Refactor Locale as child class of Intl.Locale

Author: eemeli

fluent-langneg/src/locale.ts

@@ -1,185 +1,25 @@
-function convertMasks(locale: string): string {
-  let result;
-  if (locale[0] === "*") {
-    result = `und${locale.substring(1)}`;
-  } else {
-    result = locale;
-  }
-  return result.replace(/-\*/g, "");
-}
-
-function getVisibleLangTagLength(
-  language: string,
-  script: string | undefined,
-  region: string | undefined
-): number {
-  let result = 0;
-  result += language ? language.length : "und".length;
-  result += script ? script.length + 1 : 0;
-  result += region ? region.length + 1 : 0;
-  return result;
-}
-
-function getExtensionStart(locale: string): number | undefined {
-  let pos = locale.search(/-[a-zA-Z]-/);
-  if (pos === -1) {
-    return undefined;
-  }
-  return pos;
-}
-
-export class Locale {
-  isWellFormed: boolean;
-  language: string;
-  script?: string;
-  region?: string;
-  variant?: string;
+export class LocaleWrapper extends Intl.Locale {
+  variants?: string;
 
-  /**
-   * Parses a locale id using the localeRe into an array with four elements.
-   *
-   * If the second argument `range` is set to true, it places range `*` char
-   * in place of any missing piece.
-   *
-   * It also allows skipping the script section of the id, so `en-US` is
-   * properly parsed as `en-*-US-*`.
-   */
   constructor(locale: string) {
-    let result;
-    let normalized = convertMasks(locale.replace(/_/g, "-"));
-    try {
-      result = new Intl.Locale(normalized);
-    } catch {
-      this.isWellFormed = false;
-      this.language = "und";
-      return;
-    }
-
-    this.language = result.language;
-    this.script = result.script;
-    this.region = result.region;
-
-    let visiblelangTagLength = getVisibleLangTagLength(
-      this.language,
-      this.script,
-      this.region
-    );
-
-    if (normalized.length > visiblelangTagLength) {
-      let extStart = getExtensionStart(locale);
-      this.variant = locale.substring(visiblelangTagLength + 1, extStart);
-    }
-
-    this.isWellFormed = true;
-  }
-
-  matches(other: Locale, thisRange = false, otherRange = false): boolean {
-    return (
-      this.isWellFormed &&
-      other.isWellFormed &&
-      (this.language === other.language ||
-        (thisRange && this.language === "und") ||
-        (otherRange && other.language === "und")) &&
-      (this.script === other.script ||
-        (thisRange && this.script === undefined) ||
-        (otherRange && other.script === undefined)) &&
-      (this.region === other.region ||
-        (thisRange && this.region === undefined) ||
-        (otherRange && other.region === undefined)) &&
-      (this.variant === other.variant ||
-        (thisRange && this.variant === undefined) ||
-        (otherRange && other.variant === undefined))
-    );
-  }
-
-  toString(): string {
-    return [this.language, this.script, this.region, this.variant]
-      .filter(part => part !== undefined)
-      .join("-");
-  }
-
-  clearVariants(): void {
-    this.variant = undefined;
-  }
-
-  clearRegion(): void {
-    this.region = undefined;
-  }
-
-  addLikelySubtags(): boolean {
-    const newLocale = getLikelySubtagsMin(this.toString().toLowerCase());
-    if (newLocale) {
-      this.language = newLocale.language;
-      this.script = newLocale.script;
-      this.region = newLocale.region;
-      this.variant = newLocale.variant;
-      return true;
+    let tag = locale
+      .replace(/_/g, "-")
+      .replace(/^\*/, "und")
+      .replace(/-\*/g, "");
+
+    super(tag);
+
+    if (!("variants" in this)) {
+      // Available on Firefox 141 & later
+      let lsrTagLength = this.language.length;
+      if (this.script) lsrTagLength += this.script.length + 1;
+      if (this.region) lsrTagLength += this.region.length + 1;
+
+      if (tag.length > lsrTagLength) {
+        let unicodeExtStart: number | undefined = tag.search(/-[a-zA-Z]-/);
+        if (unicodeExtStart === -1) unicodeExtStart = undefined;
+        this.variants = tag.substring(lsrTagLength + 1, unicodeExtStart);
+      }
     }
-    return false;
-  }
-}
-
-/**
- * Below is a manually a list of likely subtags corresponding to Unicode
- * CLDR likelySubtags list.
- * This list is curated by the maintainers of Project Fluent and is
- * intended to be used in place of the full likelySubtags list in use cases
- * where full list cannot be (for example, due to the size).
- *
- * This version of the list is based on CLDR 30.0.3.
- */
-const likelySubtagsMin: Record<string, string> = {
-  ar: "ar-arab-eg",
-  "az-arab": "az-arab-ir",
-  "az-ir": "az-arab-ir",
-  be: "be-cyrl-by",
-  da: "da-latn-dk",
-  el: "el-grek-gr",
-  en: "en-latn-us",
-  fa: "fa-arab-ir",
-  ja: "ja-jpan-jp",
-  ko: "ko-kore-kr",
-  pt: "pt-latn-br",
-  sr: "sr-cyrl-rs",
-  "sr-ru": "sr-latn-ru",
-  sv: "sv-latn-se",
-  ta: "ta-taml-in",
-  uk: "uk-cyrl-ua",
-  zh: "zh-hans-cn",
-  "zh-hant": "zh-hant-tw",
-  "zh-hk": "zh-hant-hk",
-  "zh-mo": "zh-hant-mo",
-  "zh-tw": "zh-hant-tw",
-  "zh-gb": "zh-hant-gb",
-  "zh-us": "zh-hant-us",
-};
-
-const regionMatchingLangs = [
-  "az",
-  "bg",
-  "cs",
-  "de",
-  "es",
-  "fi",
-  "fr",
-  "hu",
-  "it",
-  "lt",
-  "lv",
-  "nl",
-  "pl",
-  "ro",
-  "ru",
-];
-
-function getLikelySubtagsMin(loc: string): Locale | null {
-  if (Object.prototype.hasOwnProperty.call(likelySubtagsMin, loc)) {
-    return new Locale(likelySubtagsMin[loc]);
-  }
-  const locale = new Locale(loc);
-  if (locale.language && regionMatchingLangs.includes(locale.language)) {
-    locale.region = locale.language.toUpperCase();
-    return locale;
   }
-  return null;
 }