1 files changed, 49 insertions, 0 deletions
diff --git a/js/src/tests/non262/Intl/NumberFormat/duplicate-singleton-variant.js b/js/src/tests/non262/Intl/NumberFormat/duplicate-singleton-variant.js
new file mode 100644
index 0000000000..42bf78c3fe
--- /dev/null
+++ b/js/src/tests/non262/Intl/NumberFormat/duplicate-singleton-variant.js
@@ -0,0 +1,49 @@
+// |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/. */
+
+// Check for duplicate variants and singletons case-insensitively, but don't
+// check in privateuse components.
+
+function checkInvalidLocale(locale)
+{
+  try
+  {
+    new Intl.NumberFormat(locale);
+    throw new Error("didn't throw");
+  }
+  catch (e)
+  {
+    assertEq(e instanceof RangeError, true,
+             "expected RangeError for locale '" + locale + "', got " + e);
+  }
+}
+
+var badLocales =
+  [
+   "en-u-foo-U-foo",
+   "en-tester-Tester",
+   "en-tesTER-TESter",
+   "de-DE-u-kn-true-U-kn-true",
+   "ar-u-foo-q-bar-u-baz",
+   "ar-z-moo-u-foo-q-bar-z-eit-u-baz",
+  ];
+
+for (var locale of badLocales)
+  checkInvalidLocale(locale);
+
+// Fully-privateuse locales are rejected.
+for (var locale of badLocales)
+  assertThrowsInstanceOf(() => new Intl.NumberFormat("x-" + locale), RangeError);
+
+// Locales with trailing privateuse also okay.
+for (var locale of badLocales)
+{
+  new Intl.NumberFormat("en-x-" + locale).format(5);
+  new Intl.NumberFormat("en-u-foo-x-u-" + locale).format(5);
+}
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);