Use ESM

Author: wooorm

.gitignore

@@ -2,7 +2,6 @@
 *.d.ts
 *.log
 *.tgz
-.nyc_output/
 coverage/
 node_modules/
 yarn.lock

.prettierignore

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

build.js

@@ -1,13 +1,11 @@
-'use strict'
-
 // Based on:
 // <https://github.com/babel/babel/blob/main/packages/babel-helper-validator-identifier/scripts/generate-identifier-regex.js>
 
-var fs = require('fs')
-var path = require('path')
-var regenerate = require('regenerate')
-var idStart = require('@unicode/unicode-13.0.0/Binary_Property/ID_Start/code-points.js')
-var idCont = require('@unicode/unicode-13.0.0/Binary_Property/ID_Continue/code-points.js')
+import fs from 'fs'
+import path from 'path'
+import regenerate from 'regenerate'
+import idStart from '@unicode/unicode-13.0.0/Binary_Property/ID_Start/code-points.js'
+import idCont from '@unicode/unicode-13.0.0/Binary_Property/ID_Continue/code-points.js'
 
 var start = [36 /* `$` */, 95 /* `_` */].concat(idStart.filter((d) => bmp(d)))
 var cont = [0x200c, 0x200d].concat(idCont.filter((d) => bmp(d)))
@@ -19,8 +17,8 @@ fs.writeFileSync(
   path.join('regex.js'),
   [
     '// This module is generated by `build.js`.',
-    'exports.start = ' + startRe,
-    'exports.cont = ' + contRe,
+    'export var start = ' + startRe,
+    'export var cont = ' + contRe,
     ''
   ].join('\n')
 )

index.js

@@ -1,19 +1,13 @@
-'use strict'
-
-exports.start = start
-exports.cont = cont
-exports.name = name
-
-var id = require('./regex')
+import {start as startRe, cont as contRe} from './regex.js'
 
 /**
  * Checks if the given character code can start an identifier.
  *
  * @param {number} code
  */
 // To do: support astrals.
-function start(code) {
-  return id.start.test(String.fromCharCode(code))
+export function start(code) {
+  return startRe.test(String.fromCharCode(code))
 }
 
 /**
@@ -22,17 +16,17 @@ function start(code) {
  * @param {number} code
  */
 // To do: support astrals.
-function cont(code) {
+export function cont(code) {
   var character = String.fromCharCode(code)
-  return id.start.test(character) || id.cont.test(character)
+  return startRe.test(character) || contRe.test(character)
 }
 
 /**
  * Checks if the given string is a valid identifier name.
  *
  * @param {string} name
  */
-function name(name) {
+export function name(name) {
   var index = -1
 
   while (++index < name.length) {

package.json

@@ -22,14 +22,20 @@
   "contributors": [
     "Titus Wormer <[email protected]> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
+  "types": "index.d.ts",
   "files": [
+    "index.d.ts",
     "index.js",
-    "regex.js",
-    "*.d.ts"
+    "regex.d.ts",
+    "regex.js"
   ],
   "devDependencies": {
     "@types/tape": "^4.0.0",
     "@unicode/unicode-13.0.0": "^1.0.0",
+    "c8": "^7.6.0",
     "nyc": "^15.0.0",
     "prettier": "^2.0.0",
     "regenerate": "^1.0.0",
@@ -42,12 +48,12 @@
     "xo": "^0.38.0"
   },
   "scripts": {
+    "build": "rimraf \"*.d.ts\" && tsc && type-coverage",
     "generate": "node build",
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
-    "test-api": "node test",
-    "test-coverage": "nyc --reporter lcov tape test.js",
-    "build": "rimraf \"*.d.ts\" && tsc && type-coverage",
-    "test": "npm run generate && npm run format && npm run test-coverage && npm run build",
+    "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 generate && npm run build && npm run format && npm run test-coverage",
     "prepack": "npm run build && npm run format"
   },
   "prettier": {
@@ -60,21 +66,13 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
     "rules": {
+      "import/no-mutable-exports": "off",
       "no-misleading-character-class": "off",
-      "no-useless-escape": "off",
-      "unicorn/no-fn-reference-in-iterator": "off",
-      "unicorn/no-hex-escape": "off",
-      "unicorn/better-regex": "off"
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
     }
   },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
-  },
   "remarkConfig": {
     "plugins": [
       "preset-wooorm"

readme.md

@@ -9,6 +9,9 @@ Check if something can be an identifier name.
 
 ## Install
 
+This package is ESM only: Node 12+ is needed to use it and it must be `import`ed
+instead of `require`d.
+
 [npm][]:
 
 ```sh
@@ -18,27 +21,30 @@ npm install estree-util-is-identifier-name
 ## Use
 
 ```js
-var isIdentifierName = require('estree-util-is-identifier-name')
+import {name, start, cont} from 'estree-util-is-identifier-name'
 
-isIdentifierName.name('$something69') // => true
-isIdentifierName.name('69') // => false
-isIdentifierName.name('var') // => true (this does not handle keywords)
+name('$something69') // => true
+name('69') // => false
+name('var') // => true (this does not handle keywords)
 
-isIdentifierName.start(48) // => false (character code for `0`)
-isIdentifierName.cont(48) // => true (character code for `0`)
+start(48) // => false (character code for `0`)
+cont(48) // => true (character code for `0`)
 ```
 
 ## API
 
-### `isIdentifierName.name(value)`
+This package exports the following identifiers: `name`, `start`, and `cont`.
+There is no default export.
+
+### `name(value)`
 
 Checks if the given string is a valid identifier name.
 
-### `isIdentifierName.start(code)`
+### `start(code)`
 
 Checks if the given character code can start an identifier.
 
-### `isIdentifierName.cont(code)`
+### `cont(code)`
 
 Checks if the given character code can continue an identifier.