@babel/helper-validator-identifier

@babel/helper-validator-identifier is a utility package for parsing JavaScript keywords and identifiers. It provides several helper functions for identifying valid identifier names and detecting reserved words and keywords.

Installation

npm

npm install @babel/helper-validator-identifier

Yarn

yarn add @babel/helper-validator-identifier

pnpm

pnpm add @babel/helper-validator-identifier

Usage

To use the package in your code, import the required functions from @babel/helper-validator-identifier:

my-babel-plugin.js

import {
  isIdentifierName,
  isIdentifierStart,
  isIdentifierChar,
  isReservedWord,
  isStrictBindOnlyReservedWord,
  isStrictBindReservedWord,
  isStrictReservedWord,
  isKeyword,
} from "@babel/helper-validator-identifier";

isIdentifierName

function isIdentifierName(name: string): boolean

The isIdentifierName function checks whether a given string can be a valid identifier name. Note that it doesn't handle unicode escape sequences. For example, isIdentifierName("\\u0061") returns false while \u0061 could be an JavaScript identifier name (a).

isIdentifierStart

function isIdentifierStart(codepoint: number): boolean

The isIdentifierStart function checks whether a given Unicode code point can start an identifier, as defined by the IdentifierStartChar.

isIdentifierChar

function isIdentifierChar(codepoint: number): boolean

The isIdentifierChar function checks whether a given Unicode code point can be part of an identifier, as defined by the IdentifierPartChar.

Keywords and Reserved words helpers

These helpers detect keyword and reserved words. For more information, see the implementation.

function isReservedWord(word: string, inModule: boolean): boolean
function isStrictReservedWord(word: string, inModule: boolean): boolean
function isStrictBindOnlyReservedWord(word: string): boolean
function isStrictBindReservedWord(word: string, inModule: boolean): boolean
function isKeyword(word: string): boolean