is-pw-match

Password Match Percentage Library

A lightweight utility to calculate the similarity percentage between two strings (like passwords) with support for both Node.js and React environments.

Features:

• Calculate percentage match between any two strings
• Optional React component for UI integration
• Works in Node.js, browsers, and React apps
• Configurable options (case sensitivity, minimum length)
• Based on Levenshtein distance algorithm
• Zero dependencies

Installation:

npm install password-match-percent
# or
yarn add password-match-percent

Basic Usage:

In Node.js/Express:

const similarity = matchPercent('password123', 'Password123!');
console.log(`Match: ${similarity}%`);

In React:

function PasswordMatch({ password, confirmPassword }) {
const percent = matchPercent(password, confirmPassword);
return <div>Password match: {percent}%</div>;
}

Using the React Component:

import PasswordMatcher from 'password-match-percent/react';
function PasswordForm() {
const [pass1, setPass1] = useState('');
const [pass2, setPass2] = useState('');
return (

<div>
<input type="password" value={pass1} onChange={(e) => setPass1(e.target.value)} />
<input type="password" value={pass2} onChange={(e) => setPass2(e.target.value)} />
<PasswordMatcher str1={pass1} str2={pass2} as="div" />
</div>
);
}

API Reference:

matchPercent(str1, str2, [options])

Calculates the percentage match between two strings.

Parameters:

• str1 (string): First string to compare
• str2 (string): Second string to compare
• options (object, optional):
  • caseSensitive (boolean): Default false
  • minLength (number): Minimum length to consider (default 0)

Returns: Number between 0-100 representing match percentage

React Component: PasswordMatcher Props:

• str1 (string): First string
• str2 (string): Second string
• options (object): Same as matchPercent options
• as (React.ElementType): Component to render (default 'div')
• children (function): Render prop (percent) => ReactNode

Advanced Usage:

With Custom Thresholds:

const percent = matchPercent(userInput, storedPassword);
if (percent > 90) {
console.log('Almost identical');
} else if (percent > 70) {
console.log('Close match');
} else {
console.log('Not similar');
}

With Minimum Length Requirement:

const percent = matchPercent(pw1, pw2, { minLength: 8 });

Case Sensitive Comparison:

const percent = matchPercent(str1, str2, { caseSensitive: true });