1 files changed, 17 insertions, 0 deletions
diff --git a/tests/wpt/tests/ai/resources/locale-util.js b/tests/wpt/tests/ai/resources/locale-util.js
index cacb11f4f25..70a00a5630b 100644
--- a/tests/wpt/tests/ai/resources/locale-util.js
+++ b/tests/wpt/tests/ai/resources/locale-util.js
@@ -42,3 +42,20 @@ function assert_is_variation(variation_language_tag, expected_language_tag) {
   const expected_locale = new Intl.Locale(expected_language_tag);
   assert_equals(variation_locale.language, expected_locale.language);
 }
+
+function assert_availability_consistent(
+    language_subtag_availability, variation_availability) {
+  if (variation_availability == 'unavailable') {
+    // If the language subtag is not available then no variation of it should
+    // be available.
+    assert_equals(language_subtag_availability, 'unavailable');
+  } else {
+    // If the language subtag is available, then it definitely shouldn't be
+    // unavailable since whatever backing it has could support any variation of
+    // it. A variation could have a different availability if a more specific
+    // backing is required.
+    assert_in_array(
+        language_subtag_availability,
+        ['downloadable', 'downloading', 'available']);
+  }
+}