Use ESM

Author: wooorm

.gitignore

@@ -1,8 +1,5 @@
 .DS_Store
 *.log
-.nyc_output/
 coverage/
 node_modules/
-nlcst-is-literal.js
-nlcst-is-literal.min.js
 yarn.lock

.prettierignore

@@ -1,5 +1,2 @@
 coverage/
-nlcst-is-literal.js
-nlcst-is-literal.min.js
-*.json
 *.md

index.js

@@ -1,8 +1,4 @@
-'use strict'
-
-var toString = require('nlcst-to-string')
-
-module.exports = isLiteral
+import {toString} from 'nlcst-to-string'
 
 var single = [
   '-', // Hyphen-minus
@@ -39,16 +35,11 @@ var pairs = {
   '「': ['」']
 }
 
-var open = []
-var key
-
-for (key in pairs) {
-  open.push(key)
-}
+var open = Object.keys(pairs)
 
 // Check if the node in `parent` at `position` is enclosed by matching
 // delimiters.
-function isLiteral(parent, index) {
+export function isLiteral(parent, index) {
   if (!(parent && parent.children)) {
     throw new Error('Parent must be a node')
   }
@@ -61,8 +52,8 @@ function isLiteral(parent, index) {
     }
   }
 
-  if (isNaN(index)) {
-    throw new Error('Index must be a number')
+  if (typeof index !== 'number' || Number.isNaN(index)) {
+    throw new TypeError('Index must be a number')
   }
 
   return Boolean(
@@ -98,7 +89,7 @@ function siblingDelimiter(parent, position, step, delimiters) {
     }
 
     if (sibling.type !== 'WhiteSpaceNode') {
-      return delimiters.indexOf(toString(sibling)) > -1 && sibling
+      return delimiters.includes(toString(sibling)) && sibling
     }
 
     index += step

package.json

@@ -22,38 +22,30 @@
   "contributors": [
     "Titus Wormer <[email protected]> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "dependencies": {
-    "nlcst-to-string": "^2.0.0"
+    "nlcst-to-string": "^3.0.0"
   },
   "devDependencies": {
-    "browserify": "^17.0.0",
-    "nyc": "^15.0.0",
+    "c8": "^7.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "retext": "^7.0.0",
     "tape": "^5.0.0",
-    "tinyify": "^3.0.0",
-    "unist-util-visit": "^2.0.0",
-    "xo": "^0.38.0"
+    "unist-util-visit": "^3.0.0",
+    "xo": "^0.39.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
-    "build-bundle": "browserify . -s nlcstIsLiteral -o nlcst-is-literal.js",
-    "build-mangle": "browserify . -s nlcstIsLiteral -o nlcst-is-literal.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,
@@ -65,16 +57,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
     "rules": {
-      "guard-for-in": "off",
-      "unicorn/prefer-includes": "off",
-      "unicorn/prefer-number-properties": "off",
-      "unicorn/prefer-type-error": "off"
-    },
-    "ignore": [
-      "nlcst-is-literal.js"
-    ]
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    }
   },
   "remarkConfig": {
     "plugins": [

readme.md

@@ -16,6 +16,9 @@ about “monsieur”.
 
 ## 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
@@ -41,12 +44,12 @@ The word — quux — is meant as a literal.
 And our script, `example.js`, looks as follows:
 
 ```js
-var vfile = require('to-vfile')
-var unified = require('unified')
-var english = require('retext-english')
-var visit = require('unist-util-visit')
-var toString = require('nlcst-to-string')
-var literal = require('nlcst-is-literal')
+import vfile from 'to-vfile'
+import unified from 'unified'
+import english from 'retext-english'
+import {visit} from 'unist-util-visit'
+import {toString} from 'nlcst-to-string'
+import {isLiteral} from 'nlcst-is-literal'
 
 var file = vfile.readSync('example.txt')
 
@@ -57,7 +60,7 @@ var tree = unified()
 visit(tree, 'WordNode', visitor)
 
 function visitor(node, index, parent) {
-  if (literal(parent, index)) {
+  if (isLiteral(parent, index)) {
     console.log(toString(node))
   }
 }
@@ -75,6 +78,9 @@ quux
 
 ## API
 
+This package exports the following identifiers: `isLiteral`.
+There is no default export.
+
 ### `isLiteral(parent, index|child)`
 
 Check if the `child` in `parent` is enclosed by matching delimiters.

test.js

@@ -1,10 +1,8 @@
-'use strict'
-
-var assert = require('assert')
-var test = require('tape')
-var visit = require('unist-util-visit')
-var retext = require('retext')
-var isLiteral = require('.')
+import assert from 'assert'
+import test from 'tape'
+import retext from 'retext'
+import {visit} from 'unist-util-visit'
+import {isLiteral} from './index.js'
 
 test('isLiteral()', function (t) {
   t.throws(