Bug 1572985: Sort "relevantExtensionKeys" to ensure the resolved locale's Unicode extension subtag is canonical. r=jwalden

Differential Revision: https://phabricator.services.mozilla.com/D41516

--HG--
extra : moz-landing-system : lando

js/src/builtin/intl/Collator.js

@@ -225,7 +225,7 @@ var collatorInternalProperties = {
         addSpecialMissingLanguageTags(locales);
         return (this._availableLocales = locales);
     },
-    relevantExtensionKeys: ["co", "kn", "kf"],
+    relevantExtensionKeys: ["co", "kf", "kn"],
 };
 
 /**

js/src/builtin/intl/DateTimeFormat.js

@@ -767,7 +767,7 @@ var dateTimeFormatInternalProperties = {
         addSpecialMissingLanguageTags(locales);
         return (this._availableLocales = locales);
     },
-    relevantExtensionKeys: ["ca", "nu", "hc"],
+    relevantExtensionKeys: ["ca", "hc", "nu"],
 };
 
 function dateTimeFormatLocaleData() {

js/src/tests/non262/Intl/resolved-locale-sorted-unicode-extension-keys.js

@@ -0,0 +1,101 @@
+// |reftest| skip-if(!this.hasOwnProperty("Intl"))
+
+function isConstructor(c) {
+    return typeof c === "function" && c.hasOwnProperty("prototype");
+}
+
+const IntlServices = Object.getOwnPropertyNames(Intl).map(name => Intl[name]).filter(isConstructor);
+
+// Examples for all possible Unicode extension keys (with the exception of deprecated "vt").
+const unicodeExtensions = [
+    // calendar
+    "ca-gregory",
+    "fw-mon",
+    "hc-h23",
+
+    // collation
+    "co-phonebk",
+    "ka-noignore",
+    "kb-false",
+    "kc-false",
+    "kf-false",
+    "kh-false",
+    "kk-false",
+    "kn-false",
+    "kr-space",
+    "ks-level1",
+    "kv-space",
+
+    // currency
+    "cf-standard",
+    "cu-eur",
+
+    // measure
+    "ms-metric",
+
+    // number
+    "nu-latn",
+
+    // segmentation
+    "lb-strict",
+    "lw-normal",
+    "ss-none",
+
+    // timezone
+    "tz-atvie",
+
+    // variant
+    "em-default",
+    "rg-atzzzz",
+    "sd-atat1",
+    "va-posix",
+];
+
+function reverse(a, b) {
+    if (a < b) {
+        return 1;
+    }
+    if (a > b) {
+        return -1;
+    }
+    return 0;
+}
+
+function findUnicodeExtensionKeys(locale) {
+    // Find the Unicode extension key subtag.
+    var extension = locale.match(/.*-u-(.*)/);
+    if (extension === null) {
+        return [];
+    }
+
+    // Replace all types in the Unicode extension keywords.
+    return extension[1].replace(/-\w{3,}/g, "").split("-");
+}
+
+// Test all Intl service constructors and ensure the Unicode extension keys in
+// the resolved locale are sorted alphabetically.
+
+for (let IntlService of IntlServices) {
+    // sort() modifies the input array, so create a copy.
+    let ext = unicodeExtensions.slice(0);
+
+    let locale, keys;
+
+    // Input keys unsorted.
+    locale = new IntlService(`de-u-${ext.join("-")}`).resolvedOptions().locale;
+    keys = findUnicodeExtensionKeys(locale);
+    assertEqArray(keys, keys.slice(0).sort());
+
+    // Input keys sorted alphabetically.
+    locale = new IntlService(`de-u-${ext.sort().join("-")}`).resolvedOptions().locale;
+    keys = findUnicodeExtensionKeys(locale);
+    assertEqArray(keys, keys.slice(0).sort());
+
+    // Input keys sorted alphabetically in reverse order.
+    locale = new IntlService(`de-u-${ext.sort(reverse).join("-")}`).resolvedOptions().locale;
+    keys = findUnicodeExtensionKeys(locale);
+    assertEqArray(keys, keys.slice(0).sort());
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);