Registry / auth-security / safe-regex-test

safe-regex-test

library1.1.0jsnpmunverified

safe-regex-test is a JavaScript utility designed to provide a robust and predictable method for testing regular expressions against strings. It addresses a specific security concern by safeguarding the regex testing mechanism from potential alterations or pollution of the global `RegExp.prototype` object, which can lead to unexpected behavior or vulnerabilities in less controlled environments. The current stable version is 1.1.0, last published over a year ago, indicating a mature project with a slow and deliberate release cadence, primarily focused on stability and specific bug fixes rather than frequent feature additions. Its key differentiator is this resilience against prototype tampering, offering a more secure alternative to direct `RegExp.prototype.test` usage, particularly in shared or potentially untrusted execution contexts.

auth-security testing

npm install safe-regex-test

github ↗package ↗

INSTALL

IMPORT

SIG · SAFE-REGEX-TEST

safe-regex-test

auth-securityjavascriptv1.1.0

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

safeRegexTest

✓ import safeRegexTest from 'safe-regex-test';

✗ import { safeRegexTest } from 'safe-regex-test';

The package exports a default function for ESM. Do not use named imports.

safeRegexTest

✓ const safeRegexTest = require('safe-regex-test');

✗ const { safeRegexTest } = require('safe-regex-test');

CommonJS imports the default function directly.

SafeRegexTester

✓ import type { SafeRegexTester } from 'safe-regex-test';

Type definition for the main exported function, useful for strict TypeScript usage.

Demonstrates how to import and use `safe-regex-test` to create a robust regex testing function, highlighting its core capability.

import safeRegexTest from 'safe-regex-test'; import assert from 'assert'; // Create a robust regex tester function const tester = safeRegexTest(/hello/i); // Test strings assert.ok(tester('Hello, world!')); assert.notOk(tester('Goodbye, world!')); // Demonstrate robustness against prototype pollution (conceptual, not runnable here without polluting global) // This library ensures that even if RegExp.prototype.test were modified, 'tester' would still behave correctly. // For example, if someone did: Object.defineProperty(RegExp.prototype, 'test', { value: () => true }); // The 'tester' function created by safe-regex-test would still use the original, unpolluted 'test' logic. const alwaysTrueTester = safeRegexTest(/any/); console.log('Testing with original regex:', alwaysTrueTester('any string'));

Debug

Known issues

gotchaThe 'safe' in 'safe-regex-test' refers to robustness against `RegExp.prototype` alterations, NOT protection against ReDoS (Regular expression Denial of Service) vulnerabilities. This package does not analyze regex patterns for catastrophic backtracking or exponential time complexity.

fix

For ReDoS protection, consider using a dedicated library like 'safe-regex' (a different package) or 'recheck'.

affects: >=1.0.0

gotchaDirectly passing a non-RegExp object or an invalid regex string to `safeRegexTest` will result in an error or unexpected behavior, as the underlying `RegExp` constructor will be invoked.

fix

Always ensure the input to `safeRegexTest` is a valid `RegExp` instance or a string that can be safely converted to one (e.g., `'a'` not `'(a+'`).

affects: >=1.0.0

deprecatedWhile CommonJS `require()` is still supported, new projects are encouraged to use ES Modules (`import`).

fix

Refactor imports from `const safeRegexTest = require('safe-regex-test');` to `import safeRegexTest from 'safe-regex-test';`

affects: <=1.1.0

Errors

Common errors & fixes

TypeError: (0, _safeRegexTest.default) is not a function

Incorrect ESM named import syntax for a default export.

fix

Change `import { safeRegexTest } from 'safe-regex-test';` to `import safeRegexTest from 'safe-regex-test';`

Error: Invalid regular expression: /(a+/): Unterminated character class

Attempting to create a regex tester with an invalid regular expression string.

fix

Ensure the input string passed to `safeRegexTest` represents a syntactically valid regular expression, e.g., `/^abc$/` or `'abc'`.

TypeError: Cannot read properties of undefined (reading 'test')

Attempting to call the returned tester function with `null` or `undefined` as a string, or binding it incorrectly.

fix

Ensure the string passed to the tester function is always a string. If using `bind`, ensure `this` context is appropriate or use an arrow function.

Upgrade

Version history

1.1.0latest on npm

Audit

Dependencies

call-boundrequiredInternal utility for robust function binding.

es-errorsrequiredProvides robust error constructors for various JavaScript error types.

is-regexrequiredDetermines if a value is a regular expression object.

Agent activity

14 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/ljharb/safe-regex-test ↗

packagehttps://www.npmjs.com/package/safe-regex-test ↗