README.md

RegExp.escape polyfill and ponyfill

Lightweight polyfill and ponyfill for the upcoming escape() static method of RegExp (proposal currently at Stage 3).

Currently passes all test262 tests except for cross-realm.js, which I'm ignoring for now.

Usage

Ponyfill (no global patching)

import { regExpEscape } from '@li/regexp-escape-polyfill'

const str = 'Hello, 🌍!$^.'

regExpEscape(str) // "\\x48ello\\x2c\\x20🌍\\x21\\$\\^\\."
new RegExp(regExpEscape(str)).test(str) // true

Polyfill (patches RegExp globally)

import '@li/regexp-escape-polyfill/global'

const str = 'Hello, 🌍!$^.'

RegExp.escape(str) // "\\x48ello\\x2c\\x20🌍\\x21\\$\\^\\."
new RegExp(RegExp.escape(str)).test(str) // true

Adding global TS support

import '@li/regexp-escape-polyfill/global'
import type { regExpEscape } from '@li/regexp-escape-polyfill/global'

declare global {
	interface RegExpConstructor {
		escape: typeof regExpEscape
	}
}

RegExp.escape("ok") // passes type checking

Benchmarks

Deno/1.46.0 x86_64-unknown-linux-gnu
Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz

Name	Time (avg)	Iter/s	Bundle size (minified + gzipped)	Details
lionel-rowe/regexp-escape-polyfill	1.222 µs	817,741.3	498 B	Modern JS/ESM only, with TS support; aims for full compatibility with the spec (verified via test262) but may differ on implementation details.
es-shims/RegExp.escape	10.808 µs	92,524.1	7.1 kB	Aims for ES3 compliance; written with CJS modules; more closely follows the implementation details of the algorithm in the spec.
zloirock/core-js	1.506 µs	663,652.8	5.29 kB	CoreJS implementation; ES5 (?) support including various other polyfills; written with CJS modules
denoland/std	574 ns	1,741,322.9	279 B	Written before the proposal reached Stage 3; written in TS/ESM; doesn't aim for spec compliance, but fulfills the same function.