libphonenumber-js/es6/helpers/extractNationalNumber.js

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

import extractNationalNumberFromPossiblyIncompleteNumber from './extractNationalNumberFromPossiblyIncompleteNumber.js';
import matchesEntirely from './matchesEntirely.js';
import checkNumberLength from './checkNumberLength.js';
/**
 * Strips national prefix and carrier code from a complete phone number.
 * The difference from the non-"FromCompleteNumber" function is that
 * it won't extract national prefix if the resultant number is too short
 * to be a complete number for the selected phone numbering plan.
 * @param  {string} number — Complete phone number digits.
 * @param  {Metadata} metadata — Metadata with a phone numbering plan selected.
 * @return {object} `{ nationalNumber: string, carrierCode: string? }`.
 */

export default function extractNationalNumber(number, metadata) {
  // Parsing national prefixes and carrier codes
  // is only required for local phone numbers
  // but some people don't understand that
  // and sometimes write international phone numbers
  // with national prefixes (or maybe even carrier codes).
  // http://ucken.blogspot.ru/2016/03/trunk-prefixes-in-skype4b.html
  // Google's original library forgives such mistakes
  // and so does this library, because it has been requested:
  // https://github.com/catamphetamine/libphonenumber-js/issues/127
  var _extractNationalNumbe = extractNationalNumberFromPossiblyIncompleteNumber(number, metadata),
      carrierCode = _extractNationalNumbe.carrierCode,
      nationalNumber = _extractNationalNumbe.nationalNumber;

  if (nationalNumber !== number) {
    if (!shouldHaveExtractedNationalPrefix(number, nationalNumber, metadata)) {
      // Don't strip the national prefix.
      return {
        nationalNumber: number
      };
    } // Check the national (significant) number length after extracting national prefix and carrier code.
    // Legacy generated metadata (before `1.0.18`) didn't support the "possible lengths" feature.


    if (metadata.possibleLengths()) {
      // The number remaining after stripping the national prefix and carrier code
      // should be long enough to have a possible length for the country.
      // Otherwise, don't strip the national prefix and carrier code,
      // since the original number could be a valid number.
      // This check has been copy-pasted "as is" from Google's original library:
      // https://github.com/google/libphonenumber/blob/876268eb1ad6cdc1b7b5bef17fc5e43052702d57/java/libphonenumber/src/com/google/i18n/phonenumbers/PhoneNumberUtil.java#L3236-L3250
      // It doesn't check for the "possibility" of the original `number`.
      // I guess it's fine not checking that one. It works as is anyway.
      if (!isPossibleIncompleteNationalNumber(nationalNumber, metadata)) {
        // Don't strip the national prefix.
        return {
          nationalNumber: number
        };
      }
    }
  }

  return {
    nationalNumber: nationalNumber,
    carrierCode: carrierCode
  };
} // In some countries, the same digit could be a national prefix
// or a leading digit of a valid phone number.
// For example, in Russia, national prefix is `8`,
// and also `800 555 35 35` is a valid number
// in which `8` is not a national prefix, but the first digit
// of a national (significant) number.
// Same's with Belarus:
// `82004910060` is a valid national (significant) number,
// but `2004910060` is not.
// To support such cases (to prevent the code from always stripping
// national prefix), a condition is imposed: a national prefix
// is not extracted when the original number is "viable" and the
// resultant number is not, a "viable" national number being the one
// that matches `national_number_pattern`.

function shouldHaveExtractedNationalPrefix(nationalNumberBefore, nationalNumberAfter, metadata) {
  // The equivalent in Google's code is:
  // https://github.com/google/libphonenumber/blob/e326fa1fc4283bb05eb35cb3c15c18f98a31af33/java/libphonenumber/src/com/google/i18n/phonenumbers/PhoneNumberUtil.java#L2969-L3004
  if (matchesEntirely(nationalNumberBefore, metadata.nationalNumberPattern()) && !matchesEntirely(nationalNumberAfter, metadata.nationalNumberPattern())) {
    return false;
  } // This "is possible" national number (length) check has been commented out
  // because it's superceded by the (effectively) same check done in the
  // `extractNationalNumber()` function after it calls `shouldHaveExtractedNationalPrefix()`.
  // In other words, why run the same check twice if it could only be run once.
  // // Check the national (significant) number length after extracting national prefix and carrier code.
  // // Fixes a minor "weird behavior" bug: https://gitlab.com/catamphetamine/libphonenumber-js/-/issues/57
  // // (Legacy generated metadata (before `1.0.18`) didn't support the "possible lengths" feature).
  // if (metadata.possibleLengths()) {
  // 	if (isPossibleIncompleteNationalNumber(nationalNumberBefore, metadata) &&
  // 		!isPossibleIncompleteNationalNumber(nationalNumberAfter, metadata)) {
  // 		return false
  // 	}
  // }


  return true;
}

function isPossibleIncompleteNationalNumber(nationalNumber, metadata) {
  switch (checkNumberLength(nationalNumber, metadata)) {
    case 'TOO_SHORT':
    case 'INVALID_LENGTH':
      // This library ignores "local-only" phone numbers (for simplicity).
      // See the readme for more info on what are "local-only" phone numbers.
      // case 'IS_POSSIBLE_LOCAL_ONLY':
      return false;

    default:
      return true;
  }
}
//# sourceMappingURL=extractNationalNumber.js.map