1 files changed, 44 insertions, 0 deletions
diff --git a/intl/locale/tests/unit/test_osPreferences.js b/intl/locale/tests/unit/test_osPreferences.js
new file mode 100644
index 0000000000..6d1bb637ff
--- /dev/null
+++ b/intl/locale/tests/unit/test_osPreferences.js
@@ -0,0 +1,44 @@
+/* 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/. */
+
+function run_test() {
+  const osprefs = Cc["@mozilla.org/intl/ospreferences;1"].getService(
+    Ci.mozIOSPreferences
+  );
+
+  const systemLocale = osprefs.systemLocale;
+  Assert.ok(systemLocale != "", "systemLocale is non-empty");
+
+  const systemLocales = osprefs.systemLocales;
+  Assert.ok(Array.isArray(systemLocales), "systemLocales returns an array");
+
+  Assert.ok(
+    systemLocale == systemLocales[0],
+    "systemLocale matches first entry in systemLocales"
+  );
+
+  const rgLocales = osprefs.regionalPrefsLocales;
+  Assert.ok(Array.isArray(rgLocales), "regionalPrefsLocales returns an array");
+
+  const getDateTimePatternTests = [
+    [osprefs.dateTimeFormatStyleNone, osprefs.dateTimeFormatStyleNone, ""],
+    [osprefs.dateTimeFormatStyleShort, osprefs.dateTimeFormatStyleNone, ""],
+    [osprefs.dateTimeFormatStyleNone, osprefs.dateTimeFormatStyleLong, "ar"],
+    [osprefs.dateTimeFormatStyleFull, osprefs.dateTimeFormatStyleMedium, "ru"],
+  ];
+
+  for (let i = 0; i < getDateTimePatternTests.length; i++) {
+    const test = getDateTimePatternTests[i];
+
+    const pattern = osprefs.getDateTimePattern(...test);
+    if (
+      test[0] !== osprefs.dateTimeFormatStyleNone &&
+      test[1] !== osprefs.dateTImeFormatStyleNone
+    ) {
+      Assert.greater(pattern.length, 0, "pattern is not empty.");
+    }
+  }
+
+  Assert.ok(1, "osprefs didn't crash");
+}