Backport Basilisk internal userscripts

browser/internaluserscripts/bundled-scripts/intl-displaynames-polyfill.user.js

@@ -0,0 +1,104 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+// ==UserScript==
+// @name         Intl.DisplayNames Polyfill (minimal)
+// @namespace    internal-userscripts
+// @description  Provides a minimal Intl.DisplayNames implementation for environments without native support.
+// @match        *://*/*
+// @grant        none
+// @run-at       document-start
+// ==/UserScript==
+(function () {
+  "use strict";
+
+  if (typeof Intl !== "object" || typeof Intl.DisplayNames === "function") {
+    return;
+  }
+
+  var STYLE_VALUES = { long: true, short: true, narrow: true };
+  var TYPE_VALUES = { language: true, region: true, script: true, currency: true };
+  var FALLBACK_VALUES = { code: true, none: true };
+
+  function canonicalizeLocales(locales) {
+    if (typeof Intl.getCanonicalLocales === "function") {
+      return Intl.getCanonicalLocales(locales);
+    }
+    if (locales == null) {
+      return [];
+    }
+    if (Array.isArray(locales)) {
+      return locales.map(function (loc) { return String(loc); });
+    }
+    return [String(locales)];
+  }
+
+  function defaultLocale() {
+    try {
+      if (typeof Intl.DateTimeFormat === "function") {
+        return Intl.DateTimeFormat().resolvedOptions().locale;
+      }
+    } catch (e) {}
+    if (typeof navigator !== "undefined" && navigator.language) {
+      return String(navigator.language);
+    }
+    return "en-US";
+  }
+
+  function DisplayNames(locales, options) {
+    if (!(this instanceof DisplayNames)) {
+      throw new TypeError("Intl.DisplayNames must be called with new");
+    }
+    options = options || {};
+
+    var type = options.type;
+    if (type == null) {
+      throw new TypeError("Intl.DisplayNames requires a type option");
+    }
+    type = String(type);
+    if (!TYPE_VALUES[type]) {
+      throw new RangeError("Invalid type");
+    }
+
+    var style = options.style == null ? "long" : String(options.style);
+    if (!STYLE_VALUES[style]) {
+      throw new RangeError("Invalid style");
+    }
+
+    var fallback = options.fallback == null ? "code" : String(options.fallback);
+    if (!FALLBACK_VALUES[fallback]) {
+      throw new RangeError("Invalid fallback");
+    }
+
+    var localeList = canonicalizeLocales(locales);
+    this._locale = localeList.length ? localeList[0] : defaultLocale();
+    this._style = style;
+    this._type = type;
+    this._fallback = fallback;
+  }
+
+  DisplayNames.supportedLocalesOf = function (locales) {
+    return canonicalizeLocales(locales);
+  };
+
+  DisplayNames.prototype.resolvedOptions = function () {
+    return {
+      locale: this._locale,
+      style: this._style,
+      type: this._type,
+      fallback: this._fallback,
+    };
+  };
+
+  DisplayNames.prototype.of = function (code) {
+    if (this._fallback === "none") {
+      return undefined;
+    }
+    return String(code);
+  };
+
+  Intl.DisplayNames = DisplayNames;
+  try {
+    window.__internalUserscriptsIntlDisplayNamesPolyfill = true;
+  } catch (e) {}
+})();