libphonenumber-js/source/legacy/isValidNumberForRegion.js

A simpler (and smaller) rewrite of Google Android's libphonenumber library in javascript

import isViablePhoneNumber from '../helpers/isViablePhoneNumber.js'
import parseNumber from '../parse.js'
import _isValidNumberForRegion from './isValidNumberForRegion_.js'

// This function has been deprecated and is not exported as
// `isValidPhoneNumberForCountry()` or `isValidPhoneNumberForRegion()`.
//
// The rationale is:
//
// * We don't use the "region" word, so "country" would be better.
//
// * It could be substituted with:
//
// ```js
// export default function isValidPhoneNumberForCountry(phoneNumberString, country) {
// 	const phoneNumber = parsePhoneNumber(phoneNumberString, {
// 		defaultCountry: country,
// 		// Demand that the entire input string must be a phone number.
// 		// Otherwise, it would "extract" a phone number from an input string.
// 		extract: false
// 	})
// 	if (!phoneNumber) {
// 		return false
// 	}
// 	if (phoneNumber.country !== country) {
// 		return false
// 	}
// 	return phoneNumber.isValid()
// }
// ```
//
// * Same function could be used for `isPossiblePhoneNumberForCountry()`
//   by replacing `isValid()` with `isPossible()`.
//
// * The reason why this function is not exported is because its result is ambiguous.
//   Suppose `false` is returned. It could mean any of:
//   * Not a phone number.
//   * The phone number is valid but belongs to another country or another calling code.
//   * The phone number belongs to the correct country but is not valid digit-wise.
//   All those three cases should be handled separately from a "User Experience" standpoint.
//   Simply showing "Invalid phone number" error in all of those cases would be lazy UX.

export default function isValidNumberForRegion(number, country, metadata) {
	if (typeof number !== 'string') {
		throw new TypeError('number must be a string')
	}
	if (typeof country !== 'string') {
		throw new TypeError('country must be a string')
	}
	// `parse` extracts phone numbers from raw text,
	// therefore it will cut off all "garbage" characters,
	// while this `validate` function needs to verify
	// that the phone number contains no "garbage"
	// therefore the explicit `isViablePhoneNumber` check.
	let input
	if (isViablePhoneNumber(number)) {
		input = parseNumber(number, { defaultCountry: country }, metadata)
	} else {
		input = {}
	}
	return _isValidNumberForRegion(input, country, undefined, metadata)
}