diff --git a/test/cases/i18n/util.mjs b/test/cases/i18n/util.mjs
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+import {getGlobal} from "../../../source/types/global.mjs";
+
+import * as chai from 'chai';
+import {chaiDom} from "../../util/chai-dom.mjs";
+import {initJSDOM} from "../../util/jsdom.mjs";
+
+let expect = chai.expect;
+chai.use(chaiDom);
+
+describe('LocalPicker', function () {
+
+ let LocalPicker, documentLanguage, linkTags, originalLanguages, getPreferredLanguage;
+
+ before(function (done) {
+ initJSDOM().then(() => {
+
+ documentLanguage = document.documentElement.lang;
+ linkTags = Array.from(document.querySelectorAll('link[rel="alternate"]'));
+ linkTags.forEach(item => item.remove());
+
+ import("element-internals-polyfill").catch(e => done(e));
+
+ import("../../../source/i18n/util.mjs").then((m) => {
+
+ LocalPicker = m['LocalPicker'];
+ getPreferredLanguage = m['detectUserLanguagePreference'];
+
+ originalLanguages = navigator.languages;
+
+ done()
+ }).catch(e => done(e))
+
+
+ });
+ })
+
+ after(function () {
+ document.documentElement.lang = documentLanguage;
+
+ linkTags.forEach(item => {
+ const link = document.createElement('link');
+ link.setAttribute('rel', 'alternate');
+ link.setAttribute('hreflang', item.hreflang);
+ link.setAttribute('href', item.href);
+
+ // check if already exits
+ if (!document.querySelector(`link[hreflang="${item.hreflang}"]`)) {
+ document.querySelector('head').appendChild(link);
+ }
+ });
+
+
+ Object.defineProperty(navigator, 'languages', {
+ value: originalLanguages,
+ writable: true
+ });
+
+
+ })
+
+ // Hilfsfunktion zum Setup eines JSDOM-Dokuments mit <html> und ggf. link-Tags
+ function setupDOM({htmlLang = '', linkHreflangs = [], navLang = ""}) {
+
+ linkTags = Array.from(document.querySelectorAll('link[rel="alternate"]'));
+ linkTags.forEach(item => item.remove());
+
+ // Links hinzufügen
+ const head = window.document.querySelector('head');
+ linkHreflangs.forEach(item => {
+ const link = window.document.createElement('link');
+ link.setAttribute('rel', 'alternate');
+ link.setAttribute('hreflang', item.hreflang);
+ link.setAttribute('href', item.href);
+ head.appendChild(link);
+ });
+
+ window.document.documentElement.lang = htmlLang;
+
+
+ Object.defineProperty(navigator, 'language', {
+ value: navLang[0] || "",
+ writable: true
+ });
+
+ Object.defineProperty(navigator, 'languages', {
+ value: navLang,
+ writable: true
+ });
+ }
+
+ describe('getPreferredLanguage()', () => {
+
+ // 1) No document language, no navigator.languages => "No language information available."
+ it('should return "No language information available." when no current and no user preferences', () => {
+ setupDOM({htmlLang: '', linkHreflangs: [], navLang: []});
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('message').that.not.empty;
+ });
+
+ // 2) Document lang is set, but no <link> tags => "No <link> tags with hreflang available."
+ it('should return "No <link> tags with hreflang available." when there are no link tags', () => {
+ setupDOM({htmlLang: 'en', linkHreflangs: []});
+ window.navigator.languages = [];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'en');
+ expect(result).to.have.property('message').that.equals('No <link> tags with hreflang available.');
+ });
+
+ // 3) Document lang 'en', no user preferences, but link tags exist => "None of the preferred languages are available."
+ it('should return "None of the preferred languages are available." when there are link tags but no matching user preferences', () => {
+ setupDOM({
+ htmlLang: 'en',
+ linkHreflangs: [
+ {hreflang: 'de', href: 'http://example.com/de'},
+ {hreflang: 'fr', href: 'http://example.com/fr'}
+ ],
+ navLang: []
+ });
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'en');
+ expect(result).to.have.property('message').that.equals('No available languages match the user\'s preferences.');
+ expect(result.available).to.be.an('array').that.has.lengthOf(2);
+ });
+
+ // 4) Document lang 'en', user prefers ['en'], link tags with 'en' and 'de' => best match is 'en'
+ it('should return best match = "en" when user prefers en', () => {
+ setupDOM({
+ htmlLang: 'en',
+ linkHreflangs: [
+ {hreflang: 'en', href: 'http://example.com/en'},
+ {hreflang: 'de', href: 'http://example.com/de'}
+ ]
+ });
+ window.navigator.languages = ['en'];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'en');
+ console.log(JSON.stringify(result.preferred));
+ expect(result.preferred).to.have.property('full', "en");
+ expect(result.preferred).to.have.property('base', "en");
+ expect(result.preferred).to.have.property('label', "English");
+ expect(result.preferred).to.have.property('href', "http://example.com/en");
+ });
+
+ // 5) Document lang 'de-DE', user prefers ['de-DE'], link tags with 'de-DE' & 'en-US' => best match is 'de-DE'
+ it('should return best match = "de-DE" when user prefers de-DE', () => {
+ setupDOM({
+ htmlLang: 'de-DE',
+ linkHreflangs: [
+ {hreflang: 'de-DE', href: 'http://example.com/de-DE'},
+ {hreflang: 'en-US', href: 'http://example.com/en-US'}
+ ]
+ });
+ window.navigator.languages = ['de-DE'];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'de-DE');
+
+ expect(result.preferred).to.have.property('full', "de-DE");
+ expect(result.preferred).to.have.property('base', "de");
+ expect(result.preferred).to.have.property('label', "Deutsch (Deutschland)");
+ expect(result.preferred).to.have.property('href', "http://example.com/de-DE");
+
+ });
+
+
+ // 5x) Document lang 'de-DE', user prefers ['de-DE'], link tags with 'de-DE' & 'en-US' => best match is 'de-DE'
+ it('should return best match = "de-DE" when user prefers de-DE', () => {
+ setupDOM({
+ htmlLang: 'en',
+ linkHreflangs: [
+ {hreflang: 'de', href: 'http://example.com/de-DE'},
+ {hreflang: 'en', href: 'http://example.com/en-US'}
+ ]
+ });
+ window.navigator.languages = ['de-DE'];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'en');
+
+ expect(result.preferred).to.have.property('full', "de");
+ expect(result.preferred).to.have.property('base', "de");
+ expect(result.preferred).to.have.property('label', "Deutsch");
+ expect(result.preferred).to.have.property('href', "http://example.com/de-DE");
+
+ });
+
+ // 6) Document lang 'de-DE', user prefers ['en-US', 'en'], link tags with 'en-US' & 'en-GB' => best match = 'en-US'
+ it('should return best match = "en-US" for user preferences [en-US, en]', () => {
+ setupDOM({
+ htmlLang: 'de-DE',
+ linkHreflangs: [
+ {hreflang: 'en-US', href: 'http://example.com/en-US'},
+ {hreflang: 'en-GB', href: 'http://example.com/en-GB'}
+ ]
+ });
+ window.navigator.languages = ['en-US', 'en'];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'de-DE');
+ expect(result.preferred).to.have.property('full', "en-US");
+ expect(result.preferred).to.have.property('base', "en");
+ expect(result.preferred).to.have.property('label', "English (United States)");
+ expect(result.preferred).to.have.property('href', "http://example.com/en-US");
+
+ });
+
+ // 7) Document lang 'de-DE', user prefers ['de','en'], link tags with 'de-DE' & 'en-US' => best match = 'de-DE' (baseLang = 'de')
+ it('should return best match = "de-DE" when user preferences include its base language "de"', () => {
+ setupDOM({
+ htmlLang: 'de-DE',
+ linkHreflangs: [
+ {hreflang: 'de-DE', href: 'http://example.com/de-DE'},
+ {hreflang: 'en-US', href: 'http://example.com/en-US'}
+ ]
+ });
+ window.navigator.languages = ['de', 'en'];
+
+ const result = getPreferredLanguage();
+ expect(result).to.have.property('current', 'de-DE');
+
+ expect(result.preferred).to.have.property('full', "de-DE");
+ expect(result.preferred).to.have.property('base', "de");
+ expect(result.preferred).to.have.property('label', "Deutsch (Deutschland)");
+ expect(result.preferred).to.have.property('href', "http://example.com/de-DE");
+
+ });
+
+ // 8) Multiple link tags share the same weight => the first in the sorted array should be returned
+ it('should return the first item when multiple link tags have the same weight', () => {
+ setupDOM({
+ htmlLang: 'en',
+ linkHreflangs: [
+ {hreflang: 'fr', href: 'http://example.com/fr'},
+ {hreflang: 'es', href: 'http://example.com/es'}
+ ]
+ });
+ // Neither "fr" nor "es" is in the user preferences => both have weight = 1
+ window.navigator.languages = ['de'];
+
+ const result = getPreferredLanguage();
+ // Both 'fr' and 'es' have weight 1. After sorting, 'fr' appears first (as it was added first).
+ expect(result.available[0].fullLang).to.equal('fr');
+ expect(result.available[1].fullLang).to.equal('es');
+ expect(result.offerable).to.be.undefined;
+ expect(result).to.have.property('message', 'No available languages match the user\'s preferences.');
+ });
+
+ // 9) Check that bestURL is returned if a best match is found
+ it('should include bestURL when a best match is found', () => {
+ setupDOM({
+ htmlLang: 'fr',
+ linkHreflangs: [
+ {hreflang: 'fr-FR', href: 'http://example.com/fr-FR'},
+ {hreflang: 'de-DE', href: 'http://example.com/de-DE'}
+ ]
+ });
+ window.navigator.languages = ['fr-FR', 'de-DE'];
+
+ const result = getPreferredLanguage();
+
+ expect(result.preferred).to.have.property('full', "fr-FR");
+ expect(result.preferred).to.have.property('base', "fr");
+ expect(result.preferred).to.have.property('label', "Français (France)");
+ expect(result.preferred).to.have.property('href', "http://example.com/fr-FR");
+
+ });
+
+ // 10) Check presence of availableLanguages array, ensuring it has weight info
+ it('should return availableLanguages with weight for each link', () => {
+ setupDOM({
+ htmlLang: 'en-GB',
+ linkHreflangs: [
+ {hreflang: 'en-GB', href: 'http://example.com/en-GB'},
+ {hreflang: 'en-US', href: 'http://example.com/en-US'}
+ ]
+ });
+ window.navigator.languages = ['en-GB', 'en', 'en-US'];
+
+ const result = getPreferredLanguage();
+ expect(result.available).to.be.an('array').with.lengthOf(2);
+ result.available.forEach(item => {
+ expect(item).to.have.property('weight');
+ expect(item).to.have.property('fullLang');
+ expect(item).to.have.property('baseLang');
+ expect(item).to.have.property('href');
+ });
+ });
+
+ });
+
+})
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