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@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 install @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