Add test

Author: Vellumic

core/engine/src/builtins/intl/date_time_format/tests.rs

@@ -65,3 +65,26 @@ fn dtf_basic() {
         TestAction::assert_eq("result === 'Sunday, 20 December 2020 at 14:23:16'", true),
     ]);
 }
+
+#[cfg(feature = "intl_bundled")]
+#[test]
+fn date_to_locale_string() {
+    run_test_actions([
+        TestAction::run(indoc! {"
+            // Setup date
+            const date = new Date(Date.UTC(2021, 3, 12, 6, 7));
+
+            let result = date.toLocaleString('en-US', { dateStyle: 'short' });
+        "}),
+        TestAction::assert_eq("result === '4/12/21'", true),
+    ]);
+    run_test_actions([
+        TestAction::run(indoc! {"
+            // Setup date
+            const date = new Date(Date.UTC(2021, 3, 12, 6, 7));
+
+            let result = date.toLocaleString('en-US', { timeStyle: 'short' });
+        "}),
+        TestAction::assert_eq("result === '6:07\u{202f}AM'", true),
+    ]);
+}