i18n: accept array of locales in lookupLocale (#11349)

GoogleChrome · Aug 31, 2020 · aac0b68 · aac0b68
1 parent e9215f1
commit aac0b68
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Showing 3 changed files with 23 additions and 10 deletions.
diff --git a/lighthouse-core/lib/i18n/i18n.js b/lighthouse-core/lib/i18n/i18n.js
@@ -12,6 +12,8 @@ const MessageFormat = require('intl-messageformat').default;
 const lookupClosestLocale = require('lookup-closest-locale');
 const LOCALES = require('./locales.js');
 
+const DEFAULT_LOCALE = 'en';
+
 /** @typedef {import('intl-messageformat-parser').Element} MessageElement */
 /** @typedef {import('intl-messageformat-parser').ArgumentElement} ArgumentElement */
 
@@ -157,18 +159,17 @@ 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') if no match is found
  *
- * If `locale` isn't provided, the default is used.
- * @param {string=} locale
+ * If `locale` isn't provided or one could not be found, DEFAULT_LOCALE is returned.
+ * @param {string|string[]=} locales
  * @return {LH.Locale}
  */
-function lookupLocale(locale) {
+function lookupLocale(locales) {
   // TODO: could do more work to sniff out default locale
-  const canonicalLocale = Intl.getCanonicalLocales(locale)[0];
+  const canonicalLocales = Intl.getCanonicalLocales(locales);
 
-  const closestLocale = lookupClosestLocale(canonicalLocale, LOCALES);
-  return closestLocale || 'en';
+  const closestLocale = lookupClosestLocale(canonicalLocales, LOCALES);
+  return closestLocale || DEFAULT_LOCALE;
 }
 
 /**

diff --git a/lighthouse-core/test/lib/i18n/i18n-test.js b/lighthouse-core/test/lib/i18n/i18n-test.js
@@ -118,16 +118,28 @@ describe('i18n', () => {
   });
 
   describe('#lookupLocale', () => {
+    const invalidLocale = 'jk-Latn-DE-1996-a-ext-x-phonebk-i-klingon';
+
     it('canonicalizes the locale', () => {
       expect(i18n.lookupLocale('en-xa')).toEqual('en-XA');
     });
 
+    it('canonicalizes the locales', () => {
+      expect(i18n.lookupLocale([invalidLocale, 'en-xa'])).toEqual('en-XA');
+    });
+
+    it('falls back to default if locale not provided or cant be found', () => {
+      expect(i18n.lookupLocale(undefined)).toEqual('en');
+      expect(i18n.lookupLocale(invalidLocale)).toEqual('en');
+      expect(i18n.lookupLocale([invalidLocale, invalidLocale])).toEqual('en');
+    });
+
     it('falls back to root tag prefix if specific locale not available', () => {
-      expect(i18n.lookupLocale('en-JKJK')).toEqual('en');
+      expect(i18n.lookupLocale('es-JKJK')).toEqual('es');
     });
 
     it('falls back to en if no match is available', () => {
-      expect(i18n.lookupLocale('jk-Latn-DE-1996-a-ext-x-phonebk-i-klingon')).toEqual('en');
+      expect(i18n.lookupLocale(invalidLocale)).toEqual('en');
     });
   });
 

diff --git a/types/lookup-closest-locale/index.d.ts b/types/lookup-closest-locale/index.d.ts
@@ -5,7 +5,7 @@
  */
 
 declare module 'lookup-closest-locale' {
-  function lookupClosestLocale(locale: string|undefined, available: Record<LH.Locale, any>): LH.Locale|undefined;
+  function lookupClosestLocale(locale: string[]|string|undefined, available: Record<LH.Locale, any>): LH.Locale|undefined;
 
   export = lookupClosestLocale;
 }