1 files changed, 22 insertions, 0 deletions
diff --git a/js/src/tests/non262/Intl/four-letter-language-codes.js b/js/src/tests/non262/Intl/four-letter-language-codes.js
new file mode 100644
index 0000000000..394efacf29
--- /dev/null
+++ b/js/src/tests/non262/Intl/four-letter-language-codes.js
@@ -0,0 +1,22 @@
+// |reftest| skip-if(!this.hasOwnProperty("Intl"))
+/* 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/. */
+
+// Four letter language subtags are not allowed.
+const languageTags = [
+    "root", // Special meaning in Unicode CLDR locale identifiers.
+    "Latn", // Unicode CLDR locale identifiers can start with a script subtag.
+    "Flob", // And now some non-sense input.
+    "ZORK",
+    "Blah-latn",
+    "QuuX-latn-us",
+    "SPAM-gb-x-Sausages-BACON-eggs",
+];
+
+for (let tag of languageTags) {
+    assertThrowsInstanceOf(() => Intl.getCanonicalLocales(tag), RangeError);
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);