libphonenumber-js/source/helpers/formatNationalNumberUsingFormat.js

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

import applyInternationalSeparatorStyle from './applyInternationalSeparatorStyle.js'

// This was originally set to $1 but there are some countries for which the
// first group is not used in the national pattern (e.g. Argentina) so the $1
// group does not match correctly. Therefore, we use `\d`, so that the first
// group actually used in the pattern will be matched.
export const FIRST_GROUP_PATTERN = /(\$\d)/

export default function formatNationalNumberUsingFormat(
	number,
	format,
	{
		useInternationalFormat,
		withNationalPrefix,
		carrierCode,
		metadata
	}
) {
	const formattedNumber = number.replace(
		new RegExp(format.pattern()),
		useInternationalFormat
			? format.internationalFormat()
			: (
				// This library doesn't use `domestic_carrier_code_formatting_rule`,
				// because that one is only used when formatting phone numbers
				// for dialing from a mobile phone, and this is not a dialing library.
				// carrierCode && format.domesticCarrierCodeFormattingRule()
				// 	// First, replace the $CC in the formatting rule with the desired carrier code.
				// 	// Then, replace the $FG in the formatting rule with the first group
				// 	// and the carrier code combined in the appropriate way.
				// 	? format.format().replace(FIRST_GROUP_PATTERN, format.domesticCarrierCodeFormattingRule().replace('$CC', carrierCode))
				// 	: (
				// 		withNationalPrefix && format.nationalPrefixFormattingRule()
				// 			? format.format().replace(FIRST_GROUP_PATTERN, format.nationalPrefixFormattingRule())
				// 			: format.format()
				// 	)
				withNationalPrefix && format.nationalPrefixFormattingRule()
					? format.format().replace(FIRST_GROUP_PATTERN, format.nationalPrefixFormattingRule())
					: format.format()
			)
	)
	if (useInternationalFormat) {
		return applyInternationalSeparatorStyle(formattedNumber)
	}
	return formattedNumber
}