core(i18n): incorporate 52 languages into messages pipeline

lighthouse-cli/cli-flags.js

@@ -64,6 +64,7 @@ function getFlags(manualArgv) {
         ],
         'Configuration:')
       .describe({
+        // We don't allowlist specific locales. Why? So we can support the user who requests 'es-MX' (unsupported) and we'll fall back to 'es' (supported)
         'locale': 'The locale/language the report should be formatted in',
         'enable-error-reporting':
             'Enables error reporting, overriding any saved preference. --no-enable-error-reporting will do the opposite. More: https://git.io/vFFTO',
@@ -119,14 +120,6 @@ function getFlags(manualArgv) {
         'disable-storage-reset', 'disable-device-emulation', 'save-assets', 'list-all-audits',
         'list-trace-categories', 'view', 'verbose', 'quiet', 'help',
       ])
-      .choices('locale', [
-        // Later, this could be Object.keys(require('../lighthouse-core/lib/locales/index.js'))
-        // But we'll curate the list for now..
-
-        'en-US', // English
-        'en-XA', // Accented English, good for testing
-        'ar-XB', // RTL English, good for testing
-      ])
       .choices('output', printer.getValidOutputOptions())
       .choices('throttling-method', ['devtools', 'provided', 'simulate'])
       .choices('preset', ['full', 'perf', 'mixed-content'])

lighthouse-core/lib/i18n.js

@@ -71,7 +71,7 @@ const formats = {
  * Look up the best available locale for the requested language through these fall backs:
  * - exact match
  * - progressively shorter prefixes (`de-CH-1996` -> `de-CH` -> `de`)
- * - the default locale ('en-US') if no match is found
+ * - the default locale ('en') if no match is found
  *
  * If `locale` isn't provided, the default is used.
  * @param {string=} locale
@@ -82,7 +82,7 @@ function lookupLocale(locale) {
   const canonicalLocale = Intl.getCanonicalLocales(locale)[0];
 
   const closestLocale = lookupClosestLocale(canonicalLocale, LOCALES);
-  return closestLocale || 'en-US';
+  return closestLocale || 'en';
 }
 
 /**

lighthouse-core/lib/locales/index.js

@@ -9,11 +9,63 @@
 
 /** @type {Record<LH.Locale, LocaleMessages>} */
 const locales = {
-  'ar': require('./ar-XB.json'), // TODO: fallback not needed when ar translation available
-  'ar-XB': require('./ar-XB.json'),
-  'en': require('./en-US.json'), // en-* fallback
-  'en-US': require('./en-US.json'),
-  'en-XA': require('./en-XA.json'),
+  'en-US': require('./en-US.json'), // The 'source' strings, with descriptions
+  'en': require('./en-US.json'), // According to CLDR/ICU, 'en' == 'en-US' dates/numbers (Why?!)
+
+  // TODO: en-IE has just ~10 messages that are different from en-US. We should only ship those.
+  'en-AU': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+  'en-GB': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+  'en-IE': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+  'en-SG': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+  'en-ZA': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+  'en-IN': require('./en-IE.json'), // Don't fallback to en (which -> en-US)
+
+  'gsw': require('./de.json'), // swiss german. identical (for our purposes) to 'de'
+
+  // All locales from here have a messages file, though we allow fallback to the base locale when the files are identical
+  'ar-XB': require('./ar-XB.json'), // psuedolocalization
+  'ar': require('./ar.json'),
+  'bg': require('./bg.json'),
+  'ca': require('./ca.json'),
+  'cs': require('./cs.json'),
+  'da': require('./da.json'),
+  'de': require('./de.json'), // de-AT, de-CH identical, so they fall back into de
+  'el': require('./el.json'),
+  'en-XA': require('./en-XA.json'), // psuedolocalization
+  'es': require('./es.json'),
+  'fi': require('./fi.json'),
+  'fil': require('./fil.json'),
+  'fr': require('./fr.json'), // fr-CH identical, so it falls back into fr
+  'hi': require('./hi.json'),
+  'hr': require('./hr.json'),
+  'hu': require('./hu.json'),
+  'id': require('./id.json'),
+  'it': require('./it.json'),
+  'iw': require('./iw.json'),
+  'ja': require('./ja.json'),
+  'ko': require('./ko.json'),
+  'lt': require('./lt.json'),
+  'lv': require('./lv.json'),
+  'nl': require('./nl.json'),
+  'no': require('./no.json'),
+  'pl': require('./pl.json'),
+  'pt': require('./pt.json'), // pt-BR identical, so it falls back into pt
+  'pt-PT': require('./pt-PT.json'),
+  'ro': require('./ro.json'),
+  'ru': require('./ru.json'),
+  'sk': require('./sk.json'),
+  'sl': require('./sl.json'),
+  'sr': require('./sr.json'),
+  'sv': require('./sv.json'),
+  'ta': require('./ta.json'),
+  'te': require('./te.json'),
+  'th': require('./th.json'),
+  'tr': require('./tr.json'),
+  'uk': require('./uk.json'),
+  'vi': require('./vi.json'),
+  'zh-CN': require('./zh-CN.json'),
+  'zh-HK': require('./zh-HK.json'),
+  'zh-TW': require('./zh-TW.json'),
 };
 
 module.exports = locales;