeading(tree, shift) {
+export function shiftHeading(tree, shift) {
   if (
     typeof shift !== 'number' ||
     !shift ||
-    !isFinite(shift) ||
+    !Number.isFinite(shift) ||
     Math.floor(shift) !== shift
   ) {
     throw new Error('Expected a non-null finite integer, not `' + shift + '`')

package.json

@@ -27,32 +27,30 @@
   "contributors": [
     "Titus Wormer <[email protected]> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "dependencies": {
-    "hast-util-heading-rank": "^1.0.0",
-    "unist-util-visit": "^2.0.0"
+    "hast-util-heading-rank": "^2.0.0",
+    "unist-util-visit": "^3.0.0"
   },
   "devDependencies": {
-    "browserify": "^17.0.0",
-    "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",
-    "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 hastUtilShiftHeading -o hast-util-shift-heading.js",
-    "build-mangle": "browserify . -s hastUtilShiftHeading -o hast-util-shift-heading.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"
+    "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,
@@ -64,19 +62,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
     "rules": {
-      "unicorn/prefer-number-properties": "off"
-    },
-    "ignores": [
-      "hast-util-shift-heading.js"
-    ]
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+      "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
@@ -21,8 +24,8 @@ npm install hast-util-shift-heading
 ## Use
 
 ```js
-var h = require('hastscript')
-var shift = require('hast-util-shift-heading')
+import {h} from 'hastscript'
+import {shiftHeading} from 'hast-util-shift-heading'
 
 var tree = h('main', [
   h('h1', 'Alpha'),
@@ -34,7 +37,7 @@ var tree = h('main', [
   h('h6', 'Golf')
 ])
 
-shift(tree, -1)
+shiftHeading(tree, -1)
 
 console.log(tree)
 ```
@@ -78,6 +81,9 @@ Yields:
 
 ## API
 
+This package exports the following identifiers: `shiftHeading`.
+There is no default export.
+
 ### `shiftHeading(tree, shift)`
 
 Change the rank of all headings (`h1` to `h6`) in `tree`.

test.js

@@ -1,76 +1,77 @@
-'use strict'
-
-var test = require('tape')
-var h = require('hastscript')
-var shift = require('.')
+import test from 'tape'
+import {h} from 'hastscript'
+import {shiftHeading} from './index.js'
 
 test('shiftHeading', function (t) {
   t.throws(
     function () {
-      shift(h())
+      shiftHeading(h(''))
     },
     /^Error: Expected a non-null finite integer, not `undefined`$/,
     'should throw when not given a number'
   )
 
   t.throws(
     function () {
-      shift(h(), NaN)
+      shiftHeading(h(''), Number.NaN)
     },
     /^Error: Expected a non-null finite integer, not `NaN`$/,
     'should throw when given not a number'
   )
 
   t.throws(
     function () {
-      shift(h(), 0.1)
+      shiftHeading(h(''), 0.1)
     },
     /^Error: Expected a non-null finite integer, not `0.1`$/,
     'should throw when not given an integer'
   )
 
   t.throws(
     function () {
-      shift(h(), Infinity)
+      shiftHeading(h(''), Number.POSITIVE_INFINITY)
     },
     /^Error: Expected a non-null finite integer, not `Infinity`$/,
     'should throw when not given a finite number'
   )
 
   t.throws(
     function () {
-      shift(h(), 0)
+      shiftHeading(h(''), 0)
     },
     /^Error: Expected a non-null finite integer, not `0`$/,
     'should throw when not given a non-null number'
   )
 
   t.deepEqual(
-    shift(h('h1', 'Alpha'), 1),
+    shiftHeading(h('h1', 'Alpha'), 1),
     h('h2', 'Alpha'),
     'should shift nodes upwards'
   )
 
   t.deepEqual(
-    shift(h('h2', 'Bravo'), -1),
+    shiftHeading(h('h2', 'Bravo'), -1),
     h('h1', 'Bravo'),
     'should shift nodes downwards'
   )
 
   t.deepEqual(
-    shift(h('h2', 'Charlie'), -2),
+    shiftHeading(h('h2', 'Charlie'), -2),
     h('h1', 'Charlie'),
     'should not shift upwards past h1'
   )
 
   t.deepEqual(
-    shift(h('h5', 'Delta'), 2),
+    shiftHeading(h('h5', 'Delta'), 2),
     h('h6', 'Delta'),
     'should not shift downwards past h6'
   )
 
   t.deepEqual(
-    shift(h('main', [h('h1', 'Echo'), h('p', 'Foxtrot'), h('h5', 'Golf')]), 2),
+    shiftHeading(
+      h('main', [h('h1', 'Echo'), h('p', 'Foxtrot'), h('h5', 'Golf')]),
+      2
+    ),
     h('main', [h('h3', 'Echo'), h('p', 'Foxtrot'), h('h6', 'Golf')]),
     'should change a tree'
   )