valifmt

A lightweight utility library for validating and formatting:

• ✅ All major phone number formats (international-ready)
• ✅ All IBAN types from supported countries
• ✅ All common credit card types (Visa, MasterCard, Troy, AmEx, and more)
• ✅ Email addresses (RFC-compliant)

Works in any JavaScript or TypeScript environment — React Native, React, Next.js, Node.js, or plain TypeScript. No native dependencies.

🚀 Why use this library?

Unlike other libraries that handle only one input type — or require pulling in multiple large packages — valifmt provides:

• 🔹 Unified validation and formatting API
• 🔹 Minimal bundle size — much smaller than using validator.js + libphonenumber + iban + creditcard utils separately
• 🔹 Zero dependencies — works anywhere JS/TS runs

📦 Comparison

| Feature | valifmt | validator.js | libphonenumber-js | iban | | ----------------------- | --------------------------- | ------------ | ----------------- | ----- | | Phone number formatting | ✅ All formats | ❌ | ✅ | ❌ | | IBAN validation | ✅ All countries | ❌ | ❌ | ✅ | | Credit card types | ✅ Visa/Master/Troy/etc | ✅ (partial) | ❌ | ❌ | | Email validation | ✅ RFC-compliant | ✅ | ❌ | ❌ | | Bundle size | 🟢 Lightweight (3.73 kB) | ⚠️ Larger | ⚠️ Larger | Small | | All-in-one | ✅ Yes | ❌ | ❌ | ❌ |

✨ Features

• 📱 Phone Number:
  • Validate phone numbers by country code
  • Format for display using country-specific patterns (240+ countries)
• 💳 Credit Card:
  • Validate card numbers using the Luhn algorithm
  • Identify card type (Visa, MasterCard, AmericanExpress, Discover, JCB, Troy)
  • Format for display
• 🏦 IBAN:
  • Validate IBAN format using MOD-97 checksum (90+ countries)
  • Supports UBAN used in KKTC (starts with CT)
  • Format with customizable separator
• 📧 Email:
  • Validate email addresses (RFC-compliant, max 254 chars)

📦 Installation

npm install @yusefturin/valifmt
# or
yarn add @yusefturin/valifmt

📘 Usage

import {
  ValidatePhoneNumber,
  FormatPhoneNumber,
  ValidateIban,
  FormatIban,
  ValidateCreditCard,
  FormatCreditCard,
  ValidateEmail,
} from '@yusefturin/valifmt';

📱 Phone Number

// Validate — pass an object with phoneNumber and optional countryCode
ValidatePhoneNumber({ phoneNumber: '+90 552 222 22 22', countryCode: 'TR' }); // true
ValidatePhoneNumber({ phoneNumber: '+1 800 555 0199', countryCode: 'US' });   // true

// Format — same object shape, returns a formatted string
FormatPhoneNumber({ phoneNumber: '+905522222222', countryCode: 'TR' }); // '+90 552 222 22 22'
FormatPhoneNumber({ phoneNumber: '+18005550199', countryCode: 'US' });  // '+1 800 555 0199'

Note: countryCode is an ISO 3166-1 alpha-2 code (e.g. 'TR', 'US', 'GB'). It is optional but required for country-specific length validation and formatting.

🏦 IBAN

// Validate — pass the raw IBAN string
ValidateIban('TR330006100519786457841326'); // true
ValidateIban('DE89370400440532013000');     // true

// Format — pass an object with iban and an optional separator (default: ' ')
FormatIban({ iban: 'TR330006100519786457841326' });                    // 'TR33 0006 1005 1978 6457 8413 26'
FormatIban({ iban: 'DE89370400440532013000', separator: '-' });        // 'DE89-3704-0044-0532-0130-00'

Note: ValidateIban also supports UBAN used in KKTC (Turkish Republic of Northern Cyprus), which starts with CT.

💳 Credit Card

// Validate — returns { isValid: boolean, type: string | undefined }
ValidateCreditCard('4111111111111111');  // { isValid: true, type: 'Visa' }
ValidateCreditCard('5500005555555559');  // { isValid: true, type: 'MasterCard' }
ValidateCreditCard('378282246310005');   // { isValid: true, type: 'AmericanExpress' }
ValidateCreditCard('9792123456789012');  // { isValid: true, type: 'Troy' }

// Format — groups digits for display
FormatCreditCard('4111111111111111'); // '4111 1111 1111 1111'
FormatCreditCard('378282246310005');  // '3782 822463 10005'  (AmEx: 4-6-5 format)

Supported card types:

| Type | Pattern | | --------------- | ----------------------------------- | | Visa | Starts with 4 | | MasterCard | Starts with 51–55 | | AmericanExpress | Starts with 34 or 37 | | Discover | Starts with 6011 or 65 | | JCB | Starts with 2131, 1800, or 35 | | Troy | Starts with 9792 |

📧 Email

// Validate — returns boolean
ValidateEmail('[email protected]');  // true
ValidateEmail('invalid-email');     // false
ValidateEmail('[email protected]');             // true

🔤 Type Definitions

type PhoneNumberProps = {
  phoneNumber: string;
  countryCode?: string; // ISO 3166-1 alpha-2 (e.g. 'TR', 'US', 'GB')
};

type IbanFormatProp = {
  iban: string;
  separator?: string; // default: ' '
};

type CreditCardProp = string;
type IbanProp = string;
type EmailProp = string;

📄 License

MIT

🙌 Contributing

Contributions are welcome! Feel free to open issues or PRs for enhancements or regional validation formats.

🔍 Keywords

validation, formatter, credit-card, iban, phone-number, email, typescript, lightweight