polyfill-service/polyfills/Intl/update.task.js

A polyfill combinator

/* eslint-env node */

/*
 * This script will copy all of the localisation language files from the Intl
 * module and install them within a folder in this directory named ~locale.
 *
 * The detect.js file used for Intl is copied into every ~locale polyfill for
 * use on detecting whether that locale needs to be polyfilled.
 *
 * The config.json file for each locale polyfill is based off of the one for
 * Intl. The changes made ot it are:
 *  - Removing the "install" section
 *  - Adding Intl as a dependency
 */

'use strict';

const fs = require('fs');
const path = require('path');
const LocalesPath = path.dirname(require.resolve('intl/locale-data/jsonp/en.js'));
const IntlPolyfillOutput = path.resolve('polyfills/Intl');
const LocalesPolyfillOutput = path.resolve('polyfills/Intl/~locale');
const crypto = require('crypto');
const existsSync = require('exists-sync');
const mkdirp = require('mkdirp');

function md5 (contents) {
	return crypto.createHash('md5').update(contents).digest('hex');
}

function writeFileIfChanged (filePath, newFile) {
	if (existsSync(filePath)) {
		const currentFile = fs.readFileSync(filePath);
		const currentFileHash = md5(currentFile);
		const newFileHash = md5(newFile);

		if (newFileHash !== currentFileHash) {
			fs.writeFileSync(filePath, newFile);
		}
  } else {
		fs.writeFileSync(filePath, newFile);
	}
}

const configSource = require(path.join(IntlPolyfillOutput, 'config.json'));
delete configSource.install;

if (!existsSync(LocalesPolyfillOutput)) {
	mkdirp.sync(LocalesPolyfillOutput);
}

// customizing the config to add intl as a dependency
configSource.dependencies.push('Intl');

// don't test every single locale - it will be too slow
configSource.test = { ci: false };

const configFileSource = JSON.stringify(configSource, null, 4);

function intlLocaleDetectFor(locale) {
	return `'Intl' in this &&
			Intl.Collator &&
			Intl.Collator.supportedLocalesOf &&
			Intl.Collator.supportedLocalesOf('${locale}').length === 1 &&
			Intl.DateTimeFormat &&
			Intl.DateTimeFormat.supportedLocalesOf &&
			Intl.DateTimeFormat.supportedLocalesOf('${locale}').length === 1 &&
			Intl.NumberFormat &&
			Intl.NumberFormat.supportedLocalesOf &&
			Intl.NumberFormat.supportedLocalesOf('${locale}').length === 1`;
}

console.log('Importing Intl.~locale.* polyfill from ' + LocalesPath);
const locales = fs.readdirSync(LocalesPath);
locales.forEach(function (file) {
	const locale = file.slice(0, file.indexOf('.'));
	const localeOutputPath = path.join(LocalesPolyfillOutput, locale);

	if (!existsSync(localeOutputPath)) {
		mkdirp.sync(localeOutputPath);
	}

	const localePolyfillSource = fs.readFileSync(path.join(LocalesPath, file));
	const polyfillOutputPath = path.join(localeOutputPath, 'polyfill.js');
	const detectOutputPath = path.join(localeOutputPath, 'detect.js');
	const configOutputPath = path.join(localeOutputPath, 'config.json');
	writeFileIfChanged(polyfillOutputPath, localePolyfillSource);
	writeFileIfChanged(detectOutputPath, intlLocaleDetectFor(locale));
	writeFileIfChanged(configOutputPath, configFileSource);
});


console.log(locales.length + ' imported locales');
console.log('Intl polyfill imported successfully');